Novel Αntigen-Specific Tolerance-Inducing Strategies and Management
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Student International Biological &Biomedical Research
Vol. 1(1):a0000054, 2022.
Novel Αntigen-Specific Tolerance-Inducing Immunotherapy
Strategies and their Application on Myasthenia Gravis
Management
Ntoukaki Eleni*
Hellenic Pasteur Institute, GR11521 Athens, Greece
Department of Medicine, National and Kapodistrian University of Athens, Athens, Greece
⁎ Corresponding author, elenintoukaki@gmail.com
Supervisor’s statement: I have reviewed and approved the article; Lazaridis Konstantinos, Hellenic Pasteur
Institute; 127 V. Sofias Ave., GR11521Athens, Greece; E-mail address: klazaridis@pasteur.gr
ABSTRACT
Antigen-specific approaches offering novel treatment options for autoimmune diseases are
gaining interest over the years. Although antigenic targets for several autoimmune diseases have
been well characterized (e.g. myasthenia gravis, type 1 diabetes), other conditions remain ill-
defined, as multiple self-antigens and complex molecular pathways are responsible for their
pathology. Hence, identification of specific antigenic targets and signaling molecules,whichlead to
tolerance breakage and induction of autoimmunity, is imperative for the design of treatments that
meet the clinical needs of patients with different disease phenotypes. Research efforts have
allowed the development and clinical application of various novel treatment approaches that
exploit immune mechanisms against autoreactive cells and autoantibodies, whereas conventional
immunosuppressive treatments remain non-curative, lack specificity and may hold debilitating
side-effects. The focus of this review is to presentnovel antigen-specific tolerance-inducing
immunotherapies for the treatment of autoimmune diseases, focusing on Myasthenia Gravis,as a
model disorder, due to its well characterized antigenic targets and underlying pathology, as well
as to highlight the application of such strategies in recent clinical trials.
Keywords: immune tolerance, autoimmune disease, antigen specificity, immunotherapy, myasthenia gravis,
Experimental autoimmune myasthenia gravis
INTRODUCTION
Autoimmune diseases are initiated when adaptive immune cells escape negative selection or
become insufficiently tolerant towards peripheral ‘self’ proteins due to environmental triggers and
numerous polymorphic genetic cues. By specifically recognizing antigens expressed by our own
tissues, auto-reactive helper T cells (TH cells), elicit an inflammatory response that compromises
the structural and functional integrity of different cell types and tissues. T H cells are responsible
for orchestrating the function of B cells, macrophages and cytotoxic T cells by expressing
inflammatory cytokines, chemokines and costimulatory signaling molecules, thus contributing to
the generation of general or organ-specific inflammatory responses.
Myasthenia gravis (MG) is an organ-specific chronic autoimmune disorder, caused by
autoantibodies that target antigens in the neuromuscular junction, such as the acetylcholine
receptor (AChR), muscle specific kinase (MuSK), and low-density lipoprotein receptor-related
protein 4 (LRP4), leading to muscle weakness and fatigability of skeletal muscles. MG is a model
autoimmune disease due to its well-defined antigenic targets and widely studied pathological
mechanisms. Experimental autoimmune myasthenia gravis (EAMG) is an induced animal MG
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model, which has been widely used for the study of MG pathology and preclinical studies of novel
therapeutics(1,2). Passive transfer MG (PTMG) models, induced by injecting rodents with AChR
antibodies (from MG patients or monoclonal antibodies) are very useful for studying the direct
effect of autoantibodies on disease pathology, but since they only involve the efferent arm of the
immune response, they are not best suited for evaluation of immunotherapies (3). EAMG is usually
induced by active immunization of rodents with AChR extracted from the electric organ of Torpedo
californica (T-AChR), human or rat AChR, recombinant AChR domains or smaller peptides, and has
proven to be critical for human MG studies(4–6). Generally, animals mount an immune response
against the injected antigen and thus produce cross-reactive autoantibodies, which are
responsible for the emergence of EAMG. Notably, adult female Lewis rats are a common choice
for the induction of EAMG, due to their immunological profile and mild disease phenotype (5,6).
Current treatment options for most autoimmune diseases focus on general immunosuppression,
which can have debilitating side effects, increasing the risk for opportunistic infections and
tumorigenesis. Indeed, conventional treatments for MG include the use of corticosteroid therapy,
azathioprine, cyclosporine, cyclophosphamide, tacrolimus and immunomodulatory approaches
such as plasma exchange (PLEX) and intravenous immunoglobulin (IVIG), whereasthymectomy
also remains a treatment option(7). Furthermore, the application of monoclonal antibody
treatments against immunological targets, such as CD20 or the IL-6 receptor (e.g. rituximab and
tocilizumab, respectively), has shown potential over the years with more pronounced patient
improvement in cases that are refractory to previous approaches(8).
Immunological tolerance is the condition of unresponsiveness or ignorance towards self-antigens,
established during the development of T and B cells by clonal deletion of high-avidity autoreactive
cells in the thymus andbone marrow, respectively. However, this mechanism is not always
effective, thus allowing the circulation of self-reactivecells specific for peripheral antigens that
have not undergone tolerogenic presentation during negative selection. These lymphocytes can
be naturally subjectedto clonal anergy and deletion, differentiated to regulatory T cells (Tregs) or
suppressed by mature Tregs. The mechanisms of clonal deletion and immunoregulation can be
exploited therapeutically in state of the art antigen-specific approaches employing whole antigens
or small peptides delivered to autoreactive T cells as soluble molecules, expressed by regulatory
antigen-presenting-cells (APCs) or on antigen-bearing particles (9).Induction of tolerance in an
antigen-specific manner would be the ideal treatment for autoimmune diseases. By re-
establishing tolerance towards autoantigens, one can target the source of the autoimmune
reaction and dampen the immune response to a particular antigen without jeopardizing the
overall equilibrium of the immune system. The main focus of this review is to present novel
antigen-specific tolerance-inducing immunotherapies as alternative treatment strategies (Table 1)
and assess their applicability based on findings from animal models and recent clinical trials for
the treatment of autoimmune neurological diseases, using MG as an example due to its well
defined autoantigen targets and pathological mechanisms(10). We hypothesizethat the
approaches described in the following sections, could replace non-curative immunosuppressive
therapies in a more targeted and efficient manner.
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Table 1. Strategies for Ag-specific tolerance establishment in Myasthenia Gravis.
Cell-based Non-specific Cell-free
Soluble Autoantigen
Treg Therapy • Native soluble AChR α-subunit ECD
recombinant fragments
• Polyclonal ex vivo generated • Fusion proteins - APLs – Nonpathogenic AChR
autologous cell transfer intracellular epitopes
Vaccination
• AChR or α-subunit complementary RNA injection –
DC Therapy Anti-idiotypic Ab transfer
• Combined treatments
• Engineered AChR pulsed tolDCs in EAMG Nanocarriers
models • Ag-loaded -DC derived exosomes
• Combined treatments with drug encapsulation
Treg, T regulatory cells; AChR, acetylcholine receptor; ECD, extracellular domain; APLs, altered peptide ligands; tolDCs,
tolerogenic dendritic cells; Ag, antigen.
