Impact of inactivated vaccines on decrease of viral RNA levels in individuals with the SARS-CoV-2 Omicron (BA.2) variant: A retrospective cohort study in Shanghai, China.

Background: SARS-CoV-2 Omicron (BA.2) has stronger infectivity and more vaccine breakthrough capability than previous variants. Few studies have examined the impact of inactivated vaccines on the decrease of viral RNA levels in individuals with the Omicron variant, based on individuals' continuous daily cycle threshold (Ct) values and associated medical information from the infection to hospital discharge on a large population. Methods: We extracted 39,811 individuals from 174,371 Omicron-infected individuals according to data inclusion and exclusion criteria. We performed the survival data analysis and Generalized Estimating Equation to calculate the adjusted relative risk (aRR) to assess the effect of inactivated vaccines on the decrease of viral RNA levels. Results: Negative conversion was achieved in 54.7 and 94.3% of all infected individuals after one and 2 weeks, respectively. aRRs were shown weak effects on turning negative associated with vaccinations in asymptomatic infections and a little effect in mild diseases. Vaccinations had a protective effect on persistent positivity over 2 and 3 weeks. aRRs, attributed to full and booster vaccinations, were both around 0.7 and had no statistical significance in asymptomatic infections, but were both around 0.6 with statistical significance in mild diseases, respectively. Trends of viral RNA levels among vaccination groups were not significant in asymptomatic infections, but were significant between unvaccinated group and three vaccination groups in mild diseases. Conclusion: Inactivated vaccines accelerate the decrease of viral RNA levels in asymptomatic and mild Omicron-infected individuals. Vaccinated individuals have lower viral RNA levels, faster negative conversion, and fewer persisting positive proportions than unvaccinated individuals. The effects are more evident and significant in mild diseases than in asymptomatic infections.

Dynamics of disease characteristics and viral RNA decay in patients with asymptomatic and mild infections during the Omicron wave in Shanghai, China: A retrospective cohort study.

OBJECTIVES: Asymptomatic infections and mild diseases were more common during the Omicron outbreak in Shanghai, China in 2022. This study aimed to assess the characteristics and viral RNA decay between patients with asymptomatic and mild infections. METHODS: A total of 55,111 patients infected with SARS-CoV-2 who were quarantined in the National Exhibition & Convention Center (Shanghai) Fangcang shelter hospital within 3 days after diagnosis from April 9 to May 23, 2022 were enrolled. The kinetics of cycle threshold (Ct) values of reverse transcription-polymerase chain reaction were assessed. The influencing factors for disease progression and the risk factors for the viral RNA shedding time (VST) were investigated. RESULTS: On admission, 79.6% (43,852/55,111) of the cases were diagnosed with asymptomatic infections, and 20.4% were mild diseases. However, 78.0% of initially asymptomatic subjects developed mild diseases at the follow-up. The final proportion of asymptomatic infections was 17.5%. The median time of symptom onset, the duration of symptoms, and the VST were 2 days, 5 days, and 7 days, respectively. Female, age 19-40 years, underlying comorbidities with hypertension and diabetes, and vaccination were associated with higher risks of progressing to mildly symptomatic infections. In addition, mildly symptomatic infections were found to be associated with prolonged VST compared with asymptomatic infections. However, the kinetics of viral RNA decay and dynamics of Ct values were similar among asymptomatic subjects, patients with asymptomatic-to-mild infection, and patients with mild infection. CONCLUSION: A large proportion of initially diagnosed asymptomatic Omicron infections is in the presymptomatic stage. The Omicron infection has a much shorter incubation period and VST than previous variants. The infectivity of asymptomatic infections and mildly symptomatic infections with Omicron is similar.

A human immunodeficiency virus-seronegative acquired immunodeficiency syndrome patient with opportunistic infections: A case report.

