Abstract
The relationship between cell-mediated immunity to the carrier and the carrier-hapten helper effect was studied in the rat by using three forms of the carrier which differed in their capacity to induce carrier-specific delayed-type hypersensitivity. The three carriers were polymerized flagellin (POL), flagellin (FIN), and acetoacetylated flagellin (AFIN), which induced FIN-specific delayed-type hypersensitivity in the order AFIN > FIN > POL. Helper cells for the anti-DNP antibody responses to a range of DNP-FIN conjugates appeared to be almost inversely related to cell-mediated immunity to the carrier, being in the order POL > FIN =/> AFIN. These differences occurred whether the carriers were injected in saline or FCA, but were less pronounced with the heavily DNP-conjugated flagellins.