Inducible cell contact signals regulate early activation gene expression during B-T lymphocyte collaboration
Biochemistry & Molecular Pharmacology
Graduate School of Biomedical Sciences; Department of Molecular Genetics and Microbiology
Medical Subject Headings
Animals; *Antibody Formation; Antigens; Antigens, CD3; Antigens, Differentiation, T-Lymphocyte; B-Lymphocytes; Cell Communication; Cyclosporine; DNA-Binding Proteins; Early Growth Response Protein 1; Gene Expression; *Genes, myc; *Immediate-Early Proteins; *Lymphocyte Activation; *Lymphocyte Cooperation; Mice; RNA, Messenger; Receptors, Antigen, B-Cell; Receptors, Antigen, T-Cell; Signal Transduction; T-Lymphocytes; Transcription Factors
Life Sciences | Medicine and Health Sciences
B cells get help in the antibody response by presenting processed Ag to Th cells. We asked whether the Ag-presenting B cell must induce Th functions before receiving help, or whether B cell activation is a direct consequence of T cell recognition of Ag on the B cell surface. To obtain a prompt and sensitive indication of the receipt of growth signals, we measured mRNA levels of the immediate early genes, c-myc and egr-1, in T and B cells separated from Ag-specific B-T conjugates of normal, resting murine B cells and a Th line. Although Ag-dependent increases in B cell c-myc expression occur as early as 2 h after conjugation, early c-myc expression in the B cell was also seen when the Th cells were activated with immobilized anti-CD3 in the absence of Ag recognition. Therefore, T cell activation rather than Ag recognition per se appears to be responsible for the early c-myc signal in the B cells. The c-myc response in the B cell depends on induction of a contact-dependent helper function in the T cell, which is inhibitable by cyclosporin A acting on the T cell. Delivery of contact help is not blocked by anti-class II MHC antibody. Contact with activated Th cells induces a different pattern of immediate early gene expression from that induced by cross-linking the B cell Ag receptor.
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Citation: J Immunol. 1992 Sep 15;149(6):1867-75.
Journal of immunology (Baltimore, Md. : 1950)
Klaus, Stephen J. and Parker, David C., "Inducible cell contact signals regulate early activation gene expression during B-T lymphocyte collaboration" (1992). GSBS Student Publications. 611.