Joann Cutilli

An unusual syncytia-inducing human immunodeficiency virus type 1 primary isolate from the central nervous system that is restricted to CXCR4, replicates efficiently in macrophages, and induces neuronal apoptosis.

Macrophage/microglia cells are the principal targets for human immunodeficiency virus type 1 (HIV-1) in the central nervous system (CNS). Prototype HIV-1 isolates from the CNS are macrophage (M)-tropic, non-syncytia-inducing (NSI), and use CCR5 for entry (R5 strains), but whether syncytia-inducing (SI) CXCR4-using X4 strains might play a role in macrophage/microglia infection and neuronal injury is unknown. To explore the range of features among HIV-1 primary isolates from the CNS, the authors analyzed an HIV-1 strain (TYBE) from cerebrospinal fluid of an individual with acquired immunodeficiency syndrome (AIDS) that was unusual because it was SI. Like other CNS isolates, HIV-1/TYBE replicated to high level in primary human macrophages, but, in contrast to CNS prototypes, TYBE used CXCR4 exclusively to infect macrophages. A functional TYBE env clone confirmed the X4 phenotype and displayed a highly charged V3 sequence typical of X4 strains. Supernatant from TYBE-infected primary human macrophages induced apoptosis of neurons. Thus, TYBE represents a novel type of CNS-derived HIV-1 isolate that is CXCR4-restricted yet replicates efficiently in macrophages and induce neuronal injury. These results demonstrate that HIV-1 variants in the CNS may possess a broader range of biological characteristics than generally appreciated, raise the possibility that X4 strains may participate in AIDS neuropathogenesis, and provide a prototype clade B HIV-1 strain that replicates efficiently in primary macrophages through the exclusive use of CXCR4 as a coreceptor.

Centrifugal enhancement of human immunodeficiency virus type 1 infection and human cytomegalovirus gene expression in human primary monocyte/macrophages in vitro

In an effort to facilitate the efficiency of human immunodeficiency virus type 1 (HIV‐1) and/or human cytomegalovirus (HCMV) infection in primary monocyte/macrophages in vitro, the effect of low‐speed centrifugation was studied. The infectivity of Aree strains (Bai, Ada‐M, and IIIB) of HIV‐1 tested was significantly enhanced by centrifugal inoculation at a force of 1500g for 60 min. Reverse transcriptase activity and HIV‐1 p24 antigen in primary monocyte/macrophages infected by a centrifugal inoculation technique were detectable 3‐7 days earlier and were more than 10‐fold greater in magnitude (at an early stage of the infection) than those of control cells infected by the conventional inoculation technique. Examination of the cells by indirect immunofluorescence revealed higher expression of HIV‐1 p24 protein in the monocyte/macrophages infected by the centrifugal inoculation technique. These differences were directly related to centrifugal inoculation and were evident up to 3 weeks after infection. Enhancement was not observed when centrifugation was carried out before or after HIV‐1 infection. Centrifugal inoculation of HCMV also enhanced its immediate‐early and early gene expression up to 36‐ to 50‐fold, although neither late nuclear antigens and glycoproteins of HCMV nor infectious virus was detected in HCMV‐infected monocyte/ macrophage cultures. These results show that centrifugal inoculation is a useful technique for improving the efficiency of HCMV and HIV‐1 infection in vitro.

Interferon-|[gamma]| Corrects the Respiratory Burst Defect In Vitro in Monocyte-Derived Macrophages from Glycogen Storage Disease Type 1b Patients

