Immunosuppressive factor produced by a B cell line derived from an adult T cell leukemia patient.
The immunosuppressive activity of culture supernatants from human T cell leukemia virus type I (HTLV-I)-infected cell lines was examined in vitro. Culture supernatants of both a HTLV-I-infected B cell line, IWS, established from an adult T cell leukemia (ATL) patient and a T cell line, MT-2, suppressed lymphocyte proliferative responses to stimulation with the mitogens phytohemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM). The immunosuppressive factor was not cytotoxic for lymphocytes and did not inhibit the spontaneous growth of ATL cells. It inhibited interleukin-2 (IL-2) production by PHA-stimulated T cells and it arrested PHA-stimulated T cells at the G0/G1 phase of the cell cycle and inhibited entry into the S phase. Furthermore, the factor significantly inhibited the expression of CD3, CD4, and IL-2 receptor (IL-2R) alpha-chain (CD25) on PHA-stimulated T cells. These results suggest that the immunosuppressive factors produced by HTLV-I-infected cell lines might function in the regulation of normal lymphocyte proliferative responses, and that they could play some role in the induction of the immunodeficient condition observed in ATL patients.
Mori
N
N
First Department of Internal Medicine, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
Yamashita
U
U
Tanaka
Y
Y
Nagata
K
K
Nakata
K
K
Oda
S
S
Eto
S
S
D000328:Adult; D000954:Antigens, Surface / Q000187:drug effects; D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D015490:HTLV-I Infections / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007166:Immunosuppressive Agents / Q000032:analysis / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis; D015458:Leukemia, T-Cell / Q000378:metabolism* / Q000473:pathology; D008213:Lymphocyte Activation / Q000187:drug effects; D008934:Mitogens / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000954:Antigens, Surface; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D008934:Mitogens