Endocrine Abstracts

Introduction: The functional interaction between the immune and endocrine systems remains intricate, and the relationships among various cell types and humoral mediators are not fully elucidated. Natural killer T (NKT) cells, being a heterogeneous T cell subpopulation, express markers specific for both natural killer (NK) cells (NK1.1, CD56) and T cells (TCR - T cell receptor). Thyroid-stimulating hormone (TSH) influences the immune system, and TSH receptors (TSHR) have been identified in various immune cell types. Although the impact of TSH levels on the quantity of NKT cells in peripheral blood has been postulated, no reported studies have explored the expression of TSHR on NKT cells. This study aimed to assess the expression of TSHR on NKT cells, with analyses conducted on NKT cells isolated from the peripheral blood of individuals with and without autoimmune thyroid disease (AITD).

Methods: NKT cells were isolated from peripheral blood mononuclear cells (PBMC) using a magnetic beads cell separator. Fluorescence-activated cell sorting (FACS) was employed to analyze TSHR expression on the surface of NKT cells. TSHR gene expression was assessed using the RT-PCR method on total RNA isolated from both PBMC and NKT cells. Blood samples were collected from 81 individuals, including 16 AITD patients and 65 persons without AITD.

Results: Neither FACS analysis nor RT-PCR gene assays revealed the expression of TSHR on the surface of NKT cells. These findings were consistent in both AITD and non-AITD patient groups.

Conclusion: Our results suggest the absence of direct TSH-mediated effects on NKT cells via TSHR. Further investigations are warranted to elucidate potential indirect mechanisms underlying the influence of TSH on NKT cells.