Studies of monoclonal antibodies identifying two novel bovine lymphocyte antigen differentiation clusters: workshop clusters (WC) 6 and 7.

Analysis of flow cytometric staining of 50 target cells resulted in five monoclonal antibodies (mAbs) forming two adjacent clusters called temporary cluster (TC) 2. The five mAbs gave similar immunostaining of frozen sections, but flow cytometric analysis and the M(r) of molecules indicated that they comprised two distinct specificities. Mabs CC98, IL-A114 and IL-A53 all immunoprecipitated a molecule of 210 kDa that preclearing experiments with mAbs to the leukocyte common antigen (CD45) showed did not recognize isoforms within the CD45R family of molecules. The 210 kDa molecule was present on all CD2+ cells and B cells, but not expressed by WC1+ gamma/delta T cells. mAbs TH1A and TH18A precipitated molecules of 69 and 62 kDa which were present on cells expressing CD2, WC3 (B cells) and WC1 (gamma/delta T cells). It is proposed that these five mAbs should be considered as comprising two new bovine lymphocyte differentiation clusters, WC6 (mAbs CC 98, IL-A114 and IL-A53) and WC7 (TH18A and TH1A).