BACKGROUND: In rare cases, people living with chronic human immunodeficiency virus (HIV) infection do not develop antibodies despite demonstrable infection. Delayed or missed diagnosis of HIV infection leads to a lack of timely therapy, resulting in rapid disease progression with opportunistic infections or malignancies. CASE REPORT: A 44-year-old Chinese man presented with sore throat, oral leukoplakia, fever, dyspnoea and diffuse ground glass-like lesions in both lungs. Serum cytomegalovirus DNA was detectable, and CD4+ T-cell count was low. The patient was suspected of being a person living with HIV despite of the repeatedly negative HIV antibody tests using enzyme-linked immunsorbent assay and Western blot. Subsequently, high-plasma HIV RNA viral load was found on two repeated tests, while HIV DNA was also positive. Thus, the patient was confirmed as presenting with HIV-seronegative acquired immunodeficiency syndrome (AIDS). The symptoms improved in response to effective anti-fungal and anti-retroviral therapy after diagnosis. CONCLUSION: This is the third reported case of an HIV-seronegative AIDS patient in China, which are also rarely reported globally. HIV nucleic acid testing is important to screen out HIV infection, especially in those who present with severe immunodeficiency but remain HIV serogenative.

Safety and efficacy of meplazumab in healthy volunteers and COVID-19 patients: a randomized phase 1 and an exploratory phase 2 trial.

Recent evidence suggests that CD147 serves as a novel receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Blocking CD147 via anti-CD147 antibody could suppress the in vitro SARS-CoV-2 replication. Meplazumab is a humanized anti-CD147 IgG2 monoclonal antibody, which may effectively prevent SARS-CoV-2 infection in coronavirus disease 2019 (COVID-19) patients. Here, we conducted a randomized, double-blinded, placebo-controlled phase 1 trial to evaluate the safety, tolerability, and pharmacokinetics of meplazumab in healthy subjects, and an open-labeled, concurrent controlled add-on exploratory phase 2 study to determine the efficacy in COVID-19 patients. In phase 1 study, 59 subjects were enrolled and assigned to eight cohorts, and no serious treatment-emergent adverse event (TEAE) or TEAE grade ≥3 was observed. The serum and peripheral blood Cmax and area under the curve showed non-linear pharmacokinetic characteristics. No obvious relation between the incidence or titer of positive anti-drug antibody and dosage was observed in each cohort. The biodistribution study indicated that meplazumab reached lung tissue and maintained >14 days stable with the lung tissue/cardiac blood-pool ratio ranging from 0.41 to 0.32. In the exploratory phase 2 study, 17 COVID-19 patients were enrolled, and 11 hospitalized patients were involved as concurrent control. The meplazumab treatment significantly improved the discharged (P = 0.005) and case severity (P = 0.021), and reduced the time to virus negative (P = 0.045) in comparison to the control group. These results show a sound safety and tolerance of meplazumab in healthy volunteers and suggest that meplazumab could accelerate the recovery of patients from COVID-19 pneumonia with a favorable safety profile.

Generation of Hutat2:Fc Knockin Primary Human Monocytes Using CRISPR/Cas9.

The ability of monocytes to travel through the bloodstream, traverse tissue barriers, and aggregate at disease sites endows these cells with the attractive potential to carry therapeutic genes into the nervous system. However, gene editing in primary human monocytes has long been a challenge. Here, we applied the CRISPR/Cas9 system to deliver the large functional Hutat2:Fc DNA fragment into the genome of primary monocytes to neutralize HIV-1 transactivator of transcription (Tat), an essential neurotoxic factor that causes HIV-associated neurocognitive disorder (HAND) in the nervous system. Following homology-directed repair (HDR), ∼10% of the primary human monocytes exhibited knockin of the Hutat2:Fc gene in the AAVS1 locus, the "safe harbor" locus of the human genome, without selection. Importantly, the release of Hutat2:Fc by these modified monocytes protected neurons from Tat-induced neurotoxicity, reduced HIV replication, and restored T cell homeostasis. Moreover, compared with lentiviral transfection, CRISPR-mediated knockin had the advantage of maintaining the migrating function of monocytes. These results establish CRISPR/Cas9-mediated Hutat2:Fc knockin monocytes and provide a potential method to cross the blood-brain barrier for HAND therapy.

