Monocyte Activation in HIV/HCV Coinfection Correlates with Cognitive Impairment

Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) challenges the immune system with two viruses that elicit distinct immune responses. Chronic immune activation is a hallmark of HIV infection and an accurate indicator of disease progression. Suppressing HIV viremia by antiretroviral therapy (ART) effectively prolongs life and significantly improves immune function. HIV/HCV coinfected individuals have peripheral immune activation despite effective ART control of HIV viral load. Here we examined freshly isolated CD14 monocytes for gene expression using high-density cDNA microarrays and analyzed T cell subsets, CD4 and CD8, by flow cytometry to characterize immune activation in monoinfected HCV and HIV, and HIV-suppressed coinfected subjects. To determine the impact of coinfection on cognition, subjects were evaluated in 7 domains for neuropsychological performance, which were summarized as a global deficit score (GDS). Monocyte gene expression analysis in HIV-suppressed coinfected subjects identified 43 genes that were elevated greater than 2.5 fold. Correlative analysis of subjects’ GDS and gene expression found eight genes with significance after adjusting for multiple comparisons. Correlative expression of six genes was confirmed by qPCR, five of which were categorized as type 1 IFN response genes. Global deficit scores were not related to plasma lipopolysaccharide levels. In the T cell compartment, coinfection significantly increased expression of activation markers CD38 and HLADR on both CD4 and CD8 T cells but did not correlate with GDS. These findings indicate that coinfection is associated with a type 1 IFN monocyte activation profile which was further found to correlate with cognitive impairment, even in subjects with controlled HIV infection. HIV-suppressed coinfected subjects with controlled HIV viral load experiencing immune activation could benefit significantly from successful anti-HCV therapy and may be considered as preferential candidates.     

Neuroinvasion of fluorescein-positive monocytes in acute simian immunodeficiency virus infection

Monocytes and macrophages play a central role in the pathogenesis of human immunodeficiency virus (HIV)-associated dementia. They represent prominent targets for HIV infection and are thought to facilitate viral neuroinvasion and neuroinflammatory processes. However, many aspects regarding monocyte brain recruitment in HIV infection remain undefined. The nonhuman primate model of AIDS is uniquely suited for examination of the role of monocytes in the pathogenesis of AIDS-associated encephalitis. Nevertheless, an approach to monitor cell migration from peripheral blood into the central nervous system (CNS) in primates had been lacking. Here, upon autologous transfer of fluorescein dye-labeled leukocytes, we demonstrate the trafficking of dye-positive monocytes into the choroid plexus stromata and perivascular spaces in the cerebra of rhesus macaques acutely infected with simian immunodeficiency virus between days 12 and 14 postinfection (p.i.). Dye-positive cells that had migrated expressed the monocyte activation marker CD16 and the macrophage marker CD68. Monocyte neuroinvasion coincided with the presence of the virus in brain tissue and cerebrospinal fluid and with the induction of the proinflammatory mediators CXCL9/MIG and CCL2/MCP-1 in the CNS. Prior to neuroinfiltration, plasma viral load levels peaked on day 11 p.i. Furthermore, the numbers of peripheral blood monocytes rapidly increased between days 4 and 8 p.i., and circulating monocytes exhibited increased functional capacity to produce CCL2/MCP-1. Our findings demonstrate acute monocyte brain infiltration in an animal model of AIDS. Such studies facilitate future examinations of the migratory profile of CNS-homing monocytes, the role of monocytes in virus import into the brain, and the disruption of blood-cerebrospinal fluid and blood-brain barrier functions in primates.     

