Identification of a CD4 homologue in the cat.
Monoclonal antibody, Fel 7, produced against cat T cells, was found to react with a single-chain glycoprotein of Mr 65,000 present on a majority of the thymocytes, 40% of lymph node cells, 15% of splenocytes and 25% of blood mononuclear cells. Using a previously reported antibody that recognizes the feline CD8 antigen, approximately 65% of cat thymocytes were shown to express both the Fel 7 and fCD8 antigens, while 14% and 6% expressed either the Fel 7 or the fCD8 determinant respectively. The Fel 7 and fCD8 antigens were expressed by mutually-exclusive subpopulations of peripheral T cells, and not by B cells, macrophages or other types of blood cells. Expression of the Fel 7 antigen was down-regulated and the molecule was phosphorylated when T cells were stimulated with phorbol ester, while the expression of the fCD8 antigen was unaffected by this treatment. The addition of soluble Fel 7 antibodies efficiently blocked Con A-induced proliferation of T cells in a dose-dependent manner. The data suggest that the mAb Fel 7 identifies a feline CD4 homologue, providing an important reagent for the study of normal and abnormal T cell development in cats.
Department of Medicine, University of Alabama, Birmingham.
C D
CD
Ackley
E A
EA
Hoover
M D
MD
Cooper
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D015704:CD4 Antigens / Q000032:analysis / Q000276:immunology* / Q000378:metabolism; D002415:Cats / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D007075:Immunoglobulin M / Q000276:immunology; D008970:Molecular Weight; D010766:Phosphorylation; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000648:ultrastructure
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D015704:CD4 Antigens; D007075:Immunoglobulin M