Monocyte Activation Research Articles

Immune Activation Is Associated With Neurocognitive Performance in Ugandan Adolescents Living With HIV.

We examined relationships between neurocognition and immune activation in Ugandan adolescents with perinatally acquired HIV (PHIV). Eighty-nine adolescents in Kampala, Uganda (32 virally suppressed [<400 copies/mL] PHIV and 57 sociodemographically matched HIV-negative controls), completed a tablet-based neurocognitive test battery. Control-derived z-scores for 12 individual tests and a global/overall z-score were calculated. We measured plasma (soluble CD14 and CD163), monocyte (proportions of monocyte subsets), and T-cell (expression of CD38 and HLA-DR on CD4 + and CD8 + ) activation and gut markers. Spearman rank correlations and median regressions examined associations between test performance and immune activation. The median [IQR] age was 15 [13-16] years, and 40% were girls. The median time on antiretroviral therapy was 10 years [7-11] for PHIV; 87% had viral load <50 copies/mL. Compared with controls, global z-scores were lower among PHIV ( P = 0.05) and significantly worse on tests of executive functioning and delayed recall ( P 's ≤ 0.05). Overall, monocyte activation significantly correlated with worse test performance on global z-score (r = 0.21, P = 0.04), attention, processing speed, and motor speed (r = 0.2-0.3, P ≤ 0.01). T-cell activation was significantly correlated with worse performance on tests of learning, executive functioning, and working memory (r = 0.2-0.4, P ≤ 0.04). In PHIV, after adjusting for age, sex, and antiretroviral therapy duration, activated CD4 T cells remained associated with worse memory (β-0.3, 95% CI: -0.55 to -0.07, P = 0.01). PHIV with virologic suppression on antiretroviral therapy shows evidence of worse neurocognitive test performance compared with controls. Monocyte and T-cell activation is correlated with worse neurocognition in Ugandan youth with and without HIV, which has not been previously investigated in this setting.

Pluronic F127/lecithin PLGA nanoparticles as carriers of monocyte-targeted jakinibs: a potential therapeutic platform.

Aim: In this study, PLGA nanoparticles (PNPs) emulsified in Pluronic F127 (F127)/Lecithin (LEC) were designed to load Itacitinib (ITA), a selective JAK1 inhibitor, for targeting human monocytes.Materials & methods: The physicochemical characteristics of empty and ITA-loaded F127/LEC PNPs were analyzed. The binding and internalization of NPs in leukocytes were evaluated. The effect of NPs on monocyte activation and JAK1 inhibition was assessed.Results: F127/LEC PNPs were selectively bound and internalized by monocytes, sparing other leukocytes. ITA-F127/LEC PNPs significantly dampened monocyte activation. They also inhibited the monocyte's ability to promote T-cell proliferation and inhibited proinflammatory cytokine production.Conclusion: ITA-loaded F127/LEC PNPs showed potential for monocyte-targeted therapy, offering new avenues for disease treatment.

Effect of interleukin 1b inhibition with canakinumab on inflammation and viral persistence in people with human immunodeficiency virus

