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.
Coulson
P S
PS
Department of Biology, University of York, United Kingdom.
Wilson
R A
RA
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