Characterization of monocyte maturation/differentiation that facilitates their transmigration across the blood-brain barrier and infection by HIV: implications for NeuroAIDS

The prevalence of human immunodeficiency virus 1 (HIV) associated neurocognitive disorders resulting from infection of the central nervous system (CNS) by HIV continues to increase despite the success of combination antiretroviral therapy. Although monocytes are known to transport HIV across the blood–brain barrier (BBB) into the CNS, there are few specific markers that identify monocyte subpopulations susceptible to HIV infection and/or capable of infiltrating the CNS. We cultured human peripheral blood monocytes and characterized the expression of the phenotypic markers CD14, CD16, CD11b, Mac387, CD163, CD44v6 and CD166 during monocyte/macrophage (Mo/Mac) maturation/differentiation. We determined that a CD14⁺CD16⁺CD11b⁺Mac387⁺ Mo/Mac subpopulation preferentially transmigrates across our in vitro BBB model in response to CCL2. Genes associated with Mo/Mac subpopulations that transmigrate across the BBB and/or are infected by HIV were identified by cDNA microarray analyses. Our findings contribute to the understanding of monocyte maturation, infection and transmigration into the brain during the pathogenesis of NeuroAIDS.     

Simian immunodeficiency virus-induced alterations in monocyte production of tumor necrosis factor alpha contribute to reduced immune activation in sooty mangabeys

Human immunodeficiency virus type 1 (HIV-1) infection is characterized by persistent viral replication in the context of CD4(+) T cell depletion and elevated immune activation associated with disease progression. In contrast, simian immunodeficiency virus (SIV) infection of African-origin sooty mangabeys (SM) generally does not result in simian AIDS despite high viral loads and therefore affords a unique model in which to study the immunologic contributions to a nonpathogenic lentiviral disease outcome. A key feature of these natural SIV infections is the maintenance of low levels of immune activation during chronic infection. Our goal was to delineate the contribution of monocytes to maintaining low levels of immune activation in SIV-infected SM. Utilizing an ex vivo whole-blood assay, proinflammatory cytokine production was quantified in monocytes in response to multiple Toll-like receptor (TLR) ligands and a specific, significant reduction in the tumor necrosis factor alpha (TNF-α) response to lipopolysaccharide (LPS) was observed in SIV-infected SM. In contrast, monocytes from hosts of pathogenic infections (HIV-infected humans and SIV-infected Asian macaques) maintained a robust TNF-α response. In SIV-infected SM, monocyte TNF-α responses to low levels of LPS could be augmented by the presence of plasma from uninfected control animals. The impact of LPS-induced TNF-α production on immune activation was demonstrated in vitro, as TNF-α blocking antibodies inhibited downstream CD8(+) T cell activation in a dose-dependent manner. These data demonstrate an association between nonpathogenic SIV infection of SM and a reduced monocyte TNF-α response to LPS, and they identify a role for monocytes in contributing to the suppressed chronic immune activation observed in these natural hosts.     

Mycobacterial Antigen Driven Activation of CD14++CD16? Monocytes Is a Predictor of Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome

Paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an aberrant inflammatory response occurring in a subset of TB-HIV co-infected patients initiating anti-retroviral therapy (ART). Here, we examined monocyte activation by prospectively quantitating pro-inflammatory plasma markers and monocyte subsets in TB-HIV co-infected patients from a South Indian cohort at baseline and following ART initiation at the time of IRIS, or at equivalent time points in non-IRIS controls. Pro-inflammatory biomarkers of innate and myeloid cell activation were increased in plasma of IRIS patients pre-ART and at the time of IRIS; this association was confirmed in a second cohort in South Africa. Increased expression of these markers correlated with elevated antigen load as measured by higher sputum culture grade and shorter duration of anti-TB therapy. Phenotypic analysis revealed the frequency of CD14⁺⁺CD16⁻ monocytes was an independent predictor of TB-IRIS, and was closely associated with plasma levels of CRP, TNF, IL-6 and tissue factor during IRIS. In addition, production of inflammatory cytokines by monocytes was higher in IRIS patients compared to controls pre-ART. These data point to a major role of mycobacterial antigen load and myeloid cell hyperactivation in the pathogenesis of TB-IRIS, and implicate monocytes and monocyte-derived cytokines as potential targets for TB-IRIS prevention or treatment.     

