Alloantigen system L is a polymorphic protein expressed on the
surface of chicken erythrocytes and possibly certain leukocyte subpopulations.
Previous studies demonstrated that the L system affects Rous
sarcoma outcome and phagocytic function. The present experiments examined
the L system influence on antibody responses to two antigens: SRBC (T-dependent)
and Brucella abortus (BA, partially T-independent) in three B
complex genotypes. The parental stock were 50% Modified Wisconsin Line
3 x White Leghorn Line NIU 4 and 50% Inbred Line 6-15.5. Pedigree matings
of 4 B2B5L1L2 sires
to 5 B2B5L1L2 dams
per sire produced three hatches (n = 183) for the antibody response
to SRBC and two hatches (n = 198) to study antibody response to BA.
At 4 and 11 weeks of age the experimental birds were injected intravenously
with 1 mL of 2.5% SRBC or 0.1 mL of 10% BA. Total and mercaptoethanol
(ME)-resistant primary and secondary titers were analyzed by least squares
ANOVA. Alloantigen L had a significant effect on total primary antibody
titer to SRBC in a B5B5 background (p <
0.004) and on total (p < 0.011) and ME-resistant (p < 0.017) secondary
titer to SRBC in the B2B5 genotype. Total
(p < 0.004) and ME-resistant (p < 0.005) secondary titers to BA in B2B5
chickens were significantly affected by alloantigen L. The data
indicate that the alloantigen L locus or genes in the immediate
chromosomal vicinity affect antibody responses to SRBC and BA.