Plasma proteome analysis reveals overlapping, yet distinct mechanisms of immune activation in chronic HCV and HIV infections. J Acquir Immune Defic Syndr. 2013;63:563-571. [PMID: 23507661 DOI: 10.1097/qai.0b013e3182909847]

Evaluating the Cardiovascular Risk in an Aging Population of People With HIV: The Impact of Hepatitis C Virus Coinfection

Background People with HIV (PWH) are at an increased risk of cardiovascular disease (CVD) with an unknown added impact of hepatitis C virus (HCV) coinfection. We aimed to identify whether HCV coinfection increases the risk of type 1 myocardial infarction (T1MI) and if the risk differs by age. Methods and Results We used data from NA-ACCORD (North American AIDS Cohort Collaboration on Research and Design) from January 1, 2000, to December 31, 2017, PWH (aged 40-79 years) who had initiated antiretroviral therapy. The primary outcome was an adjudicated T1MI event. Those who started direct-acting HCV antivirals were censored at the time of initiation. Crude incidence rates per 1000 person-years were calculated for T1MI by calendar time. Discrete time-to-event analyses with complementary log-log models were used to estimate adjusted hazard ratios and 95% CIs for T1MI among those with and without HCV. Among 23 361 PWH, 4677 (20%) had HCV. There were 89 (1.9%) T1MIs among PWH with HCV and 314 (1.7%) among PWH without HCV. HCV was not associated with increased T1MI risk in PWH (adjusted hazard ratio, 0.98 [95% CI, 0.74-1.30]). However, the risk of T1MI increased with age and was amplified in those with HCV (adjusted hazard ratio per 10-year increase in age, 1.85 [95% CI, 1.38-2.48]) compared with those without HCV (adjusted hazard ratio per 10-year increase in age,1.30 [95% CI, 1.13-1.50]; P<0.001, test of interaction). Conclusions HCV coinfection was not significantly associated with increased T1MI risk; however, the risk of T1MI with increasing age was greater in those with HCV compared with those without, and HCV status should be considered when assessing CVD risk in aging PWH.

Changes in Inflammatory and Atherogenesis Biomarkers With the 2-Drug Regimen Dolutegravir Plus Lamivudine in Antiretroviral Therapy–Experienced, Virologically Suppressed People With HIV-1: A Systematic Literature Review

Background

The 2-drug regimen dolutegravir plus lamivudine has demonstrated long-term noninferior efficacy vs 3-/4-drug regimens (3/4DRs) in phase 3 trials. This systematic literature review summarizes clinical trial and real-world evidence evaluating impact of dolutegravir plus lamivudine on inflammatory and atherogenesis biomarkers in people with human immunodeficiency virus type 1 (PWH).

Methods

Using Ovid MEDLINE, Embase, PubMed, and Cochrane library databases and conference proceedings, we searched for studies published from 1 January 2013 to 14 July 2021, reporting changes in inflammatory and atherogenesis biomarkers with dolutegravir plus lamivudine in antiretroviral therapy–experienced, virologically suppressed PWH aged ≥18 years.

Results

Four records representing 2 randomized controlled trials (RCTs) and 6 records of real-world evidence met eligibility criteria. All real-world studies evaluated CD4⁺/CD8⁺ ratio, while only 1 assessed inflammatory biomarkers. Across both RCTs, no consistent pattern of change in biomarkers was observed between dolutegravir/lamivudine and 3/4DR comparators. There were significant changes in soluble CD14 favoring dolutegravir/lamivudine in TANGO at weeks 48 and 144 and SALSA at week 48, and in interleukin-6 favoring the control group in TANGO at weeks 48 and 144. In the real-world study evaluating inflammatory biomarkers, median soluble CD14 significantly decreased 48 weeks postswitch to dolutegravir plus lamivudine (P < .001), while other biomarkers remained stable. In all 6 real-world studies, increases in CD4⁺/CD8⁺ ratio were reported after switch to dolutegravir plus lamivudine (follow-up, 12–60 months).

Conclusions

Results show that dolutegravir plus lamivudine has a comparable impact on inflammatory and atherogenesis biomarkers vs 3/4DRs, with no consistent pattern of change after switch in virologically suppressed PWH.

