B-congenic chickens differ in macrophage inflammatory responses

Abstract

The influence of the chicken major histocompatibility ( B) complex (MHC) on monocyte and macrophage recruitment and activation was examined using fully developed 15I 5- B congenic White Leghorn lines (ten backcross generations). The phagocytic activity of Sephadex-elicited peritoneal macrophages for sheep red blood cells (SRBCs) was highest in lines 15.7- B 2 and 15.P- B 13 and lowest in 15.15I- B 5 and 15.N- B 21. The same pattern of phagocytic activity was obtained when LPS ( E. coli) was used as the in vivo elicitor-activator of peritoneal macrophages. Lines with B 2 and B 13 haplotypes had elevated percentages of phagocytic macrophages and a higher internalization activity per cell than did B 5 and B 21 congenic chickens. Differential peritoneal macrophage function between congenic lines was further supported by quantitation of superoxide anion release. B 2 and B 13 haplotypes were associated with high activity in contrast with B 5, which was low, and 15I 5 ( B 15) and B 21 which were intermediate for superoxide anion release by macrophages. In vitro activation of blood monocytes with LPS resulted in similar line differences for SRBC phagocytic activity as were observed with in vivo Sephadex and LPS activation. In contrast, chemotaxis of blood mononuclear leukocytes to fmet-leu-phe produced a reciprocal response pattern among the haplotypes. Cells from lines with haplotypes B 5 and B 21 were superior to those of B 2, B 13, and B 15 congenic lines in their directed migration towards this chemoattractant. All functional differences occurred despite similarities among lines in the cellular profiles of both elicited peritoneal exudate cells and isolated blood mononuclear cells.