The Significance of Type-I Interferons in the Pathogenesis and Therapy of Human Immunodeficiency Virus 1 Infection.

Type-I interferons (IFN-I) are a widely expressed family that could promote antivirus immunity in the process of pathogens invasion. In a human immunodeficiency virus 1 (HIV-1)-infected individual, the production of IFN-I can be detected as early as the acute phase and will persist throughout the course of infection. However, sustained stimulation of immune system by IFN-I also contributes greatly to host-mediated immunopathology and diseases progression. Although the protective effects of IFN-I in the acute phase of HIV-1 infection have been observed, more studies recently focus on their detrimental role in the chronic stage. Inhibition of IFN-I signaling may reverse HIV-1-induced immune hyperactivation and furthermore reduce HIV-1 reservoirs, which suggest this strategy may provide a potential way to enhance the therapeutic effect of antiretroviral therapy. Therefore, we review the role of IFN-I in HIV-1 progression, their effects on different immunocytes, and therapeutic prospects targeting the IFN-I system.

Response-guided peginterferon therapy in patients with HBeAg-positive chronic hepatitis B: A randomized controlled study.

BACKGROUND & AIMS: Response-guided therapy has been confirmed to be an effective strategy for the treatment of chronic hepatitis C in the pegylated interferon (PegIFN) era, but no randomized trial utilizing this strategy has been conducted in chronic hepatitis B. METHODS: In this open-label, multicenter, randomized trial, HBeAg positive patients were treated with PegIFN (180µg/week) for 24weeks. Early responders (HBsAg <1500IU/ml and HBV DNA <10(5)copies/ml at week 24) received PegIFN for a further 24weeks (arm A), while non-early responders were randomized to PegIFN for another 24weeks (arm B), another 72weeks (arm C) or PegIFN for another 72weeks plus adefovir for 36weeks (arm D). The primary endpoint was the change of quantitative HBsAg from baseline to the end of follow-up (EOF). RESULTS: For non-early responders, 96-week PegIFN monotherapy did not lead to a greater reduction of HBsAg from baseline to EOF, compared with 48-week PegIFN (-0.71 vs. -0.67log10IU/ml, P=0.407). The rate of HBeAg seroconversion with HBV DNA <2000IU/ml at EOF were similar for arms B, C and D (17.9%, 23.9% and 25.0% respectively). For patients with HBsAg <1500IU/ml or HBV DNA <10(5)copies/ml at week 24, 38.4% and 37.0% achieved HBeAg seroconversion with HBV DNA <2000IU/ml at EOF respectively. CONCLUSIONS: Patients with HBsAg <1500IU/ml or HBV DNA <10(5)copies/ml at week 24 would benefit from continued PegIFN treatment. Extending the duration of PegIFN with or without adding adefovir did not show superiority over 48weeks PegIFN monotherapy. LAY SUMMARY: Extending the duration of pegylated interferon (PegIFN) alfa-2a is not recommended in HBeAg positive patients as treatment extension beyond 48weeks did not show convincing benefit. Patients who achieved HBsAg <1500IU/ml or HBV DNA <10(5)copies/ml after 24-week PegIFNα-2a showed satisfactory outcome after the withdrawal of finite PegIFNα-2a treatment. CLINICAL TRIAL NUMBER: NCT01086085.

The Efficacy of Add-on Telbivudine Versus Switching to Pegylated Interferon Alfa-2a in Chronic Hepatitis B Patients With Poor Responses to Adefovir.

