Naslov
Expression of a membrane form of regeneration and tolerance factor by human T cell line jurkat

Autori
Gudelj, Lea ; Rukavina, Daniel ; Beaman, Kenneth D.

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

Izvornik
Periodicum Biologorum / Vitale, Branko - Zagreb : Hrvatsko prirodoslovno društvo, 1998

Skup
Fourth International Meeting "Mechanisms in Local Immunity" and joint meeting Fourth Meeting of Alps Adria Society for Immunology of Reproduction (AASIR)

Mjesto i datum
Opatija, Hrvatska, 16.09.1998. - 19.09.1998

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Pregnancy; Regulation and Tolerance Factor; TJ6; T cells

Sažetak
Regeneration and tolerance factor (RTF) is a novel protein encoded by TJ6 gene. It is expressed in two forms - a membrane bound carboxyl terminal form (RTFm), and a soluble amino terminal form (RTFs), the latter being formed by proteolytic cleavage of the nascent molecule. It is expressed in mouse thymus, spleen and in high levels in the placenta and blastocyst. The treatment of mice with a RTF-binding antibody at the time of implantation caused almost complete ablation of pregnancies, a result that indicates pivotal role of RTF in the generation of peripheral tolerance towards semiallogeneic conceptus. The experiments presented here investigated the expression of RTF on human T cell line Jurkat. Jurkat T cells expressed measurable, although variable levels of RTF. The expression was detected by flow cytometric analysis of cells labelled with anti-RTFm and anti-RTFs monoclonal antibodies (mAb). It could not be enhanced by polyclonal mitogens, trophoblast and colorectal tumor cell lines, and their respective culture supernatants. Increase of RTFm expression was observed after PHA stimulation. The modes of activation of Jurkat T cells that directed them towards apoptosis, treatment with immobilised anti-CD3 mAb in combination with PMA, and with anti-CD95 mAb, caused a significant increase in RTFm expression. The percentage of cells undergoing apoptosis was determined by Annexin V labelling. Interestingly, after the apoptosis-causing treatment, cells were no longer positive for anti-RTFs mAb. When their culture supernatants where checked for presence of RTFs by sandwich ELISA, we could indeed show the presence of RTFs in the culture supernatants of Jurkat T cells that were induced to apoptose. The same culture supernatants were added during the two hours incubation in the flow cytometry NK-assay. Peripheral blood lymphocytes were used as effector, and K562 cell line as target cells. NK activity of peripheral blood lymphocytes was significantly reduced by the action of RTFs-containing Jurkat T cell culture supernatant. The increase of expression and secretion of RTF by Jurkat T cells during activation-induced apoptosis may play an important role in the control of NK activity. This seems to be of particular importance at the feto-placental level, where abundant cells with cytolytic potential are accumulated in early pregnancy.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

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