INFLAMMATORY FUNCTION OF MACROPHAGES FROM CHICKENS WITH B-RECOMBINANTHAPLOTYPES

Both in vivo macrophage activation and in vitro monocyte activation we re compared using chickens homozygous for each of two biochemically an d serologically similar B-complex recombinant (B-F2-G23) haplotypes. C hickens carrying the parental (nonrecombinant) B haplotypes (B-2 and B -23) were included for relative comparison, although the genetic backg rounds for these strains were different from the background of the rec ombinants. Elicited peritoneal macrophages from R4/R4 (international d esignation B-2r3) chickens expressed levels of sheep erythrocyte phago cytosis which were significantly higher (P < 0.05) than those from R2/ R2 (B-2r1) chickens. Differences between chickens with B genotypes wer e analogous to the differences demonstrated previously between B-2/B-2 and B-23/B-23 chickens. Similarly, lipopolysaccharide (LPS)-activated monocytes from R4/R4 chickens also expressed significantly higher (P < 0.05) levels of phagocytosis when compared with R2/R2 and B-23/B-23. In both cases, the functional level of macrophages from R2/R2 chicken s was similar to that of B-23/B-23 cells, whereas macrophages from R4/ R4 chickens were similar in functional capacity to those from B-2/B-2 chickens. These results suggest that R2 and R4 recombinants, despite t heir demonstrated similarities, may differ in DNA regions which includ e genetic factors controlling macrophage responsiveness.