Persistent infection of human pancreatic islets by coxsackievirus B is associated with alpha interferon synthesis in beta cells.
The interactions of coxsackievirus B3 (CVB3), CVB4E2 (diabetogenic), and CVB4JBV (nondiabetogenic) strains with human pancreatic islets from eight adult brain-dead donors were investigated. Persistent replication of viruses in human islets was proved by detection of viral RNA by in situ hybridization, VP1 capsid protein by immunofluorescence (IF) staining, negative-strand viral RNA by reverse transcription-PCR in extracted RNA from islets, and release of infectious particles up to 30 days after infection without obvious cytolysis. By double IF staining, glucagon-containing alpha cells and insulin-containing beta cells were shown to be susceptible to CVB. The persistence of CVB3 and CVB4 in islet cells was associated with the chronic synthesis of alpha interferon (IFN-alpha), as evidenced by the detection of IFN-alpha mRNA and immunoreactive IFN-alpha with antiviral activity. By double IF staining, IFN-alpha was detected in insulin-producing beta cells only. Experiments with neutralizing anti-coxsackievirus and adenovirus receptor (CAR) antibodies provided evidence that CAR was expressed by alpha and beta cells and that it played a role in the infection of these cells with CVB and the consecutive IFN-alpha expression in beta cells. The viral replication and the expression of IFN-alpha in islets were not restricted to the CVB4E2 diabetogenic strain and did not depend on the genetic background of the host. The neutralization of endogenous IFN-alpha significantly enhanced the CVB replication in islet cells and resulted in rapid destruction of islets. Thus, human beta cells can harbor a persistent CVB infection, and CVB-induced IFN-alpha plays a role in the initiation and/or maintenance of chronic CVB infection in human islets.
Chehadeh
W
W
Laboratoire de Virologie, CHRU, Institut Gernez-Rieux, 59037 Lille, France.
Kerr-Conte
J
J
Pattou
F
F
Alm
G
G
Lefebvre
J
J
Wattré
P
P
Hober
D
D
D000328:Adult; D000998:Antiviral Agents / Q000494:pharmacology; D002478:Cells, Cultured; D029822:Enterovirus B, Human / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D016898:Interferon-alpha / Q000096:biosynthesis* / Q000235:genetics; D007515:Islets of Langerhans / Q000378:metabolism / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014774:Virulence; D014779:Virus Replication
D000998:Antiviral Agents; D016898:Interferon-alpha