Increase In Immune Activation Research Articles

Initial results from a first-in-human, phase I study of immunomodulatory aryl hydrocarbon receptor (AhR) inhibitor BAY2416964 in patients with advanced solid tumors.

2502 Background: AhR activation is involved in tumor growth, immunomodulation, and resistance to immune checkpoint inhibitors. BAY2416964 is a novel, potent, oral AhR inhibitor (AhRi) that antagonizes AhR ligand-induced immunosuppressive effects, resulting in enhanced proinflammatory activity of antigen-presenting cells and T cells and reduced activity of immunosuppressive myeloid cells. Methods: A first-in-human, Phase I clinical trial of AhRi BAY2416964 (NCT04069026) is evaluating its safety, pharmacokinetics, pharmacodynamics, recommended Phase II dose, and anti-tumor activity per RECIST v1.1 and iRECIST. BAY2416964 was administered orally in patients with advanced solid tumors in a dose-escalation cohort using a modified toxicity probability interval (mTPI) design. The initial expansion cohorts enrolled patients with non-small-cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC). Results: As of November 4, 2022, 72 patients had been treated with BAY2416964: 39 patients in dose escalation and 33 patients in the initial dose expansion treated with 500 mg twice daily (25 NSCLC, 8 HNSCC). The most common tumor types enrolled in dose escalation were colorectal cancer ( n= 12), breast cancer ( n= 6), and pancreatic cancer ( n= 4). Median age was 61 years (range 35-80). 51/72 (70.8%) patients had received ≥3 lines of therapy (including 16 [22.2%] who had received ≥6 lines) and 47/72 (65.3%) had received immune checkpoint inhibitors. Drug-related treatment-emergent adverse events (TEAEs) of all grades reported in ≥10% of patients were nausea (13.9%; 1.4% grade 3) and fatigue (11.1%; 1.4% grade 3). Most drug-related TEAEs were grade 1 or 2; 9 (12.5%) patients experienced drug-related grade 3 TEAEs and no patients experienced drug-related grade ≥4 TEAEs. No dose-limiting toxicities were observed. Two patients in dose expansion discontinued treatment due to drug-related TEAEs. Plasma exposure to BAY2416964 increased according to dose and food intake. Analysis of biomarkers demonstrated evidence of target engagement and an increase in immune activation at the doses tested. Of 67 patients evaluable for response by RECIST, 22 (32.8%) had stable disease per RECIST v1.1, including 1 with thymoma in dose escalation achieving an iRECIST partial response. Conclusions: BAY2416964 was well tolerated across all dose levels and regimens tested. Initial evaluation of biomarkers shows BAY2416964 inhibits AhR and modulates immune functions. Encouraging preliminary anti-tumor activity was observed in heavily pretreated patients. The disease-specific dose-expansion part of this study is ongoing. The observed manageable safety profile also supports combination therapies. Clinical trial information: NCT04069026 .

Sex, age and menopause differentially impact gut barrier function and proteomic profile

Cardiovascular disease (CVD) and metabolic syndrome (MetS) depends on sex, age and hormonal status and is worsened by comprised gut barrier function. Previous work establishes that loss of estrogen and age comprises intestinal barrier function permeability exacerbating systemic inflammation, increasing gut oxidative stress, and elevating pro-inflammatory cytokines. We hypothesize that loss of estrogen during menopause underlies sex- and age-dependent pathological remodeling in gut barrier function leading to increased risk for CVD and MetS. C57BL-6 male and female mice were fed a high-fat-diet (HFD, 45% fat); menopause was induced via 21 days of 4-vinylcycohexane diepoxide (VCD) intraperitoneal injections (controls were injected with sesame oil) in adult and aged female mice. Diestrus was reached 14+days after the end of VCD injections and menopause was determined by cytology. Upon sacrifice, plasma was collected, and intestines were flash frozen. LPS assays were performed on plasma samples of premenopausal (n=8), menopausal (n=10), aged menopausal (n=6), and male mice (n=11). Male mice, and aged menopausal mice had significantly higher circulating endotoxin levels than premenopausal mice, while menopausal mice did not significantly differ from pre-menopause. These results indicate that age and sex impact barrier leakiness. Further, these results highlight that barrier integrity in menopause is distinctly different from aged menopause mice.Quantitative proteomics of ileum samples in premenopausal (n=5), menopausal (n=5), aged menopausal (n=5), and male mice (n=5) identified 7664 proteins with >1 unique peptide of which 134 proteins were significant (p<0.05) with a max fold change ˂1.27 across all groups. Protein expression of all groups was assessed using principal component analysis. Aged menopausal mice cluster closer to premenopausal mice than menopausal mice. These results indicate that changes in the ileum during menopause are different than those observed in aging. Compared to premenopausal mice, menopausal mice have significantly increased in proteins involved in the Go-biological processes including an enrichment in proteins involved in the innate immune system (6.3 fold enrichment, FE, -log10p=0.00006), phagocytosis recognition (19.82 FE, -log10p=1.14), defense response to bacterium (10.066 FE, -log10p=9.56), and B cell receptor signaling pathways (20.311 FE, -log10p=9.33). In contrast, male mice compared to premenopausal mice show a significant decrease in proteins involved in phagocytosis recognition (22.57 FE, -log10p=4.28), defense response to bacterium (12.898 FE, -log10p=2.76), and B cell receptor signaling pathway (20.56 FE, -log10p=8.12). These results indicate an increase in immune activity in menopausal female mice and a decrease in male mice compared to premenopausal female mice. In summary, these data demonstrate the change within the gut during menopause is dissimilar to those seen in male and aging mice. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

