Increased content of microbicidal cationic peptides in rabbit alveolar macrophages elicited by complete Freund adjuvant

Abstract

We measured the microbicidal peptides MCP-1 and MCP-2 in rabbit alveolar macrophages (AM), comparing rabbits pretreated with complete Freund adjuvant with untreated control animals. Levels of MCP-1 increased from 4.7 +/- 0.6 microgram/10(7) resident AM to 13.2 +/- 0.1 microgram/10(7) complete Freund adjuvant-elicited AM. MCP-2 levels rose from 1.8 +/- 0.1 microgram/10(7) resident AM to 7.3 +/- 0.4 microgram/10(7) complete Freund adjuvant-elicited AM. The activities of five lysosomal hydrolases (beta-D-glucuronidase, beta-D-galactosidase, acid phosphatase, N-acetyl-beta-D-galactosaminidase, and N-acetyl-beta-D-glucosaminidase) were 44 to 96% higher in complete Freund adjuvant-elicited AM, and lysozyme activity was three- to fourfold higher. As MCP-1 and MCP-2 are major constituents of rabbit AM and exhibit potent antibacterial and antifungal properties, they may contribute to the expression of microbicidal activity in both resident and activated states.