Soluble cluster of differentiation 14 levels elevated in bile from gallbladder cancer cases from Shanghai, China

Elevated systemic levels of soluble cluster of differentiation 14 (sCD14) have been associated with gallbladder cancer (GBC), but the association with sCD14 levels within the gallbladder has not been investigated. Here, we evaluated sCD14 in the bile of 41 GBC cases and 117 gallstone controls with data on 65 bile inflammation markers. We examined the relationship between bile sCD14 levels and GBC using logistic regression and stratified the analysis by stage. We included GBC-associated inflammatory biomarkers in the model to evaluate the influence of local inflammation. Bile sCD14 levels (third versus first tertile) were associated with GBC (adjusted odds ratio [OR]: 3.0, 95% confidence interval [CI]: 1.2–8.0). The association was equally strong for stage I/II (OR: 3.3, 95% CI: 0.9–15.6) and stage III/IV (OR: 3.2, 95% CI: 1.0–12.4) cancers. Including the GBC-associated inflammatory markers in the model removed the association between bile sCD14 and GBC (OR: 1.0, 95% CI: 0.3–3.5). The findings suggest that immune activation within the gallbladder may be related to GBC development, and the effect of sCD14 is influenced by inflammation. Similar associations across tumor stages suggest that elevated bile sCD14 levels may reflect changes early in GBC pathogenesis. Associations between GBC and sCD14 levels in both bile and plasma suggest sCD14 could be a potential biomarker for GBC.

Structure-Based Discovery of Novel Chemical Classes of Autotaxin Inhibitors

Autotaxin (ATX) is a secreted glycoprotein, widely present in biological fluids, largely responsible for extracellular lysophosphatidic acid (LPA) production. LPA is a bioactive growth-factor-like lysophospholipid that exerts pleiotropic effects in almost all cell types, exerted through at least six G-protein-coupled receptors (LPAR1-6). Increased ATX expression has been detected in different chronic inflammatory diseases, while genetic or pharmacological studies have established ATX as a promising therapeutic target, exemplified by the ongoing phase III clinical trial for idiopathic pulmonary fibrosis. In this report, we employed an in silico drug discovery workflow, aiming at the identification of structurally novel series of ATX inhibitors that would be amenable to further optimization. Towards this end, a virtual screening protocol was applied involving the search into molecular databases for new small molecules potentially binding to ATX. The crystal structure of ATX in complex with a known inhibitor (HA-155) was used as a molecular model docking reference, yielding a priority list of 30 small molecule ATX inhibitors, validated by a well-established enzymatic assay of ATX activity. The two most potent, novel and structurally different compounds were further structurally optimized by deploying further in silico tools, resulting to the overall identification of six new ATX inhibitors that belong to distinct chemical classes than existing inhibitors, expanding the arsenal of chemical scaffolds and allowing further rational design.

Elevated Autotaxin and LPA Levels During Chronic Viral Hepatitis and Hepatocellular Carcinoma Associate with Systemic Immune Activation

Circulating autotaxin (ATX) is elevated in persons with liver disease, particularly in the setting of chronic hepatitis C virus (HCV) and HCV/HIV infection. It is thought that plasma ATX levels are, in part, attributable to impaired liver clearance that is secondary to fibrotic liver disease. In a discovery data set, we identified plasma ATX to be associated with parameters of systemic immune activation during chronic HCV and HCV/HIV infection. We and others have observed a partial normalization of ATX levels within months of starting interferon-free direct-acting antiviral (DAA) HCV therapy, consistent with a non-fibrotic liver disease contribution to elevated ATX levels, or HCV-mediated hepatocyte activation. Relationships between ATX, lysophosphatidic acid (LPA) and parameters of systemic immune activation will be discussed in the context of HCV infection, age, immune health, liver health, and hepatocellular carcinoma (HCC).

