Immune Response to NIP-BSA and Brucella abortus in Two Pairs of B Congenic Chicken Lines.

Abstract

Humoral immune responses to NIP-BSA and Brucella abortus (BA) in two pairs of B congenic chicken lines were examined. Inbred line CB (B12 B12) and line HA (B11 B11), selected for graft-vs-host reaction (GVHR) high, served as the genetic background of the experiment. Chickens from these lines were crossed to produce F1 progeny and then backcrossed to CB and HA lines, respectively, upto nine generations for the production of CBH (B11 B12) and HCB (B11 B12) lines. At 14 wk of age, 40 birds from the respective lines were injected intravenously with equally mixed one ml of the above antigens. Blood samples were taken from the chickens at 7 and 14d of post primary immunization (PPI) and post secondary immunization (PSI). Total antibody titer to NIP was significantly higher in the CB line than other lines at 7d of PPI and 7 and 14d of PSI. Anti-BA total antibody titer was also significantly higher in the CB line than other lines at 7d of PPI, and than HA and HCB lines, at 14d of PSI. The CB line also showed significantly higher mercaptoethanol (ME) resistant antibody titer to BA than HA line as well as HCB line at 14d of PPI, and than other lines 7 and 14d of PSI, except, HA line at 14d of PSI. Total antibody titer to bovine serum albumin (BSA) was significantly higher in the HA line, compared to other lines, at 7d of PPI and PSI, and than CBH line at 14d of PPI and PSI. A significant difference between the CBH and HCB lines, having the same B11 B12 genotype, was observed for total antibody titers to NIP at 7 and 14d of PPI and PSI, and to BSA at 14d of PSI. These results further indicate that genes of the non MHC as well as the MHC gene play a vital role in the regulation of immune responses in chickens.