Background

AIDS-related non-Hodgkin lymphoma (AIDS-NHL) is a common AIDS-defining cancer. Prior studies suggest that chronic B-cell activation precedes AIDS-NHL diagnosis. Activation of B cells by multiple factors, including Toll-like receptor (TLR) signaling, leads to the expression of activation-induced cytidine deaminase (AID), a DNA mutating molecule that can contribute to oncogene translocations/mutations, leading to NHL. The goal of this study was to determine whether surface markers expressed on activated and/or germinal center B cells, and AID expression, were elevated on circulating B cells preceding AIDS-NHL and to determine if TLR signaling contributes to this activated B-cell phenotype.

Methods

Stored viable peripheral blood mononuclear cell specimens, obtained before AIDS-NHL diagnosis, were assessed by multicolor flow cytometry. Additionally, B cells isolated from peripheral blood mononuclear cell were exposed to TLR ligands in vitro, after which B-cell phenotype was assessed by flow cytometry.

Results

An elevated fraction of B cells expressing CD10, CD71, or CD86 was seen in those who went on to develop AIDS-NHL. AID expression was detected in some who developed AIDS-NHL, but not in HIV+ or HIV- controls. TLR2-stimulated purified B cells exhibited the activated B-cell phenotype observed in HIV+ subjects before AIDS-NHL diagnosis.

Conclusions

These results indicate that an elevated fraction of B cells display an activated/germinal center phenotype in those HIV+ subjects who go on to develop AIDS-NHL and suggest that TLR2-mediated activation may play a role in HIV infection-associated B-cell activation, potentially contributing to the genesis of AIDS-NHL.

Background

Microbial translocation has been implicated in the pathogenesis of liver fibrosis and cirrhosis. We sought to determine whether markers of microbial translocation are associated with liver disease progression during coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV).

Methods

We measured serial plasma lipopolysaccharide (LPS), endotoxin core antibody, intestinal fatty acid-binding protein (I-FABP), soluble CD14 (sCD14), interleukin 6 (IL-6), interleukin 10, and tumor necrosis factor α (TNF-α) levels over a 5-year period in 44 HIV/HCV-coinfected women, 21 of whom experienced liver disease progression and 23 were nonprogressors.

Results

While LPS levels did not differ significantly over time between progressors and nonprogressors (P = .60), progressors had significantly higher plasma levels of sCD14, a marker of monocyte activation by LPS, at the first time point measured (P = .03) and throughout the study period (P = .001); progressors also had higher IL-6 and I-FABP levels over the 5-year study period (P = .02 and .03, respectively). The associations between progression and sCD14, I-FABP, and IL-6 levels were unchanged in models controlling for HIV RNA and CD4(+) T-cell count.

Conclusions

Although LPS levels did not differ between liver disease progressors and nonprogressors, the association of sCD14, I-FABP, and IL-6 levels with liver disease progression suggests that impairment of gut epithelial integrity and consequent microbial translocation may play a role in the complex interaction of HIV and HCV pathogenesis.

HIV-infection is associated with dramatic changes in the intestinal mucosa. The impact of other viral pathogens is unclear.Eighty biopsies from left and right colon (n=63) and terminal ileum (n = 17) were collected from 19 HIV-infected and 22 HIV-uninfected subjects. Levels of cytomegalovirus (CMV) and Epstein Barr Virus (EBV) DNA were measured by droplet-digital (dd)PCR. Mucosal gene expression was measured via multiplex-assay. Microbiome analysis was performed using bacterial 16S-rDNA-pyrosequencing. The effect of CMV and EBV replication on the microbiome composition and mRNA-expression of selected cytokines (IL-6,IFN-γ,IL-1β, CCL2,IL-8 IFN-β1) was evaluated.Overall, CMV and EBV were detected in at least one intestinal site in 60.5% and 78.9% of subjects, respectively. HIV-infected individuals demonstrated less detectable CMV (p = 0.04); CMV was more frequently detected in terminal ileum than colon (p = 0.04). Detectable EBV was more frequent among HIV-infected (p = 0.05) without differences by intestinal site. The number of operational taxonomic units did not differ by CMV or EBV detection status. Among HIV-infected subjects, higher CMV was only associated with lower relative abundance of Actinobacteria in the ileum (p = 0.03). Presence of CMV was associated with up-regulated expression of all selected cytokines in the ileum (p < 0.02) and higher expression of IL-8 and IFN-β1 in the colon (P < 0.05) of HIV-uninfected subjects, but not among HIV-infected. EBV had no effect on cytokine expression or microbiome composition whatsoever.These results illustrate a complex interplay between HIV-infection, intestinal CMV replication and mucosal gut environment, and highlight a possible modulatory effect of CMV on the microbial and immune homeostasis.