TOLERANCE-INDUCING IMMUNOTHERAPY APPROACHES
Cell-free antigen-specific immunotherapy
Protein and peptide-based approaches include whole antigens, fusion proteins, unaltered or
altered peptide ligands, and MHC-antigen complex delivery for tolerance induction. These
approaches hold multiple benefits compared to cell-based techniques, such as targeted delivery,
increased bioavailability and distribution to lymphoid tissues due to their engineered
pharmacokinetic profile(11).
Autoantigen administration reestablishes tolerance in experimental autoimmune
Myasthenia Gravis
Multiple studies using animal models indicate that administration of AChR domains, the main MG
autoantigen, through the mucosa (orally, nasally) is associated with tolerance reestablishment and
EAMG prevention and amelioration due to the presence of tolerance inducing cells in lymphoid
tissues. For example, oral treatment with a recombinant fragment of the human AChR α-subunit
extracellular domain (Ha1-205) prevented or ameliorated ongoing EAMG in rats, characterized by
a decrease of Th1 response markers and a shift in auto-antibody IgG isotypes from IgG2 to IgG1.
Tolerance induction following mucosal administration seems to depend on the tolerogen’s
conformation, since non-native or denatured AChR fragments suppressed ongoing EAMG in rats
when administered orally, whereasmore native fragments cause disease exacerbation rather than
suppression (12). Oral administration of lower doses of tolerogen favored active suppression,
whereas higher doses favored clonal anergy, probably by suppressing the proliferation of T cells
specific for the autoantigen (13).More recently, oral treatment of MuSK-EAMG mice with the
recombinant extracellular domain of rat MuSK prevented disease as indicated by increased
expression of the Treg induction markers TGFβ and FOXP3, reduced IL-18 expression and
autoantibody titers, and lower clinical scores(14).
Nasal administration is considered to be an effective alternative to oral tolerance, as it involves
similar mechanisms of action,while lower antigen doses are required (13). Nasal tolerance
induction has proven to be dependent on the timingof treatment, as a 10-fold higher amount of
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nasally administered T-AChR was required to induce tolerance in Lewis rats after EAMG induction,
compared to the amount needed for EAMG prevention (15). Notably, nasal administration of low-
doses of recombinant human AChR fragments ameliorated ongoing disease by a tolerance
mechanism of active suppression, based on the upregulation of anti-inflammatory markers such
as IL-10, TGFβ and downregulation of IFNγ, IL-2 and the costimulatory markers CTL4, B7-1 and B7-
2, while excluding clonal anergy as a possible underlying mechanism (16).
More recently, intravenous administration of an α1ECD mutant with increased solubility and
similar conformation to wild type protein(4), improved the clinical characteristics of rats with
ongoing EAMG in a dose- and time-dependent manner (Lazaridis et al., unpublished data).
Intravenous injection appears to exploit a non-inflammatory route involving resident immune cells
in organs that play a critical role in tolerance re-establishment, such as the liver and spleen,
supporting its potential as a treatment approach.
Some studies support the use of antigen-derived peptides and T cell dominant epitopes, as
opposed to whole protein domains. Oral administration of high-doses of the immunodominant T-
cell epitope α146-162 of the T-AChR α-subunit resulted in disease prevention, tolerance induction
and an immune shift from Th1 to Th2/Th3 responses, through mechanisms of clonal anergy (17).
Moreover, altered peptide ligands (APLs), which consist of single amino acid-substituted analogs
of one or multiple tandemly arranged peptides representing MG immunodominant epitopes, have
been examined as therapeutic agents in the context of EAMG. Oral or subcutaneous
administration of a dual APL composed of two myasthenogenic sequences of the human AChR α-
subunit (p195– 212 and p259–271), was shown to shift the immune response towards a regulatory
phenotype, as marked by the expression of CD25+ and CTLA4 markers on CD4+ T cell populations.
Upregulation of TGFβ and IL-10, downregulation of inflammatory cytokines such as IFNγ and IL-2,
reduction of autoantibody titers and symptom amelioration in immunized mice, possibly through
anergy mechanisms, support the potential of this approach for future applications (18,19).
However, nasal treatment with different AChR α-subunit derived peptides failed to induce
tolerance, highlighting potential difficulties in tolerance induction based on epitope spreading and
scheduling of the treatment (20).
Several studies have focused on the therapeutic impact of engineered domains of the AChR and
fusion proteins that combine different mechanisms of action. Consonni et. al, have successfully
administered intranasal treatment inT-AChR-primed mice with a fusion protein (CTA1R9K-X-DD)
comprised an immunodominant AChR α-subunit epitope (a146-162) linked to an inactivated
mutant of the CTA-1 subunit of cholera toxin and a dimer of a fragment of Staphylococcus aureus
protein A(21). They demonstrated that the dimer (DD) in the CTA1R9K-X-DD allowed targeted
peptide presentation and processing by migratory dendritic cells (DCs), compared to soluble
peptide administration. Furthermore, the mutant CTA1 subunit acted as a tolerogenic agent, by
suppressing autoreactive T helper cells targeted against the α1 epitope and inducinga regulatory
response. More specifically, administration of the fusion protein resulted in symptom
improvement, upregulated gene expression of anti-inflammatory markers (TGFβ, IL-10, IL-2,
FOXP3) and reduced CD4+ T cell proliferation accompanied with decreased production of
inflammatory cytokines (IFNγ, IL-17, IL-10), in both acute and chronic EAMG. In another approach
involving chimeric molecules, soluble MHC II- immunodominant AChR a100-116 complexes
intravenously injected in the absence of co-stimulation was shown to prevent disease progression
in T-AChR immunized EAMG rats by inhibiting the proliferation of both whole-antigen and peptide-
specific autoreactive T cells (22).Another revolutionary approach is the generation of multivalent
antigen arrays that include synthetic polymers with grafted antigens acting as tolerogenic agents
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for B cells. This approach has been recently applied in experimental autoimmune encephalitis
(EAE), where subcutaneous administration of a tetramer displaying the encephalogenic
proteolipid peptide (PLP139−151) in a 4-arm polyethylene glycol (PEG) unit in miceameliorated EAE
paralysis symptoms, depleted autoreactive CD19+ B cells, reduced expression of pro –
inflammatory cytokines (IFNγ, TNF, IL-6, IL-2, IL-17A) and increased expression of T cell inhibitory
markers (CD80) (23).
Overall, a concern in designing an autoantigen-specific mucosal tolerance inducing approach is
the polyclonality of autoimmune diseases. Indeed, synthetic AChR peptides have failed to produce
a tolerogenic effect, further supporting the difficulty in reestablishing tolerance against the whole
AChR protein though a ‘spreading’ mechanism(20). Nevertheless, other studies have successfully
achievedtolerance re-establishment through the nasal and oral route inEAMG models, after
therapeutic administration of whole proteins or AChR fragments. Consequently, a tolerogen’s
spatial conformation and native context, as well as administration route, dosage and timing,
should be carefully considered for successful future experimental design and clinical application.
Treatment with non-pathogenic epitopes prevents EAMG progression in an
antigen-specific manner
Intraperitoneal administration of a mixture of extracellular and cytoplasmatic domains of the
AChR expressed in bacteria, has been shown to be more effective than oral treatment in
suppressing ongoing acute phase EAMG (24).Furthermore, subcutaneous immunization of EAMG
rats with a mixture of human AChR cytoplasmic domains of the α1, β1, γ, δ and ε subunits in
incomplete Freud’s adjuvant (IFA), which isincapable of disease induction, can prevent and revert
disease, characterized by reduced autoantibody titers and resistance to EAMG re-induction. A
possible underlying mechanism could involve antibody-mediated feedback suppression,
accompanied by increased production of antibodies against these non-pathogenic domains and
antigen-specific B cell apoptosis, that diverts the immunological response away from producing
pathogenic AChR ECD specific antibodies(25).Although isotype switching protected from disease
reoccurrence after AChR re-immunization, it did not have an immediate therapeutic effect (26).
