mRNA expression of TNFR1 and LTβR ligands on CD4⁺CD3⁻ and other cell populations. (A) mRNA for the genes indicated were assayed by quantitative PCR and corrected for β-actin expression as described in “Materials and methods.” Bars show standard deviations for 4 separate experiments. (B) Staining of CD4⁺CD3⁻ cells with LTβR-Ig. Isolated CD4⁺CD3⁻ cells were cultured in the presence of 100 ng/mL IL-7 prior to staining with LTβR-Ig (□) or control-Ig fusion protein (⊡). Of live gated CD4⁺CD3⁻ cells, 55.2% expressed LTβR ligands.