Background

Maladaptive immune responses contribute to the pathogenesis of many chronic lung diseases. Here, we tested hypotheses that CD4 and CD8 T-cell and monocyte phenotypes are associated with lung function in people living with HIV and those without HIV.

Methods

Markers of T cell differentiation, activation, exhaustion and senescence, and markers of monocyte recruitment and migration were quantified in 142 HIV-positive and 73 HIV-negative participants of the Pittsburgh HIV Lung Cohort. All participants underwent lung function testing.

Results

CD4 or CD8 T-cell phenotypes were not associated with measures of lung function in HIV-positive or HIV-negative participants after adjustment for multiple comparisons. In HIV-positive participants, however, the percentage of classical monocytes that were CD11b+ had positive associations at the Bonferroni-adjusted significance threshold of P = 0.05/63 with prebronchodilator and postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio (β = 0.36; P = 0.00003 and β = 0.31; P = 0.0003, respectively). In stratified analyses of n = 87 participants with CD4 ≥ 500 cells/µL, associations of percentage of classical monocytes that were CD11b+ with prebronchodilator and postbronchodilator FEV1/FVC ratio were stronger (β = 0.48 and β = 0.41, for pre- and post-, respectively) than in the entire HIV-positive study population. Significant associations of monocyte phenotypes were not observed in HIV-negative participants after adjustment for multiple comparisons.

Conclusions

CD11b+ expression on classical monocytes is positively associated with FEV1/FVC ratio in people living with HIV including in those with CD4 T-cell recovery. Given the normal surveillance activity of monocytes, such association suggests this monocyte subset may play a role in preservation of pulmonary function in PLWH.

Background

HIV-1 infection is associated with intestinal inflammation, changes in the enteric microbiota (dysbiosis), and intestinal epithelial cell damage. NKp44 innate lymphoid cells (ILCs) play an important role in epithelial barrier maintenance through the production of interleukin (IL)-22 but also display functional plasticity and can produce inflammatory cytokines [eg, interferon gamma (IFNγ)] in response to cytokine milieu and stimulatory signals. The objective of this pilot study was to enumerate frequencies of IL-22 and IFNγ-expressing colonic NKp44 ILCs during untreated, chronic HIV-1 infection.

Setting

A cross-sectional study was performed to compare numbers of cytokine-expressing ILCs in colonic biopsies of untreated, chronic HIV-1 infected (n = 22), and uninfected (n = 10) study participants. Associations between cytokine ILC and previously established measures of virological, immunological, and microbiome indices were analyzed.

Methods

Multicolor flow cytometry was used to measure the absolute number of colonic CD3NKp44CD56 ILCs expressing IL-22 or IFNγ after in vitro mitogenic stimulation.

Results

Numbers of colonic NKp44 ILCs that expressed IFNγ were significantly higher in HIV-1 infected versus uninfected persons and positively correlated with relative abundances of dysbiotic bacterial species in the Xanthomonadaceae and Prevotellaceae bacterial families and with colonic myeloid dendritic cell and T-cell activation.

Conclusion

Higher numbers of inflammatory colonic ILCs during untreated chronic HIV-1 infection that associated with dysbiosis and colonic myeloid dendritic cell and T-cell activation suggest that inflammatory ILCs may contribute to gut mucosal inflammation and epithelial barrier breakdown, important features of HIV-1 mucosal pathogenesis.

Background

HIV-infection is associated with dramatic changes in the intestinal mucosa. The impact of other viral pathogens is unclear.