Microbial peptides containing similar epitopes to the MG T and B cell epitopes, provide an
alternative approach to autoantigen administration. Subcutaneous pretreatment of Lewis rats
with a peptide derived from Haemophilus influenzae in IFA before T-AChR immunization, prevented
EAMG and improved its progression by mechanisms of immune tolerance through non-
pathogenic microbial mimicry, even though immunological Th1 to Th2 shift did not occur, but
rather a suppression of both Th1 and Th2 as well as reduction in AChR antibody titers was
observed(27).
Vaccines against autoreactive T cell receptor and antibodies in EAMG
Injection with a vaccine incorporating the variable regions of recombinant T cell receptor (TCR) or
complementary encoding DNA, provides an alternative to autoantigen administration. In
accordance with tolerance induction after autoantigen injection, a TCR-targeted vaccine would
stimulate a regulatory T cell response, antibody production against autoreactive TCRs and immune
deviation from Th1 to Th2 responses, as demonstrated in Multiple Sclerosis(MS) and other
disorders (28).More specifically, passive transfer of anti-idiotypic antibodies against self-targeting
antibodies or induction of anti-idiotypic antibodies after immunization with a peptide encoded by
a complementary RNA to the AChR MIR, were shown to prevent EAMG, lower autoantibody levels
against the AChR αsubunit and reverse disease symptoms (29,30). Moreover, injection of Lewis
rats twice before T-AChR-EAMG induction, with a synthetic peptide encoded by thecomplementary
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nucleotide sequence of T-AChR α100-116 peptide, which is the immunodominant T cell epitope in
Lewis rats, generated an antibody response against T-AChR α100–116- specific T cells, reduced
AChR autoantibody levels, limited AChR loss in the neuromuscular junction(NMJ) and reduced
EAMG severity(31). Also, administration of antibodies targeting Vβ5.1 expressing CD4+ T cells,
apathogenic Thpopulation found in HLA-DR3 haplotype MG patients,led to Vβ5.1 expressing T cell
depletion and prevented the anti-AChR antibody-mediated pathogenicity inimmunodeficientmice
engrafted with thymocytes from HLA-DR3 MG patients(32). Although these results require further
research and lack clinical application, TCR peptide injection in combination with current
treatments could be a promising candidate, since it alleviates the need for antibody humanization.
Nanoparticles and exosomes as vehicles for antigen-specific immunotolerance
Nanoparticles (NPs) or liposomes could act as vehicles for antigen or MHC-antigen complex
delivery. Although such approaches have not yet been explored extensively against MG, they
provide a very promising option due to their high versatility and customization potential, and
importantly for clinical application, NPs can be manufactured in a controlled and reproducible
manner.Their functionality and ability to elicit an immune response are highly affected by their
charge, size and composition. Anionic NPs demonstrate limited immunogenicity and have longer
circulation periods(33). Moreover, differences in size determine their accumulation to different
tissues, with small NPs (6-9nm) entering the blood circulation, whereas NPs between 100-200nm
tend to accumulate in lymphoid organs (lymph nodes, liver, spleen), where they can be
phagocytosed by resident APCs(34). Alternatively, NPs can be engineered to avoid phagocytosis
and release their cargo extracellularly. Their material composition should be customized to allow
controlled release and tolerogenic presentation of their encapsuled antigens. Structural
modifications, such as PEG conjugation, could improve circulation by reducing their opsonization
and aggregation. Tolerogenic NPs with distinct mechanisms of action have been examined,
involving antigen presentation alone or co-encapsulation of antigen with anti-inflammatory
mediators or pharmacological agents (such as IL-10 receptor, TGFβ, CD22, Fas antibody, NF-κBand
mTOR inhibitors) (35). Research in various autoimmune conditions has shown that monospecific
MHCII-antigen bearing NPs could upregulate memory Treg type 1 markers in antigen-experienced
CD4+ Tregs and promote B regulatory cell expansion in an antigen-dependent manner, followed
by a systemic expansion of these populations (36). Furthermore, a combinatorial approach where
the simultaneous administration of two NPs, one phagocytosable encapsulating an antigen and
drugs for intracellular targeting, and the other non-phagocytosable for controlled extracellular
release of cell signaling agents, exhibited antigen specific immunoregulation and disease
amelioration in EAE animal models during subcutaneous administration (37). The immunogenic
nature of NPs should also be considered before application, as hypersensitivity and autoimmune
reactions due to molecular mimicry should not be overlooked. Injectable nanocarriers bearing in
vitrotranscribed chimeric antigen receptor (CAR) or TCR mRNA for in vivo reprogramming of
circulating T cells against specific antigens has been applied in mouse cancer models and may
provide a viable alternative for autoimmune diseases as well. These polymeric NPs offer controlled
pharmacokinetic properties and generate de novotumor-specific T cells that induce disease
regression in similar levels as ex vivo engineered lymphocytes(38).
Finally, combination of antigen-specific tolerance-inducing strategies with cytokine or
costimulatory factor inhibitors could augment the effectiveness of the therapy and provide an
integrated approach towards permanent treatment. Indeed, antibodies against costimulatory
factors IL-18 or CD40L and next generation biologicals such as anti-CD20 or anti-CD19 agents, have
suppressed early and later onset EAMG in rats by decreasing Th1 responses and exhibited positive
results for human MG treatment, respectively (39,40).Overall, determining the pharmacodynamic
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properties of the soluble antigen or its carriers, as well as identifying biomarkers for tolerance
establishment and underlying mechanisms of action that determine the success of each approach,
are crucial for efficient drug design and clinical application (41).
Cell-Based Antigen-Specific Immunotherapy
Regulatory T Cell Therapy for targeted immunosuppression
Treg cells comprise a small anti-inflammatory subset of CD4+ T cells with different phenotypes
and subpopulations, depending on their role in central or peripheral tolerance and the residing
tissue. Many studies have demonstrated that functional impairment of Tregs is correlated with an
autoimmune phenotype (42). Hence, ex vivo or in vivogeneration and manipulation of antigen-
specific Treg populations could provide a new therapeutic perspective, by promoting deletional
tolerance of antigen-specific autoreactive cells and restoring the tolerogenic function of
endogenous Treg populations (43). On that note, ex vivo generated autologous CD4+ CD25+
Foxp3+ Treg cell treatment has also provided a personalized approach to immunomodulation in
AChR MG, as proved by lowered anti-AChR antibody titers and increased Treg cell population in
the spleen (44,45). However, the risk of general immunosuppression and susceptibility to
infectious diseases or cancer should be carefully considered before clinical application.
Furthermore, such strategies can be exploitedin combinationwith approaches such as autoantigen
administration aiming towards the expansion of antigen-specific Tregs or expansion of ex vivo
engineered Tregs expressing an auto-antigen specific TCR or CAR (46). Chimeric auto-antibody
receptors (CAARs) can also exhibit specific cytotoxicity by targeting autoantibodies expressed on
the surface of autoreactive B cells, while remaining non-responsive to circulating autoantibodies
and limiting the risk for general immunosuppression (47).
