Complement-Fixing Anti-Type VII Collagen Antibodies Are Induced in Th1-Polarized Lymph Nodes of Epidermolysis Bullosa Acquisita-Susceptible Mice

Abstract

The environment encountered in secondary lymphoid organs (e.g., lymph nodes) influences the outcome of immune responses. Immunization of mice with type VII collagen, an adhesion protein expressed at the cutaneous basement membrane, induces experimental epidermolysis bullosa acquisita (EBA). In this model, clinical disease is associated with the H2s haplotype of the MHC found in SJL/J mice. Most other strains (e.g., BALB/c, C57BL/6, NZM2410/J) are resistant to clinical disease, despite autoantibody production. Comparison of autoantibody response in EBA-resistant and -susceptible mice showed an IgG2-dominated response in the latter. We hypothesized that EBA susceptibility is due to specific cytokine gene expression in draining lymph nodes (dLN). To challenge this hypothesis, EBA-susceptible (SJL/J) and -resistant (BALB/c, C57BL/6) mice were immunized with type VII collagen, followed by analysis of clinical phenotype, subclasses of circulating and tissue-bound autoantibodies, complement activation, and cytokine gene expression in dLN. Disease manifestation was associated with induction of complement-fixing autoantibodies, confirming previous observations. Furthermore, however, IFN-γ/IL-4 ratio in dLN of EBA-susceptible mice was significantly increased compared with EBA-resistant strains, suggesting a Th1 polarization. Immunization of H2s-congenic C57BL/6 mice (B6.SJL-H2s) led to Th1 polarization in dLN and clinical disease. In addition to their cytokine milieu, EBA-susceptible and -resistant mice also differed regarding the expression of FcγR on peripheral leukocytes, in which a higher FcγRIV expression in SJL/J and B6.SJL-H2s mice, compared with C57BL/6, was associated with skin lesions. In summary, blistering in experimental EBA is regulated by both adaptive (divergent class switch recombination due to polarized cytokine expression) and innate (FcγR expression) immune mechanisms.

B Cells, Dendritic Cells, and Macrophages Are Required To Induce an Autoreactive CD4 Helper T Cell Response in Experimental Epidermolysis Bullosa Acquisita

“…In the development of an antiviral immune response, CD8 T cells were associated with a predominant Th1 polarization (47). Such a Th1 response is also associated with skin blistering in experimental EBA (39). Our results, however, document that CD8 T cells are not required for production of Abs.…”

AChR-specific immunosuppressive therapy of myasthenia gravis

“…The isotype switching after specific immunosuppressive therapy, together with preference for a Th2-promoting adjuvant, suggests that therapy may involve a shift from Th1 to Th2 response specific to extracellular epitopes. Th1 cells induce synthesis of complement-fixing antibodies that disrupt the postsynaptic membrane [102,103]. In MG patients, the predominant isotypes of anti-AChR antibodies are IgG1 and IgG3 that fix complement [104].…”

T cells mediate autoantibody-induced cutaneous inflammation and blistering in epidermolysis bullosa acquisita

“…Misbalance of T cell populations leads to autoimmune disorders, including systemic lupus erythematosus (SLE), different autoimmune bullous dermatoses (AIBDs) and rheumatoid arthritis (RA)123. In these diseases, the contribution of T cells to antibody production and maintenance of the autoimmune response has clearly been demonstrated45.…”