Document Detail


Inverse association of repressor growth factor independent-1 with CD8 T cell interleukin (IL)-7 receptor [alpha] expression and limited signal transducers and activators of transcription signaling in response to IL-7 among [gamma]-chain cytokines in HIV patients.
MedLine Citation:
PMID:  19579270     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: CD8 T lymphocytes from chronically infected HIV-positive patients degenerate into a preapoptotic state and exhibit impaired functionality. Particularly in viremic patients, this was associated with an increased proportion of interleukin-7 receptor-alpha low-expressing (IL-7Ralpha(low)) effector-like CD8 T cells. As cytokine signaling through signal transducers and activators of transcription (STAT) is essential for cellular function, we hypothesized that activation of this pathway may be impaired in these cells. OBJECTIVES: To evaluate cytokine-induced STAT activation in IL-7Ralpha(low) and IL-7Ralpha(high) CD8 T cells from chronically infected HIV-positive patients and investigate the potential molecular mechanism involved in the reduced IL-7Ralpha expression. METHODS: CD8 T cells from HIV-positive patients on and off antiretroviral therapy were assayed respectively for STAT activation, cytokine receptor, and transcription factor expression by flow cytometry and real-time PCR. RESULTS: IL-7 stimulation failed to activate STAT5 in a substantial proportion of patient CD8 T cells. This correlated with reduced IL-7Ralpha mRNA and surface protein expression. Interestingly, IL-7Ralpha(low) cells appeared to be fully capable of recruiting the STAT pathway in response to IL-2, IL-4, IL-10, and IL-15. mRNA expression suggested a potential role for growth factor independent (Gfi)-1 as an IL-7Ralpha transcriptional repressor, but not that of other transcriptional regulators studied, including Gfi-1B and GA-binding protein alpha. Programmed death-1 inhibitory receptor, though upregulated in CD8 T cells from HIV-positive patients, appeared unrelated to IL-7Ralpha expression and STAT signaling capacity.
Authors:
Anita Benoit; Khaled Abdkader; Danylo Sirskyj; Abdulkarim Alhetheel; Nadia Sant; Francisco Diaz-Mitoma; Ashok Kumar; Marko Kryworuchko
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  AIDS (London, England)     Volume:  23     ISSN:  1473-5571     ISO Abbreviation:  AIDS     Publication Date:  2009 Jul 
Date Detail:
Created Date:  2009-07-02     Completed Date:  2009-12-14     Revised Date:  2010-02-04    
Medline Journal Info:
Nlm Unique ID:  8710219     Medline TA:  AIDS     Country:  England    
Other Details:
Languages:  eng     Pagination:  1341-7     Citation Subset:  IM; X    
Affiliation:
Infectious Disease and Vaccine Research Centre, Children's Hospital of Eastern Ontario - Research Institute, Ottawa, Canada.
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MeSH Terms
Descriptor/Qualifier:
CD8-Positive T-Lymphocytes / immunology*
Cytokines / genetics,  immunology*
HIV Infections / genetics,  immunology*
Humans
Receptors, Cytokine / genetics,  immunology*
Signal Transduction / genetics,  immunology*
Transcription, Genetic
Chemical
Reg. No./Substance:
0/Cytokines; 0/Receptors, Cytokine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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