Phenotypic analysis of new world primate mononuclear cell surface antigens

We have applied a panel of monoclonal antibodies against antigens present on the surface of human mononuclear cells to the study of mononuclear cell surface antigens expressed by seven species of New World primates. Antibodies to the sheep erythrocyte receptor (OKT11a) to a thymocyte antigen (OKT10), to the I region of the major histocompatibility locus (OKIa), and to an antigen found on the surface of human monocytes (OKM1) cross-reacted with mononuclear cell surface antigens of most of the species studied. Antibodies to antigens which have been correlated with functional capabilities in the human system (OKT4, OKT5, OKT8, 3A1) were much less reactive with platyrrhine mononuclear cells. These reagents may be quite useful in studies of primate phylogeny and immunology.