MODIFICATION OF THE SENDAI VIRUS-SPECIFIC ANTIBODY AND CD8(-CELL RESPONSES IN MICE HOMOZYGOUS FOR DISRUPTION OF THE INTERLEUKIN-4 GENE() T)

Homozygous disruption (-/-) of the interleukin-4 (IL-4) gene did not o bviously modify the severity of Sendai virus infection in the highly s usceptible 129/J mouse strain. The virus was cleared from the respirat ory tract, and potent cytotoxic T lymphocyte (CTL) effecters were pres ent in the cell population recovered by bronchoalveolar lavage. Howeve r, the prevalence of virus-specific CTL precursors (p) was consistentl y diminished in the spleen and regional lymph nodes of the IL-4 -/- mi ce at day 7 after infection. Also, virus-specific serum immunoglobulin G1 (IgG1) levels were greatly reduced and few IgG1-producing cells we re detected in the lymphoid tissue. The effect on IgG1 class switching was to be expected, but the decrease in CTLp numbers has not been obs erved previously for a virus-specific immune response.