Naslov
Modulatory effects of SMS 201-995 on T cell-growth

Autori
Trobonjača, Zlatko ; Radošević-Stašić, Biserka ; Rukavina, Daniel

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Periodicum Biologorum 100 (1998), suppl. 3 / Vitale, Branko - Zagreb : Hrvatsko prirodoslovno društvo, 1998, 62-62

Skup
Fourth international meeting "Mechanisms in local immunity" and Fourth meeting of Alps Adria society for immunology of reproduction

Mjesto i datum
Opatija, Hrvatska, 16.09.1998. - 19.09.1998

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
somatostatin; apoptosis; thymus; dexamethasone

Sažetak
The crucial step for the T-cell development is formation of thymocytes of diverse TCR specificity, which signals for CD4 and CD8 expression, and regulates the processes of negative and positive selection of T cells. Negative selection removes those T cells whose receptors recognize the complex of self MHC molecules with self peptide or those T cells which receive the complete activating signals from self peptide, preventing thus the formation of autoreactive T cells clones. Processes are strictly dependent of thymic stroma, which makes a unique microenvironment of for the proper T cell development. Expression of mRNA for several hormones on thymus "nurse" epithelial cells, as well as, hormonal receptors on thymocytes and medullar stromal cells imply the existence of endocrine and local paracrine control of thymocyte maturation. In this work, therefore, we investigated the influences of somatostatin analogue SMS 201-995 on: 1) apoptosis induced in vivo and in vitro by anti-CD3 antibodies or by dexamethasone, 2) on the maturation process of normal thymocytes in vitro and 3) on the growth of Yac-1, T-cells line in vitro. For this purpose the phenotypic analysis of CD4/8, TCR, CD54 and CD44 marker expression, as well as, nucleic fragmentation of thymocytes were estimated 6, 18, 24, 36 and 72 hours after the treatment with anti-CD3 antibodies (2 mg/ml) or dexamethasone (1 mg/ml) in the presence of SMS (0,1 mg/ml). Thymocyte phenotype was determined by direct and indirect immunofluorescence technique. Percentage of apoptotic cells was calculated by cell cycle analysis on the flow cytometer in the region of "sub-G1" peak, while apoptotic DNA degradation was proved by gel electrophoresis technique. The data have shown that SMS may downregulate the apoptotic process, induced by anti-CD3 antibodies, but did not affect the dexamethasone-induced cell death. SMS changed also the phenotype of nonapoptotic cells, indicating its influence on T cell maturation.

Izvorni jezik
Engleski

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