Scorpion venom exhibits adjuvant effect by eliciting HBsAg-specific Th1 immunity through neuro-endocrine interactions.

The Hottentotta rugiscutis scorpion venom (Hrv) contains neurotoxins, which elicit a strong innate immune response through the activation of the Hypothalamus-pituitary-adrenal axis, which could improve the quality of adaptive immunity. Hence, the Hrv was used as an adjuvant for the Hepatitis-B virus surface antigen (HBsAg) and assessed its ability in the activation of innate (NGF, CORT, cellularity, NO) and adaptive (IgM, IgG, IgG1/IgG2a/IgG2b/IgG3, Th1/Th2 cytokines, avidity) immunity. Here, the Hrv and HBsAg were given in the mixed form (HBsAg-Hrv) as well as in a separate form (HBsAg+Hrv). The NGF levels in plasma/spleen and CORT in plasma were found to be elevated optimally at 5 h and 6 h post-Hrv injection, respectively. Further studies showed that CORT and NGF levels were also highly upregulated in the HBsAg-Hrv group. The HBsAg-specific IgM titer was found to be increased in the HBsAg+Hrv group and total IgG was relatively similar among alum and Hrv-test groups, but IgG2a/IgG2b/IgG3 levels were higher along with IL-1ß in HBsAg-Hrv groups. The study showed that the venom from H. rugiscutis acts as a vaccine adjuvant for HBsAg to develop strong antigen-specific Th1 immunity. The Hrv also enhances the antibody-avidity which may improve the neutralizing ability of antibodies with systemic infectious agents. The study also elucidated that the venom acts by neuroendocrine-immune mechanism and majorly impacts splenocytes through NGF and corticosterone.

Protein profile of scorpion venom from Hottentotta rugiscutis and its immunogenic potential in inducing long term memory response.

The scorpions of the Buthidae family exhibit diverse toxins with proven pharmacological activities and yet underexplored. The Hottentotta rugiscutis is a commonly found south-Indian buthid scorpion, whose venom proteomic profile is unknown. In this study, the venom was biochemically and immunologically characterized by SDS-PAGE, MALDI-TOF MS, Western blot and ELISA. The regional and seasonal variation in the venom composition from the same species was also assessed at the molecular mass level. The venom was further studied in albino mice to understand its impact on various blood parameters. The venom has varied MW proteins from 6 to 275 kDa, four of them were found to be major immunodominant proteins. The mass spectra have revealed that some proteins are predominantly present in the venom of 3-4.5 kDa or 6.5-8.0 kDa, which could be the K+ or Na+ channel blockers respectively whose ratio varied by season. The obtained venom-mass spectra could also be used as H. rugiscutis specific finger-print in identifying the region-specific species. The venom was found to elicit a stress-induced innate immune response in mice, giving rise to a strong Th2 mediated humoral immune response. Overall, this study has provided a glimpse of the venom composition and its immunogenicity.

Molecular mechanism of Escherichia coli H10407 induced diarrhoea and its control through immunomodulatory action of bioactives from Simarouba amara (Aubl.).

Enterotoxigenic Escherichia coli (ETEC) infection is a major cause of death in children under the age of five in developing countries. ETEC (O78:H11:CFA/I:LT+:ST+) mechanism has been studied in detail with either heat labile (LT) or heat stable (ST) toxins using in vitro and in vivo models. However, there is no adequate information on ETEC pathogenesis producing both the toxins (LT, ST) in BALB/c mice model. In this study, female mice have been employed to understand ETEC H10407 infection induced changes in physiology, biochemical and immunological patterns up to seven days post-infection and the antidiarrhoeal effect of Simarouba amara (Aubl.) bark aqueous extract (SAAE) has also been looked into. The results indicate that BALB/c is sensitive to ETEC infection resulting in altered jejunum and ileum histomorphology. Withal, ETEC influenced cAMP, PGE2, and NO production resulting in fluid accumulation with varied Na+, K+, Cl-, and Ca2+ levels. Meanwhile, ETEC subverted expression of IL-1ß, intestine alkaline phosphatase (IAP), and myeloperoxidase (MPO) in jejunum and ileum. Our data also indicate the severity of pathogenesis reduction which might be due to attainment of equilibrium after reaching optimum rate of infection. Nevertheless, degree of pathogenesis was highly significant (p < 0.01) in all the studied parameters. Besides that, SAAE was successful in reducing the infectious diarrhoea by inhibiting ETEC H10407 in intestine (jejunum and ileum), and shedding in feces. SAAE decreased cAMP, PGE2, and fluid accumulation effectively and boosted the functional activity of immune system in jejunum and ileum IAP, MPO, IL-1ß, and nitric oxide.