[Inhibition of CD4+ CD25+ regulatory T cells in chronic hepatitis B patients].
OBJECTIVE
To evaluate the inhibition of CD4+ CD25+ regulatory T cells (Treg) in the chronic hepatitis B patients.


METHODS
Peripheral blood samples were collected from 22 patients with chronic hepatitis B (CHB) and 18 healthy blood donors to isolate the peripheral blood mononuclear cells (PBMCs). Flow cytometry was used to analyze the proportion of CD4+ CD127(lo)CD25(hi-int) Tregs in the CD4+ T cells so as to calculate the proportion of CD4+ CD25+ Tregs in the CD4+ T cells. BrdU incorporation method was used to evaluate the immune inhibition of the CD4+ CD25+ Tregs. CD4+ CD25- cells were isolated by magnetic bead sorting technique. The CD4- T cells and CD4+ CD25- T cells ere mixed and stimulated by HBVcore 18-27 peptide. The PBMCs of the CHB patients with the Treg depleted and Treg not depleted underwent detection of HBVcore18-27 specific cytotoxic T lymphocytes (CTLs). The IFN-gamma secretion of the CTLs in the PBMCs of CHB patients with Treg depleted and Treg not depleted was detected by HLA-pentamer and enzyme-linked immunospot assay (Elispot).


RESULTS
The proportion of CD4+ CD127(lo)CD25(hi-int) Treg in the CD4+ T cells used to reflect the percentage of CD4+CD25+ Tregs in the CD4+ T cells of the CHB patients was 4.3% +/- 2.4%, significantly higher than that of the healthy controls (2.1% +/- 1.3%, t = 3.74, P <0.01). There was no significant difference in the inhibition of CD4+ CD25- T cells by autogenous CD4+ CD25+ T cells between the CHB patients and healthy controls. The frequency of CTLs induced by HBV core 18-27 of the CHB patients with their CD4+ CD25+ cells in circulation depleted was 0.74% +/- 0.31%, significantly higher than that of the patients whose CD4+ CD25+ cells in circulation were not depleted (0.17% +/- 0.08%, t = 4.75, P <0.01). The frequency of IFN-gamma secreting spots of HBVcore18-27-specific CD8+ T cells of the CHB patients with their CD4+ CD25+ cells depleted was (112 +/- 33), significantly higher than that of the CHB patients whose CD4+ CD25+ cells in circulation were not depleted [(23 +/- 14), t =7.828, P<0.01)].


CONCLUSIONS
The proportion of CD4+ CD25+ Treg in CHB patients is increased compared to the healthy blood donor. The proliferative capacity of CD4+ CD25- T cells is inhibited by the presence of CD4+ CD25+ Treg dose-dependently, and the inhibition of CD4+ CD25+ Tregs in the CHB patients is similar to the inhibition of CD4+ CD25+ Tregs in healthy donors. The elimination of Treg cells followed by stimulation with HBVcore18-27 peptide significantly improves the antivirus CTL responses in CHB patients.
Zhang
Heng-Hui
HH
Hepatology Institute, People's Hospital, Peking University, Beijing, China.
Guo
Fang
F
Fei
Ran
R
Ma
Hui
H
Cong
Xu
X
Wei
Lai
L
Chen
Hong-Song
HS
D000328:Adult; D001782:Blood Donors; D015704:CD4 Antigens / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D019694:Hepatitis B, Chronic / Q000097:blood / Q000276:immunology* / Q000473:pathology; D006801:Humans; D020382:Interleukin-18 / Q000097:blood; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology*
D015704:CD4 Antigens; D020382:Interleukin-18; D053645:Interleukin-2 Receptor alpha Subunit