The big challenge of SARS-CoV-2 latency: testes as reservoir / El gran desafío de la latencia de SARS-CoV-2: el testículo como reservorio

Abstract In the efforts to explain COVID-19 pathophysiology, studies are being carried out on the correspondence between the expression of SARS-CoV-2 cell receptors and viral sequences. ACE2, CD147 and TMPRSS2 receptors expression could indicate poorly explored potential infection targets. For the genomic analysis of SARS-CoV-2 receptors, using BioGPS information was decided, which is a portal that centralizes genetic annotation resources, in combination with that of The Human Protein Atlas, the largest portal of human transcriptome and proteome data. We also reviewed the most recent articles on the subject. RNA and viral receptor proteins expression was observed in numerous anatomical sites, which partially coincides with the information reported in the literature. High expression in testicular cells markedly stood out, and it would be therefore important ruling out whether this anatomical site is a SARS-CoV-2 reservoir; otherwise, germ cell damage, as it is observed in infections with other RNA viruses, should be determined.

Resumen En el afán por explicar la fisiopatogenia de COVID-19 se están realizando estudios en torno a la correspondencia entre la expresión de receptores celulares de SARS-CoV-2 y las secuencias virales. La expresión de los receptores ACE2, CD147 y TMPRSS2 podría indicar blancos de infección poco explorados. Para el análisis genómico de los receptores de SARS-CoV-2 se optó por utilizar la información del BioGPS, un portal que centraliza los recursos de anotación genética, en combinación con la de The Human Protein Atlas, el portal más grande de datos del transcriptoma y proteoma humanos. También se revisaron los artículos más recientemente respecto al tema. En numerosos sitios anatómicos se observó la expresión de ARN y proteínas de los receptores del virus, que coinciden parcialmente con la información reportada en la literatura. Resaltó la alta expresión en las células de los testículos, por lo que sería importante descartar si este sitio anatómico es un reservorio de SARS-CoV-2; de no ser así, determinar el daño en las células germinales, tal como sucede en infecciones por otros virus ARN.

Localization of Porcine Reproductive and Respiratory Syndrome Virus Infection in Boars by In Situ Riboprobe Hybridization

The capability of porcine reproductive and respiratory syndrome virus (PRRSV) to be shed in semen for extended periods of time has been suggested to be a principal factor for viral transmission via insemination. In attempts to gain insights into the mechanism of PRRSV persistence in boars, tissue distribution and sites of viral infection were investigated by in situ hybridization (ISH) using digoxigenin-labeled RNA probe and the ISH results were compared with those of reverse transcription-nested polymerase chain reaction (RT-nested PCR). Animals were intranasally inoculated with 104 median tissue culture infectious dose of PRRSV VR-2332 and tissues collected at different times were examined. At day 7 postinfection, limited number of hybridization positive signals was observed in cells within or between seminiferous tubules in the testis sections while relatively abundant hybridization positive signals were observed in the brain stem and tracheobronchial lymph node. At later days of infection, hybridization positive signals were observed in cells within seminiferous tubules with much reduced frequency. Lack of agreement with the RT-nested PCR assay results in testis tissues obtained at days 14, 28, and 59 postinfection suggested that PRRSV infection in the testis may be extremely restricted, and may not necessarily constitute a major viral source in semen during extended periods of seminal shedding.