Exogenous interleukin 2 (IL 2) reconstitutes deficient in vitro T-cell growth of patients with chronic lymphocytic leukemia of B-cell lineage (B-CLL).
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.
Jehn
U
U
Medizinische Klinik III, University of Munich, F.R.G.
Gross
H J
HJ
Wachholz
K
K
Pauls
R
R
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology*
D006684:HLA-DR Antigens; D007376:Interleukin-2; D015375:Receptors, Interleukin-2