The Role of Adjuvants in the Efficacy of a Peptide Vaccine for Myasthenia Gravis

2001 ◽  
Vol 226 (4) ◽  
pp. 307-311 ◽  
Author(s):  
James L. McAnally ◽  
Likang Xu ◽  
Matteo Villain ◽  
J. Edwin Blalock

Myasthenia gravis (MG) and its animal model, experimental autoimmune (EA) MG, are caused by interference with neuromuscular transmission by autoantibodies against the nicotinic acetylcholine receptor (AChR) on muscle. Previously, we have shown that two peptides, denoted RhCA 67-16 and RhCA 611-001, designed to be complementary in structure to the main immunogenic region and the dominant Lewis rat T cell epitope (α-chain residues 100-116) of the AChR, respectively, are effective vaccines that prevent EAMG in rats by inducing anti-idiotypic/clonotypic antibodies (Ab) and lowering levels of AChR Ab. These studies employed keyhole limpet hemocyanin (KLH) as a carrier and complete Freunds adjuvant (CFA). In advance of a clinical trial the present study tested the efficacy of RhCA 611-001 when combined with different adjuvants that are approved for use in humans. Adjuvants chosen for comparison were incomplete Freunds adjuvant (IFA) and aluminum hydroxide (Alum). As a second goal we evaluated diphtheria toxin (DT) as an alternative carrier protein to KLH. Alum was found to be an effective adjuvant, particularly when used with the peptide conjugated to DT. This combination of carrier and adjuvant provided protection against EAMG comparable with that observed with CFA and KLH. Using enzyme-linked immunosorbent assays for Ab against RhCA 611-001, it was found that disease protection is qualitatively, but not quantitatively, related to the anti-peptide Ab response. Our results demonstrate a vaccine formulation that should be useful in the first soon-to-be-conducted clinical trials of peptide vaccines to specifically correct aberrant T and B cell responses in an autoimmune disease.

Endocrinology ◽  
2005 ◽  
Vol 146 (11) ◽  
pp. 4721-4726 ◽  
Author(s):  
Su He Wang ◽  
Zhengyi Cao ◽  
Julie M. Wolf ◽  
Mary Van Antwerp ◽  
James R. Baker

The role of TNF-related apoptosis-inducing ligand (TRAIL) in autoimmune thyroiditis is unclear. We used experimental autoimmune thyroiditis to clarify the contribution of TRAIL to the development of autoimmune thyroiditis. CBA/J mice were immunized with murine thyroglobulin, and spleen cells from these mice were subsequently injected into irradiated recipient CBA/J mice. One week later, the recipient mice were treated with recombinant TRAIL or a control protein. Compared with control animals, TRAIL-treated mice developed a milder form of the disease with a significant decrease in mononuclear cell infiltration in the thyroid and less thyroid follicular destruction. Furthermore, the number of apoptotic thyrocytes and also thyroglobulin-specific T helper-1 cell responses in TRAIL-treated mice was lower than that in the control animals. This study suggests that exogenous TRAIL suppresses the development of autoimmune thyroiditis via altering the function of cells involved in the immune response. These findings may contribute toward a novel treatment autoimmune thyroiditis.


2004 ◽  
Vol 78 (12) ◽  
pp. 6322-6334 ◽  
Author(s):  
Daisuke Sugahara ◽  
Sachiyo Tsuji-Kawahara ◽  
Masaaki Miyazawa

ABSTRACT Recent studies have demonstrated an essential role of Gag-specific CD4+ T-cell responses for viral control in individuals infected with human immunodeficiency virus type 1. However, little is known about epitope specificities and functional roles of the Gag-specific helper T-cell responses in terms of vaccine-induced protection against a pathogenic retroviral challenge. We have previously demonstrated that immunization with Friend murine leukemia virus (F-MuLV) Gag proteins protects mice against the fatal Friend retrovirus (FV) infection. We report here the structure of a protective T helper cell (Th) epitope, (I)VTWEAIAVDPPP, identified in the p15 (MA) region of F-MuLV Gag. In mice immunized with the Th epitope-harboring peptide or a vaccinia virus-expressed native full-length MA protein, FV-induced early splenomegaly regressed rapidly. In these mice, FV-infected cells were eliminated within 4 weeks and the production of virus-neutralizing antibodies was induced rapidly after FV challenge, resulting in strong protection against the virus infection. Interestingly, mice immunized with the whole MA mounted strong CD4+ T-cell responses to the identified Th epitope, whereas mice immunized with mutant MA proteins that were not bound to the plasma membrane failed to mount efficient CD4+ T-cell responses, despite the presence of the Th epitope. These mutant MA proteins also failed to induce strong protection against FV challenge. These data indicate the importance of the properly processible MA molecule for CD4+ T-cell priming and for the resultant induction of an effective immune response against retrovirus infections.


1995 ◽  
Vol 182 (1) ◽  
pp. 75-85 ◽  
Author(s):  
B L McRae ◽  
C L Vanderlugt ◽  
M C Dal Canto ◽  
S D Miller

The role of epitope spreading in the pathology of relapsing-remitting experimental autoimmune encephalomyelitis (R-EAE) was examined. Using peripherally induced immunologic tolerance as a probe to analyze the neuropathologic T cell repertoire, we show that the majority of the immunopathologic reactivity during the acute phase of R-EAE in SJL/J mice induced by active immunization with the intact proteolipid (PLP) molecule is directed at the PLP139-151 epitope and that responses to secondary encephalitogenic PLP epitopes may contribute to the later relapsing phases of disease. Intermolecular epitope spreading was demonstrated by showing the development of T cell responses to PLP139-151 after acute disease in mice in which R-EAE was initiated by the transfer of T cells specific for the non-cross-reactive MBP84-104 determinant. Intramolecular epitope spreading was demonstrated by showing that endogenous host T cells specific for a secondary encephalitogenic PLP epitope (PLP178-191) are demonstrable by both splenic T cell proliferative and in vivo delayed-type hypersensitivity responses in mice in which acute central nervous system damage was initiated by T cells reactive with the immunodominant, non-cross-reactive PLP139-151 sequence. The PLP178-191-specific responses are activated as a result of and correlate with the degree of acute tissue damage, since they do not develop in mice tolerized to the initiating epitope before expression of acute disease. Most importantly, we show that the PLP178-191-specific responses are capable of mediating R-EAE upon adoptive secondary transfer to naive recipient mice. Furthermore, induction of tolerance to intact PLP (which inhibits responses to both the initiating PLP139-151 epitope and to the PLP178-191 epitope) after the acute disease episode is sufficient to prevent relapsing disease. These results strongly support a contributory role of T cell responses to epitopes released as a result of acute tissue damage to the immunopathogenesis of relapsing clinical episodes and have important implications for the design of antigen-specific immunotherapies for the treatment of chronic autoimmune disorders in humans.


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