Abstract Introduction Effectively treated people with HIV (PWH) have elevated risk of cardiovascular disease (CVD). Inflammatory markers are predictive of CVD and mortality among PWH. The role of the myeloid system in driving inflammation and atherosclerosis has been recently recognized. Canakinumab (a monoclonal antibody to IL-1β) reduces inflammation and CVD events among people with elevated hsCRP after myocardial infarction without HIV. We evaluated the impact of IL-1β inhibition using canakinumab on HIV parameters, inflammation, HIV persistence markers, arterial inflammation, and hematopoietic activity in PWH. Methods PWH on effective ART who had CVD or were at risk for CVD were randomized 2:1 to receive 150 mg of canakinumab subcutaneously or matched placebo at weeks 0 and 12. Arterial inflammation and bone marrow metabolic activity were assessed using F18 FDG PET/CT at baseline and week 18. T cell and monocyte activation were evaluated using multiparameter spectral cytometry. The viral reservoir was quantified using Tat/rev Induced Limiting Dilution Assay (TILDA), HIV DNA and cell-associated RNA. The primary endpoints were change in CD4 and CD8 count. We assessed group effects over time using linear mixed effects models. Results 33 individuals were randomized (median age of 60 years old (IQR 57.5, 64.5) and 94% male); 25 received canakinumab and 8 received placebo. There were no significant differences at baseline. As expected, IL-1β increased among those treated with canakinumab at weeks 4- 24 (p&amp;lt;0.01 for each) and returned to baseline at week 36. There was one death from sepsis in an individual aged 84 with CVD and poorly controlled diabetes who received canakinumab. There were no significant changes in CD4 count, CD8 count, platelet count, creatinine, AST, or ALT by group. Treatment was not associated with a greater reduction in arterial inflammation in the most diseased segment compared to placebo (-6.9%; 95% CI -30.4 to 24.5%; p=0.62). However, bone marrow metabolic activity decreased in the canakinumab group versus placebo (-14.4%, 95% CI -26.5% to -0.2%; p=0.047). Treatment was associated with increased CD163 expression on monocytes at weeks 24 (p=0.03) and 36 (p&amp;lt;0.001), and lower caspase activity at week 36 (p=0.02). There was expansion of anti-inflammatory CD16+ patrolling monocytes that co-express CD163+CX3CR1+ and a decrease in pro-inflammatory CD16+ patrolling monocytes that are Caspase1+CCR2+. Treatment was not associated with differences in hsCRP, IL-6, IL-16, IL-18, MCP-1, sCD14, sCD163, T cell subsets, NK cell subsets, or viral persistence markers. Conclusion Among treated PWH, targeted inhibition of IL-1β using canakinumab results in decreased bone marrow metabolic activity and a shift toward anti-inflammatory monocyte populations. These findings shed light on mechanisms underlying how targeted IL-1β inhibition using canakinumab prevents CVD events by altering monocyte populations and reducing systemic inflammation.

Monocyte response to mitochondrial DAMPs in elderly subjects: a possible contribution to chronic inflammation and atherosclerosis

Abstract Background Aging is an important risk factor for atherosclerosis and persists as an independent contributor when all other known factors are controlled. Circulating free mitochondrial DNA (cf-mtDNA) can activate immune cells, including monocytes, that promote plaque formation and produce proinflammatory cytokines [1]. Several receptors, including TLR9, AIM2, NLRP3, cGAS can bind cf-mtDNA and activate downstream pathways, leading to the activation of proinflammatory genes [2]. We previously showed that mtDNA increases with age, and at the highest concentrations observed in plasma, can enhance the pro-inflammatory effect of bacterial PAMPs [3]. Nevertheless, it is unknown if the pathways triggered by mtDNA are functionally preserved in elderly, and if it can synergize with oxidized low-density lipoproteins (ox-LDL), which are known to interact with TLR4 and TLR2, in concert with scavenger receptors to regulate the inflammatory microenvironment in atherosclerosis. Purpose This study aims to understand if and how the cf-mtDNA activates monocytes triggering an inflammatory response, if monocyte from young and old donors present a different response to mtDNA if age-related difference in the functional activity of these cells. Methods We selected 10 old subjects (74.4 ± 2.4 y.o.; 2M:8F) without a history of cardiovascular or peripheral arterial diseases, 4 ultranonagenarians (98.3 ± 4.7 y.o.; 1M:3F) and 9 sex-matched young controls (28.4 ± 7.3 y.o.; 0M:9F). Monocytes were isolated from blood samples, and inflammatory response to mtDNA alone or in combination with LPS was assessed, by analyzing TLR9 expression, NF-kB activation and the release in the supernatants of a panel of proinflammatory cytokines. Results Monocyte expression of the mtDNA receptor TLR9 showed a slight reduction with aging, and is similar in old subjects and ultranonagenarians. mtDNA was internalized only in cells pre-treated with LPS and co-localized with TLR9. When internalization occurred, monocytes treated with mtDNA+LPS, released pro-inflammatory cytokines at higher levels than cells treated with LPS alone. Monocytes from elderly subjects showed a partial impairment in mtDNA uptake, and a lower capability to activate TLR9 downstream pathway. However, the capability to secrete pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) was not compromised, and NF-kB translocation into the nucleus after treatment with mtDNA is preserved, suggesting that compensatory mechanisms allowed mtDNA-driven activation of monocytes in elderly people. Conclusions The capability of mtDNA to promote an inflammatory response is preserved in elderly people and is still present in ultranonagenarians subjects. As mtDNA plasma levels increase with aging, mtDNA likely act as proinflammatory agents in aged people and can contribute to maintain inflammation in the atherosclerotic plaques. Further studies will clarify if mtDNA can act synergistically with ox-LDL to promote monocyte activation.