Deregulated Lysophosphatidic Acid Metabolism and Signaling in Liver Cancer

Liver cancer is one of the leading causes of death worldwide due to late diagnosis and scarcity of treatment options. The major risk factor for liver cancer is cirrhosis with the underlying causes of cirrhosis being viral infection (hepatitis B or C), metabolic deregulation (Non-alcoholic fatty liver disease (NAFLD) in the presence of obesity and diabetes), alcohol or cholestatic disorders. Lysophosphatidic acid (LPA) is a bioactive phospholipid with numerous effects, most of them compatible with the hallmarks of cancer (proliferation, migration, invasion, survival, evasion of apoptosis, deregulated metabolism, neoangiogenesis, etc.). Autotaxin (ATX) is the enzyme responsible for the bulk of extracellular LPA production, and together with LPA signaling is involved in chronic inflammatory diseases, fibrosis and cancer. This review discusses the most important findings and the mechanisms related to ATX/LPA/LPAR involvement on metabolic, viral and cholestatic liver disorders and their progression to liver cancer in the context of human patients and mouse models. It focuses on the role of ATX/LPA in NAFLD development and its progression to liver cancer as NAFLD has an increasing incidence which is associated with the increasing incidence of liver cancer. Bearing in mind that adipose tissue accounts for the largest amount of LPA production, many studies have implicated LPA in adipose tissue metabolism and inflammation, liver steatosis, insulin resistance, glucose intolerance and lipogenesis. At the same time, LPA and ATX play crucial roles in fibrotic diseases. Given that hepatocellular carcinoma (HCC) is usually developed on the background of liver fibrosis, therapies that both delay the progression of fibrosis and prevent its development to malignancy would be very promising. Therefore, ATX/LPA signaling appears as an attractive therapeutic target as evidenced by the fact that it is involved in both liver fibrosis progression and liver cancer development.

Production of extracellular lysophosphatidic acid in the regulation of adipocyte functions and liver fibrosis

Lysophosphatidic acid (LPA), a glycerophospholipid, consists of a glycerol backbone connected to a phosphate head group and an acyl chain linked to sn-1 or sn-2 position. In the circulation, LPA is in sub-millimolar range and mainly derived from hydrolysis of lysophosphatidylcholine, a process mediated by lysophospholipase D activity in proteins such as autotaxin (ATX). Intracellular and extracellular LPAs act as bioactive lipid mediators with diverse functions in almost every mammalian cell type. The binding of LPA to its receptors LPA1-6 activates multiple cellular processes such as migration, proliferation and survival. The production of LPA and activation of LPA receptor signaling pathways in the events of physiology and pathophysiology have attracted the interest of researchers. Results from studies using transgenic and gene knockout animals with alterations of ATX and LPA receptors genes, have revealed the roles of LPA signaling pathways in metabolic active tissues and organs. The present review was aimed to summarize recent progresses in the studies of extracellular and intracellular LPA production pathways. This includes the functional, structural and biochemical properties of ATX and LPA receptors. The potential roles of LPA production and LPA receptor signaling pathways in obesity, insulin resistance and liver fibrosis are also discussed.

Pre-vaccine plasma levels of soluble inflammatory indices negatively predict responses to HAV, HBV, and tetanus vaccines in HCV and HIV infection

BACKGROUND

Chronic hepatitis C virus (HCV) and HIV infections are associated with impaired responses to neo-antigens contained in hepatitis A virus (HAV)/hepatitis B virus (HBV) vaccines, yet responsible mechanisms are unclear.

METHODS

ACTG 5232 and CFAR0910 were clinical trials where pre-vaccine levels of plasma IP10, IL-6, sCD163 and sCD14 were measured in viremic HCV- (n = 15) or HIV-infected participants (n = 24) and uninfected controls (n = 10). Accelerated dosing HAV/HBV vaccine and tetanus booster were administered and antibody response was measured at 0, 1, 3, 8, and 24 weeks.

RESULTS

Pre-vaccine plasma IP10, IL-6, and sCD14 levels were elevated in both HCV and HIV-infected participants, while sCD163 was also elevated in HCV-infected participants. Pre-immunization tetanus antibody levels were lower in HIV-infected than in uninfected participants, while vaccine induced antibody responses were intact in HCV and HIV-infected participants. After HAV/HBV vaccination, HCV and HIV-infected participants had lower and less durable HAV and HBV antibody responses than uninfected controls. Among HCV-infected participants, pre-vaccine plasma IP10, IL-6, sCD14, and sCD163 levels inversely correlated with HAV, HBV and tetanus antibody responses after vaccine. Low HAV/HBV vaccine responses in HIV-infected participants prohibited assessment of immune correlates.

CONCLUSIONS

During HCV and HIV infection markers of systemic inflammation reflect immune dysfunction as demonstrated by poor response to HAV/HBV neo-antigen vaccine.

