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Assessment of porcine endogenous retrovirus transmission across an alginate barrier used for the encapsulation of porcine islets
Author(s) -
Crossan Claire,
Mourad Nizar I.,
Smith Karen,
Gianello Pierre,
Scobie Linda
Publication year - 2018
Publication title -
xenotransplantation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.052
H-Index - 61
eISSN - 1399-3089
pISSN - 0908-665X
DOI - 10.1111/xen.12409
Subject(s) - xenotransplantation , islet , hek 293 cells , virus , specific pathogen free , reverse transcriptase , miniature swine , endogenous retrovirus , transplantation , retrovirus , immunosuppression , virology , cell culture , biology , andrology , microbiology and biotechnology , immunology , medicine , rna , diabetes mellitus , endocrinology , gene , biochemistry , genetics , genome
Background Subcutaneous implantation of a macroencapsulated patch containing human allogenic islets has been successfully used to alleviate type 1 diabetes mellitus (T1DM) in a human recipient without the need for immunosuppression. The use of encapsulated porcine islets to treat T1DM has also been reported. Although no evidence of pathogen transfer using this technology has been reported to date, we deemed it appropriate to determine if the encapsulation technology would prevent the release of virus, in particular, the porcine endogenous retrovirus (PERV). Methods HEK293 (human epithelial kidney) and swine testis (ST) cells were co‐cultured with macroencapsulated pig islets embedded in an alginate patch, macroencapsulated PK15 (swine kidney epithelial) cells embedded in an alginate patch and free PK15 cells. Cells and supernatant were harvested at weekly time points from the cultures for up to 60 days and screened for evidence of PERV release using qRT‐PCR to detect PERV RNA and SG‐PERT to detect reverse transcriptase (RT). Results No PERV virus, or evidence of PERV replication, was detected in the culture medium of HEK293 or pig cells cultured with encapsulated porcine islets. Increased PERV activity relative to the background was not detected in ST cells cultured with encapsulated PK15 cells. However, PERV was detected in 1 of the 3 experimental replicates of HEK293 cells cultured with encapsulated PK15 cells. Both HEK293 and ST cells cultured with free PK15 cells showed an increase in RT detection. Conclusions With the exception of 1 replicate, there does not appear to be evidence of transmission of replication competent PERV from the encapsulated islet cells or the positive control PK15 cells across the alginate barrier. The detection of PERV would suggest the alginate barrier of this replicate may have become compromised, emphasizing the importance of quality control when producing encapsulated islet patches.