Recognition of protozoan parasites by murine T lymphocytes. II. Role of the H-2 gene complex in interactions between antigen-presenting macrophages and Leishmania-immune T lymphocytes
Louis, J.A.; Moedder, E.; MacDonald, H.R.; Engers, H.D.
Journal of Immunology 126(5): 1661-1666
1981
ISSN/ISBN: 0022-1767 PMID: 6452473 Document Number: 169836
The proliferative response of nylon wool-purified, primed lymph node cells to L. tropica parasites in vitro was restored by the addition of either syngeneic or allogeneic adherent spleen cells as a putative source of macrophages. These results suggested a lack of H-2 restriction in Leishmania-specific T cell responses. However, when T cell blasts generated in vitro in response to the parasite were separated on Percoll density gradients and subsequently maintained for 4 days in the presence of T cell growth factor, their response to L. tropica was strictly dependent on the presence of syngeneic spleen cells. Further studies using congenic recombinant mice demonstrated that proliferation of parasite-specific blasts required the presence of spleen cells compatible with the responding cells in the I-A region of the major histocompatibility complex. This requirement for I-A compatible adherent cells in the spleen cell populations was further confirmed by a lack of proliferative responses in the presence of spleen cells treated with monoclonal anti-Ia antibodies and complement. Leishmania-immune F1 blasts responding to the parasite in the context of either parental Ia-bearing accessory cell could be obtained by positive selection from an F1 hybrid responding cell population. Using flow microfluorometry, the T cell phenotype of the L. tropica-specific blasts was determined to be Thy-1+, Lyt-1+ and Lyt-2-. [AS].