Brazilian red propolis synergistically with imipenem modulates immunological parameters and the bactericidal activity of human monocytes against methicillin-resistant Staphylococcus aureus (MRSA).

Propolis is a bee product found all over the globe and has a well-known antibacterial activity. Previous findings of our group revealed that the combination of Brazilian red propolis (BRP) with a lower concentration of imipenem (IPM) exerted a bactericidal action against methicillin-resistant Staphylococcus aureus (MRSA) in vitro. Here, we aimed at investigating the effects of BRP in combination or not with IPM on human monocytes to assess a possible immunomodulatory action. Monocyte metabolic activity was analysed by MTT assay, cytokine production (TNF-α, IL-1β, IL-6, IL-8, and IL-10) by ELISA, and the expression of cell markers (TLR-2, TLR-4, HLA-DR, and CD80) by flow cytometry. The bactericidal activity of monocytes over MRSA was determined by colony-forming units' count. BRP alone or in combination with IPM exerted no cytotoxic effects on monocytes. BRP downregulated TLR-2 expression and inhibited TNF-α, IL-1β, and IL-6 production, while BRP + IPM stimulated these parameters. BPR alone or in combination increased the bactericidal activity similarly to LPS-activated monocytes. Data indicated the potential of BRP as an anti-inflammatory agent increasing the bactericidal activity of monocytes against MRSA. The combination of BRP + IPM exhibited a stimulatory profile that may be potentially useful in treating patients with MRSA infection.

Non-classical monocyte levels correlate negatively with HIV-associated cerebral small vessel disease and cognitive performance

BackgroundDespite antiretroviral treatment (cART), aging people living with HIV (PWH) are more susceptible to neurocognitive impairment (NCI) probably due to synergistic/additive contribution of traditional cerebrovascular risk factors. Specifically, transmigration of inflammatory CD16+ monocytes through the altered blood brain barrier (BBB) may exacerbate cerebral small vessel disease (CSVD), a known cause of vascular cognitive impairment.MethodsPWH on cART (n=108) and age, sex, and Reynold’s cardiovascular risk score-matched uninfected individuals (PWoH, n=111) were enrolled. This is a longitudinal observational study but only cross-sectional data from entry visit are reported. Neuropsychological testing and brain magnetic resonance imaging (MRI) were performed. CSVD was diagnosed by Fazekas score ≥1. Flow cytometric analyses of fresh whole blood were conducted to evaluate circulating levels of monocyte subsets (classical, intermediate, and non-classical) and markers of monocyte activation (CCR2, CD40, PSGL-1, TNFR2 and tissue factor). ELISAs were used to measure sCD14, ICAM, and Osteoprotegerin. Two-way analysis of variance (ANOVA), and linear regression models were performed to study the effects of HIV status, CSVD status, and their interaction to outcome variables such as cognitive score. Two-sample t-tests and correlation analyses were performed between and within PWoH with CSVD and PWH with CSVD participants.ResultsPWH with CSVD (n=81) had significantly lower total cognitive scores, higher levels of NCMs and soluble CD14 and intracellular adhesion molecule 1 (ICAM-1) as compared to PWoH with CSVD group (n=68). sCD14 and ICAM1 were positively correlated with each other indicating that monocyte and endothelial activation are associated with each other. Cognition was negatively correlated with NCMs, especially in the PWH with CSVD group. Among other blood biomarkers measured, osteoprotegerin levels showed mild negative correlation with cognitive performance in individuals with CSVD irrespective of HIV status.ConclusionsElevated levels of NCMs may contribute to neuroinflammation, CSVD and subsequent cognitive impairment. This finding is of particular relevance in aging PWH as both HIV and aging are associated with increased levels of NCMs. NCMs may serve as a potential biomarker to address these comorbidities. Further longitudinal studies are needed to evaluate whether changes in NCM levels are associated with changes in CSVD burden and cognitive impairment.

Photocatalytic Degradation of Bacterial Lipopolysaccharides by Peptide-Coated TiO2 Nanoparticles.

