Biology subjects

Shearer, D.

Publications and source records attributed to Shearer, D..

2 recordsLinked to original sources

bioRxiv2019

Papillomavirus can be transmitted through the blood and produce infections in blood recipients: Evidence from two animal models

Human papillomavirus (HPV) infections are commonly thought to be strictly sexually transmitted. However, studies have demonstrated the presence of HPV in cancers of many non-sexual internal organs, raising the question as to how the viruses gain access to these sites. A possible connection between blood transfusion and HPV-associated disease has not received much attention. We show, in two animal models, that blood infected with papillomavirus yields infections at permissive sites. Furthermore, we demonstrate that blood from actively infected mice can transmit the infection to naive animals. Finally, we report papillomavirus infections in the stomach tissues of animals infected via the blood. Stomach tissues are not known to be permissive for papillomavirus infection, although the literature suggests that HPVs may be associated with a subset of gastric cancers. These results indicate that the human blood supply, which is not screened for papillomaviruses, could be a potential source of HPV infection and subsequent cancers. SUMMARYHuman papillomaviruses cause 5% of human cancers. Currently, blood banks do not screen for these viruses. We demonstrate that blood transfused from papillomavirus-infected animals produces infections in recipients. Public health implications are significant if the same is true for humans. DefinitionsLocal papillomavirus infection: An infection initiated by the direct application of virus or viral DNA to the site of infection Intravenous (IV) papillomavirus infection: An infection resulting from blood-borne delivery of virus or viral DNA to the site of infection.

microbiology↗

bioRxiv2018

Thrombospondins 1 and 2 affect lysyl oxidase protein and collagen matrix maturation in cortical bone of growing male and female mice via non-redundant pathways

Thrombospondin-2-deficiency is associated with impaired matrix maturation in osteoblasts and cortical bone of growing mice. Here we addressed the possibility that lysyl oxidase (LOX) contributes to this phenotype. After overnight serum starvation, pro-LOX levels were elevated compared to wild-type in marrow-derived osteoblasts from male and female TSP2-/- mice. The liberated LOX pro-peptide (LOPP) was faintly visible in serum-starved cultures. When serum was maintained, pro-LOX content was not affected by TSP2 status, but relative LOPP levels were elevated in cultures from female TSP2-/- mice. Two isoforms of pro-LOX at 75 kDa and 50 kDa were detected in detergent soluble protein extracts of diaphyseal tissue from growing mice. In female mice, TSP2 status did not affect detergent soluble pro-LOX content or the relative contribution of each band to the total signal. Instead, levels of the 50 kDa band were reduced in female TSP1-/- samples. In male diaphyseal tissue, total pro-LOX content and the contribution each isoform made to the total signal was not affected by TSP1 or TSP2 status. We did not detect 32 kDa mature LOX in detergent soluble preparations of cells or whole bone tissue. Detergent insoluble hydroxyproline content was reduced in diaphyseal tissue obtained from female TSP1-/- and TSP2-/- mice. In male diaphyseal cortical samples, TSP2 but not TSP1 deficiency was associated with reduced insoluble hydroxyproline content. Our data suggest that the trimeric thrombospondins contribute to bone matrix quality via non-redundant mechanisms that are dependent on the unique tissue milieu of the male and female skeleton.

cell biology↗