Prevalence of anti-toxoplasma gondii antibodies in young Iranians: The Caspian III study

Background: Toxoplasmosis is a worldwide neglected tropical and sub-tropical infection caused by Toxoplasma gondii (T. gondii). Most of the previous studies on the seroprevalence of T. gondii in Iran have been done at provincial level and on specific populations, including pregnant females. Socioeconomic parameters are associated with the prevalence of this disease. In this study, the authors evaluated the presence of anti-T. gondii antibodies and the related risk factors in Iranian adolescents. Methods: This was a cross-sectional study on serum samples from the third Iranian national school-based survey (the CASPIAN III study), which included 10- to 18-year-old students. Participants were selected by multistage sampling from 27 Iranian provinces. In this study, serum samples of 882 adolescents from 16 provinces were randomly selected and examined for IgG and IgM antibodies against T. gondiiby theEnzymeLinked Fluorescent Assay (ELFA).Demographicandsocioeconomic factors related to T. gondii infection were gathered using the global school-based health survey (GSHS) questionnaire. Results: The overall T. gondii IgGandIgMseropositivitywas56.3 (95 CI: 53.4 to 59.2)and3.7 (95CI: 2.7 to 4.9), respectively. In multivariate logistic regression model, family size was statistically associated with seroprevalence of anti T. gondii IgG. Living in crowded households (households with more than 4 people vs. households with less than 4 people) increased the risk of seropositivity of T. gondii (OR: 1.40, 95 CI: 1.10 to 1.99). Conclusions: The results of this study indicate that about 40 of Iranian adolescents have not had contact with the T. gondii, thus the risk of congenital toxoplasmosis might be high in young females. Also, household size was the main factor associated with T. gondii infection. Preventive strategies and health education in Iranian adolescents are recommended. © 2017, Pediartric Infections Research Center

Tetanus neurotoxin HCC protein commits T cell to IFN-γ producing cells

A protective response against tetanus toxin and toxoid demands efficient specific T cell and B cell responses. Tetanus neurotoxin (TeNT), a 150 kDa polypeptide, is the main cause of tetanus disease. TeNT consists of two structurally distinct chains, a 50 kDa N-terminal light (L) and a 100 kDa C-terminal heavy (H) chain. C-terminal heavy (H) chain (fragment C) has two sub-domains named as proximal HCN and carboxy sub-domain or HCC. Beside neural binding property, HCC has been recently found as an immunodominant module of TeNT. In the present study, we investigated the effects of recombinant HCC (rHCC) on the expression of lineage specific transcription factors and secretion of a panel of functional cytokines including IFN-γ, IL-4, and IL-17 from purified human T cells. Our results revealed that T-bet transcript level, as TH1 specific transcription factor, was significantly increased in the cells treated with 10 and 20 μg/ml of rHCC following 48 h treatment(p < 0.05). Treated purified human T cells with rHCC showed significant increase in IFN-γ mRNA level and cytokine secretion, but not IL-4 and IL-17, following 48 h treatment. In conclusion, our results showed that treatment of T cells with r HCC resulted in development of Th1 lineage phenotype, which might lead to a specific and protective antibody mediated response against tetanus toxin. © 2016 by the C.M.B. Association. All rights reserved