Characterization of feline T and B cells

SUMMARY Feline peripheral-blood lymphocyte populations (n = 22) were examined for the following markers: rosette formation with guinea pig erythrocytes (gpe-t cells), rosette formation with human rbc (hrbc-t cells), rosette formation with sheep rbc, mixed rosette formation with gpe-T cells and hrbc-t cells (total T cells), erythrocyte antibody-complement rosettes, and surface immunoglobulin. An average of 28% ± 7% (range, 16% to 39%) of the feline lymphocytes formed rosettes with gpe-t cells, and 27% ± 17c (range, 11% to 36%), with hrbc-t cells. An average of 57% ± 97r (range, 33% to 757c) of the lymphocytes formed mixed rosettes. The erythrocyte antibody-complement rosette-forming cells and surface immunoglobulin-bearing cells were found in peripheral blood lymphocytes (10% ± 6% and 24% ± 8%, respectively). The murine monoclonal antibodies OKT 11 and HuLy-m1, specific for a framework determinant of human E-rosette receptor antigens, cross-reacted with feline cell membrane molecules recognizing a bimolecular complex (45,000 to 50,000 daltons) similar to that described in persons. We investigated the distribution of these E-rosette receptor-like antigens on feline lymphocytes. By complement-mediated lymphocytotoxicity, about 30% of the feline lymphocytes expressed the antigens. When lymphocytes were treated with HuLy-m1 antibody, spontaneous rosette formation with hrbc-t cells was significantly inhibited.