Interference with the humoral immune response in diverse genetic lines of chickens II. The effect of colloidal carbon

Abstract

Two experiments were conducted to study the difference in humoral immune responses between lines of chickens selected for high (H) or low (L) antibody production to sheep red blood cells (SRBC). Prior to i.v. immunization with SRBC or Brucella abortus (BA), chicks of both lines were injected with either 2, 3 or 4 ml carbon suspension (59 mg carbon/ml) per kg body weight; controls were not injected. In both the H and L line, a higher dose of carbon showed a more progressive depression of the total antibody titer to SRBC during the initial stage of the primary response. The 2ME-resistant antibody titers to SRBC showed the same tendency during the latter phase of the primary response. However, chicks treated with 3 ml carbon had lower 2ME-resistant antibody titers than any other group. Following i.m. reimmunization with SRBC, the previous treatment with carbon doses enhanced total antibody titers throughout the secondary response, when compared to the controls. The 3 ml carbon-treated chicks had the highest total anti-SRBC titers in the secondary response. The secondary 2ME-resistant anti-SRBC titers were not affected by the carbon doses. Carbon treatment did not affect the antibody titers toBA. No differences between the H and L line were found in the effects of carbon on the humoral immune responses to SRBC or BA.