Complete nucleotide sequence of a Coxsackievirus B‐4 strain capable of establishing persistent infection in human pancreatic islet cells: Effects on insulin release, proinsulin synthesis, and cell morphology

Abstract

The aim of the present investigation was to study the effect of infection of human pancreatic islet cells with a strain (VD2921) of Coxsackie B virus serotype 4 capable of establishing persistent infection in these cells, as well as to sequence the strain, to study the determinants of virulence and persistence. Groups of islets were infected and assessments of proinsulin, insulin content, and virus replication were made. Insulin release in response to high glucose was measured. Infected and control islets displayed a strong insulin response to high glucose 3-4 days as well as 7-8 days post-infection (dpi). At 11-17 dpi, the infected islets did not respond at all to high glucose, and the response of the control islets was at this late time point somewhat reduced. The insulin and proinsulin content of the infected islets did not differ significantly from that of the control islets. TCID(50) titrations showed that the VD2921 strain replicated in the islet cells during the whole study. Electron microscopic examination of infected islets did not reveal any virus-induced changes of cell morphology compared with the controls, although higher magnifications of the infected beta-cells showed virus-like particles in the cytoplasm. These results show that certain strains of Coxsackievirus B-4 in vitro can establish a persistent infection that might mimic, the more gradual loss of beta-cell function seen during the clinical course of autoimmune diabetes. The ability of this Coxsackievirus B-4 strain to establish a persistent infection might be due to substitution of 11 amino acids located at the surface of the structural protein VP1, adjacent to the predicted receptor binding canyon of the virus.

Evaluation of the fidelity of immunolabelling obtained with clone 5D8/1, a monoclonal antibody directed against the enteroviral capsid protein, VP1, in human pancreas

“…VD2921 (GenBank accession number AF328683) was originally isolated from the cerebrospinal fluid of a patient with aseptic meningitis [20,21]. The CVB1-10802 CDC strain was isolated in Argentina in 1998 by the Centers for Disease Control and Prevention (Atlanta, GA, USA).…”

Complete Nucleotide Sequence of a Coxsackievirus B4 Strain that Establishes Infection in ICR Mice Pancreas and Induces Glucose Intolerance

“…The rapidity with which jlu06 infects and spread throughout the pancreas might prevent the tissue from mounting an effective antiviral response in time and, therefore, may induce a persistent infection. Persistent infection of CVB4 strains in human islet cells and in vivo in mice had been shown previously (Chehadeh et al, 2000;Yin et al, 2002b;Yap et al, 2003), although their results were different to some extent.…”

“…Recent studies have demonstrated the association of the virulence with the genetics of the virus strain (Yin et al, 2002b;Paananen et al, 2003;Al-Hello et al, 2005;Dotta et al, 2007). Based on the sequence comparison of the diabetogenic E2 strain of CVB4 and the nondiabetogenic JVB strains, it was revealed that some amino acid changes in the capsid and noncapsid proteins of the E2 strain might be responsible for determination of its diabetogenicity (Kang et al, 1994).…”

Thymic self-antigens for the design of a negative/tolerogenic self-vaccination against type 1 diabetes

“…By contrast, none of 12 T2D patients and none of 15 healthy adults had enterovirus sequences in their blood [43]. The CVB4 strain E2 is able to induce a persistent infection of human islet b cells [44], whereas a new isolated CVB4 variant, VD2921, causes a persistent infection of islet b cells with a consequent disturbance of proinsulin synthesis and insulin secretion [45]. CVB4 E2 and VD2921 genomes were recently detected by RT-PCR in the peripheral blood mononuclear cells (PBMCs) of a majority of T1D children at the onset of their diabetes.…”