DF-1-Derived exosomes mediate transmission of reticuloendotheliosis virus and resist REV-specific antibodies.

BACKGROUND: Reticuloendotheliosis virus (REV), a member of the family Retroviridae, is a hot area of research, and a previous study showed that exosomes purified from REV-positive semen were not blocked by REV-specific neutralizing antibodies and established productive infections. METHODS: To further verify the infectivity of exosomes from REV-infected cells, we isolated and purified exosomes from REV-infected DF-1 cells and identified them using Western blot and a transmission electron microscope. We then inoculated 7-day-old embryonated eggs, 1-day-old chicks and 23-week-old hens with and without antibody treatment. REV was administered simultaneously as a control. RESULTS: In the absence of antibodies, the results indicated that REV-exosomes and REV could infect chicks, resulting in viremia and viral shedding, compared with the infection caused by REV, REV-exosomes reduced the hatching rate and increased mortality after hatching, causing severe growth inhibition and immune organ damage in 1-day-old chicks; both REV and REV-exosomes also could infect hens, however, lead to transient infection. In the presence of antibodies, REV-exosomes were not blocked by REV-specific neutralizing antibodies and infected 7-day-old embryonated eggs. However, REV could not infect 1-day-old chicks and 23-week-old hens. CONCLUSION: In this study, we compared the infectious ability of REV-exosomes and REV, REV-exosomes could escape from REV-specific neutralizing antibodies in embryonated eggs, providing new insights into the immune escape mechanism of REV.

Porcine endogenous retroviruses in xenotransplantation.

Xenotransplantation using pig cells, tissues or organs is under development to alleviate the shortage of human donor organs. Meanwhile, remarkably long survival times of pig organs in non-human primates have been reported, as well as the functionality of pig kidneys and hearts in brain-dead humans. Most importantly, two transplantations of pig hearts in patients were performed with survival times of the patients of 8 and 6 weeks. Xenotransplantation may be associated with the transmission of porcine microorganisms including viruses to the recipient. Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pigs and cannot be eliminated like other viruses can. PERVs are able to infect certain human cells and therefore pose a risk for xenotransplantation. It is well known that retroviruses are able to induce tumors and immunodeficiencies. However, until now, PERVs were not transmitted in all infection experiments using small animals and non-human primates, in all preclinical xenotransplantation trials in non-human primates and in all clinical trials in humans. In addition, several strategies including antiretrovirals, PERV-specific small interfering RNA, vaccines and genome editing using CRISPR/Cas have been developed to prevent PERV transmission.

Simian retrovirus transmission in rhesus macaques.

Historically, to generate Simian Retrovirus (SRV) positive control materials, we performed in vivo passage by inoculating uninfected rhesus macaques with whole blood from an SRV-1 infected (antibody and PCR positive) macaque. However, recent attempts using this approach have failed. This study reports observations and explores why it has become more difficult to transmit SRV via in vivo passage.

In vitro analysis of Porcine Endogenous Retroviruses in different pig cell types.

The shortage of organs for human transplantation is a topic of extreme interest, and xenotransplantation with porcine organs has been recognized as a promising solution. However, the potential spillover linked to infectious agents present in pigs remains a concern. Among these, Pig Endogenous Retroviruses (PERVs), whose proviral DNAs are integrated in the genome of all pig breeds, represent an extremely important biological risk. This study aims to evaluate PERVs distribution in several swine cell lines and samples of domestic and feral pigs. Moreover, the capacity of PERVs to infect human and non-human primate cells and to integrate in the cellular genome was tested by Real-Time PCR and by Reverse Transcriptase assay. Results indicated a widespread diffusion of PERVs both in cell lines and samples analysed: the viral genome was found in all the established cell lines, in 40% of the primary cell lines and in 60% of the tissue samples tested. The assays indicated that the virus can be transmitted from porcine to human cells: in the specific case, infected NSK and NPTr cells allow passage to human 293 and MRC-5 cells with active production of the virus demonstrable via PCR and RT assay. In light of these aspects and also the lack of studies on PERVs, it appears clear that there are still many questions to be clarified, also by means of future studies, before xenotransplantation can be considered microbiologically safe.