In organ transplantation, immunosuppressant drugs inhibited the expansion of Tregs and thus
combinatorial therapy for tolerance induction in autoimmunity should be carefully examined (48).
The most efficient manner to obtain a sufficient dosage of antigen-specific Tregs with a high-
affinity TCR or CAR and increased function, is ex vivo transduction using lentiviral or retroviral
systems, gene editing using nucleases or the CRISPR-Cas system and delivery of transposons and
other gene editing components, since a small number of naturally occurring autoantigen-specific
Tregs are detected in the periphery and the majority are tissue-residing (49). The benefits and
drawbacks of the signaling and tissue-targeting abilities of each receptor should be carefully
considered. For instance, CARs elicit a stronger costimulatory signal against extracellular antigen,
do not require MHC-dependent antigen presentation and traffic to the inflamed tissue. However,
they can also lead to CAR Treg exhaustion, marked by low proliferation and reduced cytokine
production, as well as increased expression of inhibitory receptors and high apoptosis rates.
However, TCRs luck the high affinity and magnitude of CARs, but are more sensitive and can be
activated immediately after a single antigen-MHC interaction (50). Even though CAR-based therapy
has many challenges to overcome before entering the clinical field of autoimmunity, it is still an
innovative approach with a likely safe profile and versatile applicability (51).
Targeting tolerance to the B cell receptor
B cell-targeted approaches can influence the course of disease in many ways, as B cells participate
not only in antibody production but also in antigen-presentation to T cells and proinflammatory
cytokine release. B cell targeting methods are based on B cell receptor (BCR) binding of antigens
associated with a toxic, inhibitory, or apoptosis-inducing molecule. B cells could be targeted for
tolerance establishment or apoptosis of autoreactive lineages by utilizing strategies such as BCR-
specific binding to antigen on NPs, antibodies, and polymeric backbones or presented on the TCR
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or CAR of T cells. The combination of an antigen and an inhibitory ligand against the BCR, leads to
the recruitment of phosphatases and consequently inhibits downstream signaling, rendering the
B cell unresponsive. B-cell targeting Antibody Receptor (BAR) Tregs that specifically crosslink
antibodies on the surface of autoreactive B cells,have also exhibited positive results in the mouse
model of hemophilia for reestablishing T and B cell tolerance and reducing autoantibody
production(52). Some of the main issues to be addressed for the success of this approach include
the characterization of autoantigens responsible for disease pathogenesis, specific targeting of
autoantibody-producing cells and preventing neutralization of the therapeutic agent by circulating
autoantibodiesbefore reaching their B cell target (53).
Tolerogenic dendritic cells as a crucial component for targeted immunomodulation
DCs provide an alternative cell-based therapeutic pathway in immunotherapy for reestablishing
systemic tolerance on a long-term basis by determining the fate of both antigen-specific Tregs and
autoreactive T effector cells (Teff). Their maturation state also plays a critical role in tolerance
establishment, since mature DCs are responsible for directing T cell responses, whereas immature
or semi-mature DCs remain inactive and maintain tolerance in the periphery.Tolerogenic DCs
(tolDCs) can be acquired ex-vivo from bone marrow-derived DCs and be re-educated towards a
tolerizing phenotype by using several immunomodulatory agents such as cytokines (e.g. IL-10,
TGFβ), other compounds (e.g. corticosteroids, rapamycin, retinoid acid, vitamin D3) or genetic
manipulation. TolDCs induce tolerance by deletion or inhibition of self-reactive Teff cells, induction
of T cell anergy, de novo generation or expansion of existing antigen-specific Tregs and by re-
educating Teff to convert into Tregs. Their main mechanisms of action include downregulation of
co-stimulatory and inflammatory cytokines and upregulation of inhibitory receptors and anti-
inflammatory cytokines (54). APCs, are ideal for orchestrating an antigen-specific response to
ameliorate disease via releasing self-derived extracellular vehicles that transmit tolerogenic
signals (e.g. miRNAs) to both T or B cells in a TCR or BCR-dependent manner, respectively (55).
TolDCs can be transduced ex vivo or in vivo to elicit an anti-inflammatory signal while presenting
an antigen to T cells, depending on the DC subtype, targeted inhibitory costimulatory receptor and
tolerogenic signal from cytokines. For instance, simultaneous targeting of specific endocytic and
surface receptors, like C-type lectins and CTLA-4, respectively, ensures that a self-antigen of
defined structure and conformation is presented in a tolerogenic manner in the in vivo population
(56). Therapeutic administration of engineered AChR pulsed tolDCs has been applied in EAMG rats
and is associated with decreased autoantibody titers and decreased B cell activation. In vivo tolDC-
induced antigen-specific Treg proliferation could overcome the possible challenges of polyclonal
Treg expansion and redirect the immune response (57).
Li et.al have reported that statins have the ability to induce tolerogenic DCs that display an
immunoregulatory phenotype and alleviate symptoms in EAMG rats (58). A recent study from the
same group, utilized exosomes derived directly from the culture medium of statin-treated bone
marrow DCs obtained fromhealthy Lewis rats. The immature phenotype of statin-treated bone
marrow DCs, due to the lack of antigenic stimulation by e.g. lipopolysaccharides, determined the
tolerogenic nature of their secreted exosomes. Intravenous Injection of these exosomes in EAMG
rats was followed by upregulated expression of the regulatory markers CD40 and autoimmune
regulator (AIRE) in thymic epithelial cells and DCs, which led to increased levels of FOXP3+ Tregs
and central tolerance re-establishment through a non-autoantigen-specific manner (59).
Furthermore, intravenously injected exosomes from microRNA-146a overexpressing regulatory
Ta146–162-specific DCs suppressed ongoing EAMG in mice, in an antigen-specific and dose-
dependent manner, as indicated by lowered anti-AChR antibody titers, reduced AChR-specific
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CD4+ T cell proliferation, and an immune response shift from a Th1/Th17 to a Th2/Treg phenotype
(60).
Even though, DCs represent a very promising candidate for antigen-specific cell-based
immunotherapy, the preferred administration route, patient compliance after repetitive infusions,
manufacturing costs and potential in vivo side-effects, should be well-defined and considered
before future application in the clinic.
INNOVATIVE CLINICAL TRIALS
Recently, a plethora of clinical trials is focused on the efficacy of monoclonal antibodiesand
intravenous immunoglobulin administration (NCT03971422, NCT04735432, NCT04524273,
NCT03759366, NCT04346888, NCT03920293, NCT02950155, NCT03770403 NCT04159805,
NCT04728425)(61,62). The first in-human proof-of-concept study to ascertain the safety,
tolerability and immunogenic response after subcutaneous injection with CV-MG01, a vaccine
mimicking the AChR-specific B and T cell receptors and comprised two synthetic peptides
conjugated to a carrier protein, has completed its first phase and met its primary endpoints
(NCT02609022). A phase II trial is currently recruiting to evaluate the safety of high-dose
chemotherapy before autologous stem cell transplantation in autoimmune neurological
disorders, that responded poorly to previous therapies, including MG and MS patients
(NCT00716066). A phase Ib/IIa clinical trial that assesses the safety and efficacy of autologous T
cells expressing a CAR against B cell maturation antigen (BCMA) is under development and will be
completed during 2022 (NCT04146051) (63). Several clinical trials for MS also utilize novel
mechanisms for tolerance induction such as administration of autologous monocyte-derived
tolDCs pulsed with myelin peptides (NCT02903537) and autologous T cells for disease-specific
autoantigens (NCT01448252), as well as hematopoietic stem cell transplantation (NCT04047628,
NCT02674217), based on the therapeutic efficacy and safety status of previous studies (64,65). A
phase I (NCT01097668) and phase II (NCT01973491) study on the administration of ATX-MS-1467,
a molecule comprised four myelin protein peptides, on MS patients have both exhibited reduced
lesions and proven to be safe and well-tolerated (66). Sub-immunogenic administration of
recombinant human alpha B-crystallin to promote antigen-specific tolerance, resulted in
decreased lesions and a safe profile in MS patients, according to phase I and phase II studies
(NCT02442557, NCT02442570)(67).