In this study, we report the degradation of smooth and rough lipopolysaccharides (LPS) from Gram-negative bacteria and of lipoteichoic acid (LTA) from Gram-positive bacteria by peptide-coated TiO2 nanoparticles (TiO2 NPs). While bare TiO2 NPs displayed minor binding to both LPS and LTA, coating TiO2 NPs with the antimicrobial peptide LL-37 dramatically increased the level of binding to both LPS and LTA, decorating these uniformly. Importantly, peptide coating did not suppress reactive oxygen species generation of TiO2 NPs; hence, UV illumination triggered pronounced degradation of LPS and LTA by peptide-coated TiO2 NPs. Structural consequences of oxidative degradation were examined by neutron reflectometry for smooth LPS, showing that degradation occurred preferentially in its outer O-antigen tails. Furthermore, cryo-TEM and light scattering showed lipopolysaccharide fragments resulting from degradation to be captured by the NP/lipopolysaccharide coaggregates. The capacity of LL-37-TiO2 NPs to capture and degrade LPS and LTA was demonstrated to be of importance for their ability to suppress lipopolysaccharide-induced activation in human monocytes at simultaneously low toxicity. Together, these results suggest that peptide-coated photocatalytic NPs offer opportunities for the confinement of infection and inflammation.

The impact of trauma relevant concentrations of prostaglandin E2 on the anti-microbial activity of the innate immune system

BackgroundThe mechanisms underlying the state of systemic immune suppression that develops following major trauma are poorly understood. A post-injury increase in circulating levels of prostaglandin E2 (PGE2) has been proposed as a contributory factor, yet few studies have addressed how trauma influences PGE2 biology.MethodsBlood samples from 95 traumatically-injured patients (injury severity score ≥8) were collected across the pre-hospital (≤2 hours), acute (4-12 hours) and subacute (48-72 hours) post-injury settings. Alongside ex vivo assessments of lipopolysaccharide (LPS)-induced cytokine production by monocytes, neutrophil reactive oxygen species production and phagocytosis, serum concentrations of PGE2 and its scavenger albumin were measured, and the expression of enzymes and receptors involved in PGE2 synthesis and signalling analysed. Leukocytes from trauma patients were treated with cyclooxygenase (COX) inhibitors (indomethacin or NS-398), or the protein kinase A inhibitor H89, to determine whether injury-induced immune suppression could be reversed by targeting the PGE2 pathway. The effect that trauma relevant concentrations of PGE2 had on the anti-microbial functions of neutrophils, monocytes and monocyte-derived macrophages (MDMs) from healthy controls (HC) was examined, as was the effect of PGE2 on efferocytosis. To identify factors that may trigger PGE2 production post-trauma, leukocytes from HC were treated with mitochondrial-derived damage associated molecular patterns (mtDAMPs) and COX-2 expression and PGE2 generation measured.ResultsPGE2 concentrations peaked in blood samples acquired ≤2 hours post-injury and coincided with significantly reduced levels of albumin and impaired LPS-induced cytokine production by monocytes. Significantly higher COX-2 and phospholipase A2 expression was detected in neutrophils and/or peripheral blood mononuclear cells isolated from trauma patients. Treatment of patient leukocytes with indomethacin, NS-398 or H89 enhanced LPS-induced cytokine production and neutrophil extracellular trap generation. Exposure to physiological concentrations of PGE2 suppressed the anti-microbial activity of monocytes, neutrophils and MDMs of HC, but did not influence efferocytosis. In a formyl-peptide receptor-1 dependent manner, mtDAMP treatment significantly increased COX-2 protein expression in neutrophils and monocytes, which resulted in increased PGE2 production.ConclusionsPhysiological concentrations of PGE2 suppress the anti-microbial activities of neutrophils, monocytes and MDMs. Targeting the PGE2 pathway could be a therapeutic approach by which to enhance innate immune function post-injury.

Vaginal lactobacilli produce anti-inflammatory β-carboline compounds.

The optimal vaginal microbiome is a Lactobacillus-dominant community. Apart from Lactobacillus iners, the presence of Lactobacillus species is associated with reduced vaginal inflammation and reduced levels of pro-inflammatory cytokines. Loss of Lactobacillus-dominance is associated with inflammatory conditions, such as bacterial vaginosis (BV). We have identified that Lactobacillus crispatus, a key vaginal bacterial species, produces a family of β-carboline compounds with anti-inflammatory activity. These compounds suppress nuclear factor κB (NF-κB) and interferon (IFN) signaling downstream of multiple pattern recognition receptors in primary human cells and significantly dampen type I IFN receptor (IFNAR) activation in monocytes. Topical application of an anti-inflammatory β-carboline compound, perlolyrine, was sufficient to significantly reduce vaginal inflammation in a mouse model of genital herpes infection. These compounds are enriched in cervicovaginal lavage (CVL) of healthy people compared with people with BV. This study identifies a family of compounds by which vaginal lactobacilli mediate host immune homeostasis and highlights a potential therapeutic avenue for vaginal inflammation.

