Autor: |
Carsten Gründemann, Kathrin Thell, Karin Lengen, Manuel Garcia-Käufer, Yen-Hua Huang, Roman Huber, David J Craik, Gernot Schabbauer, Christian W Gruber |
Jazyk: |
angličtina |
Rok vydání: |
2013 |
Předmět: |
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Zdroj: |
PLoS ONE, Vol 8, Iss 6, p e68016 (2013) |
Druh dokumentu: |
article |
ISSN: |
1932-6203 |
DOI: |
10.1371/journal.pone.0068016 |
Popis: |
Cyclotides are a diverse and abundant group of ribosomally synthesized plant peptides containing a unique cyclic cystine-knotted topology that confers them with remarkable stability. Kalata B1, a representative member of this family of mini-proteins, has been found to inhibit the proliferation of human peripheral blood mononuclear cells. Analysis of T-cell proliferation upon treatment with chemically synthesized kalata B1 mutants revealed a region comprising inter-cysteine loops 1 and 2 of the cyclotide framework to be important for biological activity. Cytokine signaling analysis using an 'active' kalata B1 mutant [T20K], and the reference drug cyclosporin A (CsA) demonstrated that treatment of activated T-lymphocytes with these compounds decreased the expression of the interleukin-2 (IL-2) surface receptor as well as IL-2 cytokine secretion and IL-2 gene expression, whereas the 'inactive' kalata B1 mutant [V10K] did not cause any effects. The anti-proliferative activity of [T20K] kalata B1 was antagonized by addition of exogenous IL-2. Furthermore, treatment with [T20K] kalata B1 led to an initial reduction of the effector function, as indicated by the reduced IFN-γ and TNF-α production, but the levels of both cytokines stabilized over time and returned to their normal levels. On the other hand, the degranulation activity remained reduced. This indicated that cyclotides interfere with T-cell polyfunctionality and arrest the proliferation of immune-competent cells through inhibiting IL-2 biology at more than one site. The results open new avenues to utilize native and synthetically-optimized cyclotides for applications in immune-related disorders and as immunosuppressant peptides. |
Databáze: |
Directory of Open Access Journals |
Externí odkaz: |
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