FIG. 1.

Depletion of CD3⁺ CD4⁺ T lymphocytes. Mean percentages (± standard errors of the mean) of CD3⁺ CD4⁺ T lymphocytes in blood, spleen, or lymph nodes of thymectomized calves treated with a subclass-matched control MAb (•) or thymectomized calves treated with anti-CD4 MAb (▾). The arrows indicate the day of infection for each experiment (experiment 1, day 5 following the commencement of MAb treatment; and experiment 2, day 12 following the commencement of MAb treatment).