Functional synergy between CD40 ligand and HIV-1 Tat contributes to inflammation: implications in HIV type 1 dementia

HIV type 1 (HIV-1)-associated dementia (HAD) is believed to occur due to aberrant activation of monocyte-derived macrophages and brain-resident microglial cells by viral proteins as well as by the proinflammatory mediators released by infected cells. To investigate the inflammatory aspects of the disease, we examined the levels of soluble CD40L (sCD40L) in paired samples of plasma and cerebrospinal fluid obtained from 25 HIV-infected individuals. A significantly higher level of sCD40L was detected in both cerebrospinal fluid and plasma from HIV-infected patients with cognitive impairment, compared with their nonimpaired counterparts. The contribution of sCD40L to the pathogenesis of HAD was then examined by in vitro experiments. rCD40L synergized with HIV-1 Tat to increase TNF-alpha release from primary human monocytes and microglia, in an NF-kappaB-dependent manner. The mechanistic basis for this synergism was attributed to a Tat-mediated up-regulation of CD40 in monocytes and microglia. Finally, the CD40L-mediated increase in TNF-alpha production by monocytes was shown to be biologically important; immunodepletion experiments revealed that TNF-alpha was essential for the neurotoxic effects of conditioned medium recovered from Tat/CD40L-treated monocytes. Taken together, our results show that CD40 signaling in microglia and monocytes can synergize with the effects of Tat, further amplifying inflammatory processes within the CNS and influencing neuronal survival.     

Heterogeneity of peripheral blood monocyte populations in human immunodeficiency virus-1 seropositive patients

Abstract Monocytes from human immunodeficiency virus (HIV) patients have an increased heterogeneity of phenotype and function. In a study of 120 HIV patients we have demonstrated that they have normal monocyte differential counts but that with progression of the disease an increasing proportion of monocytes show phenotypic and functional evidence for activation or maturation. A proportion of the monocytes are larger, with increased expression of CD11b, HLA-DR, CD45 and CD16. Concomitantly there was increased expression of TNF-α, high constitutive synthesis of PGE2 and high plasma IL-6 levels. This suggested that there exist a more dynamic situation of recuitment, activation and maturation of peripheral blood monocytes driven by HIV infection which results in a broader phenotypic profile.     

人外周血单核细胞的分离和电穿孔法转染

目的:建立分离纯化人外周血单核细胞及转染的有效方法。方法:应用基于HISTOPAQUE的密度梯度离心及抗体标记纯化的方法分离单核细胞,并以电穿孔技术转染绿色荧光蛋白(GFP)表达质粒、肿瘤坏死因子受体相关因子6(TRAF6)小干扰RNA。结果:基于外周血单核细胞的表面标志分子CD14的流式细胞分析表明得到了高纯度(89.95%)的外周血单核细胞;GFP荧光照片显示GFP表达质粒的转染效率为60%～70%;免疫印迹显示TRAF6的表达抑制(90%)下调了脂多糖(LPS)对JNK的激活,说明通过电穿孔技术有效递送了TRAF6小干扰RNA,表明单核细胞若缺少TRAF6将抑制LPS-TLR4信号通路的激活。结论:建立了一种高效的从人外周血中分离原代单核细胞的方法,且应用基于NucleoFectorⅡ的电穿孔技术实现了对此原代单核细胞的高效转染,为进一步外周血单核细胞的相关功能研究奠定了方法学基础。     

Impaired monocyte maturation in response to CpG oligodeoxynucleotide is related to viral RNA levels in human immunodeficiency virus disease and is at least partially mediated by deficiencies in alpha/beta interferon responsiveness and production

