Nullbasic is a mutant form of HIV-1 Tat that has strong ability to protect cells from HIV-1 replication by inhibiting three different steps of viral replication: reverse transcription, Rev export of viral mRNA from the nucleus to the cytoplasm and transcription of viral mRNA by RNA polymerase II. We previously showed that Nullbasic inhibits transduction of human cells including T cells by HIV-1-based lentiviral vectors. Here we investigated whether the Nullbasic antagonists huTat2 (a Tat targeting intrabody), HIV-1 Tat or Rev proteins or cellular DDX1 protein could improve transduction by a HIV-1 lentiviral vector conveying Nullbasic-ZsGreen1 to human T cells. We show that overexpression of huTat2, Tat-FLAG and DDX1-HA in virus-like particle (VLP) producer cells significantly improved transduction efficiency of VLPs that convey Nullbasic in Jurkat cells. Specifically, co-expression of Tat-FLAG and DDX1-HA in the VLP producer cell improved transduction efficiency better than if used individually. Transduction efficiencies could be further improved by including a spinoculation step. However, the same optimised protocol and using the same VLPs failed to transduce primary human CD4+ T cells. The results imply that the effects of Nullbasic on VLPs on early HIV-1 replication are robust in human CD4+ T cells. Given this significant block to lentiviral vector transduction by Nullbasic in primary CD4+ T cells, our data indicate that gammaretroviral, but not lentiviral, vectors are suitable for delivering Nullbasic to primary human T cells.
Hunting is a common and popular pastime in Portugal. Hunted animals are, generally, for human consumption as meat or local products that are consumed without cooking, increasing the risk of zoonotic transmission of several infectious agents. The present study intended to characterize HEV infection in hunted wild boars (species Sus scrofa) from two regions of Portugal in order to estimate its importance as reservoir for zoonotic spread of HEV to humans, and its possible implication in public health. Markers for both past and/or ongoing HEV infection were evaluated in serum, bile and stool samples of 29 wild boars. The presence of specific HEV antibodies as marker of past infection was evaluated in serum samples, while active HEV infection was evaluated through the detection of HEV genome in bile and stool samples. HEV specific antibodies were detected in 14% of the studied animals, while none of the tested bile or stool samples revealed detectable HEV genome. Despite no active HEV infection was demonstrated in the hunted animals included in the present study, serological analysis revealed the endemicity of HEV infection in Portuguese wild boars from the studied regions, corroborating its possible role as zoonotic reservoir of such virus. The proved endemicity of HEV infection among wild boars further support the importance of including HEV in national and regional surveillance programs for wild animal diseases, as well as to the awareness for thorough cook all wild boar products and to the education of occupationally exposed people in order to prevent HEV infection.