SUMMARY
Targeted therapeutics that attenuate autoimmunity through tolerance re-establishment, have
been the focus of many studies in the past, mostly in the preclinical level by utilizing well-defined
animal models. Currently, there is a resurgence of interest in antigen-specific tolerance induction,
as exhibited by a multitude of approaches based on improved tolerogen pharmacokinetics and
cell-targeting mechanisms. Mucosal administration of soluble AChR α-subunit fragments,
expressed as single agents or conjugated with other protein moieties, has provided encouraging
results by promoting IgG antibody isotype switching and shifting the immune response from a
pro-inflammatory Th1 to a Th2/Treg phenotype. Subcutaneous injection with non-pathogenic
AChR epitopes or conformationally similar proteins also reversed EAMG through an antibody-
mediated feedback suppression mechanism. Advances in material science have madeNPs a
promising delivery method for tolerogen expression or presentation due to their versatility and
can be optimized for tissue-specific targeting, monitored pharmacokinetics and T cell
reprogramming. Despite the limited representation of cell-based therapies in MG, transplantation
with ex vivo engineered autologous autoantigen-specific Tregs and tolDCs could provide a
promising strategy as indicated by more recent results. Nevertheless, one should consider the
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limitations of cell-based therapies, such as targeting multiple antigens, epitope spreading,
durability, trafficking and safety, before entering the clinical field. Antigen-specific tolerance
strategies should limit the immune response only against pathogenic epitopes, while avoiding
general immunosuppression and hypersensitivity reactions. Therefore, autoantigen identification
and characterization of pathological mechanisms behind autoimmune diseases,remains the first
step towards developing innovative immunotherapies.
No plagiarism statement: ‘TheAuthor confirms that intact sentences or paragraphs from other publications
are not included and that there is no significant overlap with other publications’’.
Consent for publication:“TheAuthor confirms that this study has not been published or submitted for
publication in part or in full in any other Journal”.
Conflicts of interest:“There are no conflicts of interest related to this study”.
Acknowledgements and funding sources:I would like to express my gratitude to my supervisor Dr.
Konstantinos Lazaridis for his constant guidance and encouragement. Hisimmense knowledge
and plentiful experience have made for a fruitful collaboration throughout the completion of this
project.
REFERENCES
1. Lazaridis K, Tzartos SJ. Autoantibody Specificities in Myasthenia Gravis; Implications for Improved
Diagnostics and Therapeutics. Front Immunol. 2020 Feb 14;11:1–13. doi: 10.3389/fimmu.2020.00212.
PMID: 32117321; PMCID: PMC7033452.
2. Lazaridis K, Tzartos SJ. Myasthenia Gravis: Autoantibody Specificities and Their Role in MG
Management. Front Neurol. 2020 Nov 30;11:1–14. doi: 10.3389/fneur.2020.596981. PMID: 33329350;
PMCID: PMC7734299.
3. Kusner LL, Losen M, Vincent A, Lindstrom J, Tzartos S, Lazaridis K M-MP. Guidelines for pre-clinical
assessment of the acetylcholine receptor-specific passive transfer myasthenia gravis model -
recommendations for methods and experimental designs. Exp Neurol. 2015 Aug;270:3-10. doi:
10.1016/j.expneurol.2015.02.025. Epub 2015 Mar 3. PMID: 25743217; PMCID: PMC4466131.
4. Lazaridis K, Zisimopoulou P, Giastas P, Bitzopoulou K, Evangelakou P, Sideri A, et al. Expression of
human AChR extracellular domain mutants with improved characteristics. Int J Biol Macromol. 2014
Feb;63:210-7. doi: 10.1016/j.ijbiomac.2013.11.003. Epub 2013 Nov 15. PMID: 24246999.
5. Losen M, Martinez-Martinez P, Molenaar PC, Lazaridis K, Tzartos S, Brenner T, et al. Standardization
of the experimental autoimmune myasthenia gravis (EAMG) model by immunization of rats with
Torpedo californica acetylcholine receptors - Recommendations for methods and experimental
designs. Exp Neurol. 2015 Aug;270:18-28. doi: 10.1016/j.expneurol.2015.03.010. Epub 2015 Mar 18.
PMID: 25796590; PMCID: PMC4466156.
6. Lazaridis K, Baltatzidi V, Trakas N, Koutroumpi E, Karandreas N, Tzartos SJ. Characterization of a
reproducible rat EAMG model induced with various human acetylcholine receptor domains. J
Neuroimmunol. 2017 Feb 15;303:13-21. doi: 10.1016/j.jneuroim.2016.12.011. Epub 2016 Dec 21.
PMID: 28038891.
7. Farmakidis C, Dimachkie MM, Pasnoor M, Barohn RJ. Immunosuppressive and immunomodulatory
therapies for neuromuscular diseases. Part II: New and novel agents. Muscle and Nerve. 2020
Jan;61(1):17-25. doi: 10.1002/mus.26711. Epub 2019 Nov 4. PMID: 31531874.
8. Gklinos P, Papadopoulou M, Stanulovic V, Mitsikostas DD, Papadopoulos D. Monoclonal antibodies
as neurological therapeutics. Pharmaceuticals. 2021 Jan 26;14(2):1–31. doi: 10.3390/ph14020092.
PMID: 33530460; PMCID: PMC7912592.
9. Carballido JM, Santamaria P. Taming autoimmunity: Translating antigen-specific approaches to
induce immune tolerance. J Exp Med. 2019 Feb 4;216(2):247-250. doi: 10.1084/jem.20182287. Epub
2019 Jan 16. PMID: 30651299; PMCID: PMC6363422.
10. Fuchs S, Aricha R, Reuveni D, Souroujon MC. Experimental Autoimmune Myasthenia Gravis (EAMG):
10Student International Biological &Biomedical Research
Vol. 1(1):a0000054, 2022.
From immunochemical characterization to therapeutic approaches. J Autoimmun. 2014 Nov;54:51-9.
doi: 10.1016/j.jaut.2014.06.003. Epub 2014 Jun 24. PMID: 24970384.
11. Pearson RM, Casey LM, Hughes KR, Miller SD, Shea LD. In vivo reprogramming of immune cells:
Technologies for induction of antigen-specific tolerance. Adv Drug Deliv Rev. 2017 May 15;114:240-
255. doi: 10.1016/j.addr.2017.04.005. Epub 2017 Apr 14. PMID: 28414079; PMCID: PMC5582017.
