Regulation of macrophage populations. II. Synthesis and expression of Ia antigens by peritoneal exudate macrophages is a transient event

• Published in: The Journal of immunology (1950) Vol. 126; no. 1; pp. 263 - 269
• Main Authors: Beller, DI, Unanue, ER
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 01.01.1981
• Subjects: Animals; Complement System Proteins; Female; Histocompatibility Antigens Class II - metabolism; Hybrid Cells - immunology; Listeria - immunology; Lymphocyte Culture Test, Mixed; Macrophages - classification; Macrophages - immunology; Male; Mice; Mice, Inbred A; Mice, Inbred C57BL; Peptones - pharmacology; Phagocytosis; Time Factors
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.126.1.263

We have evaluated the biosynthesis and surface expression of I-A antigens by peritoneal macrophages and found that both events terminated during the 1st day in culture, in contrast to the undiminished synthesis and expression of H-2K antigens. This pattern was observed regardless of the means by which the macrophages were elicited, but was subject to modulation for a limited period of time in vitro: phagocytic stimuli were able to augment both I-A synthesis and expression. The loss of I-A and the re-expression after phagocytosis were both reflected in the stimulatory capacity of these macrophages in the mixed leukocyte reaction. Moreover, we found that I-A-bearing macrophages were lost from the exudate in vivo after irradiation. Our data suggest that, as in vitro, this phenomenon is due to the transition of individual macrophages from I-A-positive to I-A-negative, and that constant renewal is required to maintain the I-A-bearing subset in vivo.