Renal Allograft Macrophage Infiltration in Antibody-Mediated Renal Allograft Rejection

Abstract Introduction/Objective Macrophages are involved in the pathogenesis and contribute to acute and chronic renal allograft injury. We evaluated CD163+ (M2) macrophage graft tissue infiltration and its correlation with clinical and histological prognostic factors. Urinary soluble CD163, circulating total, and monocyte-derived microparticles (MMPs) in plasma were also estimated and correlated with tissue M2 macrophage infiltration. Methods/Case Report The study included forty-five renal allograft recipients with for-cause graft biopsy, with Antibody-mediated Rejection (ABMR) (n=30) or no evidence of rejection (NER) (n=15), from Jan 2021-Dec 2023, along with fifteen age-matched healthy controls (HC). On immunohistochemistry, CD163 positive cells were counted in glomeruli and tubulointerstitium. Urinary sCD163 was done by ELISA. Flow cytometry quantified plasma MPs (AnnexinV+) and MMPs (CD14+/ AnnexinV+). Results (if a Case Study enter NA) The mean age of renal allograft recipients was 35±9yrs (all males). Mean s.creatinine in ABMR and NER was 3±2.6 and 2±0.5 mg/dl, respectively. ABMR had significantly more glomerular (16.2±13.7/10 glomeruli) and tubulointerstitial (183±108/10hpf) M2 macrophage (CD163+) cell infiltration than NER (4.8±4.7/10 glomeruli; 133.5±108/10hpf). Urinary sCD163 in ABMR was also significantly raised (0.89±0.63ng/ml) than in NER. It was not detectable in HC. Plasma MMPs were elevated in ABMR [25% of total MPs (1.62x104)] as compared to NER [8.2 % of total MPs (1.4x104)] and HC [7.8% of total MPs (1.2x104)]. In ABMR, the glomerular CD163+ cells correlated with urinary sCD163 levels (r=0.350, p=0.050) and circulating MMPs (r=0.526, p=0.002). Conclusion We found that in renal allograft recipients with ABMR, there is significantly higher graft biopsy glomerular CD163+ (M2) macrophage infiltration and elevated urinary sCD163 levels as compared to NER. The plasma circulating MMPs were also elevated in ABMR. Our findings suggest that monocyte activation plays a significant role in the pathogenesis and injury in ABMR. Non-invasive markers of monocyte activation can distinguish ABMR from NER in allograft recipients presenting with allograft dysfunction.

Autoinflammation in patients with leukocytic CBL loss of heterozygosity is caused by constitutive ERK-mediated monocyte activation.

Patients heterozygous for germline CBL loss-of-function (LOF) variants can develop myeloid malignancy, autoinflammation, or both, if some or all of their leukocytes become homozygous for these variants through somatic loss of heterozygosity (LOH) via uniparental isodisomy. We observed an upregulation of the inflammatory gene expression signature in whole blood from these patients, mimicking monogenic inborn errors underlying autoinflammation. Remarkably, these patients had constitutively activated monocytes that secreted 10 to 100 times more inflammatory cytokines than those of healthy individuals and CBL LOF heterozygotes without LOH. CBL-LOH hematopoietic stem and progenitor cells (HSPCs) outgrew the other cells, accounting for the persistence of peripheral monocytes homozygous for the CBL LOF variant. ERK pathway activation was required for the excessive production of cytokines by both resting and stimulated CBL-LOF monocytes, as shown in monocytic cell lines. Finally, we found that about 1 in 10,000 individuals in the UK Biobank were heterozygous for CBL LOF variants and that these carriers were at high risk of hematological and inflammatory conditions.