BACKGROUND: There are limited options for chronic hepatitis B (CHB) patients who have poor responses to adefovir (ADV). OBJECTIVES: The aim of this study is to evaluate the effects of adding on telbivudine (LdT) or switching to pegylated interferon alfa-2a (PEG-IFN-α2a) as alternative rescue therapies for patients with poor responses to the initial ADV treatments. PATIENTS AND METHODS: Ninety-seven CHB patients with HBV DNA > 2 log10 copies/mL 48 weeks after ADV monotherapy were included in this study. Fifty-nine of these patients were treated with a combination of LdT plus ADV (LdT + ADV) daily, while thirty-eight patients were switched to PEG-IFN-α2a subcutaneous injections weekly for 48 weeks. RESULTS: Both rescue strategies were proven to be safe and the majority of patients tolerated the therapies well. LdT + ADV led to more rapid reductions in viral loads than PEG-IFN-α2a monotherapy, with 2.14 (LdT + ADV) and 0.98 (PEG-IFN-α2a) log10 copies/mL decreases 48 weeks after rescue treatments, respectively (P < 0.00001). The rates corresponding to virological and biochemical responses were also elevated in patients who received the LdT + ADV combination therapy at the end of the observation period (88.1 vs. 68.4% for virological response, P = 0.017; 83.3 vs. 47.2%, P = 0.00045). However, the decline in the hepatitis B surface antigen (HBsAg) was more pronounced in PEG-IFN-α2a treated patients. Moreover, the cumulative rates of serological responses were higher in patients who switched to the PEG-IFN-α2a therapy. CONCLUSIONS: Both add-on LdT and switching to PEG-IFN-α2a were satisfactory and optimal treatments for CHB patients with poor responses to ADV. Both rescue strategies resulted in significant reductions in serum viral load and ALT levels, and were associated with high rate of serological outcomes in our hospital.

Analysis of HIV-1c-Specific CTL Responses with HIV-1 Reservoir Size and Forms.

Cytotoxic T lymphocytes (CTL) are critical in cellular immune responses; therefore the study of CTL responses is profound in HIV-1 eradication. We aim to dissect the relationship between HIV-1 reservoir size and the magnitude and recognition of viral-specific CTL responses. An IFN-γ ELISpot assay with peptides spanning the HIV-1 clade C consensus sequences were designed to analyze HIV-1c-specific CTL responses. HIV-1 DNA, integrated HIV-1 DNA, and 2-LTR HIV-1 DNA were quantitated by real-time PCR. We observed significant increases in total HIV-1 DNA and integrated HIV-1 DNA after highly active antiretroviral treatment (HAART) compared with naive patients. Total HIV-1 DNA had a significant negative correlation with HIV-1c-specific CTL response magnitude. Baseline CD4(+) T lymphocyte counts and antiretroviral treatment affected the size of the HIV-1 reservoirs. Taken together, HIV-1-specific CTL responses correlated with the size of HIV-1 reservoir. In addition, HIV-1-specific CTL response against p17 was associated with low integral efficiency of HIV-1, which might be a biomarker to evaluate the efficacy of HAART.

Genotypes and transmitted drug resistance among treatment-naive HIV-1-infected patients in a northwestern province, China: trends from 2003 to 2013.

BACKGROUND: Transmitted drug resistance (TDR) reduces the efficacy of initial antiretroviral treatment and has become a public health concern. Little information is available regarding the genetic diversity of HIV-1 and the prevalence of TDR among treatment-naïve patients in a northwestern province of China since the implementation of national free antiretroviral therapy (ART). METHODS: Blood samples from 372 HIV-1 treatment-naive patients were collected between 2003 and 2013 in Shaanxi province. Viral RNA was extracted for nested PCR, and phylogenetic reconstruction and recombination analyses were performed to characterize patterns of the HIV-1 subtypes. Genotypic drug resistance testing was performed using an in-house assay to determine trends in the prevalence of HIV-1 transmitted drug resistance. RESULTS: Multiple genotypes were identified among the patients in Shaanxi, including B (25.0%), C (0.3%), G (0.3%), and CRF01_AE (39.2%), CRF07_BC (32.7%), CRF08_BC (0.8%), CRF55_01B (1.1%), and URFs (0.6%). The subtypes were associated with the transmission routes (χ2 = 77.113, p < 0.01). In this study, a low baseline CD4+ T cell count and a high viral load were found among CRF01_AE-infected patients compared with patients who were infected with non-CRF01_AE (p<0.01) through sexual transmission; however, the CRF01_AE subtype was not associated with a low baseline CD4+ T cell count or a high viral load in Chinese patients infected through blood transmission (p = 0.249). The overall TDR rate in this population was 4.4% between 2003 and 2013. A univariate logistic regression model revealed that a low CD4 T cell count (≤ 100 cells/µL) was associated with the development of drug-resistant strains. CONCLUSION: Our work revealed diverse HIV-1 subtype distributions in Shaanxi province. We identified a low and stable TDR time trend among ART-naive patients. These findings enhance our understanding of HIV-1 genetic diversity and provide some guidelines for the improvement and implementation of a comprehensive public health strategy of HIV-1 TDR prevention.

