title: Delayed-type hypersensitivity to sheep red blood cells in selected lines of mice with high or low antibody responses.
abstract: Interline differences in DTH to SRBC which developed in high antibody producer (H/Ab) and low antibody producer (L/Ab) genetically selected lines of mice were observed after intravenous (IV) or subcutaneous (SC) sensitization. This interline difference was more marked in female that in male mice, and with the optimal dose for DTH sensitization. The kinetics of the local inflammatory reaction after local challenge, the development and decay of the 24-h DTH reaction tested at varying intervals after sensitization, were always statistically significantly higher in H/Ab than in L/Ab mice. This higher DTH was associated with a higher capacity of these mice to produce a secondary humoral response, and the more marked difference was observed for the production of 2-mercaptoethanol-resistant specific antibodies. Higher DTH reaction in H/Ab mice could not be explained by the participation of either B lymphocytes or humoral antibodies, since high dose (200 mg/kg) of CY injected before IV-SRBC, sensitization, in order to inhibit B-cell activation, did not alter the DTH-interline difference. Moreover, IV injection of specific antibodies from H/Ab immune mice did not enhance DTH in adoptively immunization L/Ab mice. Immune serum alone was not able to adoptively transfer DTH either in H/Ab or in L/Ab mice. Also, a low dose (40 mg/kg) known to inhibit T-cell suppression, injected before SC-SRBC sensitization, was not able to modify the DTH reaction in L/Ab mice. The persisting higher 48-h local inflammatory reaction in H/Ab mice after CY pretreatment was also related to a high blood monocyte rebound. When the afferent arc of the immune response to SRBC was studied in these mice, as tested by the lymphoproliferative response in draining popliteal node after footpad sensitization and by the evaluation of the ability of the T-activated cells located in these draining nodes to transfer locally an adoptively DTH reaction into naive recipients, it was shown that in immunized mice more specifically activated T cells were produced in H/Ab than in L/Ab mice. Moreover, the H/Ab recipients had a higher capacity to develop a local inflammatory reaction than the L/Ab recipients. The mechanisms of these observed interline differences are discussed.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D003520:Cyclophosphamide / Q000494:pharmacology; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007111:Immunity, Cellular; D007125:Immunogenetics; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012737:Sex Factors; D012756:Sheep / Q000276:immunology; D013045:Species Specificity
chemical_list: D003520:Cyclophosphamide