Differential effects of CD28 costimulation upon cytokine production by CD4+ and CD8+ T cells.

The impact of CD28 ligation upon CD4+ and CD8+ T lymphocyte proliferation and cytokine production was assessed. Although costimulation increased the proliferative response of both T cell subsets, cytokine production was most markedly increased in the CD4+ subset, as evidenced by a 40-fold increase in interleukin-2 (IL-2), a 14-fold increase in interleukin-3 (IL-3) and 5-fold increases in interferon gamma and GM-colony-stimulating factor (CSF) production. The CD8+ T cell response to CD28 ligation was less marked, maxima being a 5-fold increase in IL-2 production and 2-fold increases in IL-3 and GM-CSF production.

Interplay between cdk9 and NF-kappaB factors determines the level of HIV-1 gene transcription in astrocytic cells.

Basal transcription of the HIV-1 genome is controlled by a variety of ubiquitous and inducible regulatory factors, some with the ability to associate with the viral DNA sequences within the promoter spanning the long terminal repeat (LTR). In this report we demonstrate that activation of the HIV-1 promoter through the inducible DNA binding NF-kappaB transcription factors can be affected by cdk9 in human astrocytic cells. Our results show that ectopic expression of cdk9, but not its mutant variant which lacks the domain responsible for its kinase activity, augments transcription of the LTR.

Kinetics of murine gammaherpesvirus 68 gene expression following infection of murine cells in culture and in mice.

A model system to study the pathogenesis of gammaherpesvirus infections is the infection of mice with murine gammaherpesvirus 68 (MHV-68). To define the kinetics of infection, we developed an RNase protection assay to quantitate gene expression from lytic (K3, Rta, M8, DNA polymerase [DNA pol], and gB) and candidate latency (M2, M3, M9, M11, ORF73, and ORF74) genes. All candidate latency genes were expressed during lytic infection of 3T3 cells.

Effect of nitroimidazole sensitizers on in vitro glycolytic metabolism of hypoxic squamous cell carcinoma.

Two nitroimidazole compounds, misonidazole (MISO) and nimorazole (NIMO), were evaluated for their potential to modify uptake of [5,6-3H] 2-fluoro-2-deoxy-D-glucose (3H-FDG) in the human squamous carcinoma cell line UT-SCC-5 exposed to increasing levels of hypoxia. UT-SCC-5 cells were incubated with 0-10 mM of MISO or NIMO under normal or reduced oxygen concentrations of 20%, 1.5%, or 0% with 5% CO2 for 6 h, after which 74 KBq of 3H-FDG was added in media for 1 h.

[Infection by Pseudomonas aeruginosa in patients with human immunodeficiency virus infection. Descriptive study of 35 cases].

Objective: Analysis of the spectrum of diseases attributed to Pseudomonas aeruginosa in patients with coinfection with the immunodeficiency virus (HIV).

Methods: Retrospective study of 35 cases of coinfection with P. aeruginosa-HIV, attended from 1985 until 1995.