Species conservation of the T cell lymphocyte CD2 cell surface antigen

Abstract
A rabbit polyclonal antiserum was raised against a synthetic peptide, termed CD2‐300, comprizing 18 amino acid residues which are conserved among the cytoplasmic domains of the human, rat and mouse CD2 antigens. Cross‐depletion experiments showed that the CD2 monoclonal antibody OKTl1 and purified CD2‐300 antibodies (Ab) precipitated the same molecules from the surface of human T lymphoblasts. The results of immunoprecipitation analyses indicated that the purified CD2‐300 Ab were specific for human and mouse CD2, and that the CD2‐300 peptide competitively and specifically inhibited precipitation by CD2‐300 Ab in both species. When employed to stain murine tissues, the CD2‐300 Ab gave the anticipated pattern of distribution for the CD2 antigen, although there was some nonspecific labeling of non‐T cells.