Firewalls Prevent Systemic Dissemination of Vectors Derived from Human Adenovirus Type 5 and Suppress Production of Transgene-Encoded Antigen in a Murine Model of Oral Vaccination.

To define the bottlenecks that restrict antigen expression after oral administration of viral-vectored vaccines, we tracked vectors derived from the human adenovirus type 5 at whole body, tissue, and cellular scales throughout the digestive tract in a murine model of oral delivery. After intragastric administration of vectors encoding firefly luciferase or a model antigen, detectable levels of transgene-encoded protein or mRNA were confined to the intestine, and restricted to delimited anatomical zones. Expression of luciferase in the form of multiple small bioluminescent foci in the distal ileum, cecum, and proximal colon suggested multiple crossing points.

The role of secretory immunoglobulin A in the natural sensing of commensal bacteria by mouse Peyer's patch dendritic cells.

The mammalian gastrointestinal (GI) tract harbors a diverse population of commensal species collectively known as the microbiota, which interact continuously with the host. From very early in life, secretory IgA (SIgA) is found in association with intestinal bacteria. It is considered that this helps to ensure self-limiting growth of the microbiota and hence participates in symbiosis.

Langerhans cells prime IL-17-producing T cells and dampen genital cytotoxic responses following mucosal immunization.

Langerhans cells (LCs) are dendritic cells (DCs) localized in stratified epithelia, such as those overlaying skin, buccal mucosa, and vagina. The contribution of LCs to the promotion or control of immunity initiated at epithelial sites remains debated. We report in this paper that an immunogen comprising OVA linked to the B subunit of cholera toxin, used as delivery vector, was efficient to generate CTLs after vaginal immunization.

Antigenemia in patients with mediterranean visceral leishmaniasis.

Antigenemia in patients with Mediterranean visceral leishmaniasis (MVL) due to Leishmania infantum was retrospectively assessed by sandwich enzyme-linked immunosorbent assay (ELISA). Circulating Leishmania antigens, partially in free form, were in evidence in 53% of serum samples from immunocompetent individuals with MVL. Following successful therapy, antigenemia decline as measured by ELISA was more pronounced than antibody decrease.