Amino-terminal sequencing of sheep CD1 antigens and identification of a sheep CD1D gene

The anti-CD1 monoclonal antibodies IAH-CC14 and SBU-T6 were used to immunop urify CD1 antigens from sheep thymocytes. The amino-terminal sequence of IA H-CC14 yielded 13 amino acids, and 29 amino acids were obtained from the SB U-T6 antigen. The sequence of the IAH-CC14 antigen was 100% identical to th e predicted sequence of the sheep CD1B clone, SCD1B-42. The 29 amino acid s equence of the SBU-T6 antigen did not match identically with the derived am ino acid sequence of any of the previously reported sheep CD1 genes but had closest similarity to the derived sequence of human CD1E. Degenerate polym erase chain reaction primers based on this sequence identified a group 2 sh eep CD1 gene. The predicted amino acid sequence of this gene shows that it is not identical to the SBU-T6 peptide, indicating that a different, CD1D-l ike gene was cloned.