Differential effect of aging on membrane immunoglobulin (mIg)-mediated endocytosis in the inductive and effector sites of the mucosal immune system.
The effect of aging on the endocytosis of anti-immunoglobulin (Ig) antibody as ligand by membrane Ig receptors (mIg) of B cells in the spleen, the mesenteric lymph nodes (MLN), and the Peyer's patches (PP) was investigated. Horse radish peroxidase (HRP) labelled (Fab')2 anti-mouse Ig specific for IgM, IgG, and IgA was used as the ligand. The rate of mIg mediated ligand endocytosis by aged B cells was significantly reduced in the PP as compared to the young group. In contrast, there were no age-related differences in the rate of mIg-mediated ligand endocytosis by B cells in the spleen and MLN. After 2 hr of incubation, about 70-80% of ligand added was internalized by splenic and MLN B cells from both young and old mice. Aged PP B cells showed significantly slower rate of ligand internalization as compared to those cells from young mice. This effect was pronounced at 30 and 60 min after incubation. Young PP B cells were found to internalize about 50% of the ligand within 30 min, while it took 60 min for aged B cells to internalize the same amount. The age-related rate of mIg-mediated endocytosis by B cells in the MLN, as opposed to a slower rate of endocytosis by B cells in the PP, emphasizes its distinct nature as a mucosal site.(ABSTRACT TRUNCATED AT 250 WORDS)
Haq
J A
JA
Department of Microbiology & Immunology, Queen's University, Kingston, Ontario, Canada.
Szewczuk
M R
MR
D000375:Aging / Q000276:immunology*; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D004705:Endocytosis / Q000276:immunology*; D007070:Immunoglobulin A / Q000096:biosynthesis; D007700:Kinetics; D008198:Lymph Nodes / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009092:Mucous Membrane / Q000276:immunology; D009928:Organ Specificity; D010581:Peyer's Patches / Q000276:immunology; D011947:Receptors, Antigen, B-Cell; D013154:Spleen / Q000276:immunology
D007070:Immunoglobulin A; D011947:Receptors, Antigen, B-Cell