%0 Journal Article
%@ 0021-9258
%A Vinay, D S
%A Raje, Manoj
%A Verma, R K
%A Mishra, G C
%D 1995
%F open:390
%I ASBMB
%J The Journal of biological chemistry
%N 40
%P 23429-36
%T Characterization of novel costimulatory molecules. A protein of 38-42 kDa from B cell surface is concerned with T cell activation and differentiation.
%U http://crdd.osdd.net/open/390/
%V 270
%X Optimal activation of T cells often requires signals delivered by the ligation of T cell receptor (TcR) and those resulting from costimulatory interaction between certain T cell surface accessory molecules and their respective counter receptors on antigen presenting cells. The molecular events underlying the co-stimulatory activity are still not understood fully. Here we describe a 38-42-kDa (B3) protein, present on the surface of lipopolysaccharide-activated B cells, which can provide co-stimulation to resting T cells leading to a predominant release of interleukin (IL)-4 and IL-5 and negligible amounts of IL-2 and interferon-gamma. Binding assay and electron microscopic autoradiography data suggest that this molecule binds T cells, and the same can be competed by unlabeled B3. Characterization experiments point out that B3 shows up as a single prominent peak on reverse phase-high performance liquid chromatography, runs as a single spot in reducing two-dimensional gel electrophoresis, and is a phosphoglycoprotein. The Western analysis indicate that it does not cross-react with antibodies directed against murine ICAM-1, LFA-1 alpha, VCAM-1, HSA, and B7 suggesting the novelty of the protein. The internal amino acid sequence of this molecule suggests that it does not belong to a known category of murine B cell surface molecules.
%Z Copyright of this article belongs to ASBMB