A serum-deprived human embryo pancreatic islet cell culture system: a culture method suitable for double-label antibody technique to detect virus infection of beta cells.

By the use of serum-free Eagle's MEM instead of serum-supplemented culture medium in human embryo islet cell culture, it was possible to increase the proportion of beta cells identified by the indirect fluorescent antibody (IFA) technique. With the combination of the serum-deprived culture system and the double-label antibody technique, it was possible to show that the human embryo beta cells in culture were susceptible to infection with human papovavirus BK (BKV). Furthermore, this combination enabled us to assay quantitatively the BKV-infected beta cells, and it was shown that the proportion of BKV-infected beta cells in the islet cultures from three subjects were not significantly different either in BKV tumor antigen (T-Ag)-positive ratio or in BKV virion antigen (V-Ag)-positive ratio. The quantitative assay also showed that the percentages of BKV T-Ag- or V-Ag-positive cells in insulin-positive cells and in insulin-negative cells were almost the same.