Activation and coreceptor expression of T lymphocytes induced by highly active antiretroviral therapy in Chinese HIV/AIDS patients:

Serological surveillance for Penicillium marneffei infection in HIV-infected patients during 2004-2011 in Guangzhou, China

Prevalence of disseminated Penicillium marneffei infection is not known in human immunodeficiency virus (HIV)-infected patients. This retrospective study aimed to evaluate the prevalence of and risk factors for disseminated P. marneffei infection in HIV-infected patients during 2004-11 in Guangzhou, China. We tested 8131 archived HIV-infected patient serum samples for P. marneffei-specific mannoprotein (Mp1p) antigen using a highly sensitive and specific ELISA that we previously established. The CD4 count of 2686 cases was determined by flow cytometry. Logistic regression was used to assess predictors of Mp1p antigenaemia. The overall prevalence of disseminated penicilliosis as detected by positive serum Mp1p antigen was 9.36% (761/8131), in good concordance with Platelia™ Aspergillus immunoassay. During 2004-11, the prevalence increased to a peak of 12.58% (158/1256) in 2010 and decreased in 2011. Penicilliosis was strongly associated with progression from HIV to AIDS (OR 4.66, 95% CI 3.94-5.51, p <0.001) and humidity (OR 1.02, 95% CI 1.01-1.03, p 0.002). Disseminated penicilliosis occurred mainly during the rainy seasons (p <0.001). For 2686 cases with known CD4 count, logistic regression showed that CD4 count of <200 cells/μL was a risk factor for penicilliosis (OR 2.90, 95% CI 1.10-7.66, p 0.032), especially when it was <50 cells/μL (OR 24.26, 95% CI 10.63-55.36, p <0.001) during which 28.06% of patients developed disseminated penicilliosis. In conclusion, approximately 9.36% of the HIV-infected patients in our study developed disseminated penicilliosis. Rapid diagnosis may be achieved by performing serological surveillance for Mp1p antigenaemia as a routine procedure for all HIV-infected patients with CD4 count of <50 cells/μL.

Immune activation and viral replication after vaccination with an influenza A H1N1 2009 vaccine in HIV-infected children receiving antiretroviral therapy

Immunization with a pandemic influenza A H1N1 2009 was recommended for HIV-infected patients. However, there is limited information concerning the impact of immunization with this vaccine on immune activation and HIV viral replication. In this study, 45 HIV-infected children and adolescents receiving antiretroviral therapy were immunized with a 2-dose series of nonadjuvated monovalent influenza A H1N1 2009 vaccine upon enrollment and approximately 1 month later. Immunogenicity was determined by haemagglutination inhibition assay. The level of immune activation was determined by identification of CD38 and HLA-DR on CD8+ T cells. Patients were divided into 2 groups which include patients who had an undetectable HIV viral load (HIV detectable group) and patients who show virological failure (HIV nondetectable group). The results showed seroconversion rate of 55.2% in HIV nondetectable group, whereas 31.3% was found in HIV detectable group. Both groups of patients showed no major increase in immune activation after immunization. Interestingly, a decrease in the frequency of CD8+ T cells that coexpressed CD38 and HLA-DR was observed after immunization in both groups of patients. We suggested that immunization with influenza A H1N1 2009 vaccine can induce immune response to the pandemic virus without major impact on HIV viral replication and immune activation.

T Cell Activation and Cytokine Profile of Tuberculosis and HIV-Positive Individuals during Antituberculous Treatment and Efavirenz-Based Regimens

Introduction

The profile of immune activation markers in tuberculosis and HIV-infected patients is already known. The impact of simultaneous infections on the immune parameters is still not fully explored.

Methods

We conducted a prospective study to estimate trajectories of activated T cell subsets and the profile of anti- and pro-inflammatory cytokines in a group of HIV-TB individuals, previously naïve for HAART, recruited from a randomized clinical trial during TB treatment and first antiretroviral therapy with efavirenz. Patients were evaluated according to the immunosuppression levels at baseline as group 1 (CD4<200 cells/mm³) and group 2 (CD4>200 cells/mm³). These parameters were measured at the time of HAART initiation (started about 30 days after the onset of TB treatment) and at the follow-up visits after 30, 60, 90 and 180 days. Trajectories were estimated using least squares estimates of the coefficients of a restricted cubic spline function in time after adjusting for subject effects, bootstrapping it 500 times.

Results

Increase of CD4 T cell counts and suppression of HIV viral load were observed for all patients under HAART and TB treatment. Descendent trajectories were observed for the activated CD8⁺/CD38⁺ and CD3⁺/HLA-DR⁺ T cell subsets, and for plasma concentration of gamma- interferon (IFN-γ). Except for TNF-α and IL-2 discrete variations were observed for the other cytokines. Differences in the trajectories of these parameters were observed for groups 1 and 2. Higher values of IFN-γ, IL-2, IL-6 and IL-10 were observed for group 1 from the baseline to two months after treatment initiation, whereas reduced levels of TNF-α were observed for this group between 60 and 120 days of HAART.