The biological activity of CpG oligodeoxynucleotide 2216 (ODN2216), a Toll-like receptor 9 agonist, was investigated with monocytes from human immunodeficiency virus (HIV)-negative and HIV-positive (HIV+) donors. Exposure of peripheral blood mononuclear cells to CpG ODN2216 led to decreased expression of the monocyte marker CD14 and increased expression of the dendritic cell marker CD83, as well as increased expression of HLA-DR, CD40, CD80, and CD86 among the monocytes. Several features of the CpG ODN-induced maturation were diminished in monocytes from HIV+ donors, and these deficiencies were related to increased viremia but not to CD4 cell counts. Alpha interferon (IFN-alpha) was implicated as at least a partial mediator of the CpG ODN-induced monocyte maturation. Reduced production of IFN-alpha in response to CpG ODN and reduced frequencies of plasmacytoid dendritic cells, the principal IFN-alpha-producing cell type in peripheral blood, were observed in peripheral blood mononuclear cells from HIV+ donors. These deficiencies also were related to levels of plasma HIV RNA. Responses of monocytes from HIV+ donors to direct stimulation with IFN-alpha also were partially impaired. Thus, reduced production of IFN-alpha and reduced IFN-alpha responsiveness may contribute to diminished functional responses to CpG ODN in HIV disease. Application of CpG ODNs in HIV disease for adjuvant or immunoregulatory purposes may be particularly useful for HIV+ donors without high-level viremia.     

Soluble form of the endothelial adhesion molecule CD146 binds preferentially CD16+ monocytes

The cell adhesion molecule CD146 is normally located at the endothelial cell-to-cell junction and colocalizes with actin cytoskeleton. The soluble form of CD146 (sCD146) has been identified in the endothelial cell supernatant and in normal human plasma, and is increased in pathologic conditions with altered endothelial function. Soluble CD146 binding to monocytes promotes their transendothelial migration, which represents a central step in the development of atherosclerotic plaque. Since peripheral blood monocytes are characterized by a phenotypic and functional heterogeneity, with different transendothelial migration capacity, we hypothesized that monocyte subsets differently bind sCD146. Based on surface CD14 and CD16 expression monocytes were distinguished by flow cytometry (FACS) into three subsets: CD14++/CD16−, CD14++/CD16+ and CD14+/CD16+. CD16+ monocytes have been found to possess higher transendothelial migration ability. FACS analysis on blood monocytes from 30 healthy subjects revealed that higher percentages of CD14++/CD16+ (median, first and third quartile: 2.26, 1.62–3.87) and of CD14+/CD16+ (2.59, 1.28–4.80) were positive for CD146 (both p < 0.01), in comparison to CD14++/CD16− (0.66, 0.47–1.01). Moreover, in vitro treatment of ficoll separated monocytes with recombinant CD146 showed that both CD16+ subsets increased their percentage of CD146-positive events compared to CD16− monocytes (p < 0.01). Soluble CD146 levels were evaluated by ELISA in plasma samples of subjects from our study group and showed a correlation with percentage of CD146-positive CD14+/CD16+ monocyte subset. In this work we have demonstrated that monocyte subsets behave differently with regard to their sCD146 binding activity; because binding of CD146 influences transendothelial migration of monocytes, modulation of monocyte-CD146 interaction may represent a potential target to limit atherosclerotic plaque development.     

Redox and activation status of monocytes from human immunodeficiency virus-infected patients: relationship with viral load