ABSTRACT: Glycogen storage disease (GSD) type 1b is accompanied by decreased respiratory burst activity in peripheral blood phagocytic cells (i.e. monocytes and neutrophils). To elucidate whether this depressed respiratory burst was due to an intrinsic defect of phagocytic cells or due in part to in vivo host factors, we examined superoxide anion (O2−) production in monocytes from five GSD 1b patients cultured 9 d in vitro to allow for differentiation into macrophages (MDM). O2− production in MDM was measured in response to concanavalin A, fMet-Leu-Phe, and phorbol myristate acetate (PMA) stimulation. GSD 1b MDM had significantly depressed O2− generation with fMet-Leu-Phe and concanavalin A stimulation; however, unlike peripheral blood monocytes, GSD 1b MDM responded to PMA stimulation with O2− production comparable to healthy control donors. The cytokine interferon- (IFN-) has been shown to enhance O2− production in MDM. When GSD 1 b MDM were cultured in the presence of IFN- (1 ± 105 U/L), O2− production in response to fMet-Leu-Phe, concanavalin A, and PMA was enhanced to rates similar to those of control MDM cultured in the presence of IFN-. Thus, the respiratory burst defect observed in circulating phagocytic cells is also present in vitro in cultured GSD 1b MDM. However, in contrast to circulating phagocytic cells, depressed O2− production in GSD 1 b MDM is selective to receptor-mediated activation, but not to PMA stimulation. This defect is correctable after short-term treatment with IFN-, suggesting a role for IFN- in treating the phagocytic defect in this disease.

Suppression of Human Immunodeficiency Virus Type 1 (HIV-1) Infection In Vitro in Cord Blood Monocyte Derived Macrophages by IL-3, IL-4, IL-10, and IL-13.♦ 1319

Suppression of Human Immunodeficiency Virus Type 1 (HIV-1) Infection In Vitro in Cord Blood Monocyte Derived Macrophages by IL-3, IL-4, IL-10, and IL-13.♦ 1319

VITAMIN A AND HUMAN IMMUNODEFICIENCY VIRUS TYPE 1(HIV-1) IN VITRO INFECTION IN CORD BLOOD LYMPHOCYTES AND MONOCYTES. |[bull]| 1760

Vitamin A deficiency maybe a risk factor for perinatal transmission of HIV-1 (Lancet. 1994;343:1593). Vitamin A enhances T-cell function and leukocyte phagocytic activity in vitro. Levels of vitamin A are decreased in newborns and infected HIV-1 pregnant mothers. Our hypothesis is that vitamin A may effect HIV-1 infection in cord blood lymphocytes and monocyte derived macrophages. We studied the effect of different concentrations of vitamin A and HIV-1 infection in cord blood lymphocytes and monocytes from 4 healthy(HIV negative) term infants. Lymphocytes and monocytes were isolated and cultured separately, then infected with HIV-1 (BAL strain). Supernatant was collected in triplicate on successive days for reverse transcriptase(RT) and p24 antigen analysis by radioimmunoassay and ELISA(Coulter, Miami, FL) respectively. Vitamin A significantly inhibited p24 viral replication by 50% at concentrations greater than 34.9 μmol/L in cord lymphocytes(101.1± 30.1 vs 219.4 ± 39.2, pg/ml, M±SD, p<0.0001, n=2) and 75% in monocytes(117.6 ±63.4 vs 507.0 ± 8.5 pg/ml p24, M±SD, p<0.025, n=2). Monocyte RT activity was decreased by 60%(3632± 1206 vs 9096 ± 1670 cpm/5μl, M±SEM, p<0.025, n=2). At concentrations less than 7.0 μmol/L p24 viral replication in lymphocytes was increased twofold(457.5 ± 77.2 vs 219.4 ± 39.2 pg/ml, M±SD, p<0.0001, n=2). In macrophages, RT was stimulated nearly threefold at concentrations less than 34.9 μmol/L (26078 ± 4757 vs 9096 ± 1670 cpm/5μl, M±SEM, p<0.025, n=2), but p24 antigen levels were unchanged. There was no cytotoxicity at 139.6 μmol/L. In summary, vitamin A significantly suppresses HIV-1 expression in both cord blood lymphocytes and macrophages at concentrations greater than 34.9μmol/L in a concentration dependent fashion. However, at concentrations less than 7.0 μmol/L vitamin A significantly stimulates viral replication. Thus, these observations may indicate that at high concentrations vitamin A may have the potential to inhibit HIV-1 replication in lymphocytes and monocytes in vivo and prevent perinatal transmission.