Bacterial extract OM85-BV induces interleukin-12-dependent IFN-gamma production by human CD4+ T cells.

To obtain insight into the possible mode of action of bacterial extracts used as immunostimulants in Europe, we used the ELISPOT technique to investigate the effects of one of them (OM85-BV, Broncho-Vaxom) on interferon-y (IFN-gamma) production by peripheral blood mononuclear cells (PBMC). We found that (1) OM85-BV stimulates IFN-gamma secretion by PBMC from normal individuals and human immunodeficiency virus (HIV)-infected patients, (2) CD4+ cells represent the major source of IFN-gamma produced in response to OM85-BV, and (3) this effect of OM85-BV involves the induction of interleukin-12 (IL-12) secretion by accessory cells. We conclude that bacterial extracts might enhance antimicrobial defenses by eliciting IL-12-dependent IFN-gamma synthesis by CD4+ T cells.

Persistent T cell and B cell activities in the duodenal mucosa of AIDS patients.

Objective: As HIV infection most commonly occurs via a mucosal surface, and as gastrointestinal symptoms are very frequent among HIV-infected patients, we investigated the functional properties of residual lymphocytes in the duodenal mucosa from HIV-infected individuals.

Design: Duodenal biopsies and blood samples were obtained from 19 HIV-infected patients [Centers for Disease Control and Prevention (CDC) stage III] and from 19 controls.

Methods: Phenotypic analysis of lymphocytes was performed by flow cytometry and/or immunocytochemistry.

Spontaneous secretion of interferon gamma and interleukin 4 by human intraepithelial and lamina propria gut lymphocytes.

Background: Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses.

Aims: To quantify interferon gamma (IFN-gamma) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation.

Patients: Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa.

An unusual case of severe combined immunodeficiency with hypereosinophilia.

Investigation of the cytokine profile in a 26-year-old man, suffering from combined immunodeficiency with hypereosinophilia, revealed high levels of interleukin-4 and interleukin-5 and relatively low levels of interleukin-2 and interferon gamma, consistent with a T-helper type 2 pattern, as has been reported in Omenn's syndrome. However, some distinct clinical and immunological features suggest that this case may represent a unique disease with specific pathogenesis.