Monocytes are precursors of tissue macrophages, which are major targets of human immunodeficiency virus type 1 (HIV-1) infection. Although few blood monocytes are infected, their resulting activation could play a key role in the pathogenesis of HIV disease by modulating their transendothelial migration and inducing the production of reactive oxygen species (ROS). ROS participate in chronic inflammation, HIV replication, and the apoptosis of immune system cells seen in HIV-infected subjects. Published data on monocyte activation are controversial, possibly because most studies have involved monocytes isolated from their blood environment by various procedures that may alter cell responses. We therefore used flow cytometry to study, in whole blood, the activation and redox status of monocytes from HIV-infected patients at different stages of the disease. We studied the expression of adhesion molecules, actin polymerization, and cellular levels of H2O2, Bcl-2, and thioredoxin. Basal H2O2 production correlated with viral load and was further enhanced by bacterial N-formyl peptides and endotoxin. The enhanced H2O2 production by monocytes from asymptomatic untreated patients with CD4(+) cell counts above 500/microliter was associated with a decrease in the levels of Bcl-2 and thioredoxin. In contrast, in patients with AIDS, Bcl-2 levels returned to normal and thioredoxin levels were higher than in healthy controls. Restoration of these antioxidant and antiapoptotic molecules might explain, at least in part, why monocyte numbers remain relatively stable throughout the disease. Alterations of adhesion molecule expression and increased actin polymerization could play a role in transendothelial migration of these activated monocytes.     

Complementary Role of HCV and HIV in T-Cell Activation and Exhaustion in HIV/HCV Coinfection

Objectives

To investigate whether T-cell activation and exhaustion is linked to HCV- and HIV disease parameters in HIV/HCV infected individuals, we studied T-cell characteristics in HIV/HCV coinfected patients and controls.

Methods

14 HIV/HCV coinfected, 19 HCV monoinfected, 10 HIV monoinfected patients and 15 healthy controls were included in this cross-sectional study. Differences in expression of activation and exhaustion markers (HLA-DR, CD38, PD-1, Tim-3 and Fas) and phenotypic markers on CD4⁺ and CD8⁺ T-cells were analysed by flow cytometry and were related to HCV disease parameters (HCV-viremia, ALT and liver fibrosis).

Results

Frequencies of activated CD4⁺ and CD8⁺ T-cells were higher in HIV/HCV-coinfected compared to healthy controls and HCV or HIV mono-infected individuals. Coinfected patients also showed high expression of the exhaustion marker PD-1 and death receptor Fas. In contrast, the exhaustion marker Tim-3 was only elevated in HIV-monoinfected patients. T-cell activation and exhaustion were correlated with HCV-RNA, suggesting that viral antigen influences T-cell activation and exhaustion. Interestingly, increased percentages of effector CD8⁺ T-cells were found in patients with severe (F3–F4) liver fibrosis compared to those with no to minimal fibrosis (F0–F2).

Conclusions

HIV/HCV coinfected patients display a high level of T-cell activation and exhaustion in the peripheral blood. Our data suggest that T-cell activation and exhaustion are influenced by the level of HCV viremia. Furthermore, high percentages of cytotoxic/effector CD8⁺ T-cells are associated with liver fibrosis in both HCV monoinfected and HIV/HCV coinfected patients.     

Suppressed Th17 Levels Correlate with Elevated PIAS3, SHP2, and SOCS3 Expression in CD4 T Cells during Acute Simian Immunodeficiency Virus Infection

T helper 17 (Th17) cells play an important role in mucosal immune homeostasis and maintaining the integrity of the mucosal epithelial barrier. Loss of Th17 cells has been extensively documented during human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections. The lack of effective repopulation of Th17 cells has been associated with chronic immune activation mediated by the translocation of microbial products. Using ex vivo analysis of purified peripheral blood CD4 T cells from SIV-infected rhesus macaques, we show that the suppression of interleukin-17 (IL-17) expression correlated with upregulated expression of negative regulatory genes PIAS3, SHP2, and SOCS3 in CD4 T cells. Suppressed Th17 expression was accompanied by elevated levels of soluble CD14 (sCD14) and lipopolysaccharide binding protein (LBP) in the plasma during early stages of infection. Plasma viral loads rather than sCD14 or LBP levels correlated with acute immune activation. Additionally, we observed a significant increase in the expression of CD14 on peripheral blood monocytes that correlated with IL-23 expression and markers of microbial translocation. Taken together, our results provide new insights into the early events associated with acute SIV pathogenesis and suggest additional mechanisms playing a role in suppression of Th17 cells.     

