Inhibition of IFN-γ production by CT favors Ig-SC development and Ig production. Splenic cell suspensions were depleted of CD138+
cells and cultured for 7 days with 2 μg/ml ConA plus 1 μg/ml CT in the presence or absence of 10 ng/ml of IFN-γ or 10 ng/ml of IL-4. (A) Levels of IgA, IgM, and IgG secreted into culture supernatants were determined by ELISA.
, significant differences at a P
value of 0.001 compared to CT or CT + IL-4. (B) Frequencies of IFN-γ-producing CD4+
T cells in cultures treated with ConA plus CT or ConA alone were determined by FACS at day 2 of culture and are given as percentages (means ± standard deviations). (C) Purified preparations of CD8+
cells, preincubated in the presence or absence of CT, were mixed together as described in the text and stimulated for 7 days with ConA, and the frequencies of cells expressing CD8 and CD138 were determined by FACS and are given as percentages. Representative data from three independent experiments are shown. (D) Levels of IgA, IgG, and IgM secreted into culture supernatants were determined by ELISA. (E) Levels of IFN-γ secreted into culture supernatants were measured by a Luminex cytokine assay.
, significant differences at P
values of ≤0.01 and ≤0.001, respectively, compared to CD8+
-untreated and CD8−