Relationship of antigen to the effect of tolerized cells on naive T cells.

Tolerized cells exert their down-regulatory effect on naive T cells in an antigen-nonspecific manner but do not inhibit naive T-cell responses to third-party antigen if antigen is present at optimal concentration and the responding T cells are present in high frequency. (A) BALB/c CD4⁺ T cells were tolerized to B6 alloantigen by an 8-day culture with anti-CD40L mAb. The tolerized cells were washed and added to a primary MLR culture containing naive BALB/c CD4⁺ T cells and B6 stimulators at the indicated ratios of tolerized-to-naive cells. (B) BALB/c CD4⁺ T cells tolerized to B6 alloantigen were plated with naive DO11.10 CD4⁺ T cells, BALB/c APCs, and OVA peptide (5.0 μg/mL). (C) BALB/c CD4⁺ T cells tolerized to B6 alloantigen were plated with naive DO11.10 CD4⁺ T cells, CB6 F1 APCs, and OVA peptide (5.0 μg/mL). (D) BALB/c CD4⁺ T cells tolerized to B6 alloantigen were plated with naive DO11.10 CD4⁺ T cells (3 × 10⁴ per well each), CB6 F1 APCs, and OVA peptide (0.5 μg/mL). These data were reproduced in a second experiment. The y-axis presents the mean cpm ± 1 SD. On the x-axis are days in primary culture.