Strong CD4 T cell responses to Zika virus antigens in a cohort of Dengue virus immune mothers of congenital Zika virus syndrome infants

Background: There is an urgent need to understand the complex relationship between cross-reactive anti-viral immunity, disease susceptibility, and severity in the face of differential exposure to related, circulating Flaviviruses. Co-exposure to Dengue virus and Zika virus in Brazil is a case in point. A devastating aspect of the 2015-2016 South American Zika outbreak was the dramatic increase in numbers of infants born with microcephaly to mothers exposed to Zika virus during pregnancy. It has been proposed that this is more likely to ensue from Zika infection in women lacking cross-protective Dengue immunity. In this case series we measure the prevalence of Dengue immunity in a cohort of mothers exposed to Zika virus during pregnancy in the 2015-2016 Zika outbreak that gave birth to an infant affected by microcephaly and explore their adaptive immunity to Zika virus. Results: Fifty women from Sergipe, Brazil who gave birth to infants with microcephaly following Zika virus exposure during the 2015-16 outbreak were tested for serological evidence of Dengue exposure and IFNγ ELISpot spot forming cell (SFC) response to Zika virus. The majority (46/50) demonstrated Dengue immunity. IFNγ ELISpot responses to Zika virus antigens showed the following hierarchy: Env>NS1>NS3>C protein. Twenty T cell epitopes from Zika virus Env were identified. Responses to Zika virus antigens Env and NS1 were polyfunctional with cells making IFNγ, TNFα, IL-4, IL-13, and IL-10. In contrast, responses to NS5 only produced the immune regulatory TGFβ1 cytokine. There were SFC responses against Zika virus Env (1-20) and variant peptide sequences from West Nile virus, Dengue virus 1-4 and Yellow Fever virus. Conclusion: Almost all the women in our study showed serological evidence of Dengue immunity, suggesting that microcephaly can occur in DENV immune mothers. T cell immunity to Zika virus showed a multifunctional response to the antigens Env and NS1 and immune regulatory responses to NS5 and C protein. Our data support an argument that different viral products may skew the antiviral response to a more pro or anti-inflammatory outcome, with an associated impact on immunopathogenesis

Chequered fortunes in global exports: The sociogenesis of African entrepreneurship in the Nile Perch Business at Lake Victoria, Uganda

Item does not contain fulltextThis article looks at African entrepreneurship in the Nile perch export business at Lake Victoria, Uganda. Often heralded as an economic success story, this business has perhaps another tale to tell. The fishermen, traders and other small-scale entrepreneurs at the lower end of the export chain face frequent financial setbacks coupled with an occasional lucky strike. Their chequered fortunes may be related to economic uncertainties, but this study rather points to a major contribution from highly individualistic entrepreneurship. This is the outcome of a self-fulfilling prophecy of anticipated deceit, which conditions the entrepreneurs to regard other persons as opportunistic adversaries. Although this behaviour seems to resemble that of the neoclassical entrepreneur, the study shows that it originates and is reproduced in complicated social links. The article argues, therefore, that an appraisal of the sociogenesis of entrepreneurship has a place in understanding emerging global export markets in Africa.17 p