Immunomodulating activity of chemotactic peptide conjugated with liposomal antigen

The capacity for changing immunogenicity of bovine serum albumin (BSA) and for inducing primary and secondary immune response in mice against BSA was investigated in the macrophage-activating chemotactic peptide N-f-Met-Leu-Phe-Gly conjugated on the basis of liposomas with BSA. To elucidate the mechanism of immunomodulating activity of chemotactic peptide (CP) with an antigen, the capacity of the synthetic immunogen for inducing macrophage-dependent and independent lymphocyte proliferation was evaluated. It has been shown that coimmobilization of BSA and CP based on lyposomas permits obtaining preparations that being injected subcutaneously induce in CBF₁ mice humoral immune response similar to that observed when BSA with Freund's adjuvant is administered. CP has a macrophage-mediated mitogenic action upon mouse splenocytes. Immunomodulating activity of CP is manifested only in cases when the immunomodulator and antigen are coimmobilized on the surface of liposomas (are involved into the lipid bi-layer of liposomas). It is suggested that the immunostimulating effect observed is caused by immunomodulator capacity for involving the maximum number of clones of the antigen-reactive cells into the immune response to CP immobilized with the antigen.