Autotaxin-lysophosphatidic acid receptor signalling regulates hepatitis C virus replication

BACKGROUND & AIMS

Chronic hepatitis C is a global health problem with an estimated 170 million hepatitis C virus (HCV) infected individuals at risk of progressive liver disease and hepatocellular carcinoma (HCC). Autotaxin (ATX, gene name: ENPP2) is a phospholipase with diverse roles in the physiological and pathological processes including inflammation and oncogenesis. Clinical studies have reported increased ATX expression in chronic hepatitis C, however, the pathways regulating ATX and its role in the viral life cycle are not well understood.

METHODS

In vitro hepatocyte and ex vivo liver culture systems along with chimeric humanized liver mice and HCC tissue enabled us to assess the interplay between ATX and the HCV life cycle.

RESULTS

HCV infection increased hepatocellular ATX RNA and protein expression. HCV infection stabilizes hypoxia inducible factors (HIFs) and we investigated a role for these transcription factors to regulate ATX. In vitro studies show that low oxygen increases hepatocellular ATX expression and transcriptome analysis showed a positive correlation between ATX mRNA levels and hypoxia gene score in HCC tumour tissue associated with HCV and other aetiologies. Importantly, inhibiting ATX-lysophosphatidic acid (LPA) signalling reduced HCV replication, demonstrating a positive role for this phospholipase in the viral life cycle. LPA activates phosphoinositide-3-kinase that stabilizes HIF-1α and inhibiting the HIF signalling pathway abrogates the pro-viral activity of LPA.

CONCLUSIONS

Our data support a model where HCV infection increases ATX expression which supports viral replication and HCC progression.

LAY SUMMARY

Chronic hepatitis C is a global health problem with infected individuals at risk of developing liver disease that can progress to hepatocellular carcinoma. Autotaxin generates the biologically active lipid lysophosphatidic acid that has been reported to play a tumorigenic role in a wide number of cancers. In this study we show that hepatitis C virus infection increases autotaxin expression via hypoxia inducible transcription factor and provides an environment in the liver that promotes fibrosis and liver injury. Importantly, we show a new role for lysophosphatidic acid in positively regulating hepatitis C virus replication.

During Hepatitis C Virus (HCV) Infection and HCV-HIV Coinfection, an Elevated Plasma Level of Autotaxin Is Associated With Lysophosphatidic Acid and Markers of Immune Activation That Normalize During Interferon-Free HCV Therapy

BACKGROUND

 Immune activation predicts morbidity during hepatitis C virus (HCV) infection and human immunodeficiency virus (HIV) infection, although mechanisms underlying immune activation are unclear. Plasma levels of autotaxin and its enzymatic product, lysophosphatidic acid (LPA), are elevated during HCV infection, and LPA activates immunocytes, but whether this contributes to immune activation is unknown.

METHODS

 We evaluated plasma levels of autotaxin, interleukin 6 (IL-6), soluble CD14 (sCD14), soluble CD163 (sCD163), and Mac2 binding protein (Mac2BP) during HCV infection, HIV infection, and HCV-HIV coinfection, as well as in uninfected controls, before and after HIV antiretroviral therapy (ART) initiation and during interferon-free HCV therapy.

RESULTS

 We observed greater plasma autotaxin levels in HCV-infected and HCV-HIV-coinfected participants, compared with uninfected participants, primarily those with a higher ratio of aspartate aminotransferase level to platelet count. Autotaxin levels correlated with IL-6, sCD14, sCD163, Mac2BP, and LPA levels in HCV-infected participants and with Mac2BP levels in HCV-HIV-coinfected participants, while in HIV-infected individuals, sCD14 levels correlated with Mac2BP levels. Autotaxin, LPA, and sCD14 levels normalized, while sCD163 and Mac2BP levels partially normalized within 6 months of starting interferon-free HCV therapy. sCD163 and IL-6 levels normalized within 6 months of starting ART for HIV infection. In vitro, LPA activated monocytes.

CONCLUSIONS

 These data indicate that elevated levels of autotaxin and soluble markers of immune activation during HCV infection are partially reversible within 6 months of initiating interferon-free HCV treatment and that autotaxin may be causally linked to immune activation during HCV infection and HCV-HIV coinfection.

Systemic inflammation and liver damage in HIV/hepatitis C virus coinfection

OBJECTIVES

Chronic hepatitis C virus (HCV) and HIV viral infections are characterized by systemic inflammation. Yet the relative levels, drivers and correlates of inflammation in these settings are not well defined.