12. Im SH, Barchan D, Fuchs S, Souroujon MC. Suppression of ongoing experimental myasthenia by oral
treatment with an acetylcholine receptor recombinant fragment. J Clin Invest. 1999 Dec;104(12):1723-
30. doi: 10.1172/JCI8121. PMID: 10606626; PMCID: PMC409886.
13. Faria AMC, Weiner HL. Oral tolerance: Therapeutic implications for autoimmune diseases. Clin Dev
Immunol. 2006 Jun-Dec;13(2-4):143-57. doi: 10.1080/17402520600876804. PMID: 17162357; PMCID:
PMC2270752.
14. Reuveni D, Aricha R, Souroujon MC, Fuchs S. MuSK EAMG: Immunological Characterization and
Suppression by Induction of Oral Tolerance. Front Immunol. 2020 Mar 17;11:1–9. doi:
10.3389/fimmu.2020.00403. PMID: 32256489; PMCID: PMC7089875.
15. Shi FD, Bai XF, Li HL, Huang YM, Van Der Meide PH, Link H. Nasal tolerance in experimental
autoimmune myasthenia gravis (EAMG): Induction of protective tolerance in primed animals. Clin Exp
Immunol. 1998 Mar;111(3):506-12. doi: 10.1046/j.1365-2249.1998.00521.x. PMID: 9528890; PMCID:
PMC1904894.
16. Im SH, Barchan D, Fuchs S, Souroujon MC. Mechanism of nasal tolerance induced by a recombinant
fragment of acetylcholine receptor for treatment of experimental myasthenia gravis. J
Neuroimmunol. 2000 Nov 1;111(1-2):161-168. DOI: 10.1016/s0165-5728(00)00395-7. PMID:
11063834.
17. Baggi F, Andreetta F, Caspani E, Milani M, Longhi R, Mantegazza R, et al. Oral administration of an
immunodominant T-cell epitope downregulates Th1/Th2 cytokines and prevents experimental
myasthenia gravis. J Clin Invest. 1999 Nov;104(9):1287-95. doi: 10.1172/JCI7121. PMID: 10545527;
PMCID: PMC409818.
18. Paas-rozner M, Sela M, Mozes E. A dual altered peptide ligand down-regulates myasthenogenic T cell
responses by up-regulating CD25- and CTLA-4-expressing CD4 ؉ T cells. 2003 May 27;100(11):6676-
81. doi: 10.1073/pnas.1131898100. Epub 2003 May 12. Erratum in: Proc Natl Acad Sci U S A. 2005 Aug
23;102(34):12288. PMID: 12743364; PMCID: PMC164506.
19. Paas-Rozner M, Sela M, Mozes E. The nature of the active suppression of responses associated with
experimental autoimmune myasthenia gravis by a dual altered peptide ligand administered by
different routes. Proc Natl Acad Sci U S A. 2001 Oct 23;98(22):12642-7. doi: 10.1073/pnas.221456798.
Epub 2001 Oct 16. PMID: 11606745; PMCID: PMC60107.
20. Zhang GX, Shi FD, Zhu J, Xiao BG, Levi M, Wahren B, et al. Synthetic peptides fail to induce nasal
tolerance to experimental autoimmune myasthenia gravis. J Neuroimmunol. 1998 May 1;85(1):96-
101. doi: 10.1016/s0165-5728(97)00243-9. PMID: 9627002.
21. Consonni A, Sharma S, Schön K, Lebrero-Fernández C, Rinaldi E, Lycke NY, et al. A novel approach to
reinstating tolerance in experimental autoimmune myasthenia gravis using a targeted fusion protein,
mCTA1-T146. Front Immunol. 2017 Sep 13;8:1133. doi: 10.3389/fimmu.2017.01133. PMID: 28959261;
PMCID: PMC5604076.
22. Spack EG, McCutcheon M, Corbelletta N, Nag B, Passmore D, Sharma SD. Induction of tolerance in
experimental autoimmune myasthenia gravis with solubilized MHC class II:acetylcholine receptor
peptide complexes. J Autoimmun. 1995 Dec;8(6):787-807. doi: 10.1016/s0896-8411(95)80018-2. PMID:
8824707.
23. Christopher MA, Johnson SN, Griffin JD, Berkland CJ. Autoantigen Tetramer Silences Autoreactive B
Cell Populations. Mol Pharm. 2020 Nov 2;17(11):4201-4211. doi:
10.1021/acs.molpharmaceut.0c00665. Epub 2020 Oct 6. PMID: 32903002; PMCID: PMC7606775.
24. Lindstrom J, Luo J, Kuryatov A. Myasthenia Gravis and the Tops and Bottoms of AChRs Antigenic
Structure of the MIR and Specific Immunosuppression of EAMG Using AChR Cytoplasmic Domains.
Ann N Y Acad Sci. 2008;1132:29-41. doi: 10.1196/annals.1405.007. PMID: 18567851; PMCID:
PMC2765226.
25. Luo J LJ. Antigen-specific Immunotherapeutic Vaccine for Experimental Autoimmune Myasthenia
Gravis. J Immunol. 2014 Nov 15;193(10):5044-55. doi: 10.4049/jimmunol.1401392. Epub 2014 Oct 6.
PMID: 25288571; PMCID: PMC4273672
11Student International Biological &Biomedical Research
Vol. 1(1):a0000054, 2022.
26. Luo J, Lindstrom J. Acetylcholine receptor–specific immunosuppressive therapy of experimental
autoimmune myasthenia gravis and myasthenia gravis. Ann N Y Acad Sci. 2018 Feb;1413(1):76-81.
doi: 10.1111/nyas.13550. Epub 2018 Jan 29. PMID: 29377167.
27. Im SH, Barchan D, Feferman T, Raveh L, Souroujon MC, Fuchs S. Protective molecular mimicry in
experimental myasthenia gravis. J Neuroimmunol. 2002 May;126(1-2):99-106. doi: 10.1016/s0165-
5728(02)00069-3. PMID: 12020961.
28. Cohen-Kaminsky S, Jambou F. Prospects for a T-cell receptor vaccination against myasthenia gravis.
Expert Rev Vaccines. 2005 Aug;4(4):473-92. doi: 10.1586/14760584.4.4.473. PMID: 16117705.
29. Berrih-Aknin S, Fuchs S, Souroujon MC. Vaccines against myasthenia gravis. Expert Opin Biol Ther.
2005 Jul;5(7):983-95. doi: 10.1517/14712598.5.7.983. PMID: 16018742; PMCID: PMC1847363.
30. Araga S, LeBoeuf RD BJ. Prevention of experimental autoimmune myasthenia gravis by manipulation
of the immune network with a complementary peptide for the acetylcholine receptor. Proc Natl Acad
Sci U S A. 1993 Sep 15;90(18):8747-51. doi: 10.1073/pnas.90.18.8747. Erratum in: Proc Natl Acad Sci U
S A 1994 Feb 15;91(4):1598. PMID: 8378359; PMCID: PMC47435.
31. Araga S, Xu L, Nakashima K, Villain M, Blalock JE. A peptide vaccine that prevents experimental
autoimmune myasthenia gravis by specifically blocking T cell help. FASEB J. 2000 Jan;14(1):185-96. doi:
10.1096/fasebj.14.1.185. PMID: 10627293.
