IL-15 induces IFN-beta and iNOS gene expression, and antiviral activity of murine macrophage RAW 264.7 cells.

The effects of interleukine-15 (IL-15) on macrophage activation and antiviral activity have been investigated in this study. We have provided evidence that IL-15 stimulates murine macrophage RAW 264.7 cells to release nitric oxide (NO) and inhibit vaccinia virus (VV) replication in bystander human 293 cells in a dose-dependent manner.

Systemic cytokine response in murine anthrax.

Systemic pro-inflammatory cytokine release has been previously implicated as a major death-causing factor in anthrax, however, direct data have been absent. We determined the levels of IL-1 beta, IL-6 and TNF-alpha in serum of mice challenged with virulent (Ames) or attenuated (Sterne) strains of Bacillus anthracis. More than 10-fold increase in the IL-1beta levels was detected in Ames-challenged Balb/c mice, in contrast to more susceptible C57BL/6 mice, which showed no IL-1beta response.

In vitro-generated respiratory mucosa: a new tool to study inhalational anthrax.

We generated a three-dimensional (3-D) model of human airway tissues in order to study initiation of inhalational form of anthrax infection. The system was designed to model the air-blood barrier of the respiratory tract represented by epithelial cells and macrophages. When grown on collagen/fibronectin gel support at an air-liquid interface, airway epithelial cells formed cell layers morphologically resembling those in vivo.

Immunologic profile of highly exposed yet HIV type 1-seronegative men.

The host immune factors that determine susceptibility to HIV-1 infection are poorly understood. We compared multiple immunologic parameters in three groups of HIV-1-seronegative men: 14 highly exposed (HR10), 7 previously reported possibly to have sustained transient infection (PTI), and a control group of 14 low risk blood bank donors (BB). Virus-specific cellular immune assays were performed for CD4(+) T helper cell responses, CD8(+) cytotoxic T lymphocyte activity, CD8(+) cell chemokine release, and CD8(+) cell-derived antiviral soluble factor activity.

Effect of Bacillus anthracis lethal toxin on human peripheral blood mononuclear cells.

Lethal toxin (LeTx) plays a central role in anthrax pathogenesis, however a cytotoxicity of LeTx has been difficult to demonstrate in vitro. No cytolytic effect has been reported for human cells, in contrast to murine cell lines, indicating that cell lysis can not be considered as a marker of LeTx activity. We have recently shown that murine macrophage-like RAW 264.

Lethal toxin of Bacillus anthracis causes apoptosis of macrophages.

Lethal toxin is a major anthrax virulence factor, causing the rapid death of experimental animals. Lethal toxin can enter most cell types, but only certain macrophages and cell lines are susceptible to toxin-mediated cytolysis. We have shown that in murine RAW 264.