Role of Nogo­A in the regulation of hepatocellular carcinoma SMMC­7721 cell apoptosis.

Nogo-A has been identified as an inhibitor of neurite outgrowth specific to the central nervous system. However, little is known about the role of Nogo-A in hepatocellular carcinoma (HCC), the most common primary malignant tumor with a high mortality rate. This study aimed to investigate the role of endogenous Nogo-A in human liver cancer cells. Reverse transcription polymerase chain reaction was used to detect the expression of Nogo-A in four liver cancer cell lines. A lentivirus vector was then constructed to mediate RNA interference (RNAi) targeting of Nogo­A (LV­Nogo-A­siRNA) and was confirmed to successfully suppress the expression of the Nogo-A gene in SMMC-7721 cells. Furthermore, Nogo-A was observed to be highly expressed in liver cancer cell lines. RNAi of Nogo-A using the LV­Nogo-A­siRNA construct significantly decreased Nogo-A protein expression and specifically inhibited the growth of SMMC-7721 cells. This growth inhibitory effect may be attributed to an increase in G2/M phase arrest and apoptosis in SMMC-7721 cells containing Nogo-A­siRNA. The results of this study demonstrate that Nogo-A may represent a novel therapeutic target for the treatment of liver cancer, in addition to its potent roles in neural systems.

Inhibition of connective tissue growth factor suppresses hepatic stellate cell activation in vitro and prevents liver fibrosis in vivo.

Activation of hepatic stellate cells (HSC) represents a critical event in fibrosis, and connective tissue growth factor (CTGF) plays a profibrotic activity and a key factor in the pathogenesis of tissue fibrosis. The current study aimed to determine whether lentivirus-mediated short hairpin RNA (shRNA)-targeted CTGF downregulates the CTGF expression and furthermore whether it suppresses the activation and proliferation of HSC in vitro and prevents liver fibrosis in vivo. HSC-T6 cells were treated with recombinant lentivirus carrying CTGF siRNA. Real-time PCR, Western blotting, MTT, and flow cytometry were performed to investigate the activation and proliferation of HSC-T6 cells in response to CTGF silence. CCl4-induced rats were received lentivirus containing CTGF siRNA by intraportal vein injection. Levels of liver fibrosis were assessed by biochemical and histopathologic examinations. Recombinant lentivirus containing CTGF siRNA could effectively and specifically downregulate the expression of CTGF in both HSC-T6 cells and CCl4-induced rats with liver fibrosis. Blockade of CTGF resulted in significant inhibition of HSC activation and proliferation with decrease in TIMPs, MMP2, MMP9, and collagen I, as well as increase in cells in S phase. Silencing CTGF expression with siRNA prevented liver fibrosis in CCl4-induced rat model. These findings indicated that CTGF plays a key role in the pathogenesis of liver fibrosis and lentiviral-mediated CTGF siRNA has the potential to be an effective treatment for liver fibrosis.

Kinetics of Th17 cytokines during telbivudine therapy in patients with chronic hepatitis B.

