Pulmonary T helper lymphocytes are CD44hi, CD45RB- effector/memory cells in mice vaccinated with attenuated cercariae of Schistosoma mansoni.
Percutaneous exposure of C57Bl/6 strain mice to radiation-attenuated schistosome cercariae stimulates proliferation of Ag-specific T lymphocytes in the draining lymph nodes (LN), followed by an intense leukocytic infiltration into the pulmonary parenchyma and airways. The airway T cells persist at elevated levels at least up to 10 wk and will secrete IFN-gamma and IL-3 upon antigenic stimulation in vitro. We report here that more CD4+ T cells from the airways responded rapidly to mitogen by up-regulating the p55 subunit of the IL-2R than did splenocytes from the same animal, suggesting that the bulk of the pulmonary Th infiltrate comprised previously activated cells. A four-fold higher response to Ag indicated the greater abundance of schistosome-specific cells in the lungs than the spleen. Virtually all of the pulmonary CD4+ T cells expressed high levels of the memory marker CD44 (Pgp-1), in contrast with the situation in the draining LN and circulation where only a minority were in that category. Very few Th cells from the inflamed lung bound antibody to an epitope coded for by the B exon of CD45, unlike those from the LN and circulation; the antibody normally binds strongly to naive and weakly to memory CD4+ T cells. Overall, the airway CD4+ T lymphocytes in the schistosome-vaccinated mouse display the functional and phenotypic characteristics of short-term effector/memory cells. We believe that their presence endows the lung with the ability to respond rapidly to recall Ag in the form of challenge parasites.
Department of Biology, University of York, United Kingdom.
P S
PS
Coulson
R A
RA
Wilson
D000818:Animals; D015704:CD4 Antigens / Q000032:analysis; D002478:Cells, Cultured; D005260:Female; D007156:Immunologic Memory; D017493:Leukocyte Common Antigens / Q000032:analysis*; D008168:Lung / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D015375:Receptors, Interleukin-2 / Q000032:analysis; D016201:Receptors, Lymphocyte Homing / Q000032:analysis*; D012550:Schistosoma mansoni / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000276:immunology
D015704:CD4 Antigens; D015375:Receptors, Interleukin-2; D016201:Receptors, Lymphocyte Homing; D014613:Vaccines, Attenuated; D017493:Leukocyte Common Antigens