Expansion of CD4+ CD25+ FoxP3+ regulatory T cells in chronic hepatitis C virus infection.
BACKGROUND
Regulatory T cells (Tregs) have been involved in impaired immunity and may have a pivotal role in persistence of viral infections.


OBJECTIVE
To develop a simple and reliable in-house three color flow cytometery of peripheral blood to understand the role of HCV infection in the increase of Tregs.


METHODS
The level of naturally occurring CD4+ CD25+ FoxP3+ regulatory T cells (nTregs) in 20 chronically infected with hepatitis C virus (HCV) patients was compared to those of 15 healthy individuals by flowcytometry. In a different approach we performed permeabilization and intracellular staining before surface staining which allows the preservation of the surface molecules in the combined detection process and results in the normal frequency of nTregs in blood.


RESULTS
Using the optimized method, it was shown that a significantly higher proportion of nTregs in the total CD4+ T cell population was seen in the peripheral blood of chronic HCV patients (0.83 ± 0.21%, p=0.05) as compared to controls (0.26 ± 0.1, p=0.05).


CONCLUSIONS
In accordance with other studies, we showed that HCV infection induces a dramatic increase in Tregs, which might contribute to the immune response failure during HCV infection.
Hashempoor
Tayebeh
T
Department of Virology, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran, e-mail: Bamdad_T@modares.ac.ir.
Bamdad
Taravat
T
Merat
Shahin
S
Janzamin
Ehsan
E
Nemati
Leila
L
Jabbari
Hossain
H
Sharifi
Amir-Houshang
AH
Zamini
Hediyeh
H
D000328:Adult; D015704:CD4 Antigens / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D019698:Hepatitis C, Chronic / Q000276:immunology* / Q000378:metabolism / Q000821:virology; D006801:Humans; D016130:Immunophenotyping; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D019562:Viral Load
D015704:CD4 Antigens; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit