Field strains of Echovirus 6 infect human endocrine and exocrine pancreatic cells and induce pro-inflammatory innate immune responses.
(English)Article in journal (Refereed) In press
Increasing evidence suggests that type 1 diabetes (T1D) is a combined endocrine-exocrine disease. Human enteroviruses (HEV) have been suggested to induce T1D, but so far evidence on HEV infection in human pancreas has been reported only in islets and ductal cells. Aim of this study was to investigate the capability of HEV strains to infect primary human endocrine and exocrine pancreatic cells and to induce the expression of innate immunity genes in both cell types. Isolated human pancreatic islets and exocrine cells were either mock-infected or inoculated with seven field isolates of Echovirus 6 (E6). Beta-cell tropic strains of E4, E16 and E30 were assayed in primary exocrine cells. Viral infection, replication, virus-induced cytopathic effect (CPE) and expression of innate immunity genes were measured. All the seven strains of E6 replicated in both pancreatic endocrine and exocrine cells with infectious progeny production and appearance of CPE. By contrast, no virus titer increase or CPE were observed in exocrine cells exposed to E4, E16 and E30. Virus particles were found in E6-infected acinar cells, both free in cytoplasm and enclosed in vacuoles. Insulin granules accumulation in proximity to virus particles and beta cells functional impairment were demonstrated in E6-infected islets. Endocrine and exocrine cells responded to E6 infection by upregulating the transcription of genes involved in viral recognition (IF1H1), antiviral defense (OAS1, IFN-β) and inflammation (CXCL10, CCL5). Our results indicate that islets and exocrine pancreatic cells productively support the E6 infection and suggest that HEV-associated T1D may involve both endocrine and exocrine pancreas.
Clinical Medicine Microbiology
IdentifiersURN: urn:nbn:se:uu:diva-283276OAI: oai:DiVA.org:uu-283276DiVA: diva2:918879