| Autor: |
Kierszenbaum F; Department of Microbiology, Michigan State University, East Lansing 48824-1101, USA., Majumder S, Mejia Lopez H, Sztein MB |
| Jazyk: |
angličtina |
| Zdroj: |
Parasite immunology [Parasite Immunol] 1995 Apr; Vol. 17 (4), pp. 197-205. |
| DOI: |
10.1111/j.1365-3024.1995.tb00889.x |
| Abstrakt: |
Mitogen-activated lymphocytes co-cultured with either purified Trypanosoma cruzi trypomastigotes or the filtrate of trypomastigote suspensions in culture medium manifest a significant decrease in their capacities to express p55 interleukin-2 receptor molecules (p55IL-2R) on their membrane and proliferate. In this study we found that the cytoplasmic levels of p55IL-2R are also markedly reduced under these conditions. This inhibition appeared to result from altered gene transcription since the levels of p55IL-2R mRNA in phytohaemagglutinin (PHA)-stimulated human peripheral blood mononuclear cells (PBMC) dropped substantially in the presence of parasite suspension filtrate. The rates of decay for p55IL-2R mRNA determined in cultures lacking and containing the parasite filtrate after addition of actinomycin D to inhibit further RNA synthesis were comparable. These results indicated that decreased p55IL-2R mRNA was not due to decreased stability of this mRNA under our conditions and pointed to a transcriptional or pre-transcriptional modification as the likely mechanism by which T. cruzi affects activated lymphocytes. The parasite filtrate did not appear to affect transcription of c-fos or c-myc (known to occur in the very early stages of lymphocyte activation) or that of CD69 (which is concomitant with p55IL-2R transcription). Thus, decreased p55IL-2R gene transcription appears to be a somewhat selective effect of a T. cruzi-derived molecule(s) rather than the consequence of an overall shutdown of gene transcription. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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