Exogenous interleukin 2 (IL 2) reconstitutes deficient in vitro T-cell growth of patients with chronic lymphocytic leukemia of B-cell lineage (B-CLL)
Jehn, U.; Gross, H.J.; Wachholz, K.; Pauls, R.
Anticancer Research 10(4): 929-934
1990
ISSN/ISBN: 0250-7005 PMID: 2382990 Document Number: 353460
Mechanisms of tumor growth are concerned with the possibility that neoplasms are disturbed in their response to growth factors. Interleukin 2 (IL 2) is secreted by activated T-cells and is required for autocrine T-cell growth. Controversy exists as to the functional capacity of T-lymphocytes in patients with B-cell chronic lymphocytic leukemia (CLL). We studied 14 patients with previously untreated, early CLL. Data were compared to 16 healthy individuals. Immunophenotyping showed that T-cells in B-CLL are highly activated as evidenced by HLA-DR and IL 2 receptor expression. Membrane receptors for IL 2 on the patients' T-cells were overexpressed. The T4:T8 ratio was 1.5. T-cells for in vitro studies were isolated by their ability to form E-rosettes with AET and repeated Ficoll density gradient centrifugation. Purified T-cells were grown on semisolid agar and their capability to form colonies investigated using a variety of exogenous stimulants. It was found that patients with CLL showed a pronounced impairment in forming T-cell colonies. However, colony formation was restored to normal by adding exogenous recombinant IL 2, indicating that endogenous IL 2 production of T-cells is deficient. This finding might have implications for the therapeutical use of IL 2 in CLL patients.