Methods

One hundred and eight (108) biopsies from left and right colon (n = 79) and terminal ileum (n = 29) were collected from 19 HIV-infected and 22 HIV-uninfected participants. Levels of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) DNA were measured by droplet digital PCR. Mucosal gene expression was measured via multiplex-assay. Microbiome analysis was performed using bacterial 16S-rDNA-pyrosequencing. The effect of CMV and EBV replication on the microbiome composition and mRNA-expression of selected cytokines (IL-6, IFN-γ, IL-1β, CCL2, IL-8, and IFN-β1) was evaluated.

Results

Overall, CMV and EBV were detected in at least one intestinal site in 60.5 and 78.9% of participants, respectively. HIV-infected individuals demonstrated less detectable CMV (PB = 0.02); CMV was more frequently detected in terminal ileum than colon (PB = 0.05). Detectable EBV was more frequent among HIV-infected (P B= 0.04) without differences by intestinal site. The number of operational taxonomic units did not differ by CMV or EBV detection status. Among HIV-infected participants, higher CMV was only associated with lower relative abundance of Actinobacteria in the ileum (P = 0.03). Presence of CMV was associated with upregulated expression of all selected cytokines in the ileum (all P < 0.02) and higher expression of IL-8 and IFN-β1 in the colon (all P < 0.05) of HIV-uninfected participants, but not among HIV-infected. EBV had no effect on cytokine expression or microbiome composition whatsoever.

Conclusion

These results illustrate a complex interplay among HIV-infection, intestinal CMV replication, and mucosal gut environment, and highlight a possible modulatory effect of CMV on the microbial and immune homeostasis.

Background

We examined changes in soluble inflammatory cytokines and T-cell activation after antiretroviral therapy (ART) initiation in an AIDS Clinical Trials Group (ACTG) nested case-control study.

Methods

Cases were 143 human immunodeficiency virus (HIV)-infected adults who developed a non-AIDS event; 315 controls remained event-free. Specimens were tested pre-ART, year 1 post-ART, and at the visit preceding the event. Conditional logistic regression evaluated the associations of biomarker changes with non-AIDS events.

Results

Inflammatory and most activation biomarkers declined from pre-ART to year 1 for cases and controls. Subsequently, inflammatory biomarkers remained mostly stable in controls but not cases. Cellular activation markers generally declined for both cases and controls between year 1 and the pre-event sampling. Controls with greater pre-ART RNA levels or lower CD4+ levels had higher biomarker levels while also experiencing greater biomarker declines in the first year of ART. Changes in biomarkers to year 1 showed no significant associations with non-AIDS events. Cases, however, had significantly greater increases in all plasma biomarkers (but not cellular activation) from year 1 to the visit preceding the event.

Conclusions

Inflammation increases prior to non-AIDS events in treated HIV-infected adults. These biomarker changes may reflect subclinical disease processes or other alterations in the inflammatory environment that causally contribute to disease.

Clinical trials registration

NCT00001137.

HIV-infection is associated with dramatic changes in the intestinal mucosa. The impact of other viral pathogens is unclear.Eighty biopsies from left and right colon (n=63) and terminal ileum (n = 17) were collected from 19 HIV-infected and 22 HIV-uninfected subjects. Levels of cytomegalovirus (CMV) and Epstein Barr Virus (EBV) DNA were measured by droplet-digital (dd)PCR. Mucosal gene expression was measured via multiplex-assay. Microbiome analysis was performed using bacterial 16S-rDNA-pyrosequencing. The effect of CMV and EBV replication on the microbiome composition and mRNA-expression of selected cytokines (IL-6,IFN-γ,IL-1β, CCL2,IL-8 IFN-β1) was evaluated.Overall, CMV and EBV were detected in at least one intestinal site in 60.5% and 78.9% of subjects, respectively. HIV-infected individuals demonstrated less detectable CMV (p = 0.04); CMV was more frequently detected in terminal ileum than colon (p = 0.04). Detectable EBV was more frequent among HIV-infected (p = 0.05) without differences by intestinal site. The number of operational taxonomic units did not differ by CMV or EBV detection status. Among HIV-infected subjects, higher CMV was only associated with lower relative abundance of Actinobacteria in the ileum (p = 0.03). Presence of CMV was associated with up-regulated expression of all selected cytokines in the ileum (p < 0.02) and higher expression of IL-8 and IFN-β1 in the colon (P < 0.05) of HIV-uninfected subjects, but not among HIV-infected. EBV had no effect on cytokine expression or microbiome composition whatsoever.These results illustrate a complex interplay between HIV-infection, intestinal CMV replication and mucosal gut environment, and highlight a possible modulatory effect of CMV on the microbial and immune homeostasis.

