Effects of variation in the level of haptenation of heterologous protein immunogen on cellular and humoral responses of the guinea pig.

Groups of guinea pigs were sensitized with bovine gamma-globulin (BGG) substituted with 0, 4, 12, or 40 dinitrophenyl (DNP) groups per molecule. Skin tests, lymphocyte stimulation, two lymphokine assays and antibody determinations were carried out after 21 days using all four antigens. In the extreme situations when BGG-sensitized animals were challenged with DNP40-BGG, or when DNP40-BGG-sensitized animals were challenged with BGG, the delayed skin reactions were transient and weakly indurated. BGG-sensitized guinea pigs injected with anti-DNP40-GBB serum showed no change in delayed skin response to DNP40-BGG, whereas anti-BGG serum enhanced the response of DNP40-BGG-sensitized anamals to BGG. All immunized groups showed lymphocyte stimulation and lymphokine production by all antigens, but migration inhibition and lymphocyte stimulation followed less closely the pattern of delayed skin responses than did mitogenic factor output. The serum antibody response to DNP40-BGG as immunogen indicated that all carrier determinants were masked. At lower levels of substitution, anti-hapten titres were reduced and appreciable levels of anti-carrier antibody obtained.