Brief Report: Increased Expression of the Type I Interferon Receptor on CD4+ T Lymphocytes in HIV-1-Infected Individuals.

Background: Type I interferons (IFN1s; eg, interferon-alpha and interferon-beta) are potent cytokines that inhibit the replication of human immunodeficiency virus-1 (HIV-1) and other viruses. The antiviral and immunoregulatory activities of IFN1 are mediated through ligand-receptor interactions with the IFN1 receptor complex (IFNAR). Variation in the cell-surface density of IFNAR could play a role in HIV-1 pathogenesis.

Plasmacytoid dendritic cell number and responses to Toll-like receptor 7 and 9 agonists vary in HIV Type 1-infected individuals in relation to clinical state.

In HIV-1 infection, plasmacytoid dendritic cell (PDC) numbers and function are decreased. No detailed comparisons of PDC responses to various stimuli in HIV-1-infected patients are available. Using for the first time purified PDCs, we compared PDC responses [interferon (IFN)-α production/cell] to various stimuli in a large number (n=48) of HIV-1-infected patients and healthy volunteers (n=19).

Transfection optimization for primary human CD8+ cells.

Electroporation, a non-virus-mediated gene transfection method, has traditionally had poor outcomes with low gene transfection efficiency and poor cellular viability, particularly in primary human lymphocytes. Herein we have optimized the electroporation conditions for primary CD8+ cells resulting in a maximum rate of 81.3%, and a mean transfection efficiency of 59.

Natural suppression of human immunodeficiency virus type 1 replication is mediated by transitional memory CD8+ T cells.

HIV replication is suppressed in vitro by a CD8(+) cell noncytotoxic antiviral response (CNAR). This activity directly correlates with an asymptomatic clinical state. The objective of this study was to identify the phenotype of CD8(+) cell subsets having strong CNAR activity.

Similar changes in plasmacytoid dendritic cell and CD4 T-cell counts during primary HIV-1 infection and treatment.

Objectives: Reduced dendritic cell (DC) frequencies and functions in individuals with longstanding HIV-1 infection are predictive of opportunistic infections and AIDS. To investigate possible early alterations in DC levels after HIV infection, we prospectively examined plasmacytoid dendritic cell (pDC) and myeloid dendritic cell (mDC) frequencies and plasma IFN-alpha levels in patients undergoing primary HIV-1 infection (PHI).

Methods: Peripheral blood DC frequencies and absolute counts were determined by flow cytometry.

Variations in plasmacytoid dendritic cell (PDC) and myeloid dendritic cell (MDC) levels in HIV-infected subjects on and off antiretroviral therapy.

Plasmacytoid and myeloid dendritic cells are reduced in AIDS patients. The number of these circulating cells was assessed cross-sectionally and longitudinally in 27 uninfected and 72 HIV-infected subjects on and off antiretroviral therapy. The plasmacytoid dendritic cell numbers were significantly reduced in the HIV-infected subjects compared to controls (p < 0.

HIV-infected cells are major inducers of plasmacytoid dendritic cell interferon production, maturation, and migration.

Plasmacytoid dendritic cells (PDC), natural type-1 interferon (IFN) producing cells, could play a role in the innate anti-HIV immune response. Previous reports indicated that PDC IFN production is induced by HIV. Our results show a more robust IFN induction when purified PDC (>95%) were exposed to HIV-infected cells.

Differential effects of R5 and X4 human immunodeficiency virus type 1 infection on CD4+ cell proliferation and activation.

Human immunodeficiency virus type 1 (HIV-1) isolates can be distinguished by their chemokine coreceptor usage. Non-syncytium-inducing (NSI), macrophage-tropic viruses utilize CCR5 and are called R5 viruses; syncytium-inducing (SI) isolates use CXCR4 and are known as X4 viruses. R5 and X4 HIV isolates are both transmitted but, in most cases, R5 viruses predominate in the blood prior to the development of AIDS-related pathogenesis.

VCAM-1 expression on CD8+ cells correlates with enhanced anti-HIV suppressing activity.

CD8(+) cells from HIV-infected individuals showing the CD8(+) cell noncytotoxic antiviral response unexpectedly revealed mRNA for VCAM-1, a cell surface molecule found on endothelial cells. Uninfected subjects had undetectable levels of VCAM-1 mRNA in their CD8(+) cells. Flow cytometry analysis showed that up to 12% of the CD8(+) cells from HIV-positive individuals expressed VCAM-1 compared with 0.

Low-level HIV infection of plasmacytoid dendritic cells: onset of cytopathic effects and cell death after PDC maturation.

Plasmacytoid dendritic cells (PDC), the natural type-1 interferon (IFN) producing cells, are part of the innate immune defense against human immunodeficiency virus (HIV). PDC numbers are reduced in advanced stages of infection. These cells can be infected in vivo by HIV since highly purified PDC showed evidence of infectious HIV.

Expression patterns of phenotypic markers on lymphocytes from human immunodeficiency virus type 2-infected baboons.

The development of AIDS in HIV-1-infected humans is associated with profound changes in the expression patterns of lymphocyte phenotypic markers associated with increased immune activation and with decreased recall immune responses. In assessing these immunologic changes in an animal model, we characterized the expression patterns of immune activation markers on lymphocyte subsets during the acute, chronic, and end stages of HIV-2 infection in baboons. Using flow cytometry, we identified 21 human-specific monoclonal antibodies that were cross-reactive with baboon lymphocytes; however, expression of only 2 of these markers was altered significantly after HIV-2 infection.