The cellular immune system of patients with acute leukemia and severe chemotherapy-induced leukopenia: characterization of T lymphocyte subsets responsive to IL-16 and IL-17.
The aim of the present study was to characterize the effects of IL-16 and IL-17 on CD4+ and CD8+ T cell responses in patients with acute leukemia and severe chemotherapy-induced leukopenia. We investigated (1) the function of cytokines as growth factors for preactivated monoclonal T cell populations which had been prepared by long-term in vitro culture, and (2) the ability of cytokines to modulate anti-CD3-stimulated proliferation of polyclonal, nonexpanded T cells. A subset of CD4+ and CD8+ clones could utilize IL-16 and IL-17 as growth factors after previous mitogenic activation, but for the CD4+ subset IL-16 responses were significantly higher than IL-17 responses. Cytokine-dependent proliferation was higher for the CD4+ than for the CD8+ clones in the presence of both IL-16 and IL-17. The effects of IL-16/IL-17 were modulated by the presence of exogenous IL-2 and IL-4. The IL-16-responsive CD8+ clones seemed to represent a minor subset expressing the phenotype CD4lowCD8high. The anti-CD3-stimulated polyclonal responses were generally lower for the cytopenic patients than for healthy individuals, and this decreased responsiveness was probably caused by a combination of quantitative T cell defects and suboptimal accessory cell costimulation. Although IL-16 and IL-17 could function as growth factors for a large subset of our T cell clones, both cytokines had either no or only minor effects on the polyclonal T cell responses for cytopenic patients (e.g. only weak enhancement of anti-CD3 and anti-CD3+anti-CD28 responses, no alteration of the cytokine responsiveness profile after anti-CD3 stimulation). We conclude that both IL-16 and IL-17 are potentially immunostimulatory cytokines in patients with acute leukemia and chemotherapy-induced leukopenia, but the final effects of IL-16/IL-17 on proliferative T cell responses are modulated by local immunoregulatory networks.
Bruserud
O
O
Section for Hematology, Department of Medicine, Haukeland University Hospital, University of Bergen, Bergen, Norway.
von Volkman
H L
HL
Ulvestad
E
E
D000208:Acute Disease; D000328:Adult; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D018106:CD28 Antigens / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D002999:Clone Cells / Q000276:immunology; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects / Q000276:immunology; D019410:Interleukin-16 / Q000276:immunology / Q000502:physiology*; D020381:Interleukin-17 / Q000276:immunology / Q000502:physiology*; D007376:Interleukin-2 / Q000502:physiology; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D007970:Leukopenia / Q000139:chemically induced* / Q000276:immunology* / Q000473:pathology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D016853:Muromonab-CD3 / Q000494:pharmacology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D018106:CD28 Antigens; D019410:Interleukin-16; D020381:Interleukin-17; D007376:Interleukin-2; D016853:Muromonab-CD3