The distribution of adiponectin receptors on human peripheral blood mononuclear cells.

Adiponectin, an adipocytokine with anti-inflammatory and insulin-sensitizing properties, may provide a mechanism by which insulin resistance accelerates autoimmunity in type 1 diabetes (T1D). Its actions are mediated by two receptors, adiponectin receptors 1 (ADIPOR1) and 2 (ADIPOR2). In this study, we measured their distribution on human peripheral mononuclear cells by flow cytometry. ADIPOR1 is present approximately on 1% of T cells, 93% of monocytes, 47% of B cells, and 21% of NK cells (P < 0.01 for difference between subsets). The distribution of ADIPOR2 was found to be similar (r= 0.992, P < 0.01), and staining could be blocked in an antigen-specific manner. We were also able to confirm our finding at an RNA level by PCR using sequence-specific primers. Our data are consistent with an immunoregulatory role for adiponectin in T1D.