ENHANCED CELLULAR-RESPONSE IN MICE TREATED WITH A BRUCELLA ANTIGEN LIPOSOME MIXTURE

The capacity of liposomes constituted by dycetyl-phosphate (0.009 mM), cholesterol (0.017 mM), lecithin (0.003 mM) and myristic (0.1 mM), st earic (0.1 mM), or oleic acid (0.1 mM) to modify the lymphocyte respon se to Brucella melitensis;is antigens in mice was studied. Mice treate d with antigens mixed with liposomes containing myristic, stearic or o leic acid had higher antibody titres than mice given antigen suspended in a saline solution. Liposomes alone, without Brucella antigens, res ulted in increased H-3-thymidine incorporation by lymphocytes both in vivo and in vitro. The addition of polyclonal activators (LPS and ConA ) caused a further increase of H-3-thymidine uptake. Moreover, spleen lymphocytes from mice inoculated with Brucella antigens mixed with the liposomes had a significantly lower population of B lymphocytes (10%) , and a notable increase in the T-c lymphocytes (20%). Autoradiography of sections of popliteal ganglia of treated mice showed that the radi oactivity was concentrated mainly in the membrane structures of the ce ll.