Submitted to: Journal of Endocrinology and Reproduction
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/30/2007
Publication Date: 5/12/2008
Citation: Rath, N.C., Kannan, L., Liyanage, R., Lay, J.O. 2008. Thymosin beta in macrophages. Journal of Endocrinology and Reproduction. 11(2):1-7. Interpretive Summary: Thymosin is a small protein present in cells which controls the functions of another larger protein called actin. Actin is involved in cell movement, cell division and adherence of cells to tissues. We identified and isolated thymosin from a type of chicken blood cell called macrophages which are involved in killing and digesting bacteria and wound healing. This review deals with possible roles and scenarios where thymosin from macrophages is involved to maintain health and prevent aggravation of inflammation.
Technical Abstract: Thymosin, originally discovered as a thymic hormone regulating maturation of T cells, is found in many hematopoetic and non hematopoetic tissues including bone marrow, spleen, and lungs. While studying chicken monocyte- and granulocyte- associated peptides by Matrix Assisted Laser Desorption Ionization/Time-of-Flight (MALDI-TOF) mass spectrometry, we found a peptide corresponding to mass/charge ratio (m/z) of 4963. This peptide was prominently associated with monocytes but not with the granulocyte population. Further experiments showed a similar presence of this peptide in chicken macrophage cell lines. We purified the 4963Da peptide from the macrophages by reverse phase HPLC and identified it as thymosin B4 (TB4) by peptide mass fingerprinting. TB4 binds to B-actin, and regulates its polymerization which is essential for cell motility. Besides, it is also involved in multitude of other functions regulating immunity and wound healing. This review surveys the physiological significance of TB4 in relation to macrophage function.