Regulatory T cells modulate monocyte functions in immunocompetent antiretroviral therapy naive HIV-1 infected people

We previously demonstrated that the overall number of regulatory T (Treg) cells decrease proportionately with helper CD4+ T cells and their frequencies increase in antiretroviral therapy (ART)-naive human immunodeficiency virus type-1 (HIV-1) infected individuals. The question now is whether the discrepancies in Treg cell numbers and frequencies are synonymous to an impairment of their functions. To address this, we purified Treg cells and assessed their ability to modulate autologous monocytes functions. We observed that Treg cells were able to down modulate autologous monocytes activation as well as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) production during stimulation with polyinosinic-polycytidylic acid stabilized with poly-L-lysine and carboxymethylcellulose (poly-ICLC). This activity of Treg cells has been shown to be influenced by immunocompetence including but not limited to helper CD4+ T cell counts, in individuals with HIV-1 infection. Compared to immunosuppressed participants (CD4 < 500 cells/µL), immunocompetent participants (CD4 ≥ 500 cells/µL) showed significantly higher levels of transforming growth factor beta (TGF-β) and IL-10 (p < 0.001 and p < 0.05, respectively), key cytokines used by Treg cells to exert their immunosuppressive functions. Our findings suggest the contribution of both TGF-β and IL-10 in the suppressive activity of Treg cells.

Association of circulating monocyte number and monocyte–lymphocyte ratio with cardiovascular disease in patients with bipolar disorder

BackgroundCardiovascular disease (CVD) is the leading cause of excessive and premature mortality in patients with bipolar disorder (BD). Despite immune cells participating considerably in the pathogenesis of CVD, limited data are available regarding leukocyte phenotypes in patients with BD and CVD. This study aimed to evaluate associations between circulating leukocyte subset and CVD among patients with BD.MethodsA total of 109 patients with BD-I and cardiologist-confirmed CVD diagnosis (i.e., case) were matched with 109 BD-I patients without CVD (i.e., control) according to the age (± 2 years), sex, and date of most recent psychiatric admission because of acute mood episode (± 2 years). Leukocyte subset data were retrieved from complete blood count tests performed on the next morning after the most recent acute psychiatric admission.ResultsDuring the most recent acute psychiatric hospitalization, circulating monocyte counts in the case group were significantly higher than those in the age- and sex-matched controls (p = 0.020). In addition, monocyte–lymphocyte ratios (MLRs) in the case group were significantly higher than those in the control group (p = 0.032). Multiple logistic regression showed that together with serum levels of uric acid and manic symptoms, circulating monocyte counts (95% CI, OR: 1.01–1.05) and MLRs (95% CI, OR: 1.01–1.09) were significantly associated with CVD in patients with BD, respectively.ConclusionsMonocyte activation in an acute manic episode may play a critical role in the pathogenesis of CVD among patients with BD. Future research is required to investigate markers of monocyte activation and indices of cardiovascular structure and function across the different mood states of BD.

Rs2564978(T) allele associated with severe influenza a disrupts binding site for myeloid differentiation factor PU.1 and reduces &lt;i&gt;CD55/DAF&lt;/i&gt; gene promoter activity in macrophages

An inhibitor of the complement system CD55/DAF is expressed on many cell types. Dysregulation of CD55 expression is associated with increased disease severity during influenza A infection, as well as with vascular complications in pathologies involving excessive activation of the complement system. Using a luciferase reporter system, we performed functional analysis of the single nucleotide polymorphism rs2564978 located in the promoter of the CD55 gene in human pro-monocytic cell line U937. We have shown a decreased activity in activated U937 cells of the CD55 gene promoter carrying minor rs2564978(T) allele associated with the severe course of influenza A(H1N1)pdm09. Using bioinformatic resources, we determined that transcription factor PU.1 can potentially bind to the CD55 promoter region containing rs2564978 in an allele-specific manner. The involvement of PU.1 in modulating CD55 promoter activity was determined by genetic knockdown of PU.1 using small interfering RNAs under specific monocyte activation conditions.

Neutrophil extracellular traps activate hepatic stellate cells and monocytes via NLRP3 sensing in alcohol-induced acceleration of MASH fibrosis

ObjectiveAlcohol use in metabolic dysfunction-associated steatohepatitis (MASH) is associated with an increased risk of fibrosis and liver-related death. Here, we aimed to identify a mechanism through which repeated alcohol binges...

