Recombinant Human Thyroid-Stimulating Hormone Increases the Percentages of Natural Killer T Cells and B Lymphocytes in Human Peripheral Blood In Vivo

Abstract

Multiple cellular and humoral components of the immune system play a significant role in the physiology and pathophysiology of various organs including the thyroid. On the other hand, both thyroid hormones and thyroid-stimulating hormone (TSH) have been shown to exert immunoregulatory activities, which are difficult to assess independently in vivo. In our study we employed a unique clinical model for the assessment of TSH biological function in humans. The structure of peripheral blood mononuclear cell populations was investigated, using flow cytometry, in athyroid patients (n = 109) after treatment because of the differentiated thyroid carcinoma (DTC) at two time-points: directly before and five days after recombinant human TSH (rhTSH) administration. The analysis revealed significant increase in the percentage of natural killer T cells and B lymphocytes in the peripheral blood of rhTSH treated patients, whereas, we did not observe any effects on investigated subpopulations of dendritic cells and monocytes, T cells and natural killer cells. The findings of the study indicate the immune regulatory role of TSH, directed specifically on selected cell subtypes.

The interplay of thyroid hormones and the immune system – where we stand and why we need to know about it

“…Although still a matter of debate, TSH itself has been proposed as a potential regulator of the immune system as different immune cells were shown to express TSHR (for review see ( 107 )). In agreement with this, recombinant human TSH was shown to promote lymphocyte proliferation and activation, including NK, T and B cells in thyroidectomised patients in vivo ( 108 ). Moreover, TSH was suggested to promote thymic T cell development in humans and mice, based on the interaction with thymic T cell expressed TSHR ( 109 ).…”

The Independent Association of TSH and Free Triiodothyronine Levels With Lymphocyte Counts Among COVID-19 Patients

“…A study of athyreotic patients due to total thyroidectomy for differentiated thyroid cancer showed that administration of recombinant human TSH led to a significant rise in the percentage of natural killer T cells and B lymphocytes in their peripheral blood. This showed a potential direct impact of TSH on immune cells, independent of thyroid hormone action ( 28 ). Indeed, in our subgroup analysis, TSH still positively correlated with lymphocyte counts among patients with low fT3, further highlighting the independent association between TSH and lymphocyte counts.…”

The Mysterious Universe of the TSH Receptor

“…This receptor has been found to be expressed on monocytes, dendritic cells, natural killer cells, T and B cells ( 32 ). Stimulation with recombinant human TSH has been shown to promote proliferation of natural killer cells, T and B cells ( 35 ). In dendritic cells, TSH stimulation was shown to lead to the production of pro-inflammatory cytokines and increased phagocytic activity ( 36 ).…”

“…• Thymic hyperplasia in Graves's Disease • Immune dysregulation in cancer (23,(33)(34)(35)(36) Red blood cells (protein)…”