Anti-CD1B monoclonal antibody, clone DD31

For decades immunologists thought that T cells solely recognize peptides bound to Major Histocompatibility Complex (MHC) proteins. Therefore, nearly all medical technology that seeks to measure and manipulate human T cells during immunization, infection, allergy and autoimmune diseases relies on peptide antigens. Newer insights into alpha beta and gamma delta T cell activation by CD1 or MR1 proteins greatly expand the biochemical range of T cell antigens to include lipids and non-peptidic small molecules. Moving beyond in vitro studies, the recent development of human CD1a, CD1b, CD1c and MR1 tetramers allows direct and specific enumeration of lipid-reactive and small molecule-reactive T cells, providing a new approach to study of T cell-mediated diseases.

The response of the mucosal immune system of 4-6-week old lambs to viable Trichostrongylus colubriformis larvae was compared in two groups of animals, one exposed to T colubriformis antigen and the other to saline while in utero. Exposure to larval antigen two-thirds of the way through gestation resulted in significant reduction in the frequency of jejunal goblet cells and of ileal eosinophils, CD1b(+) antigen-presenting cells and CD4(+), CD5(+) and CD8(+) cells. However, it resulted in a significant increase in the jejunal CD8+ response to postnatal challenge. The expression of the cytokines TNF-alpha and IL-1beta in the ileum, and of jejunal NSE, was significantly reduced by in utero exposure, whereas those of jejunal TNF-a and ileal TGF-beta were increased. The observed changes in cellular and cytokine responses to challenge with viable larvae, in those lambs previously exposed in utero, indicated that the intestinal mucosal immune system remains susceptible to down-regulation until considerably later in foetal development than is the case for other components of the immune system. (C) 2003 Elsevier Science B.V. All rights reserved.