Differential Antibody Responses in 6.B Major Histocompatibility (B) Complex Congenic Chickens


Lines 6.6-2 (B 2 B 2) and 6.15-5 (B 2 B 2), congenic for the major histocompatibility (B) complex with > 99.9% background gene uniformity, were used to examine primary antibody responses to two antigens. In each of two trials, 1 mL of 5% SRBC, a T cell-dependent antigen, or 0.1 mL of Brucella abortus (BA), a T cell-independent antigen, was injected into separate groups of each B genotype aged 3 and 6 wk. Blood samples were taken from the chickens 7 d after immunization. Serum titers (log2) for both total antibody and mercaptoethanol (ME)-sensitive antibody to detect IgG were assayed by microtiter procedures. Least squares analysis of variance and Fisher’s protected Least Significant Difference at P < 0.05 were used to evaluate the data. The total anti-SRBC antibody titer was significantly higher in B 5 B 5 chicks than in B 2 B 2 chicks at 4 and 7 w k of age. There was no significant difference in ME-sensitive antibody to SRBC. Chicks of the B 5 B 5 genotype also had significantly higher total and IgG antibody titers to BA at both ages than B 2 B 2 chicks. The results indicate that 4- and 7-wk-old B 5 B 5 chicks had a significantly stronger antibody response to SRBC or BA than B 2 B 2 chicks.

Publication Date


Journal Title

Poultry Science


Oxford Journals

Digital Object Identifier (DOI)


Scientific Contribution Number


Document Type