%0 Journal Article
%T Peptides Regulate Cortical Thymocytes Differentiation, Proliferation, and Apoptosis
%A V. Kh. Khavinson
%A V. O. Polyakova
%A N. S. Linkova
%A A. V. Dudkov
%A I. M. Kvetnoy
%J Journal of Amino Acids
%D 2011
%I Hindawi Publishing Corporation
%R 10.4061/2011/517137
%X The processes of differentiation, proliferation, and apoptosis were studied in a cell culture of human cortical thymocytes under the influence of short peptides T-32 (Glu-Asp-Ala) and T-38 (Lys-Glu-Asp). Peptides T-32 and T-38 amplified cortical thymocytes differentiation towards regulatory T cells, increased their proliferative activity, and decreased the level of apoptosis. Moreover, peptides under study stimulated proliferative and antiapoptotic activity of the mature regulatory T cells. 1. Introduction Being a major organ of the immune system, thymus plays a key role in the T cell immunity formation [1, 2]. An overt lowering of thymus functional activity in humans can be traced from the beginning of puberty and is associated with an early involution of this organ [3, 4]. Thymus involution is largely manifested by the reduced count of cortical thymocytes and mature T cells [1, 5]. Age-related reduction of thymus functional activity is a main cause of immunodeficiency, allergic reactions, respiratory infections, and other pathologies associated with a malfunction of the immune system [6, 7]. Therefore, the search of drugs able to revitalize thymus activity in its involution stage is one of the goals of immunology and gerontology [8¨C10]. The aim of the study has been to estimate the impact of the synthetic peptides on the differentiation of cortical thymocytes and mature T cells. 2. Materials and Methods The cultures of human embryo thymus cells (14¨C26 weeks of gestation) were subject to investigation. They were studied in the following stages of their differentiation: immature cortical cells (CD4+CD8+) and mature regulatory T lymphocytes (CD4+CD25+). Culture samples were obtained from the Laboratory of Cell Immunology of the Institute of the Federal Medical and Biological Agency. 4 control, and 12 experimental samples were incubated with synthetic peptides T-32 (Glu-Asp-Ala) and T-38 (Lys-Glu-Asp) at a single dose of 200£¿ng/mL for an hour at the temperature of 37¡ãC. The above peptides were designed at the Saint-Petersburg Institute of Bioregulation and Gerontology of the Russian Academy of Medical Sciences (Russia). They were synthesized on the basis of amino acid sequences found in polypeptide extracts from the cattle thymus and vessels. It was previously determined that peptides T-32 and T-38 facilitated the expression of differentiation markers of thymes epithelial cells¡ªproteins Pax1, Hoxa3, and TLP in cell culture. This effect was more pronounced in old cultures (8 passages) than in young cultures (1 passage) [11].Apart from that, the influence
%U http://www.hindawi.com/journals/jaa/2011/517137/