Elevated Plasma Soluble CD14 and Skewed CD16+ Monocyte Distribution Persist despite Normalisation of Soluble CD163 and CXCL10 by Effective HIV Therapy: A Changing Paradigm for Routine HIV Laboratory Monitoring?

Objective

We investigated plasma and flow cytometric biomarkers of monocyte status that have been associated with prognostic utility in HIV infection and other chronic inflammatory diseases, comparing 81 HIV⁺ individuals with a range of treatment outcomes to a group of 21 healthy control blood donors. Our aim is to develop and optimise monocyte assays that combine biological relevance, clinical utility, and ease of adoption into routine HIV laboratory practice.

Design

Cross-sectional evaluation of concurrent plasma and whole blood samples.

Methods

A flow cytometry protocol was developed comprising single-tube CD45, CD14, CD16, CD64, CD163, CD143 analysis with appropriately matched isotype controls. Plasma levels of soluble CD14 (sCD14), soluble CD163 (sCD163) and CXCL10 were measured by ELISA.

Results

HIV status was associated with significantly increased expression of CD64, CD143 and CD163 on CD16⁺ monocytes, irrespective of the virological response to HIV therapy. Plasma levels of sCD14, sCD163 and CXCL10 were also significantly elevated in association with viremic HIV infection. Plasma sCD163 and CXCL10 levels were restored to healthy control levels by effective antiretroviral therapy while sCD14 levels remained elevated despite virological suppression (p<0.001).

Conclusions

Flow cytometric and plasma biomarkers of monocyte activation indicate an ongoing systemic inflammatory response to HIV infection, characterised by persistent alterations of CD16⁺ monocyte expression profiles and elevated sCD14 levels, that are not corrected by antiretroviral therapy and likely to be prognostically significant. In contrast, sCD163 and CXCL10 levels declined on antiretroviral therapy, suggesting multiple activation pathways revealed by these biomarkers. Incorporation of these assays into routine clinical care is feasible and warrants further consideration, particularly in light of emerging therapeutic strategies that specifically target innate immune activation in HIV infection.     

Activation of extrinsic apoptosis pathway in HCV monoinfected and HIV–HCV coinfected patients,irrespective of liver disease severity

Chronic hepatitis C virus (HCV) infection is associated with increased levels of peripheral T cell apoptosis. We aimed to study whether T cell apoptosis markers indicate pathways that may contribute to clinical progression in HCV monoinfected and HIV–HCV coinfected patients. Activation of the extrinsic apoptosis pathways was measured by levels of death receptor Fas, initiator caspase 8 and effector caspases 3 and 7 activity and Annexin V binding on peripheral CD4 and CD8 T cells of HCV monoinfected and HIV/HCV coinfected patients, as well as healthy controls and HIV-infected, hepatitis B virus-infected and primary biliary cirrhosis disease controls. Association with liver fibrosis was assessed by biopsy or by transient elastography. HCV monoinfected and HIV–HCV coinfected patients displayed enhanced peripheral CD4 and CD8 T cell apoptosis. Caspase 8 activity was highest in HIV–HCV coinfection, without enhanced downstream activity of caspases 3 and 7. Level of peripheral T cell apoptosis was independent of liver fibrosis or other disease parameters in all disease groups. The extrinsic apoptosis pathway is upregulated in HCV monoinfection and HIV–HCV coinfection, but this is independent of liver disease severity.     

