Details

Autor(en) / Beteiligte

• Hathcock, Karen S.
• Hodes, Richard J.

Titel

Role of the CD28-B7 Costimulatory Pathways in T Cell-Dependent B Cell Responses

Ist Teil von

• Advances in Immunology, 1996, Vol.62, p.131-166

Ort / Verlag

United States: Elsevier Science & Technology

Erscheinungsjahr

1996

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• This chapter summarizes the contribution of CD28-B7 costimulation to immune responses and presents an understanding of the role that this costimulatory pathway may play in T cell-dependent (Td) B cell activation. Costimulatory signals are neither antigen-specific nor major histocompatibility complex (MHC) restricted and arise from the coligation of counter-receptors on the cell surface of T cells and B cells or professional antigen-presenting cells (APCs). Costimulatory signals are discrete from but complementary to T cell receptor (TCR)- or B cell receptor (BCR)-derived signals. A role for CD28-B7 costimulatory signals in formation and function of germinal centers (GCs) was initially suggested by immunohistochemical studies that identified B7-expressing cells in both human and murine GCs. Analysis of normal human spleen sections revealed a subset of GC B cells that stained positively for both B7-1 and B7-2 expression. In certain situations, T cells or B cells that encounter their antigens in the absence of costimulation may be anergized or deleted. Studies indicate that cross-linking of CD28 and CTLA-4 may have markedly distinct functional consequences. The further elucidation is the characterization of the signal transduction events mediated by CD28/CTLA-4-B7 interactions. Considerable information has been obtained describing the signal pathways that are coupled to CD28 and the potential interactions of these signal transduction pathways with TCR-linked signaling events.