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Preparation and Use of HIV-1 Infected Primary CD4+ T-Cells as Target Cells in Natural Killer Cell Cytotoxic Assays
Published on: March 14, 2011
Early changes in natural killer cell function indicate virologic response to interferon therapy for hepatitis C
Golo Ahlenstiel1, Birgit Edlich, Leah J Hogdal
1Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, USA.
Gastroenterology
|July 12, 2011
Summary
Natural killer (NK) cells are activated by interferon (IFN) treatment early on, showing increased cytotoxic function that correlates with viral clearance in hepatitis C virus (HCV) patients. This suggests NK cells play a key role in the innate immune response to HCV infection.
Area of Science:
- Immunology
- Virology
- Hepatology
Background:
- Mathematical models suggest cellular immunity aids interferon (IFN) in clearing hepatitis C virus (HCV).
- Natural killer (NK) cells are a key component of the innate immune system and their role in HCV clearance was investigated.
Purpose of the Study:
- To investigate the role of natural killer (NK) cells in interferon-alfa and ribavirin treatment response in hepatitis C virus (HCV) patients.
- To analyze the phenotype and function of NK cells during the early phase of antiviral therapy.
Main Methods:
- Blood and liver NK cells were analyzed for phenotype and function during the first 12 weeks of pegylated IFN-alfa and ribavirin treatment.
- NK cell activation markers, cytotoxicity (degranulation, TNF-related apoptosis-inducing ligand production), and IFN-γ production were measured.
- Changes in NK cell populations and function were correlated with early virological response and viral load dynamics.
Main Results:
- Early virological responders showed rapid NK cell activation within hours of treatment initiation, with increased expression of activating receptors and decreased inhibitory receptors.
- NK cell cytotoxicity peaked at 24 hours, correlating with initial viral load decrease and increased alanine aminotransferase levels.
- Liver NK cells showed increased cytotoxic CD16+ populations and TNF-related apoptosis-inducing ligand production, while peripheral blood NK cell degranulation correlated with viral load reduction.
Conclusions:
- Interferon (IFN) treatment rapidly activates NK cells, particularly enhancing their cytotoxic function.
- Induced NK cell cytotoxicity correlates significantly with virologic response to IFN-α-based therapy.
- NK cell activation serves as an indicator of responsiveness to IFN-α treatment, highlighting the innate immune system's role in HCV clearance.
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