Back to Search
Start Over
CD4+ T cells apoptosis in Plasmodium vivax infection is mediated by activation of both intrinsic and extrinsic pathways.
- Source :
-
Malaria journal [Malar J] 2015 Jan 05; Vol. 14, pp. 5. Date of Electronic Publication: 2015 Jan 05. - Publication Year :
- 2015
-
Abstract
- Background: Reduction in the number of circulating blood lymphocytes (lymphocytopaenia) has been reported during clinical episodes of malaria and is normalized after treatment with anti-malaria drugs. While this phenomenon is well established in malaria infection, the underlying mechanisms are still not fully elucidated. In the present study, the occurrence of apoptosis and its pathways in CD4+ T cells was investigated in naturally Plasmodium vivax-infected individuals from a Brazilian endemic area (Porto Velho - RO).<br />Methods: Blood samples were collected from P. vivax-infected individuals and healthy donors. The apoptosis was characterized by cell staining with Annexin V/FITC and propidium iodide and the apoptosis-associated gene expression profile was carried out using RT2 Profiler PCR Array-Human Apoptosis. The plasma TNF level was determined by ELISA. The unpaired t-test or Mann-Whitney test was applied according to the data distribution.<br />Results: Plasmodium vivax-infected individuals present low number of leukocytes and lymphocytes with a higher percentage of CD4+ T cells in early and/or late apoptosis. Increased gene expression was observed for TNFRSF1B and Bid, associated with a reduction of Bcl-2, in individuals with P. vivax malaria. Furthermore, these individuals showed increased plasma levels of TNF compared to malaria-naive donors.<br />Conclusions: The results of the present study suggest that P. vivax infection induces apoptosis of CD4+ T cells mediated by two types of signaling: by activation of the TNFR1 death receptor (extrinsic pathway), which is amplified by Bid, and by decreased expression of the anti-apoptotic protein Bcl-2 (intrinsic pathway). The T lymphocytes apoptosis could reflect a strategy of immune evasion triggered by the parasite, enabling their persistence but also limiting the occurrence of immunopathology.
- Subjects :
- Adult
Brazil
Cytological Techniques
Female
Gene Expression Profiling
Humans
Male
Middle Aged
Signal Transduction
Young Adult
Apoptosis
CD4-Positive T-Lymphocytes physiology
Host-Pathogen Interactions
Malaria, Vivax immunology
Proto-Oncogene Proteins c-bcl-2 biosynthesis
Receptors, Tumor Necrosis Factor, Type I biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 1475-2875
- Volume :
- 14
- Database :
- MEDLINE
- Journal :
- Malaria journal
- Publication Type :
- Academic Journal
- Accession number :
- 25559491
- Full Text :
- https://doi.org/10.1186/1475-2875-14-5