Conclusion

Independent of the immunosuppression profile at baseline, HIV-TB patients under HAART were able to recover the CD4⁺ T cell counts, and control viral replication and immune activation parameters over time.

Short-term antiretroviral therapy fails to reduce the expanded activated CCR5-expressing CD4+ T lymphocyte population or to restore the depleted naive population in chronically HIV-infected individuals with active pulmonary tuberculosis

The effective role of antiretroviral (ARV) therapy in the regulation of CD4 T cell subset distribution, coreceptor expression, and activation status in individuals with chronic HIV also presenting with active pulmonary TB is not clearly understood. A cross-sectional analysis was performed on a total of 137 South African individuals. CCR5, CXCR4, and CD38 expression of CD4 T cell subsets in HIV-infected individuals with and without active pulmonary tuberculosis (TB) disease, pre- and post-ARV therapy, were determined by flow cytometry. In treatment-naive patients, CD4 T cells showed elevated surface expression of CCR5 and CD38 in TB/HIV coinfection as compared to HIV infection alone despite the overall percentage of CD4 T cells expressing CCR5 being reduced. Total CD38+ CD4 T cells were not significantly increased in either group; however, mean CD38 fluorescence was significantly higher in the context of TB infection. HIV/TB-coinfected individuals also displayed an increased percentage of activated (CD38+) CCR5+ CD4 T cells as compared to HIV patients alone. The naive CD4 T cell subset was depleted similarly in both HIV and HIV/TB groups. Only the HIV treatment group and not the TB-coinfected treatment group showed significantly decreased activated CCR5+ CD4 T cells, an increased percentage of naive T cells, and a decreased percentage of antigen-experienced T cells. This study highlighted an association of TB disease with immune activation, particularly of the CCR5+ CD4 T cell subset in HIV infection and the differential impact of ARV treatment. Further studies are needed to understand how TB coinfection confounds normal responses to ARV.

The activation and dynamics of cytokine expression by CD4+ T cells and AIDS progression in HIV-1-infected Chinese individuals

CD4(+) T cells are the main targets of HIV-1 and play a central role during the progression of AIDS, but the mechanism has not been clearly elucidated. In the present study, blood samples were collected from HIV-1-infected Chinese individuals, including typical progressors (TPs) and long-term nonprogressors (LTNPs). More HIV-1 productively infected CD4(+) T cells were obtained through co-cultures and the infected CD4(+) T cells were discriminated from bystander cells by intracellular p24 staining. The activation level and dynamics of cytokine expression of CD4(+) T cells were analyzed. After stimulating the freshly isolated PBMCs with PHA, the frequencies of CD69(+)CD4(+) T cells/CD25(+)CD4(+) T cells were higher in TP than in LTNP group and were positively correlated with viral load and negatively correlated with CD4(+) T cell counts. The activation level of CD4(+) T cells in the co-cultured PBMCs was higher in TP than in LTNP group, and HIV-1 productively infected CD4(+) T cells were more activated than bystander CD4(+) T cells. The expression of Th1 cytokines (IL-2 and IFN-γ) and the frequency of Th1 cells in co-cultured PBMCs were lower in TP than in LTNP group. HIV-1 productively infected CD4(+) T cells expressed higher level of Th1/Th2 cytokines than bystander cells. More productive HIV-1 infection occurred in Th1 than in Th2 cells, followed by Th0 cells. The present results suggest that the excessive activation level of CD4(+) T cells and the preferential replication of HIV-1 in Th1 cells that lead to the shift of Th1 to Th2 are likely crucial to AIDS progression in HIV-1-infected Chinese individuals.

Immune exhaustion occurs concomitantly with immune activation and decrease in regulatory T cells in viremic chronically HIV-1-infected patients

BACKGROUND

Chronic HIV-1 infection is associated with excessive immune activation and immune exhaustion. We investigated the relationship of these 2 phenotypes and frequency of regulatory T cells (Tregs) in controlled and uncontrolled chronic HIV-1 infection.

METHODS

Immune exhaustion marker PD-1, its ligand PD-L1, CD4CD25 FoxP3 Tregs, HLA-DR, and CD38 coexpression as activation markers were investigated in peripheral blood lymphocytes of 44 HIV-1-infected patients and 11 HIV-1-uninfected controls by multicolor flow cytometry.

RESULTS

Activated and PD-1 expressing T cells were increased, and Tregs were decreased in HIV-1-infected patients as compared with controls, and alterations were greatest in viremic patients. The proportion of activated CD8 T cells exceeded activated CD4 T cells. Tregs had an inverse correlation with activated T cells and PD-1 expressing T cells. PD-L1 was highly expressed on monocytes and to a lesser extent on T lymphocytes of patients. These abnormalities partially reversed with virologic control after potent antiretroviral therapy.

CONCLUSIONS

Immune exhaustion is a component of aberrant immune activation in chronic HIV-1 infection and is associated with loss of Tregs and ongoing virus replication. These defects are corrected partially with effective virologic control by potent antiretroviral therapy.