A well-written article by Yi et al. (1) was published in Diabetes in 2012 that demonstrates the ability of human regulatory T cells (Tregs) to prevent T-cell effector function and the importance of interleukin (IL)-10 in this response. Furthermore, the study pointed to a strategy for using Tregs as adjunctive therapy with the potential to reduce the immunosuppressive burden in islet xenotransplantation, thereby increasing the feasibility of clinical trials in the future. However, we found an important mistake in this article.
The authors declared that real-time PCR analysis showed reduced interferon-γ and upregulated IL-10 gene expression in the neonatal porcine islet cell cluster (NICC) grafts from mice receiving human peripheral blood mononuclear cells (PBMCs) and recombinant human IL-10 (rhIL-10) compared with that detected in the rejecting grafts from recipients receiving human PBMCs alone (see Fig. 8D in ref. 1). However, Fig. 8D showed increased interferon-γ and downregulated IL-10 gene expression in the NICC grafts from mice receiving human PBMCs and rhIL-10 when compared with that detected in the rejecting grafts from recipients receiving human PBMCs alone. Furthermore, Fig. 8D showed that intragraft mRNA expression of Treg function–associated molecules were downregulated in the NICC grafts from mice receiving human PBMCs and rhIL-10 using real-time PCR analysis. There is contradictory information that reveals an important mistake. We firmly believe that Fig. 8D showed an opposite result and PBMC + rhIL-10 group (black bars) and PBMC only group (white bars) needed to be switched with each other; namely, the black bars should represent the PBMC only group, and the white bars, the PBMC + rhIL-10 group. We think it is essential for the editors to declare this error to facilitate the better understanding of this important article.
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Duality of Interest. No potential conflicts of interest relevant to this article were reported.
