The generation of interferon-gamma-producing T lymphocytes in skin-draining lymph nodes, and their recruitment to the lungs, is associated with protective immunity to Schistosoma mansoni

• Published in: Immunology Vol. 75; no. 2; pp. 250 - 256
• Main Authors: MOUNTFORD, A. P, COULSON, P. S, PEMBERTON, R. M, SMYTHIES, L. E, WILSON, R. A
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell 01.02.1992
• Subjects: Animals; Antigens, Helminth - immunology; Biological and medical sciences; Bronchoalveolar Lavage Fluid - immunology; Cells, Cultured; Diseases caused by trematodes; Female; Helminthic diseases; Infectious diseases; Interferon-gamma - biosynthesis; Lung - immunology; Lymph Nodes - immunology; Mediastinum; Medical sciences; Mice; Mice, Inbred C57BL; Parasitic diseases; Schistosoma mansoni; Schistosoma mansoni - immunology; Schistosomiases; Schistosomiasis mansoni - immunology; Schistosomiasis mansoni - prevention & control; Skin; T-Lymphocytes, Helper-Inducer - immunology; Immunoprotection; Schistosoma mansoni; Immune response; Lymph node; Lung; Vaccination; Rodentia; Cytokine; Plathelmintha; Helper cell; Biosynthesis; Cellular immunity; Trematoda; Vertebrata; Mammalia; Mouse; T-Lymphocyte; Helmintha; Skin; Invertebrata; Attenuated strain; Gamma interferon
• ISSN: 0019-2805; 1365-2567

We have examined immunological responses in the skin-draining lymph nodes (SLN) and lungs of mice during the 3 weeks after percutaneous exposure to attenuated larvae of Schistosoma mansoni. Cercariae irradiated with 20 krads (V20) were highly protective and sustained an increased number of CD4+ T cells in the SLN. On secondary exposure to schistosome antigen in vitro, these cells were capable of proliferating and secreting high levels of interferon-gamma (IFN-gamma) and interleukin-3 (IL-3). However, in mice exposed to non-protective 80 krad-irradiated (V80) cercariae, secretion of these cytokines occurred early and only transiently. Significantly elevated numbers of CD4+ T lymphocytes were recoverable on Day 21 from the lungs of V20, but not V80 mice. These cells secreted high levels of IFN-gamma and IL-3 in vitro, but not IL-2 and IL-4. Mice immunized intravenously with attenuated lung-stage schistosomula were not protected, despite having an elevated pulmonary lymphocyte population. Moreover these cells failed to secrete IFN-gamma and IL-3. However, significant protection was achieved where exposure of mice to a combination of V80 cercariae and lung-stage schistosomula resulted in the recruitment of IFN-gamma secreting cells to the lungs. We conclude that the success of the irradiated vaccine depends not only on the generation of a population of antigen-specific T-helper cells in the SLN, but also recruitment of these cells to the lungs before challenge.