Differential Migration and Activation Profile of Monocytes after Trophoblast Interaction

Macrophages at the maternal-placental interface coordinate opposite demands under the control of trophoblast cells such as the response against pathogens on one hand, and apoptotic cell clearance and wound healing with the production of suppressor cytokines. Here, we investigated whether trophoblast cells induce maternal monocyte activation towards an alternative activated macrophage profile and whether bacterial or viral stimuli modulate their migratory properties. We used an in vitro model of the maternal-placental interface represented by co-cultures of CD14+ cells isolated from fertile women with first trimester trophoblast cell line (Swan-71 cells) in the presence or absence of pathogen associated molecular pattern (PAMP) stimuli lipopolysaccharide (LPS), peptidoglycan (PGN) or poly [I:C]). Maternal CD14+ cells showed increased CD16 and CD39 expression, both markers associated to an alternative activation profile, with no changes in CD80 expression after trophoblast cell interaction. These changes were accompanied by increased IL-10 and decreased IL-12 production by CD14+ cells. After stimulation with LPS, PGN or poly [I:C], monocytes co-cultured with trophoblast cells had lower production of TNF-α and IL-1β compared with non co-cultured monocytes. Interestingly, monocyte migration towards trophoblast cells was prevented in the presence of LPS or PGN but not after 24h of stimulation with poly [I:C]. LPS or PGN also decreased CCR5, CXCL-8 and CCL5 expression. Finally, trophoblast cells co-cultured with monocytes in the presence of pathological stimuli failed to increase chemokine expression, indicating a bidirectional effect. In conclusion, trophoblast might ‘instruct’ maternal monocytes to express an alternative activation profile and restrain their early recruitment under pathological threats as one of the first strategies to avoid potential tissue damage at the maternal-placental interface.     

外周血CD14~(high)CD16~+单核细胞在HIV/HCV重叠感染者肝损伤中的作用

目的:探讨HIV/HCV重叠感染患者外周血单核细胞亚群与肝损伤的关系。方法:观察对象为HIV/HCV重叠感染患者,分为对照组(n=11)、肝纤维化组(n=12)和肝硬化组(n=7)。运用流式细胞仪检测单核细胞及其亚群变化,瞬时弹性成像(Fibroscan)检测肝纤维化情况。比较单核细胞各亚群在不同程度肝损伤中的差异,并对HIV/HCV重叠感染患者外周血的单核细胞数与肝纤维化情况进行相关性分析。结果:HIV/HCV重叠感染患者肝硬化组与对照组比较,单核细胞CD14low CD16+和CD14high CD16+亚群显著增多(P=0.047,P=0.018)。HIV/HCV重叠感染患者肝纤维化组与对照组比较,单核细胞各亚群差异无统计学意义(P=0.84,P=0.812)。HIV/HCV重叠感染患者CD14high CD16+单核细胞与肝纤维化情况存在正性线性相关,方程成立,并且系数有统计学意义(P=0.018),方程似然比(r 2)0.45。结论:HIV/HCV重叠感染患者CD14high CD16+单核细胞增高有可能是肝损伤加重的原因之一。     

Immune Activation Response in Chronic HIV-Infected Patients: Influence of Hepatitis C Virus Coinfection

Objectives

We have analyzed the parameters (bacterial translocation, immune activation and regulation, presence of HCV coinfection) which could be implicated in an inappropriate immune response from individuals with chronic HIV infection. The influence of them on the evolution of CD4+ T cell count has been investigated.

Patients and methods

Seventy HIV-infected patients [monoinfected by HIV (n = 20), HCV-coinfected (with (n = 25) and without (n = 25) liver cirrhosis)] and 25 healthy controls were included. Median duration of HIV infection was 20 years. HIV- and HCV-related parameters, as well as markers relative to bacterial translocation, monocyte and lymphocyte activation and regulation were considered as independent variables. Dependent variables were the increase of CD4+ T cell count during the follow-up (12 months).

Results

Increased values of bacterial translocation, measured by lipopolysaccharide-binding protein, monocyte and lymphocyte activation markers and T regulatory lymphocytes were detected in HIV-monoinfected and HIV/HCV coinfected patients. Serum sCD14 and IL-6 were increased in HIV/HCV-coinfected patients with liver cirrhosis in comparison with those with chronic hepatitis or HIV-monoinfected individuals. Time with undetectable HIV load was not related with these parameters. The presence of cirrhosis was negatively associated with a CD4+ T cell count increase.

