Prevalent human coxsackie B-5 virus infects porcine islet cells primarily using the coxsackie-adenovirus receptor.
BACKGROUND
We have previously demonstrated that transplanting porcine encephalomyocarditis virus (EMCV)-infected porcine islet cells (PICs) results in transmission of the virus to recipient mice, which is manifested by acute fatal infection within 5 to 8 days. Here, we determined PIC susceptibility to a related and highly prevalent human picornavirus, coxsackie B-5 virus (CVB-5).


METHODS
PICs were inoculated with CVB-5 in vitro for up to 96 hours and infectivity, level of virus replication, and cellular function determined. Subsequently, monoclonal and polyclonal antibody blocking experiments were used to investigate the receptor CVB-5 uses to enter PICs, and the ability of CVB-5-infected islets to reverse diabetes analyzed in mice.


RESULTS
Adult pig islets inoculated with CVB-5 in vitro showed a typical picornaviral replication cycle with a 2-h lag phase followed by a 4-h exponential phase during which the virus titer increased by 4 logs. However, CVB-5 was less cytolytic to PICs than EMCV, resulting in a persistent productive infection lasting for up to 96 h, with minimal evidence of cell lysis. Double immunostaining confirmed the presence of CVB-5 antigens in insulin-producing islets. Infection of PICs in the presence of antibodies against human coxsackie-adenovirus receptor (CAR) resulted in near complete blockage in production of infectious virus particles whereas blocking with anti-porcine decay-accelerating factor (DAF, also called CD55) or anti-porcine membrane cofactor protein (MCP, also called CD46) only slightly decreased the number of infectious CVB-5 particles produced. Immunofluoresence staining showed CAR and MCP expression on the islet surface, but not DAF. Transplanting CVB-5-infected PICs into diabetic C57BL/6 mice resulted in reversal of diabetes.


CONCLUSIONS
Although PICs are susceptible to human CVB-5, the infection does not appear to affect xenograft function in vitro or in vivo in the short term.
Myers
Suzanne E
SE
Pathobiology Graduate Program, Veterinary Science Department, Pennsylvania State University, University Park, PA, USA.
Brewer
Laurie
L
Shaw
Daniel P
DP
Greene
Wallace H
WH
Love
Brenda C
BC
Hering
Bernhard
B
Spiller
O Brad
OB
Njenga
M Kariuki
MK
D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000628:therapy*; D029822:Enterovirus B, Human / Q000302:isolation & purification*; D004769:Enterovirus Infections / Q000453:epidemiology*; D006801:Humans; D007515:Islets of Langerhans / Q000821:virology*; D016381:Islets of Langerhans Transplantation; D051379:Mice; D008810:Mice, Inbred C57BL; D009500:Neutralization Tests; D011991:Receptors, Virus / Q000276:immunology / Q000378:metabolism; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D013552:Swine; D014183:Transplantation, Heterologous
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D011991:Receptors, Virus; C085301:adenovirus receptor