T cells from CD98hc^f/f-CD4 mice cannot mount immune responses against-<i>Leishmania major</i>.

<p>CD98hc^+/+-CD4 or CD98hc^f/f-CD4 mice under a C57BL/6 background were infected with <i>Leishmania majo</i>r in the footpad. (A) Footpad swelling in CD98hc^+/+-CD4 (closed) or CD98hc^f/f-CD4 (open) mice was measured after infection. Results are means ± S.D. of 8 mice; *or ** significant difference (<i>p</i> < 0.05 or p < 0.01, respectively). (B) Total popliteal lymph nodes from <i>Leishmania major</i>-infected CD98hc^+/+-CD4 or CD98hc^f/f-CD4 mice (day 30) were cultured for 5 days. Then, parasite numbers were counted and parasites/lymph node cells were determined. Results are means ± S.D. of 8 mice; ** significant difference (<i>p</i><0.01). (C) Purified CD4⁺ T cells (5 x 10⁵/well) from lymph node cells from CD98hc^f/f-CD4 (closed) or CD98hc^+/+-CD4 (open) mice infected with <i>Leishmania major</i> (day 10 and day 70) were stimulated with irradiated spleen cells (2 x 10⁵/well) and parasite-derived antigens for 3 days. Then, IFN-γ and IL–4 in culture supernatants were determined by ELISA. Results are means ± S.D. of 8 mice; * or ** significant difference (<i>p</i><0.05 or p < 0.01, respectively). Purified CD4⁺ T cells (5 x 10⁵/well) from lymph node cells from CD98hc^f/f-CD4 (closed circle) or CD98hc^+/+-CD4 (open circle) mice infected with <i>Leishmania major</i> (day 20) were stimulated with irradiated spleen cells (2 x 10⁵/well) and parasite-derived antigens for 3 days. Then, [³H]-thymidine incorporation was determined. Results are means ± S.D. from 8 mice; ** significant difference (<i>p</i><0.01). Data shown in this Figure are representative of three experiments.