Dissociation in the production of B cell-stimulating factors (BCGF and BCDF) and interleukin 2 by T cells from a common variable immunodeficient patient.

In the course of an analysis of lymphocyte functions of common variable immunodeficiency patients, we found one patient whose T lymphocytes released B cell differentiation factor (BCDF) and B cell growth factor (BCGF) without IL 2 production upon stimulation with Con A. The patient was a 68-yr-old woman with hypo-gamma-globulinemia (IgM: 31 mg/dl, IgG: 223 mg/dl, IgA: 23 mg/dl); she suffered from cryptococcal meningitis and pulmonary tuberculosis with a negative result of skin tests to PPD and cryptococcal antigen. The number of T cells and the ratio of T cell subsets (Leu-2a and Leu-3a) was normal. T cells showed no proliferative response to Con A and a low response to PHA (one-tenth of normal response). The addition of patient T cells to normal T cells did not inhibit the proliferation of normal T cells when stimulated by Con A. The culture supernatant of Con A-stimulated T cells contained no IL 2 activity when assayed by an IL 2-dependent T cell line. Expression of Tac antigen was not impaired by Con A stimulation and the addition of partially purified IL 2 from the supernatant of Jurkat T cell line-induced proliferation of Con A-stimulated T cells, indicating that the defect observed was not in IL 2-responding cells but in IL 2-producing cells. In contrast, the culture supernatant of the T cells stimulated by Con A or PHA contained BCDF activity as much as that of normal T cells when assayed by Cowan I-stimulated normal B cells or the B lymphoblastoid cell line SKW6-CL4. The supernatant also contained BCGF activity. These results suggest that B cell-stimulating factor (BCGF, BCDF) and IL 2 may be synthesized by different subsets of T cells or that the synthesis of those lymphokines are independently regulated in the same cells.