interleukin-8 and Burkitt-Lymphoma

Interleukin 8 (IL-8), a member of the CXC subfamily of chemokines, is a potent inflammatory cytokine produced by many cell types in response to several stimuli. In an attempt to determine whether human B-cell IL-8 functions as an autocrine growth factor, a wide panel of B-cell lines derived from patients with AIDS-associated B-cell lymphomas (AABCL) (n = 5) and from non-AABCLs (n = 8) was studied for expression of IL-8, IL-8 Receptor type A (IL-8R), and secretion of IL-8 protein. Using RT-PCR and Northern Blot analysis, we were able to observe IL-8 expression ubiquitously. However, IL-8R expression was seen only in EBV negative (4 out of 7) B-cell lines. EBV and HIV-1 activated B-cell line; HBL-1, was the major secretor of IL-8. Our results demonstrate that IL-8 is expressed in malignant B-cell phenotypes that correspond to a narrow window in the B-cell differentiation pathway (pre-B, early-B, and intermediate-B) as well as in normal CD19-enriched B-cells. Furthermore, IL-8 autocrine loops were not evident since IL-8R was detected only in cell lines that did not secrete IL-8 protein.

Topics: B-Lymphocytes; Base Sequence; Blotting, Northern; Burkitt Lymphoma; Cloning, Molecular; DNA Primers; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Interleukin-8; Lymphoma, AIDS-Related; Lymphoma, B-Cell; Receptors, Interleukin-8A; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Tumor Cells, Cultured

Burkitt's lymphoma (BL) represents a high malignant B cell tumour. It has been proposed that cytokines are responsible for some of the characteristics of BL. We have analysed a panel of different BL and lymphoblastoid cell lines (LCLs) for the expression of cytokines, including: IL 1 alpha, IL 1 beta, IL2, IL3, IL4, IL6, IL8, IL10, TNF alpha and TNF beta and for the soluble cytokine receptor for IL2 (slL2R). Our results show that expression of IL8, IL10, TNF alpha or TNF beta was detected frequently in several of the Burkitt or lymphoblastoid cell lines. There was a correlation between Epstein-Barr virus (EBV) infection and cytokine protein production. Our results suggest that EBV promote the expression of IL8, IL10, TNF alpha and TNF beta.

Topics: Burkitt Lymphoma; Cytokines; Herpesviridae Infections; Herpesvirus 4, Human; Humans; Interleukin-10; Interleukin-8; Interleukins; Lymphotoxin-alpha; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha; Tumor Virus Infections

The culture supernatants from 43 human cell lines obtained during log phase and from purified normal peripheral blood B-lymphocytes cultured at 10(6) cells ml-1 for 48 h in RPMI 1640-5% fetal calf serum were examined for interleukin-8 (IL-8) using Elisa kits. Constitutive IL-8 production was found for 14/15 B-cell lines (5 derived from normal persons and 2 from AML patients, 1 pre-B-ALL, 2 CLL with trisomy 12, 2 HTLV-I+, 1 HTLV-II+, 1/2 Burkitt lymphoma), 4/16 T-cell lines (3/6 HTLV-I+, 1 HTLV-II+, 0/9 T-ALL), myeloid line HL-60, monocytoid line U937, 3/3 ovarian carcinoma, 1/1 endometriosis, 2/2 normal fibroblast, 0/2 C-ALL, 0/1 pre-erythroid line K562, as well as for normal B-lymphocytes. Later, cells examined by indirect immunofluorescence using IL-8 antibodies gave a positive reaction. DNA from 4 IL-8 producing and 3 non-producing cell lines, when probed with IL-8 cDNA gave the same 3.5 kb EcoRI fragment indicating similarities of the IL-8 gene in these cells. Two B-cell lines examined showed the expression of 1.8 kb IL-8 mRNA. These results indicate IL-8 production by a greater variety of cells than previously believed which open possibilities for new IL-8-mediated immune functions by such cells as B-cells.

Topics: B-Lymphocytes; Blotting, Southern; Burkitt Lymphoma; Cell Line; DNA Probes; Enzyme-Linked Immunosorbent Assay; HTLV-I Infections; HTLV-II Infections; Humans; Interleukin-8; Leukemia; Reference Values; T-Lymphocytes; Tumor Cells, Cultured

In this study we have characterized the cell surface interleukin 1 (IL-1) receptor in HepG2 hepatoma cells. We found that HepG2 cells bind both IL-1 alpha and beta with high affinity, KDs of 136 and 180 pM and receptor densities of 16,000 and 8500 binding sites/cell respectively. The binding sites appeared to be predominantly type II since phorbol ester treatment of the cells, which selectively downregulates type II IL-1 receptors, reduced binding by 68% while treatment of the cells with an inhibitory monoclonal antibody specific for the type I receptor had no significant effect on IL-1 binding. Competition studies with a modified IL-1 beta analog (Glu4) also revealed binding kinetics more consistent with binding to type II receptors than to type I. Crosslinking and ligand blotting with human 125I-IL-1 demonstrated the presence of two bands, a 78 kDa band typical of crosslinking to type II (p60) receptor, and a 98 kDa band, typical of crosslinking to the type I (p80) receptor. Low level expression of the type I receptor was consistent with molecular biological studies employing polymerase chain reaction (PCR) amplification which indicated that mRNA for the type I receptor was produced by the HepG2 cells. Functional receptors were demonstrated by the induction of IL-8 by IL-1 stimulated cells.

Topics: Animals; Antibodies, Monoclonal; Binding, Competitive; Burkitt Lymphoma; Carcinoma, Hepatocellular; CHO Cells; Cricetinae; Cross-Linking Reagents; Down-Regulation; Humans; Interleukin-1; Interleukin-8; Liver Neoplasms; Neoplasm Proteins; Phorbol Esters; Polymerase Chain Reaction; Receptors, Immunologic; Receptors, Interleukin-1; Recombinant Proteins; RNA, Messenger; RNA, Neoplasm; Tumor Cells, Cultured