Th17 cells and the secreting cytokines play an important role in the immune response and inflammation that is induced by hepatitis B virus (HBV). However, it remains not fully elucidated how the antiviral agents affect Th17 cytokines and signal pathway. Telbivudine therapy has been proved to inhibit HBV replication effectively and to improve clinical outcome of chronic hepatitis B (CHB). Thus, in this study, the effect of decrease in viral load and liver dysfunction resulting from telbivudine treatment on Th17 cells and the related cytokines IL-17, IL-22, and IL-23 were analyzed. Peripheral blood mononuclear cells and serum from twenty-four CHB patients were harvested at 0, 12, 24, 36, and 48 weeks after initiation of telbivudine treatment. In parallel to the reduction of HBV DNA and normalization of serum ALT, significant declines in circulating HBV-specific Th17 cells and IL-22 production were found during antiviral therapy. The expression of serum IL-22 and IL-23, but not IL-17 also decreased during therapy. Our findings suggest that antiviral effect of telbivudine may attribute to both direct virus inhibition and regulation of inflammation, which further improve the understanding of pathogenesis of HBV infection and develop antiviral strategy for controlling viral hepatitis.

Changes in levels of T cell subpopulations to monitor the response to antiretroviral therapy among HIV-1-infected patients during two years of HIV-1 replication suppression.

OBJECTIVES: The aim of this study was to compare the effect of 2 y of antiretroviral therapy (ART) on the percentage of activated CD38⁺CD8⁺ T cells and human leukocyte antigen (HLA)-DR⁺CD8⁺ T cells, and the expression of the co-stimulatory molecule CD28 on CD4⁺ and CD8⁺ T cells in the peripheral blood of HIV-infected adults, and to assess the use of immune activation markers to predict the virological response to ART in a cohort of HIV-1-infected patients in the north-western part of China. METHODS: We analyzed changes in the CD4⁺ T cell count, viral load, and the percentages of CD38⁺CD8⁺ T cells, HLA-DR⁺CD8⁺ T cells, CD28⁺CD4⁺ T cells, and CD28⁺CD8⁺ T cells in 48 patients with HIV diseases during 2 y of suppressive highly active antiretroviral therapy (HAART). Good virological responders (n = 20) were defined as those who had suppressed and maintained a plasma viral load below the detection limit of the assay for at least 12 months. Poor virological responders (n = 28) were defined as those with a detectable viral load at 6 and 12 months after beginning HAART. RESULTS: Among the 20 good responders, baseline median levels of CD38⁺CD8⁺ T cells were elevated, but had decreased significantly at 24 months of therapy (p < 0.0001). Median levels of HLA-DR⁺CD8⁺ T cells also decreased at 24 months of therapy (p < 0.0001). Levels of expression of CD28⁺CD4⁺ T cells rose steadily to 6 months (p = 0.03), and smoothly reached levels observed among HIV-negative blood donors during the 24 months of therapy (p > 0.05). Levels of expression of CD28⁺CD8⁺ T cells increased at 24 months (p = 0.04). Among the 28 poor responders, median levels of CD38⁺CD8⁺ T cells decreased significantly at 24 months (p < 0.0001). Levels of HLA-DR⁺CD8⁺ T cells also decreased at 24 months (p < 0.001). Levels of CD28⁺CD8⁺ T cells and levels of CD28⁺CD4⁺ T cells increased at 24 months remained unchanged. The percentage of CD38⁺CD8⁺ T cells appeared to provide a sensitive estimate of the overall immune recovery in comparison with the percentage of HLA-DR⁺CD8⁺ T cells, although this lacked specificity for the determination of early virological drug failure and did not appear to be a reliable surrogate for RNA viral load. CONCLUSIONS: We show that HAART can be used successfully in Chinese populations with elevated baseline immune activation markers and that the percentage of CD38⁺CD8⁺ T cells may be an additional parameter to the current criteria for estimating the antiretroviral response with HAART.

[Peg-IFNa-2a/RBV antiviral efficacy in cirrhotic hepatitis C patients after splenectomy or partial splenic embolization].