Prevalence and risk factors for HIV, syphilis, hepatitis B, hepatitis C, and HTLV-I/II infection in low-income postpartum and pregnant women in Greater Metropolitan Vitória, Espírito Santo State, Brazil / Prevalência e fatores de risco para a infecção por HIV, sífilis, hepatite B, hepatite C e HTLV-I/II em parturientes e gestantes de baixa renda atendidas na Região Metropolitana de Vitória, Espírito Santo, Brasil

Sexually transmitted infections during pregnancy pose a major risk to the fetus due to vertical transmission. The study's objective was to determine the prevalence of HIV, syphilis, hepatitis B and C, and HTLV-I/II infection among low-income postpartum and pregnant women treated in Greater Metropolitan Vitória, Espírito Santo State, Brazil, and the risk factors associated with these infections. A cross-sectional study was conducted from February to October 1999 assessing postpartum and pregnant women from the maternity ward of the Vitória Mercy Hospital and the Carapina Outpatient Referral Unit in the Municipality of Serra, respectively. Patients were systematically interviewed and had blood samples drawn for serological tests (HIV 1&2, VDRL, HbsAg, anti-HCV, and HTLV-I/II). A total of 534 patients (332 postpartum and 202 pregnant women) were assessed. Seroprevalence rates for the target infections in postpartum and pregnant women and the overall sample were as follows, respectively: HIV 0.9 percent, 0 percent, and 0.6 percent; syphilis 2.1 percent, 3.6 percent, and 2.7 percent; HBV 1.2 percent, 1 percent, and 1.1 percent; HCV 1.8 percent, 0.6 percent, and 1.4 percent; and HTLV-I/II 1.7 percent, 0.6 percent, and 1.3 percent. Factors associated with the various infections are presented and analyzed in light of other research findings from the literature.

A ocorrência de doenças sexualmente transmissíveis durante a gravidez representa risco aumentado de morbidade e mortalidade para o feto e neonato em virtude da transmissão vertical. O objetivo deste estudo foi identificar a prevalência da infecção por HIV, sífilis, hepatites B e C e por HTLV-I/II em parturientes e gestantes de baixa renda da Região Metropolitana de Vitória, Espírito Santo, Brasil, e avaliar fatores de risco associados a essas infecções. Foi realizado estudo de corte transversal de fevereiro a outubro de 1999, avaliando 534 pacientes (332 parturientes e 202 gestantes). Todas as participantes foram submetidas a entrevista semi-estruturada, após a qual foi coletada uma amostra de sangue para realização de testes sorológicos (HIV 1 e 2, VDRL, HbsAg, anti-HCV e HTLV-I/II). A soroprevalência das infecções estudadas entre as parturientes, as gestantes e no total da amostra foi, respectivamente: HIV 0,9 por cento, 0 por cento e 0,6 por cento; sífilis 2,1 por cento, 3,6 por cento e 2,7 por cento; HBV 1,2 por cento, 1 por cento e 1,1 por cento; HCV 1,8 por cento, 0,6 por cento e 1,4 por cento e HTV-I/II 1,7 por cento, 0,6 por cento e 1,3 por cento. Os fatores associados às infecções avaliadas são descritos e analisados à luz de achados de outros investigadores.

Research of antigen and antibodies from retrovirus, CMV and HBV among prisoners of the penitentiary complex of the region of Campinas, SP, Brazil

Alguns virus das familias Retroviridae, tais como, o Virus do Linfoma Humano de Celulas T (HTLV); Herpesviridae, tais como o Virus Citomegalico (CMV) e da Hepatite B (HBV) podem ser co-transmitidos com o Virus da Imunodeficiencia Adquirida (HIV). Uma vez que prisioneiros estao expostos a diversos fatores de risco envolvidos na transmissao do HIV e dos virus acima mencionados, prisioneiros do sexo masculino do Complexo Penitenciario de Campinas, SP, Brasil, incluindo aqueles que eram HIV+ e HIV-, foram examinados para a presenca de anticorpos anti-HTLV-I/II; anticorpos IgG e IgM anti-virus citomegalico e a presenca do antigeno de superficie do HBV (HbsAg). A presenca de anti-HTLV-I/II foi determinada pela tecnica de Western Blot, enquanto IgG e IgM anti-CMV e a pesquisa do HbsAg foram feitas por ensaio Imunoenzimatico (MEIA-Abbott Lab)...