Single-cell RNA Sequencing Reveals the Diversity of the Immunological Landscape Response to Genital Herpes

Genital herpes (GH) is a common sexually transmitted disease, which is primarily caused by herpes simplex virus type 2 (HSV-2), and continues to be a global health concern. Although our understanding of the alterations in immune cell populations and immunomodulation in GH patients is still limited, it is evident that systemic intrinsic immunity, innate immunity, and adaptive immunity play crucial roles during HSV-2 infection and GH reactivation. To investigate the mechanisms underlying HSV-2 infection and recurrence, single-cell RNA sequencing (scRNA-seq) was performed on immune cells isolated from the peripheral blood of both healthy individuals and patients with recurrent GH. Furthermore, the systemic immune response in patients with recurrent GH showed activation of classical monocytes, CD4+ T cells, natural killer cells (NK cells), and plasmacytoid dendritic cells (pDCs), especially of genes associated with the Toll-like receptor signaling pathway and T cell activation. Circulating immune cells in GH patients show higher expression of genes associated with inflammation and antiviral responses both in the scRNA-Seq data set and in independent quantitative real-time polymerase chain reaction (qRT-PCR) analysis and ELISA experiments. This study demonstrated that localized genital herpes, resulting from HSV reactivation, may influence the functionality of circulating immune cells, suggesting a potential avenue for future research into the role of systemic immunity during HSV infection and recurrence.

Safe and potent anti-CD19 CAR T-cells with shRNA-IL-6 gene silencing element in patients with refractory or relapsed B-cell acute lymphoblastic leukemia.

Severe cytokine release syndrome (sCRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) have limited the widespread use of chimeric antigen receptor T (CAR T)-cell therapy. We designed a novel anti-CD19 CAR (ssCART-19) with a small hairpin RNA (shRNA) element to silence the interleukin-6 (IL-6) gene, hypothesizing it could reduce sCRS and ICANS by alleviating monocyte activation and proinflammatory cytokine release. In a post hoc analysis of two clinical trials, we compared ssCART-19 with common CAR T-cells (cCART-19) in relapsed/refractory B-cell acute lymphoblastic leukemia (r/r B-ALL). Among 87 patients, 47 received ssCART-19 and 40 received cCART-19. Grade ≥3 CRS occurred in 14.89% (7/47) of the ssCART-19 group versus 37.5% (15/40) in the cCART-19 group (p = 0.036). ICANS occurred in 4.26% (2/47) of the ssCART-19 group (all grade 1) compared to 15% (2/40) of the cCART-19 group. Patients in the ssCART-19 group showed comparable rates of treatment response (calculated with rates of complete remission and incomplete hematological recovery) were 91.49% (43/47) for ssCART-19 and 85% (34/40) for cCART-19 (p = 0.999). With a median follow-up of 21.9 months, cumulative nonrelapse mortality was 10.4% for ssCART-19 and 13.6% for cCART-19 (p = 0.33). Median overall survival was 37.17 months for ssCART-19 and 32.93 months for cCART-19 (p = 0.40). Median progression-free survival was 24.17 months for ssCART-19 and 9.33 months for cCART-19 (p = 0.23). These data support the safety and efficacy of ssCART-19 for r/r B-ALL, suggesting its potential as a promising therapy.

Catechin reduces liver inflammation by regulating Kupffer cell activation in rats

The liver is a defense against infections due to its strategic location between the gastrointestinal and systemic circulations. In dogs and cats, infectious hepatitis encompasses a range of contagious diseases affecting the liver either directly or as part of a broader systemic infection, including bacterial, mycobacterial, viral, fungal, protozoal, parasitic, and rickettsial diseases. Catechins possess well-recognized natural antioxidant properties. This study investigated their therapeutic potential for applications in hepatology, evaluating whether catechins reduce hepatic inflammation in rats repeatedly exposed to carbon tetrachloride (CCl4). Sprague-Dawley rats were given catechin 50 (C50) or 100 (C100) mg/kg body weight orally daily for 3 days. This treatment was given with or without concurrent intraperitoneal injections of CCl4. Phosphate-buffered saline served as the vehicle control, while silymarin administered at 100 mg/kg was used as the positive control.Gross examination revealed significant enlargement, edema, and darker tissue in CCl4-induced livers treated with vehicle. Additionally, spotty discoloration was observed on the surface. Kupffer cell activation suppressed the expression of inflammatory mediators, including inducible nitric oxide synthase (iNOS), in groups co-treated with catechin and CCl4; this effect was reversed when catalase replaced catechin in CCl4-injured rats. Catechin alleviates hepatic inflammation in rats repeatedly exposed to CCl4; it also modulates the activation of Kupffer cells and monocytes. These results should lead to new treatments for liver inflammation in veterinary practice.

