Recognition of the Self Idiotype by T Cells: Induction of a Rapid Increase in Cytoplasmic Free Calcium in T Cells Recognizing a Variable L Chain Determinant

• Published in: MICROBIOLOGY and IMMUNOLOGY 1992, Vol.36(4), pp.407-418
• Main Authors: Utsunomiya-Tate, Naoko, Nakanishi, Mamoru, Arata, Yoji, Sugiyama, Haruo, Vera-Antola, Maria E., Fujio, Hajime, Sakato, Nobuo
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, immunoglobulins; Antigen-Presenting Cells - drug effects; Antigen-Presenting Cells - immunology; Biological and medical sciences; Calcium - metabolism; CD4 Antigens - immunology; CD4-Positive T-Lymphocytes - immunology; Chloroquine - pharmacology; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Genetic markers (allotypes, idiotypes); Immunoglobulin Idiotypes - immunology; Immunoglobulin Light Chains - immunology; Immunoglobulin Variable Region - immunology; Immunologic Surveillance - immunology; Lymphocyte Activation - immunology; Mice; Mice, Inbred BALB C; Molecular immunology; Peptide Fragments - immunology; Signal Transduction
• ISSN: 0385-5600; 1348-0421
• DOI: 10.1111/j.1348-0421.1992.tb02039.x

To investigate the initial stages of recognition of the self idiotype (Id) by T cells, we examined the early increase in cytoplasmic free calcium ([Ca2+]i) occurring in murine CD4+ T cells specific for a model Id, Id315, following their interaction with the Id. The changes in [Ca2+]i were monitored with stopped-flow fluorometry by loading T cells with fura 2, a Ca2+-binding fluorescent dye. An increase of [Ca2+]i in the Id-specific T cell line was dependent on the presence of both antigen-presenting cells (APC) and Id315. When T cells were mixed with APC pulsed with M315 for 90min at 37C, a significant increase in T cell [Ca2+]i was observed within one second. A pronounced elevation in [Ca2+]i was also observed in T cells after their interaction with APC which had been pulsed for 90min with VL-315 Id-containing proteins (such as VL-315, L315, Fv-315 or Fab'-315 fragments). In contrast, pulsing APC for 5min with the VL fragment produced little or no change in the [Ca2+]i. These results suggest that VL must be further processed by APC before it can be recognized by T cells. Indeed, a synthetic VL region peptide (positions 91-108, designated as P18) produced an elevation in T cell [Ca2+]i when mixed with APC without pulsing.