METHODS

Seventy-nine HIV-infected patients who had been receiving antiretroviral therapy (ART) for more than 2 years and who had suppressed plasma HIV levels (< 50 HIV-1 RNA copies/mL) were included in the study. Two patient groups, HCV-positive/HIV-positive and HCV-negative/HIV-positive, and a control group comprised of healthy volunteers (n = 20) were examined. Markers of systemic inflammation [interleukin (IL)-6, interferon gamma-induced protein (IP)-10, soluble tumour necrosis factor receptor-I (sTNF-RI) and sTNF-RII], monocyte/macrophage activation [soluble CD163 (sCD163), soluble CD14 and neopterin], intestinal epithelial barrier loss [intestinal fatty acid binding protein (I-FABP) and lipopolysaccharide (LPS)] and coagulation (d-dimers) were analysed. CD4 naïve T cells and CD4 recent thymic emigrants (RTEs) were enumerated.

RESULTS

Plasma levels of IP-10, neopterin and sCD163 were higher in HCV/HIV coinfection than in HIV monoinfection and were positively correlated with indices of hepatic damage [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the AST to platelet ratio index (APRI)]. Levels of I-FABP were comparably increased in HIV monoinfection and HIV/HCV coinfection but LPS concentrations were highest in HCV/HIV coinfection, suggesting impaired hepatic clearance of LPS. Plasma HCV levels were not related to any inflammatory indices except sCD163. In coinfected subjects, a previously recognized relationship of CD4 naïve T-cell and RTE counts to hepatocellular injury was defined more mechanistically by an inverse relationship to sCD163.

CONCLUSIONS

Hepatocellular injury in HCV/HIV coinfection is linked to elevated levels of certain inflammatory cytokines and an apparent failure to clear systemically translocated microbial products. A related decrease in CD4 naïve T cells and RTEs also merits further exploration.

Soluble CD14 is a nonspecific marker of monocyte activation

Soluble CD14 is associated with morbidity and mortality in HIV disease. It is a co-receptor for lipopolysaccharide (LPS) that is released from monocytes upon activation. We demonstrate here, that inflammatory cytokines can induce the release of sCD14 in peripheral blood mononuclear cell cultures from healthy donors, and that TLR ligands other than LPS can cause a decrease in the monocyte cell surface expression of CD14. Thus, sCD14 is a marker of monocyte activation, not restricted to activation by LPS.

Acute and chronic immune biomarker changes during interferon/ribavirin treatment in HIV/HCV co-infected patients

Chronic viral infections lead to persistent immune activation, which is alleviated by eradicating or suppressing the infection. To understand the effects of interferon treatment on immune system activation by chronic infections, we evaluated kinetic patterns of a broad spectrum of serum biomarkers during HCV treatment in HIV/HCV co-infected patients. HCV viral load and 50 biomarkers were analysed at baseline and 27 time points during pegylated interferon-alpha and ribavirin (IFN/RBV) treatment of 12 HIV/HCV co-infected patients. We evaluated biomarker changes from baseline for each time point and biomarker correlations with clinical parameters, treatment response and liver histopathology. IL-1α, IL-12p40, IL-1RA, IP-10, MIG, MIP-1α/1β, HGF, sCD40L, TRAIL and leptin increased in the first day. IL-12p70, IL-17A, IL-10, GROα, IL-8, MCP-3, IL-4 and M-CSF peaked later during week 1. IL-1α, HGF, IP-10, MIP-1α, TRAIL, sCD40L, IL-10, IL-12p70, MCP-3, FGFb, ENA-78, TGF-β, IL-2, IFN-γ, IL-6, IL-15, IL-7 and PDGF-BB decreased below baseline over the course of treatment. Higher BMI, baseline HCV viral load and leptin levels were associated with lack of sustained virologic response. ENA-78 was associated with sustained viral response. Positive correlations were found between liver inflammation and baseline CD4 count, sVCAM and HGF; fibrosis stage and HGF; liver steatosis, BMI and leptin. Our findings suggest IFN/RBV treatment initially increases levels of several biomarkers, but eventually leads to a decline in many immune markers. These findings shed light on the relationship between IFN treatment and immune activation by chronic viral infections, such as HCV.