In vitro induction of primary and secondary xenoimmune responses by liposomes containing human colon tumor cell antigens.

Abstract Liposomes prepared with human LS174T colon tumor cell membranes induce specific primary and secondary xenogeneic immune responses in BALB/c splenocytes in vitro . The multilamellar vesicular liposomes were prepared by adding sonicated membrane fragments in 8 m M CaCl 2 to a dried lipid film. Cytotoxic splenocytes generated in vivo exhibited specificity for the LS174T cell; liposomes elicited higher levels of cytotoxicity than did membranes ( P in vivo -primed spleen cells by liposome-antigens also produced a significantly greater ( P in vitro induction of primary blastogenic and cytotoxic responses by liposome-antigens were accomplished and revealed similar kinetics to that of whole LS174T cell immunogens. Specificity of the in vitro -primed spleen cells was clearly demonstrated ( P in vitro to human colon cancer antigens and may afford an adaptable means to evaluate and to select desired immune responses, as well as to identify colon tumor-specific determinants.