Analysis of the antiviral activities of natural IFN-alpha preparations and their subtype compositions.

Here we report on the antiviral effects of two commercially available natural interferon-alpha (IFN-alpha) preparations, their subtype compositions, and the effects of combinations of pairs of the subtypes on virally infected cells. Our results show that the antiviral effects of these preparations depend on the target cell and on the infecting virus. The component subtypes vary with the preparations, and combinations of pairs of IFN-alpha subtypes may have synergistic or competitive effects. Our results suggest that optimal preparations of synergistically acting subtypes may provide more therapeutic benefit to patients.

Alteration in CD29(high) CD4(+) lymphocyte subset is a common feature of early HIV disease and of active tuberculosis.

Peripheral CD4 T-cell depletion has been observed in human immunodeficiency virus (HIV)-negative patients with pulmonary tuberculosis (TB). To investigate more accurately this alteration, we studied peripheral blood CD45RA(+) and CD29(high) CD4 subsets in 79 TB patients with (HIV(+)TB(+)) or without (HIV(-)TB(+)) HIV infection, 85 HIV-infected patients without TB (HIV(+)TB(-)), and 43 healthy controls, all living in West Africa. The high proportion of CD4(+)CD29(high) T cells observed in controls was dramatically decreased in CDC-A stage HIV(+)TB(-) patients. CD45RA(+) CD4(+) T cells were depleted during the CDC-B stage. Both the percentage and the absolute count of CD29(high)CD4(+) T cells were decreased in HIV(-)TB(+) and HIV(+)TB(+) patients versus controls, but CD45RA(+)CD4(+) T cells were not decreased in TB patients without HIV-infection. Although distinct alterations in the CD4(+) T-cell homeostasis are involved in TB(-) versus HIV-infected subjects, our data suggest that the CD29(+)CD4(+) T-cell depletion observed during the early HIV disease contributes to the risk of active TB, by reducing the pool of T cells able to relocalize to the sites of the M. tuberculosis multiplication.

Purification and characterization of the human interleukin-18 receptor.

Interleukin (IL)-18 was identified as a molecule that induces IFN-gamma production and enhances NK cell cytotoxicity. In this paper, we report upon the purification and characterization of human IL-18 receptor (hIL-18R). We selected the Hodgkin's disease cell line, L428, as the most strongly hIL-18R-expressing cell line based on the results of binding assays. This binding was inhibited by IL-18 but not by IL-1beta. The dissociation constant (Kd) of 125I-IL-18 binding to L428 cells was about 18.5 nM, with 18,000 binding sites/cell. After immunizing mice with L428 cells and cloning, a single monoclonal antibody (mAb) against hIL-18R was obtained (mAb 117-10C). Sequentially, hIL-18R was purified from 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid (CHAPS)-extracted L428 cells by wheat germ lectin-Sepharose 4B chromatography and mAb 117-10C-Sepharose chromatography. The internal amino acid sequences of hIL-18R all matched those of human IL-1 receptor-related protein (IL-1Rrp), the ligand of which was unknown to date. When expressed in COS-1 cells, the cDNA of IL-1Rrp conferred IL-18 binding properties on the cells and the capacity for signal transduction. From these results, we conclude that a functional IL-18 receptor component is IL-1Rrp.

A study of Toxoplasma and Cytomegalovirus serology in tuberculosis and in HIV-infected patients in Burkina Faso.

Seroreactivity to Toxoplasma gondii (Tg) and to Cytomegalovirus (Cmv) was compared between symptomatic HIV-infected patients (40 with pulmonary tuberculosis and 38 with AIDS) and HIV-seronegative patients (40 tuberculosis patients and 30 healthy patients), in an urban area of Burkina Faso. Prevalence of IgG antibodies to Tg antigens (> 50.0%) did not differ amongst the four groups, but tuberculosis HIV+ patients and AIDS patients showed more higher titers of Tg antibodies more often than healthy patients (p < 0.05 and p < 0.005, respectively). Prevalence of specific IgG to Cmv was higher in tuberculosis HIV-seronegative patients (97.5%) and in AIDS patients (100%) than in healthy patients (82%; p < 0.03 and p < 0.001, respectively). Higher Cmv antibodies titers were found in relation to AIDS but also to tuberculosis. Tuberculosis HIV+ as tuberculosis HIV-patients showed higher Cmv antibodies titers than healthy patients (p < 0.002 and < 0.02 respectively). These data emphasize the need for taking into account the risk of Tg reactivation during the follow-up of HIV infected patients in Burkina Faso and suggest possible relationships between Cmv and tuberculosis reactivations.

Simultaneous production of natural human tumor necrosis factor-alpha, -beta and interferon-alpha from BALL-1 cells stimulated by HVJ.

B-cell human lymphoblastoid cell line, BALL-1, produced interferon-alpha (IFN-alpha) and cytotoxic factors by the stimulation of hemagglutinating virus of Japan (HVJ). These cytotoxic factors were identified to be tumor necrosis factor-alpha (TNF-alpha) and tumor necrosis factor-beta (TNF-beta) on the basis of molecular level analysis. In the kinetic study, it was found that the maximum production of IFN-alpha was reached at 16-20 hr and that of TNF-alpha was at 10-16 hr after the stimulation by HVJ, whereas the maximum production of TNF-beta was at 40-50 hr, suggesting that the regulation of TNF-alpha and TNF-beta genes are different. These cytokines were purified by monoclonal antibody linked column chromatography, respectively. IFN-alpha was further separated into 9 subspecies on the basis of the difference of isoelectric point by FPLC chromatofocusing method. From the N-terminal amino acid sequence analyses of the 7 species of 9 subspecies, these subspecies were classified into 3 subtypes according to the Weissmann's notation. On the other hand, the amino acid sequence of the tryptic peptides of purified TNF-alpha and TNF-beta coincided well with the parts of the complete amino acid sequences which had been deduced from complementary DNA of TNF-alpha and TNF-beta of BALL-1 cell.