To investigate the antiviral efficacy of combination therapy with pegylated-interferon alpha (peg-IFNa)-2a and ribavirin (RBV) in hepatitis C patients with liver cirrhosis after splenectomy or partial splenic embolization. Forty-nine hepatitis C patients with liver cirrhosis who were unable to use antiviral therapy because of hypersplenism were recruited for study and treated with splenectomy or partial splenic embolization. Three months later, a regimen of antiviral combination therapy was initiated with peg-IFNa-2a (once-weekly subcutaneous injection: 135 µg or 180 µg) and RBV (daily oral: 800 to 1200 mg), and was maintained for 48 weeks. The patients were followed up at treatment weeks 1, 2, 4, 6, 8, and 12. Thereafter, follow-up was conducted every four weeks. The patients were observed until 24 weeks after treatment discontinuation. Follow-up testing included liver function, blood chemistry, renal function, and HCV RNA level. Any adverse reactions were recorded. Liver cirrhosis patients complicated by hypersplenism can be treated effectively with peg-IFNa-2a/RBV combination antiviral therapy after splenectomy or partial splenic embolization. The antiviral-induced sustained viral response rates was 65.00% in cirrhotic/hypersplenic hepatitis C patients receiving splenectomy and 58.62% in those receiving partial splenic embolization. Hypersplenism patients with hepatitis C-related cirrhosis achieved a good antiviral therapeutic effect with peg-IFNa-2a/RBV combination therapy following splenectomy or partial splenic embolization. This sequence of treatment may help to decrease incidences of chronic hepatitis C-induced liver failure and liver cancer in these patients.

Dynamic analysis of Th1/Th2 cytokine concentration during antiretroviral therapy of HIV-1/HCV co-infected patients.

BACKGROUND: Co-infection with hepatitis C (HCV) is very common in human immunodeficiency virus 1 (HIV-1) infected patients. Although HIV co-infection clearly accelerates progression of HCV-related fibrosis and liver disease, controversy remains as to the impact of HCV on HIV disease progression in co-infected patients. HIV can cause immune dysfunction, in which the regulatory function of T helper (Th) cells is very essential. Moreover, cytokines derived from Th cells play a prominent role in viral infection. Investigating the functional changes of Th1 and Th2 cells in cytokine level can improve the understanding of the effect of co-infected HCV on HIV infection. METHODS: In this study, we measured the baseline Th1/Th2 cytokine concentration in sera by using flow cytometry in HIV/HCV co-infection, HIV mono-infection, HCV mono-infection, and healthy control group, as well as the dynamic changes of these cytokine levels after receiving highly active antiretroviral therapy (HAART). RESULTS: The ratio of Th1 and Th2 cytokine concentration in HIV/HCV co-infection was higher than HCV mono-infection and healthy control group, while lower than HIV mono-infection group. After HAART was initiated, the Th1/Th2 ratio of HIV/HCV co-infection group decreased to the same level of healthy control, while HIV mono-infection group was still higher than the control group. CONCLUSIONS: There was no significant evidence showing co-infected with HCV had negative effect on HIV related diseases. However, co-infected with HCV can decrease Th1/Th2 ratio by affecting Th1 cytokine level, especially the secretion of IFN-γ. With the initiation of HAART, Th1 and Th2 cytokine levels were progressively reduced. HIV was the main stimulating factor of T cells in HIV/HCV co-infection group.

HCV coinfection does not alter the frequency of regulatory T cells or CD8+ T cell immune activation in chronically infected HIV+ Chinese subjects.

Regulatory T cell (Treg) is a subset of CD4(+) T cells that play a critical role in regulating the immune responses. Human immunodeficiency virus (HIV) infection is associated with T cell abnormalities and alters effector T cell function. There are a large number of patients coinfected with HIV and hepatitis C virus (HCV). Here, we evaluated the proportion of CD4(+) Treg cells expressing CD25 and FOXP3, and the status of immune activation of CD8(+) T cells in 60 Chinese patients chronically infected with HIV and/or HCV. Furthermore, we investigated the influence of highly active antiretroviral therapy (HAART) on the level of Treg cells and immune activated CD8(+) T cells. We observed that the Treg level was upregulated in HIV infection and HCV infection could not enhance this kind of upregulation significantly. The level of Treg cells was negatively correlated with CD4(+) T cell counts and positively correlated with HIV viral loads. We observed considerably elevated CD38 and HLA-DR expression in CD8(+) T cells in HIV-infected subjects but not in HCV-infected patients in comparison to that in healthy controls. There is no significant difference concerning the proportion of CD8(+) T cells expressing CD38 or HLA-DR between HIV-1-monoinfected and HIV/HCV-coinfected patients. After 12-week HAART, the proportion of Treg cells dropped, but still more than the level in healthy controls. HAART could reverse the abnormal immune activation of CD8(+) T cells. The decrease of Tregs did not alter the downregulation of HIV-1-specific CTL responses in these HIV-infected patients after HAART therapy. The level of HIV virus might be the key point for the decline of CTL responses.