Background

People with HIV (PWH) on antiretroviral therapy (ART) still experience an increased risk of morbidity and mortality, presumably driven by chronic inflammation, yet predictors of discrete or combinatorial outcomes remain unclear. Galectin-9 (Gal-9), a driver of both inflammatory and immunosuppressive responses, has been associated with HIV disease progression and multimorbidity.

Objective

To determine whether plasma Gal-9 levels are associated with the occurrence of specific non-AIDS events (NAEs) in PWH initiating ART.

Design

We performed a nested case-control study of PWH enrolled from 2001 to 2009 and evaluated pre-ART (66 cases, 97 controls), a year post-ART (112 cases, 211 controls), and immediately preceding an event (89 cases, 162 controls). Events included myocardial infarction/stroke, malignancy, serious bacterial infection, or death.

Methods

Plasma Gal-9 levels were assessed by ELISA. Conditional logistic regression assessed associations with NAEs and Spearman's correlations compared Gal-9 with other previously assessed biomarkers.

Results

NAEs occurred at a median of 2.8 years (1.7-4.6) after ART initiation. Higher Gal-9 levels were associated with increased risk of NAEs at year 1 and preevent [odds ratio (OR) per 1 interquartile range = 1.4-1.6; all P < 0.05], specifically myocardial infarction/stroke at year 1 (OR = 1.9; P = 0.029). Gal-9 also correlated with multiple inflammatory and immune activation predictors of NAEs (all timepoints).

Conclusion

Elevated Gal-9 levels are predictive of deleterious NAEs, particularly cardiovascular complications. Whether the Gal-9 pathway, potentially binding to its putative ligands, is active in the pathogenesis of these outcomes warrants further investigation to determine if targeting Gal-9 may slow or reverse the risk of NAEs.

Background

HIV-1 infection is associated with intestinal inflammation, changes in the enteric microbiota (dysbiosis), and intestinal epithelial cell damage. NKp44 innate lymphoid cells (ILCs) play an important role in epithelial barrier maintenance through the production of interleukin (IL)-22 but also display functional plasticity and can produce inflammatory cytokines [eg, interferon gamma (IFNγ)] in response to cytokine milieu and stimulatory signals. The objective of this pilot study was to enumerate frequencies of IL-22 and IFNγ-expressing colonic NKp44 ILCs during untreated, chronic HIV-1 infection.

Setting

A cross-sectional study was performed to compare numbers of cytokine-expressing ILCs in colonic biopsies of untreated, chronic HIV-1 infected (n = 22), and uninfected (n = 10) study participants. Associations between cytokine ILC and previously established measures of virological, immunological, and microbiome indices were analyzed.

Methods

Multicolor flow cytometry was used to measure the absolute number of colonic CD3NKp44CD56 ILCs expressing IL-22 or IFNγ after in vitro mitogenic stimulation.

Results

Numbers of colonic NKp44 ILCs that expressed IFNγ were significantly higher in HIV-1 infected versus uninfected persons and positively correlated with relative abundances of dysbiotic bacterial species in the Xanthomonadaceae and Prevotellaceae bacterial families and with colonic myeloid dendritic cell and T-cell activation.

Conclusion

Higher numbers of inflammatory colonic ILCs during untreated chronic HIV-1 infection that associated with dysbiosis and colonic myeloid dendritic cell and T-cell activation suggest that inflammatory ILCs may contribute to gut mucosal inflammation and epithelial barrier breakdown, important features of HIV-1 mucosal pathogenesis.