32. Aissaoui A, Klingel-Schmitt I, Couderc J, Chateau D, Romagne F, Jambou F, et al. Prevention of
autoimmune attack by targeting specific T-cell receptors in a severe combined immunodeficiency
mouse model of myasthenia gravis. Ann Neurol. 1999 Oct;46(4):559-67. doi: 10.1002/1531-
8249(199910)46:43.0.co;2-s. PMID: 10514092.
33. Getts DR, Martin AJ, McCarthy DP, Terry RL, Hunter ZN, Yap WT, Getts MT, Pleiss M, Luo X, King NJ,
Shea LD, Miller SD. Microparticles bearing encephalitogenic peptides induce T-cell tolerance and
ameliorate experimental autoimmune encephalomyelitis. Nat Biotechnol. 2012 Dec;30(12):1217-24.
doi: 10.1038/nbt.2434. Epub 2012 Nov 18. PMID: 23159881; PMCID: PMC3589822.
34. Getts DR, Shea LD, Miller SD, King NJ. Harnessing nanoparticles for immune modulation. Trends
Immunol. 2015 Jul;36(7):419-27. doi: 10.1016/j.it.2015.05.007. Epub 2015 Jun 15. Erratum in: Trends
Immunol. 2016 Oct;37(10 ):715. PMID: 26088391; PMCID: PMC4603374.
35. Kishimoto TK, Maldonado RA. Nanoparticles for the induction of antigen-specific immunological
tolerance. 2018 Feb 20;9:230. doi: 10.3389/fimmu.2018.00230. PMID: 29515571; PMCID:
PMC5826312.
36. Clemente-Casares X, Blanco J, Ambalavanan P, Yamanouchi J, Singha S, Fandos C, Tsai S, Wang J,
Garabatos N, Izquierdo C, Agrawal S, Keough MB, Yong VW, James E, Moore A, Yang Y, Stratmann T,
Serra P, Santamaria P. Expanding antigen-specific regulatory networks to treat autoimmunity. Nature.
2016 Feb 25;530(7591):434-40. doi: 10.1038/nature16962. Epub 2016 Feb 17. PMID: 26886799.
37. Cho JJ, Stewart JM, Drashansky TT, Brusko MA, Zuniga AN, Lorentsen KJ, Keselowsky BG, Avram D. An
antigen-specific semi-therapeutic treatment with local delivery of tolerogenic factors through a dual-
sized microparticle system blocks experimental autoimmune encephalomyelitis. Biomaterials. 2017
Oct;143:79-92. doi: 10.1016/j.biomaterials.2017.07.029. Epub 2017 Jul 24. PMID: 28772190; PMCID:
PMC5870833.
38. Parayath NN, Stephan SB, Koehne AL, Nelson PS, Stephan MT. In vitro-transcribed antigen receptor
mRNA nanocarriers for transient expression in circulating T cells in vivo. Nat Commun. 2020 Nov
27;11(1):6080. doi: 10.1038/s41467-020-19486-2. PMID: 33247092; PMCID: PMC7695830.
39. Souroujon MC, Maiti PK, Feferman T, Im SH, Raveh L, Fuchs S. Suppression of myasthenia gravis by
antigen-specific mucosal tolerance and modulation of cytokines and costimulatory factors. Ann N Y
Acad Sci. 2003 Sep;998:533-6. doi: 10.1196/annals.1254.069. PMID: 14592924.
40. Menon D, Barnett C, Bril V. Novel Treatments in Myasthenia Gravis. Front Neurol. 2020 Jun 30;11:1–
12. doi: 10.3389/fneur.2020.00538. PMID: 32714266; PMCID: PMC7344308.
41. Serra P, Santamaria P. Antigen-specific therapeutic approaches for autoimmunity. Nat Biotechnol.
2019 Mar;37(3):238-251. doi: 10.1038/s41587-019-0015-4. Epub 2019 Feb 25. PMID: 30804535.
42. Dejaco C, Duftner C, Grubeck-Loebenstein B, Schirmer M. Imbalance of regulatory T cells in human
autoimmune diseases. Immunology. 2006 Mar;117(3):289-300. doi: 10.1111/j.1365-
2567.2005.02317.x. PMID: 16476048; PMCID: PMC1782226.
43. Bayati F, Mohammadi M, Valadi M, Jamshidi S. The Therapeutic Potential of Regulatory T Cells :
Challenges and Opportunities. 2021 Jan 15;11:1–25. doi: 10.3389/fimmu.2020.585819. PMID:
12Student International Biological &Biomedical Research
Vol. 1(1):a0000054, 2022.
33519807; PMCID: PMC7844143.
44. Aricha R, Feferman T, Fuchs S, Souroujon MC. Ex vivo generated regulatory T cells modulate
experimental autoimmune myasthenia gravis. J Immunol. 2008 Feb 15;180(4):2132-9. doi:
10.4049/jimmunol.180.4.2132. PMID: 18250419.
45. Aricha R, Reuveni D, Fuchs S, Souroujon MC. Suppression of experimental autoimmune myasthenia
gravis by autologous T regulatory cells. J Autoimmun. 2016 Feb;67:57-64. doi:
10.1016/j.jaut.2015.09.005. Epub 2015 Oct 17. PMID: 26489998.
46. Eggenhuizen PJ, Ng BH, Ooi JD. Treg Enhancing Therapies to Treat Autoimmune Diseases. Int J Mol
Sci. 2020 Sep 23;21(19): 1–18. doi: 10.3390/ijms21197015. PMID: 32977677; PMCID: PMC7582931.
47. Ellebrecht CT, Bhoj VG, Nace A, Choi EJ, Mao X, Cho MJ, Di Zenzo G, Lanzavecchia A, Seykora JT,
Cotsarelis G, Milone MC, Payne AS. Reengineering chimeric antigen receptor T cells for targeted
therapy of autoimmune disease. Science. 2016 Jul 8;353(6295):179-84. doi: 10.1126/science.aaf6756.
Epub 2016 Jun 30. PMID: 27365313; PMCID: PMC5343513.
48. San Segundo D, Ruiz JC, Fernández-Fresnedo G, Izquierdo M, Gómez-Alamillo C, Cacho E, Benito MJ,
Rodrigo E, Palomar R, López-Hoyos M, Arias M. Calcineurin inhibitors affect circulating regulatory T
cells in stable renal transplant recipients. Transplant Proc. 2006 Oct;38(8):2391-3. doi:
10.1016/j.transproceed.2006.08.081. PMID: 17097943.
49. Amini L, Greig J, Schmueck-Henneresse M, Volk HD, Bézie S, Reinke P, Guillonneau C, Wagner DL,
Anegon I. Super-Treg: Toward a New Era of Adoptive Treg Therapy Enabled by Genetic Modifications.
Front Immunol. 2021 Feb 24;11: 1–17. doi: 10.3389/fimmu.2020.611638. PMID: 33717052; PMCID:
PMC7945682.
50. Harris DT, Kranz DM. Adoptive T Cell Therapies: A Comparison of T Cell Receptors and Chimeric
Antigen Receptors. Trends Pharmacol Sci. 2016 Mar;37(3):220-230. doi: 10.1016/j.tips.2015.11.004.
Epub 2015 Dec 17. PMID: 26705086; PMCID: PMC4764454.
