| Co-Investigator(Kenkyū-buntansha) |
TAKENO Mitsuhiro St. Marianna University School of Medicine, The Medical Department, Assistant Pr, 医学部, 助手 (50236494)
SUZUKI Noboru St. Marianna University School of Medicine, Institute of Medical Science, Associ, 医学部, 講師 (40235982)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1991: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
The intracellular accumulation of a series of cytokines in freshly- isolated CD4+ T cells in individual patients with systemic lupus erythematosus (SLE) has been studied to determine what factors may be produced by these cells in vivo. The cytokine-producing cells were identified at a single cell level using by cytokine-specific antibodies and an indirect immunofluorescence technique with flow microfluorometry. CD4+ T cells from patients with SLE, but not normal subjects, were shown to spontaneously produce interleukin (IL)-2, IL-4, IL-6, interferon-gamma, and tumor necrosis factor-alpha. By performing two-color immunofluorescence studies, we observed a variegated production pattern with cells making no, one or several cytokines simultaneously. The results indicate that CD4+ T cells in patients with SLE may reactivated polyclonally in vivo, and thus that the expanded population of these polyclonally activated CD4+ T cells spontaneously produces several cytokines which may. cause sustai
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ned activation of immunological effector cells such as B cells. This may have important roles in both the development and maintenance of human SLE.
In the course of our studies of the cytokine production pattern, we found overexpression of cell adhesion molecules such as LFA-1 and ICAM-+L on peripheral blood lymphocytes (PBL) of SLE patients. Moreover, there existed a novel CD4+ T lymphocyte subset, which expressed CD45RA and ICAM-1 simultaneously in the blood of patients with SLE. Introduction of anti-LFA-1 or anti-ICAM-1 monoclonal antibodies (mabsi into the in vitro cultures of freshly isolated SLE PBL resulted in inhibition of both the spontaneous polyclonal IgG production and spontaneous IgG anti-DNA antibody production. Thus, overexpression of LFA-1 and ICAM-1 molecules of SLE lymphocytes facilitates T-B cell communication, thereby causing them to produce excessive antibodies. This finding may be offer a possible strategy for therapeutic immune intervention by mabs.
Extensive studies in the murine model of lupus nephritis have shown that cationic anti-DNA autoantibodies have nephritogenic potential. We have also investigated whether cationic anti-DNA antibodies of IgG class are also produced in vivo in patients with active lupus nephritis, and analyzed the mechanism by which such antibodies are produced. The highly cationic anti-DNA antibodies of IgG class were prominent in the isoelectric focusing-immunoblots of serum antibodies from the patients with lupus nephritis. Decreased proteinuria after successful treatment with preunisolone was associated with disappearance of the cationic anti-DNA antibodies in the circulation. Moreover, the cationic anti-DNA antibodies were produced through numerous point mutations in the genes, including substitution of neutral amino acids of germline sequences for cationic amino acids. The results indicate that these antibodies may be produced by antigen-driven manner. Less
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