Abstract: Objective To analyze the relationships between CD4⁺CD25⁺Foxp3⁺ regulatory T cells(Treg) or non-CD4⁺CD25⁺Foxp3⁺ regulatory T cells(non-Treg) and disease progression in Chinese HIV-infected individuals,and thereby to investigate the role of Treg in the process of HIV-1-infection.Methods Seventy-six HIV-infected adult patients were enrolled in this study.According to their CD4⁺ T cell counts in peripheral blood,patients were divided into Group A(CD4<200/μL),Group B(CD4 200～400/μL) and Group C(CD4>400/μL),respectively.The CD4⁺CD25⁺Foxp3⁺ regulatory T cells were examined with intracellular staining flow cytometric technique.The relationship between CD4⁺ T cells counts and the plasma HIV-1 viral load was analyzed.Results With the progression of disease the percentages of Treg cells were raised gradually,and this reached statistical significance;compared with the healthy control,both the absolute counts of Treg cells and non-Treg cells decreased significantly in HIV-infected individuals and mainly in the non-Treg cells.Furthermore,the absolute numbers of Treg cells were inversely correlated with plasma HIV-1 RNA viral load(r=-0.334,P<0.05).Conclusion With disease progression in Chinese HIV-1-infected patients,the reduction in the frequency of non-Treg cells,such as helper T cells(Th),dampened the immune protection,while the diminished frequency and function of Treg cells decreased the inhibition of the excessive immune activation,which may favor viral replication and drive HIV disease progression.

Key words: CD4⁺ regulatory T cells(Treg), human immunodeficiency virus(HIV), HIV virus load