PubMed Health⌕ Search

Biomedical subjects

Tracy D Wilkins

Publications and source records attributed to Tracy D Wilkins.

4 recordsLinked to original sources

Revised nomenclature of Clostridium difficile toxins and associated genes.

Several different nomenclatures have been applied to the Clostridium difficile toxins and their associated genes. This paper summarizes the new nomenclature that has been agreed to by the research groups currently active in the field. The revised nomenclature includes C. difficile toxins and other related large clostridial toxins produced by Clostridium sordellii and Clostridium novyi, and corresponding toxin genes, as well as toxin production types of C. difficile strains.

Bacterial Proteins↗

A non-toxic lectin for antigen delivery of plant-based mucosal vaccines.

RicinB, the non-toxic galactose/N-acetylgalactosamine-binding subunit of ricin, was fused to a model antigen, green fluorescent protein (GFP), and expressed in tobacco plants and hairy root cultures to test for utility in mucosal vaccine delivery/adjuvancy. The fusion protein retained both GFP fluorescence and galactose/galactosamine-binding activity. Intranasal immunization of mice with galactosamine-affinity purified ricinB:GFP recovered from tobacco root cultures triggered significant increases in GFP-specific serum IgGs. This strong humoral response was comparable to that observed following GFP immunization with cholera toxin adjuvant. GFP at the same concentrations but without an adjuvant was non-immunogenic. Induction of higher levels of IgG(1) than IgG(2a) following ricinB:GFP immunization suggested the presence of a Th2 response. Serum and fecal anti-GFP IgA were also induced by immunization with ricinB:GFP. Our data suggest that ricinB can be used as an adjuvant and antigen carrier to the mucosa and is efficient in eliciting systemic and mucosal immune responses.

Adjuvants, Immunologic↗

The mouse model of amebic colitis reveals mouse strain susceptibility to infection and exacerbation of disease by CD4+ T cells.

Amebic colitis is an important worldwide parasitic disease for which there is not a well-established animal model. In this work we show that intracecal inoculation of Entamoeba histolytica trophozoites led to established infection in 60% of C3H mice, while C57BL/6 or BALB/c mice were resistant, including mice genetically deficient for IL-12, IFN-gamma, or inducible NO synthase. Infection was a chronic and nonhealing cecitis that pathologically mirrored human disease. Characterization of the inflammation by gene chip analysis revealed abundant mast cell activity. Parasite-specific Ab and cellular proliferative responses were robust and marked by IL-4 and IL-13 production. Depletion of CD4(+) cells significantly diminished both parasite burden and inflammation and correlated with decreased IL-4 and IL-13 production and loss of mast cell infiltration. This model reveals important immune factors that influence susceptibility to infection and demonstrates for the first time the pathologic contribution of the host immune response in amebiasis.

Animals↗