HIV reverse transcriptase activity assay: a feasible surrogate for HIV viral load measurement in China.

The quantitation of HIV viral load using an assay that measures the activity of reverse transcriptase (RT) may provide an alternative strategy for the monitoring of HIV viral load within resource-limited areas in China. Plasma viral load analyses of 215 samples from 87 patients infected with HIV were detected using the RT activity assay (ExaVir Load versions 2 and 3; Cavidi, Uppsala, Sweden) and RT polymerase chain reaction (PCR) (COBAS TaqMan 48, Amplink version 3.2; Roche Molecular Systems, Branchburg, NJ). The RT activity assay versions 3 (RT3) and 2 (RT2) could detect 95.3% and 86.9% of samples with measurable RNA by RT-PCR, respectively. A stronger correlation was observed between viral loads detected by RT3 and RT-PCR than between RT2 and RT-PCR (r = 0.95, P < 0.001, and r = 0.92, P < 0.001, respectively). The correlation between serial samples collected from 6 patients at 1, 3, 6, 12, 18, and 24 months after beginning triple combination antiretroviral therapy, using the 2 different methodologies, was also strong (r = 0.99, P < 0.001, for RT3 and RT-PCR, r = 0.98, P < 0.001, for RT2 and RT-PCR). The viral loads detected by RT activity assay were inversely correlated with CD4(+) T-cell counts. Reproducibility of the RT activity assay was assessed by testing 3 samples in triplicate by 3 different operators. Viral load testing using assays that measure HIV RT activity is an affordable, feasible, simple, and reliable alternative for HIV RNA viral load determination in laboratories in China and other developing countries.

Increased expression of TLR7 in CD8(+) T cells leads to TLR7-mediated activation and accessory cell-dependent IFN-gamma production in HIV type 1 infection.

It has recently been demonstrated that toll-like receptors (TLRs) can recognize structural conserved motifs carried by circulating microbial products and lead to systemic immune responses in individuals infected with HIV-1. TLRs have been detected in CD8(+) T cells at either a protein or RNA level. The role of TLRs on CD8(+) T cells involved in the host's immune responses during HIV-1 infection has not been well characterized. In this study, we analyzed expression of TLR4, TLR5, TLR7, and TLR8 in CD8(+) T cells in HIV-1 infection. All these four TLRs could be detected in CD8(+) T cells, but only TLR7 in CD8(+) T cells from HIV-1-infected individuals showed a higher expression level compared with that from healthy individuals (p < 0.05). The function of TLR7 in CD8(+) T cells was then investigated. We found that TLR7 ligand responsiveness significantly increased the expression of immune activation markers on purified CD8(+) T cells in HIV-1-infected individuals compared with healthy controls. And the levels of these markers were equivalent to those achieved by CD8(+) T cells from peripheral blood mononuclear cells (PBMCs). However, we also observed that TLR7 ligand stimulated significant IFN-gamma production by CD8(+) T cells in an accessory cell-dependent manner. Therefore, although CD8(+) T cells can be directly activated by TLR7, accessory cells must play an essential role in the activation of effective functions such as IFN-gamma production. These findings suggest that the abnormal expression of TLR7 in CD8(+) T cells from HIV-1-infected individuals may contribute to the abnormal immune activation in HIV-1 infection and play an important role in HIV-1 pathogenesis.