Conclusion

In patients with a chronic HIV infection, a persistent increase of lipopolysaccharide-binding protein and monocyte and lymphocyte modifications are present. HCV-related cirrhosis is associated with more elevated serum concentrations of monocyte-derived markers. Cirrhosis influences the continued immune reconstitution of these patients.     

Low Levels of Microbial Translocation Marker LBP Are Associated with Sustained Viral Response after Anti-HCV Treatment in HIV-1/HCV Co-Infected Patients

Background

Microbial translocation (MT) contributes to immune activation during HIV and HCV infections. We investigated the kinetics of MT markers during anti-HCV and anti-HIV treatments, and if baseline plasma levels of lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP) and soluble CD14 (sCD14) could predict anti-HCV treatment outcome.

Methods

Plasma from 78 HIV-infected patients was evaluated for LPS, LBP and sCD14. The patients starting anti-HCV treatment (with ongoing antiretroviral (ART) treatment) were categorized into sustained viral responders (SVR; n = 21) or non-responders (NR; n = 15) based on treatment outcome. ART starting subjects—were categorized into chronically HCV-infected (CH; n = 24) and mono-infected (HIV; n = 18), based on the HCV infection status. Samples were collected before start (at baseline) of pegylated-interferon-alpha/ribavirin (peg-IFN/RBV) or antiretroviral-therapy and two years after treatment start (at follow up). χ²–test, non-parametric statistics and logistic regression were applied to determine the associations with treatment response and changes of the soluble markers.

Results

Plasma levels of LPS and sCD14 were elevated in all subjects before antiviral-treatment but remained unchanged at follow-up. Elevated levels of LBP were present in patients with HIV and HIV/HCV co-infection and were reduced by ART. Additionally, higher levels of LBP were present at baseline in NR vs. SVR. Higher levels of LBP at baseline were associated with non-response to peg-IFN/RBV treatment in both bivariate (OR: 0.19 95% CI: 0.06–0.31, p = 0.004) and multivariate analysis (OR: 1.43, 95% CI: 1.1–1.86, p = 0.07).

Conclusion

In HIV/HCV co-infected patients high baseline LBP levels are associated with non-response to peg-IFN/RBV therapy. Plasma LBP (decreased by ART) may be a more relevant MT marker than LPS and sCD14.     

Cellular Activation and Intracellular HCV Load in Peripheral Blood Monocytes Isolated from HCV Monoinfected and HIV-HCV Coinfected Patients

Background

During HCV infection, the activation status of peripheral blood monocytes and its impact on HCV replication are poorly understood. We hypothesized that a modified activation of peripheral blood monocytes in HIV-HCV coinfected compared to HCV monoinfected patients may contribute to different monocytes reservoirs of HCV replication.

Methods

We performed a case-control analysis involving HCV-infected patients with and without HIV coinfection. In peripheral blood mononuclear cells (PBMCs), peripheral blood lymphocytes (PBLs) and peripheral blood monocytes isolated from HCV monoinfected and HIV-HCV coinfected patients, intracellular HCV load and a marker of cellular activation, nuclear factor-kappaB (NF-κB) activation, were quantified using intracellular detection of HCV-core protein and electrophoretic mobility shift assay, respectively.

Results

Intracellular HCV loads were higher in monocytes isolated from HIV-HCV coinfected patients than in those of monoinfected patients. Among PBMCs isolated from HIV-HCV coinfected patients, intracellular HCV loads were higher in monocytes compared to PBLs. Cellular activation as measured by NF-κB activation was higher in monocytes isolated from HIV-HCV coinfected patients than in those of monoinfected patients.

Conclusions

Our results reveal the peripheral blood monocytes as an important extrahepatic reservoir for HCV in HIV-HCV coinfected patients and indicate a potential association between the activation state of monocytes and the size of the HCV reservoir in HIV-HCV coinfected patients.