No abstract

In this study, we investigated the capacity of the recombinant proteins SpaC, NanH, SodC, and PLD of C. pseudotuberculosis to trigger protective humoral and cellular immune responses against experimentally induced C. pseudotuberculosis infection in sheep. The antigens were produced in a heterologous system and were purified by affinity chromatography. Nine sheep were randomly divided into three groups, which were immunized as follows: Group 1 (control)—a mix of adjuvants composed of the inactivated T1 strain of C. pseudotuberculosis and commercial Montanide™ISA 61 VG (T1M); Group 2—rSpaC, rSodC, rPLD, and T1M; Group 3—rNanH, rSodC, rPLD, and T1M. All groups were immunized twice (on days 0 and 30) and challenged on day 90 of the experiment. Humoral and cellular immune responses were evaluated by Enzyme-Linked Immunosorbent Assay (ELISA) to quantify the IgG antibodies and interferon-gamma (IFN-y). Both vaccine formulations with recombinant proteins (groups 2 and 3) could induce a significant humoral IgG immune response in sheep. The proteins rSodC, rPLD, and rNanH were more immunogenic, inducing significant levels of IgG antibodies after the first dose of the vaccine or after the challenge, maintaining constant levels until the end of the experiment. However, it was not possible to differentiate between the cellular responses induced by the vaccines. This lack of effectiveness points toward the need for further studies to improve the efficacy of this subunit-based vaccine approach.

The IFNG+874 polymorphism was not shown to influence QuantiFERON-TB Gold In-Tube test performance in an admixed population from northeastern Brazil.

The aim of the study was to evaluate the association between salivary anti-Porphyromonas gingivalis IgA antibodies and the leprosy reaction. The levels of salivary anti - P. gingivalis IgA antibodies, together with salivary flow and pH were measured in individuals diagnosed with leprosy and associated with the development of the leprosy reaction. Saliva was collected from 202 individuals diagnosed with leprosy at a reference leprosy treatment center, 106 cases with leprosy reaction and 96 controls without leprosy reaction. Anti - P. gingivalis IgA was evaluated by indirect immunoenzyme assay. Non-conditional logistic regression analysis was employed to estimate the association between antibody levels and the leprosy reaction. There was a positive statistically significant association between the levels of anti - P. gingivalis IgA and the presence of the leprosy reaction, controlling for confounders: age, sex, level of education and alcoholic beverage consumption: ORajusted: 2.55; IC 95%: 1.34–4.87. Individuals with leprosy who had high production of salivary anti - P. gingivalis IgA had approximately twice as many chances of developing the leprosy reaction. The findings suggest a possible relationship between salivary anti - P. gingivalis IgA antibodies and the leprosy reaction.