51. S Sadeqi Nezhad M, Seifalian A, Bagheri N, Yaghoubi S, Karimi MH, Adbollahpour-Alitappeh M.
Chimeric Antigen Receptor Based Therapy as a Potential Approach in Autoimmune Diseases: How
Close Are We to the Treatment? Front Immunol. 2020 Nov 26;11:1–12. doi:
10.3389/fimmu.2020.603237. PMID: 33324420; PMCID: PMC7727445.
52. Moorman CD, Sohn SJ, Phee H. Emerging Therapeutics for Immune Tolerance: Tolerogenic Vaccines,
T cell Therapy, and IL-2 Therapy. Front Immunol. 2021 Mar 29;12:657768. doi:
10.3389/fimmu.2021.657768. PMID: 33854514; PMCID: PMC8039385.
53. Stensland ZC, Cambier JC, Smith MJ. Therapeutic Targeting of Autoreactive B Cells: Why, How, and
When? Biomedicines. 2021 Jan 16;9(1):1–10. doi: 10.3390/biomedicines9010083. PMID: 33467130;
PMCID: PMC7829839.
54. Passerini L, Gregori S. Induction of Antigen-Specific Tolerance in T Cell Mediated Diseases. Front
Immunol. 2020 Sep 29;11:1–14. doi: 10.3389/fimmu.2020.02194. PMID: 33133064; PMCID:
PMC7550404.
55. Nazimek K, Bryniarski K. Approaches to inducing antigen-specific immune tolerance in allergy and
autoimmunity: Focus on antigen-presenting cells and extracellular vesicles. Scand J Immunol. 2020
Jun;91(6): 1–19. doi: 10.1111/sji.12881. Epub 2020 May 7. PMID: 32243636.
56. Castenmiller C, Keumatio-Doungtsop BC, van Ree R, de Jong EC, van Kooyk Y. Tolerogenic
Immunotherapy: Targeting DC Surface Receptors to Induce Antigen-Specific Tolerance. Front
Immunol. 2021 Feb 19;12:643240. doi: 10.3389/fimmu.2021.643240. PMID: 33679806; PMCID:
PMC7933040.
57. Xiao BG, Duan RS, Link H, Huang YM. Induction of peripheral tolerance to experimental autoimmune
myasthenia gravis by acetylcholine receptor-pulsed dendritic cells. Cell Immunol. 2003 May;223(1):63-
9. doi: 10.1016/s0008-8749(03)00118-7. PMID: 12914759.
58. Li XL, Liu Y, Cao LL, Li H, Yue LT, Wang S, Zhang M, Li XH, Dou YC, Duan RS. Atorvastatin-modified
dendritic cells in vitro ameliorate experimental autoimmune myasthenia gravis by up-regulated Treg
cells and shifted Th1/Th17 to Th2 cytokines. Mol Cell Neurosci. 2013 Sep;56:85-95. doi:
10.1016/j.mcn.2013.03.005. Epub 2013 Mar 27. PMID: 23541702.
59. Zhang P, Liu RT, Du T, Yang CL, Liu YD, Ge MR, Zhang M, Li XL, Li H, Dou YC, Duan RS. Exosomes derived
from statin-modified bone marrow dendritic cells increase thymus-derived natural regulatory T cells
in experimental autoimmune myasthenia gravis. J Neuroinflammation. 2019 Nov 3;16(1):1–12. doi:
10.1186/s12974-019-1587-0. PMID: 31679515; PMCID: PMC6825716.
13Student International Biological &Biomedical Research
Vol. 1(1):a0000054, 2022.
60. Yin W, Ouyang S, Luo Z, Zeng Q, Hu B, Xu L, Li Y, Xiao B, Yang H. Immature Exosomes Derived from
MicroRNA-146a Overexpressing Dendritic Cells Act as Antigen-Specific Therapy for Myasthenia Gravis.
Inflammation. 2017 Aug;40(4):1460-1473. doi: 10.1007/s10753-017-0589-2. PMID: 28523463.
61. Karelis G, Balasa R, De Bleecker JL, Stuchevskaya T, Villa A, Van Damme P, Lagrange E, Heckmann JM,
Nicolle M, Vilciu C, Bril V, Mondou E, Griffin R, Chen J, Henriquez W, Garcia B, Camprubi S, Ayguasanosa
J. A Phase 3 Multicenter, Prospective, Open-Label Efficacy and Safety Study of Immune Globulin
(Human) 10% Caprylate/Chromatography Purified in Patients with Myasthenia Gravis Exacerbations.
Eur Neurol. 2019;81(5-6):223-230. doi: 10.1159/000502818. Epub 2019 Oct 25. PMID: 31655810.
62. Bril V, Benatar M, Andersen H, Vissing J, Brock M, Greve B, Kiessling P, Woltering F, Griffin L, Van den
Bergh P; MG0002 Investigators. Efficacy and Safety of Rozanolixizumab in Moderate to Severe
Generalized Myasthenia Gravis: A Phase 2 Randomized Control Trial. Neurology. 2021 Feb
9;96(6):e853-e865. doi: 10.1212/WNL.0000000000011108. Epub 2020 Nov 20. PMID: 33219142;
PMCID: PMC8105899.
63. Chen Y, Sun J, Liu H, Yin G, Xie Q. Immunotherapy Deriving from CAR-T Cell Treatment in Autoimmune
Diseases. J Immunol Res. 2019 Dec 31;2019:5727516. doi: 10.1155/2019/5727516. PMID: 32083141;
PMCID: PMC7012264.
64. Karussis D, Shor H, Yachnin J, Lanxner N, Amiel M, Baruch K, Keren-Zur Y, Haviv O, Filippi M, Petrou P,
Hajag S, Vourka-Karussis U, Vaknin-Dembinsky A, Khoury S, Abramsky O, Atlan H, Cohen IR, Abulafia-
Lapid R. T cell vaccination benefits relapsing progressive multiple sclerosis patients: a randomized,
double-blind clinical trial. PLoS One. 2012;7(12):e50478. doi: 10.1371/journal.pone.0050478. Epub
2012 Dec 14. PMID: 23272061; PMCID: PMC3522721.
65. Nash RA, Hutton GJ, Racke MK, Popat U, Devine SM, Griffith LM, Muraro PA, Openshaw H, Sayre PH,
Stüve O, Arnold DL, Spychala ME, McConville KC, Harris KM, Phippard D, Georges GE, Wundes A, Kraft
GH, Bowen JD. High-dose immunosuppressive therapy and autologous hematopoietic cell
transplantation for relapsing-remitting multiple sclerosis (HALT-MS): a 3-year interim report. JAMA
Neurol. 2015 Feb;72(2):159-69. doi: 10.1001/jamaneurol.2014.3780. PMID: 25546364; PMCID:
PMC5261862.
66. Chataway J, Martin K, Barrell K, Sharrack B, Stolt P, Wraith DC; ATX-MS1467 Study Group. Effects of
ATX-MS-1467 immunotherapy over 16 weeks in relapsing multiple sclerosis. Neurology. 2018 Mar
13;90(11):e955-e962. doi: 10.1212/WNL.0000000000005118. Epub 2018 Feb 21. PMID: 29467307.
67. Van Noort JM, Bsibsi M, Nacken PJ, Verbeek R, Venneker EH. Therapeutic Intervention in Multiple
Sclerosis with Alpha B-Crystallin: A Randomized Controlled Phase IIa Trial. PLoS One. 2015 Nov
23;10(11):1–19. doi: 10.1371/journal.pone.0143366. PMID: 26599332; PMCID: PMC4657879.
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