In Vitro Immune Response of SLE Lymphocytes

The Mechanism Involved in B-Cell Activation

Authors

  • T. TAKEUCHI,

    1. Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan, and Division of Tumor Immunology, Sidney Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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  • T. ABE,

    Corresponding author
    1. Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan, and Division of Tumor Immunology, Sidney Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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  • M. KIYOTAKI,

    1. Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan, and Division of Tumor Immunology, Sidney Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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  • T. TOGUCHl,

    1. Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan, and Division of Tumor Immunology, Sidney Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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  • J. KOIDE,

    1. Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan, and Division of Tumor Immunology, Sidney Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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  • C. MORIMOTO,

    1. Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan, and Division of Tumor Immunology, Sidney Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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  • M. HOMMA

    1. Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan, and Division of Tumor Immunology, Sidney Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
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Tohru Abe, Department of Internal Medicine, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160, Japan

Abstract

Peripheral blood lymphocytes from 26 patients with systemic lupus erythematosus (SLE) and six normal individuals were tested for IgG synthesis in the presence or absence of PWM. Lymphocytes from patients with active SLE synthesized increased amounts of IgG in the absence of PWM and reduced amounts of IgG in the presence of PWM. Serum from patients with active SLE had an enhancing effect on the in vitro IgG synthesis of normal lymphocytes. The IgG or F(ab′)2 fractions of SLE serum retained the enhancing effect on in vitro IgG synthesis, and the enhancing activity was absorbed by human spleen cells. As little as 4 h of incubation with SLE serum was needed for the enhancing activity of normal lymphocytes. Treatment of B lymphocytes appeared to be of main importance for an increase in the in vitro IgG synthesis of SLE serum-treated lymphocytes. These results suggest that anti-B-lymphocyte antibodies from patients with active SLE are responsible in part for the hyperactive response of SLE B lymphocytes.

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