Proc. Natl. Acad. Sci. USA Vol. 93, pp. 15341–15345, December 1996 Medical Sciences CD8 T-cell-derived soluble factor(s), but not -chemokines RANTES, MIP-1, and MIP-1, suppress HIV-1 replication in monocytemacrophages HIROYUKI MORIUCHI* † ,MASAKO MORIUCHI*, CHRISTOPHE COMBADIERE ‡ ,PHILIP M. MURPHY ‡ , AND ANTHONY S. FAUCI* *Laboratory of Immunoregulation and ‡ Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892 Contributed by Anthony S. Fauci, October 18, 1996 ABSTRACT It has been demonstrated that CD8 T cells produce a soluble factor(s) that suppresses human immuno- deficiency virus (HIV) replication in CD4 T cells. The role of soluble factors in the suppression of HIV replication in monocytemacrophages (MM) has not been fully delineated. To investigate whether a CD8 T-cell-derived soluble factor(s) can also suppress HIV infection in the MM system, primary macrophages were infected with the macrophage tropic HIV-1 strain Ba-L. CD8 T-cell-depleted peripheral blood mononu- clear cells were also infected with HIV-1 IIIB or Ba-L. HIV expression from the chronically infected macrophage cell line U1 was also determined in the presence of CD8 T-cell supernatants or -chemokines. We demonstrate that: (i) CD8 T-cell supernatants did, but -chemokines did not, suppress HIV replication in the MM system; (ii) antibodies to regulated on activation normal T-cell expressed and Se- creted (RANTES), macrophage inflammatory protein 1 (MIP-1) and MIP-1 did not, whereas antibodies to inter- leukin 10, interleukin 13, interferon , or interferon mod- estly reduced anti-HIV activity of the CD8 T-cell superna- tants; and (iii) the CD8 T-cell supernatants did, but -che- mokines did not, suppress HIV-1 IIIB replication in peripheral blood mononuclear cells as well as HIV expression in U1 cells. These results suggest that HIV-suppressor activity of CD8 T cells is a multifactorial phenomenon, and that RANTES, MIP-1, and MIP-1 do not account for the entire scope of CD8 T-cell-derived HIV-suppressor factors. Cells of the monocytemacrophage (MM) lineage are major targets of HIV (1, 2). Unlike CD4 + T cells, which are the other major target of HIV and which are depleted during the course of HIV disease, infection of cells of the MM lineage does not necessarily lead to rapid cytolysis; rather, infection of these cells generally results in latency or persistent low-level chronic infection (3, 4). Different strains of HIV-1 vary markedly in their ability to infect cells belonging to the MM lineage (5, 6). HIV-1 strains tend to lose macrophage tropism during labo- ratory adaptation or progression of clinical disease. Thus, the MM system seems to play a substantial role in the pathogen- esis of HIV disease, especially during primary infection and the clinically latent period; however, the mechanisms involved in establishment of viral latency or persistent infection in the MM system are not well understood. A number of cytokines, including tumor necrosis factor , interleukin 1 (IL-1), IL-6, granulocytemacrophage colony- stimulating factor (GM-CSF), and macrophage CSF, have been shown to upregulate HIV replication in the MM system (reviewed in ref. 7). In contrast, interferons (IFNs) and and IL-13 (8) suppress, and IL-10 (9), IFN- (10), and transform- ing growth factor (11) have dichotomous effects on HIV replication in the MM system. Interestingly, these anti-HIV cytokines have little or no effect on HIV replication in primary lymphocytes, suggesting that regulation of HIV replication by cytokines is dependent on the cell type in question. It was initially demonstrated by Walker et al. (12) and subsequently confirmed by others (13–15) that CD8 + T cells are capable of suppressing in vitro HIV replication in CD4 + T cells or peripheral blood mononuclear cells (PBMCs) in a noncytolytic, major histocompatibility complex nonrestricted manner (reviewed in ref. 16). This suppressive effect is medi- ated, at least in part, by a soluble factor(s) produced by CD8 + T cells (17). It is unclear whether a CD8 + T-cell-derived soluble factor(s) is also capable of suppressing HIV infection in cells belonging to the MM lineage. Recently, Cocchi et al. (18) reported that the -chemokines RANTES (regulated on activation, normal T-cell expressed and secreted), macrophage inflammatory protein 1 (MIP-1), and MIP-1, derived from CD8 + T cells, suppressed HIV replication in a CD4 + T-cell clone and in PBMCs. Several laboratories have recently iden- tified CCR5, a receptor for RANTES, MIP-1, and MIP-1 as a coreceptor for HIV-1 macrophage tropic strains, indicating that the -chemokines inhibit HIV-1 infection by interfering with viral entry (19 –23). However, their activity in cells of the MM lineage is still in question. In this study, we have examined the relative effects of crude supernatants from CD8 + T cells compared with purified RANTES, MIP-1, MIP-1, and a number of other cytokines on the regulation of HIV-1 Ba-L replication in acutely infected MM and primary PBMCs as well as on the regulation of HIV expression in chronically infected promonocytic cell lines. Our results indicate that the HIV-suppressor effects of CD8 + T-cell supernatants are complex and multifactorial and that these effects cannot be accounted for exclusively by RANTES, MIP-1, and MIP-1. MATERIALS AND METHODS Isolation and Culture of Peripheral Monocytes and Lym- phocytes. PBMCs were obtained from HIV-negative, healthy donors by FicollHypaque centrifugation, and seeded on plastic tissue culture plates. After 3– 4 hr incubation at 37°C in humidified 5% CO 2 95% air atmosphere, nonadherent cells were removed by vigorous pipetting, and adherent cells were maintained in DMEM supplemented with 10% human male AB serum (Sigma) and GM-CSF (2 ngml; R & D Systems) for The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked ‘‘advertisement’’ in accordance with 18 U.S.C. §1734 solely to indicate this fact. Abbreviations: MM, monocytemacrophages; MDM, monocyte- derived macrophages; PBMC, peripheral blood mononuclear cells; RANTES, regulated on activation normal T-cell expressed and se- creted; MIP, macrophage inf lammatory protein; IL, interleukin; IFN, interferon; GM-CSF, granulocytemacrophage colony-stimulating factor; HVS, herpesvirus saimiri; RT, reverse transcriptase. † To whom reprint requests should be addressed at: Building 10, Room 6A-11, National Institutes of Health, 10 Center Drive, MSC-1576, Bethesda, MD 20892-1576. 15341 Downloaded by guest on May 25, 2020