Expression of growth hormone receptors by lymphocyte subpopulations in the human tonsil

Area of Science:

• Immunology
• Endocrinology
• Cell Biology

Background:

• The immune system's response can be influenced by hormones.
• Growth hormone (GH) plays a critical role in various physiological processes.
• Understanding GH interaction with immune cells is crucial for neuroendocrine-immune axis research.

Purpose of the Study:

• To investigate the expression of the growth hormone receptor (hGH-N-R) on human tonsillar lymphoid cells.
• To determine how receptor expression differs across various immune cell subsets and activation states.

Main Methods:

• Flow cytometry was employed to analyze hGH-N-R expression.
• FITC-coupled recombinant human growth hormone (hGH-N) was used as a probe.
• Phenotype markers were utilized in conjunction with hGH-N to identify specific lymphoid cell populations.

Main Results:

• Tonsillar B cells constitutively express hGH-N-R, unlike T cells.
• Receptor expression is higher on activated lymphoid cells compared to quiescent cells.
• Activated T cells express hGH-N-R, but germinal center CD4+ CD57+ T cells do not.
• B cell populations within lymph follicles show varying hGH-N-R density, with lower expression on dividing dark-zone cells.

Conclusions:

• Lymphoid cell populations exhibit distinct patterns of hGH-N-R expression, influenced by activation status.
• This differential expression underscores the intricate connection between the neuroendocrine system and immune defense mechanisms.