RAT ANTI HUMAN CD28 from MyBioSource.com

Rat anti Human CD28 antibody, clone YTH913.12 recognizes human CD28, a ~44kDa single pass type 1 trans-membrane protein expressed as a homodimer on a major subset of human T-cells (Thompson et al. 1989), responsible for activation of these cells via interaction with the TCR. CD28 is involved in the tuning of the T-cell for activation via TCR, lowering the threshold for activation from around 8000 triggered TCRs to approximately 1500 (Viola et al.1996). CD28 along with CD152, also known as CTLA-4 acts as a co-receptor for the co-stimulatory molecules CD80 and CD86 (Azuma et al. 1993). CD28 offers a positive stimulatory role on ligation of CD80 and CD86 while CTLA-4 offers a negative feedback signal preventing CD28 mediated T-cell activation of CD86 (Krummel et al. 1995) Rat anti human CD28, clone YTH913.12 has been reported to recognize an epitope of CD28 expressed by NK cells, which is not recognized by other anti human CD28 clones such as 9.3 and CD28.2 (Galea-Lauri et al 1999.) Other reports however have failed to demonstrate CD28 staining on peripheral blood derived KK cells using clone YTH913.12 (Wilson et al. 1999)