Elevated levels of damage-associated molecular patterns HMGB1 and S100A8/A9 coupled with toll-like receptor-triggered monocyte activation are associated with inflammation in patients with myelofibrosis.

Inflammation plays a pivotal role in the pathogenesis of primary and post-essential thrombocythemia or post-polycythemia vera myelofibrosis (MF) in close cooperation with the underlying molecular drivers. This inflammatory state is induced by a dynamic spectrum of inflammatory cytokines, although recent evidence points to the participation of additional soluble inflammatory mediators. Damage-associated molecular patterns (DAMPs) represent endogenous signals released upon cell death or damage which trigger a potent innate immune response. We assessed the contribution of two prototypical DAMPs, HMGB1 and S100A8/A9, to MF inflammation. Circulating HMGB1 and S100A8/A9 were elevated in MF patients in parallel to the degree of systemic inflammation and levels increased progressively during advanced disease stages. Patients with elevated DAMPs had higher frequency of adverse clinical features, such as anemia, and inferior survival, suggesting their contribution to disease progression. Monocytes, which are key players in MF inflammation, were identified as a source of S100A8/A9 but not HMGB1 release, while both DAMPs correlated with cell death parameters, such as serum LDH and cell-free DNA, indicating that passive release is an additional mechanism leading to increased DAMPs. HMGB1 and S100A8/A9 promote inflammation through binding to Toll-like receptor (TLR) 4, whereas the former also binds TLR2. Monocytes from MF patients were shown to be hyperactivated at baseline, as reflected by higher CD11b and tissue factor exposure and increased expression levels of proinflammatory cytokines IL-1β and IL-6. Patient monocytes showed preserved TLR4 and TLR2 expression and were able to mount normal or even exacerbated functional responses and cytokine upregulation following stimulation of TLR4 and TLR2. Elevated levels of endogenous TLR ligands HMGB1 and S100A8/A9 coupled to the finding of preserved or hyperreactive TLR-triggered responses indicate that DAMPs may promote monocyte activation and cytokine production in MF, fueling inflammation. Plasma IL-1β and IL-6 were elevated in MF and correlated with DAMPs levels, raising the possibility that DAMPs could contribute to cytokine generation in vivo. In conclusion, this study highlights that, in cooperation with classic proinflammatory cytokines, DAMPs represent additional inflammatory mediators that may participate in the generation of MF inflammatory state, potentially providing novel biomarkers of disease progression and new therapeutic targets.

Mycophenolate mofetil directly modulates myeloid viability and pro-fibrotic activation of human macrophages.

Mycophenolate mofetil (MMF) is an immunosuppressant used to treat rheumatological diseases, including Systemic Sclerosis (SSc). While MMF is an established inhibitor of lymphocyte proliferation, recent evidence suggests MMF also mediates effects on other cell types. The goal of this study was to determine the effect of MMF on monocytes and macrophages, which have been implicated in SSc pathogenesis. Human monocyte-derived macrophages were cultured with the active MMF metabolite, mycophenolic acid (MPA), and assessed for changes in viability and immuno-phenotype. Guanosine supplementation studies were performed to determine whether MPA-mediated effects were dependent on de novo purine synthesis. The ability of MPA-treated macrophages to induce fibroblast activation was evaluated, and dermal myeloid expression signatures were analyzed in MMF-treated SSc patients. MPA reduced viability and induced apoptosis in monocytes and macrophages at doses (average IC50 = 1.15 µg/ml) within the target serum concentration of MMF patients (1-3µg/ml). These effects were reversed by guanosine supplementation. Low-dose MPA (0.5 µg/ml) attenuated IL-4 or SSc plasma-mediated macrophage activation, and inhibited the ability of SSc plasma-activated macrophages to induce SSc fibroblast activation. Gene expression studies demonstrated significant reductions in dermal myeloid signatures in MMF-responsive SSc patients. For the first time, we demonstrate that MMF inhibits the viability and pro-fibrotic activation of human monocytes and macrophages, which is dependent on de novo purine synthesis. Coupled with myeloid gene expression attenuation following MMF treatment in patients, these results suggest that fibrotic inhibition observed with MMF may be attributable, at least in part, to direct effects on myeloid cells.