Immunohistochemical evidences showing the presence of thymulin containing cells located in involuted thymus and in peripheral lymphoid organs

Abstract

Thymulin is a well-characterized thymic hormone that exists as a nonapeptide coupled to equimolar amounts of Zn 2+ . Thymulin is known to have multiple biological roles, including T cell differentiation, immune regulation, and analgesic functions. It has been shown that thymulin is produced by the reticulo-epithelial cells of the thymus, and it circulates in the blood from the moment of birth, maintain its serum level until puberty diminishing thereafter in life. To study the localization of this hormone, we prepared polyclonal and monoclonal antibodies against the commercial peptide and utilized immunocytochemical techniques for visualization. The results indicate that thymulin stains the thymic reticular cells, the outer layers of Hassall´s corpuscles and a large round cellular type, which is keratin-negative and does not show affinity for the common leukocyte antigen (CD-45). In mice, this thymulin-positive cell remains in the thymus throughout life and even appears in relatively increased numbers in old involuted thymi. It also appears in thymusdependent areas of the spleen and lymph nodes, demonstrating that at least one of the thymus cells containing this peptide can be found in peripheral lymphoid tissue.

High-throughput ultra high performance liquid chromatography combined with mass spectrometry approach for the rapid analysis and characterization of multiple constituents of the fruit ofAcanthopanax senticosus(Rupr. et Maxim.) Harms

“…The central immunological organs including thymus and peripheral lymphoid organs including spleen all play an important role in the immune system . The differentiation, nature, and store of T lymphocyte was found in these immune organs.…”

Thymic Peptides Differentially Modulate Human Hair Follicle Growth

“…PTMA is involved in many cellular processes such as apoptosis, chromatin remodeling, and transcriptional regulation (reviewed in Hannappel and Huff (2003)); Supplementary Information S1 online). TYL has been claimed to be thymus specific, although TYL immunoreactivity has also been reported in murine epidermis and skin appendages (Kato et al, 1981) and in murine spleen (Folch et al, 2010). Interactions between TYL and the neuroendocrine system have been reported to lead to a release of prolactin, thyrotropin, and ACTH (Hadley et al, 1997;Brown et al, 1998).…”

“…Despite their historical name, most thymic peptides (TPs), such as thymosin b4 (TB4), prothymosin alpha (PTMA), and thymulin (TYL), are much more widely distributed than in the thymic epithelium where they were first identified (Kato et al, 1981;Moll et al, 1996;Folch et al, 2010; Supplementary Information S1 online).…”