1700P Radiation therapy elicits a consistent myeloid and lymphoid immune response in breast and rectal cancer

Radiotherapy (RT) is broadly used for cancer treatment, including early breast (eBRCA) and rectal cancers (RC). However, many components of the tumor microenvironment (TME) contribute to RT resistance. RT induces cancer cell death resulting in tumor antigen release that triggers the recruitment of a variety of immune cells that can act either stimulatory or suppressive on anti-tumor immunity. A deeper understanding of the immune suppressive components of anti-tumor immunity is integral to discover novel treatments to improve RT effectiveness. In this study, RT induced transcriptional changes were identified that associate with cellular consequences that may promote radio-resistance. Moreover, the delineation of tumor-specific changes can help selecting patients undergoing RT that are likely to have tumor recurrence. Datasets of patients with eBRCA (Horton 2015) and RC (Petty 2009) that received single-dose RT were analyzed. Gene signatures of immune activation and suppression were summarized for each patient as an average of the standard score and evaluated at the baseline and after RT. Fractions of immune cell populations were estimated by cell type deconvolution using xCell (Aran 2017) and compared pre and post RT. Evaluation of gene signatures of immune activation (inflammatory response, T-cell inflammation) and immune suppression (M2 macrophages, TGF-b signaling) in eBRCA and RC patients showed a consistent increase in pre compared to post RT. The comparison of score fold-change (pre-post RT) showed a stronger increase of the signatures in RC compared to eBRCA, with similar change for the TGF-b signaling score. Cell type deconvolution analysis showed that M1 and M2 macrophages and cancer-associated fibroblasts increase after RT in both tumor types, while NK T cells decrease. The main differences were found in neutrophils and regulatory T cells that have opposite trends in the two tumor types. The results showed an overall increase of immune activation and suppression genes after RT, more pronounced in RC compared to eBRCA patients. Moreover, the TME of RC showed a more immune-suppressive profile with an increase of regulatory T cells in addition to M2 macrophages.

Pre-Clinical and Clinical Immunomodulatory Effects of Pomalidomide or CC-92480 in Combination with Bortezomib in Multiple Myeloma

▪Background: Pomalidomide (POM) is an established agent in relapsed/refractory (R/R) multiple myeloma (MM) with direct cytotoxicity against MM cells and immunostimulatory activities in multiple cell types including T cells and NK cells. CC-92480 is a novel Aiolos/Ikaros degrading cereblon E3 ligase modulator (CELMoD ®) agent is currently being investigated in combination with the proteasome inhibitor (PI) bortezomib (BTZ) and corticosteroid dexamethasone (DEX), or with DEX only in R/R MM (CC-92480-MM-002 and CC-92480-MM-001). Previous results indicate that triplet combination of POM/BTZ/DEX may enhance some T, B and NK cell subpopulations, overcoming immunosuppression when compared to BTZ/DEX-only treated patients (Rao et al, 2019). Mechanisms of action (MOA) of CC-92480- and POM-mediated substrate depletion occurs via ubiquitination and proteasome degradation, where BTZ has been speculated as potentially antagonistic as a PI. Here, we report pre-clinical and clinical observations of an immune MOA of CC-92480 or POM in combination with BTZ.Results: To mimic the clinical pharmacokinetics, BTZ was utilized as a high-dose pulse method alone and in combination with POM or CC-92480, followed by flow cytometric measurements of Aiolos and Ikaros protein abundance in healthy donor (HD) T cells. The addition of BTZ modestly delayed CRBN-dependent substrate depletion compared to single agent POM or CC-92480; however, this effect was only apparent at early time points (1-6 hr) where the effect was negligible by 24 hr.To understand the functional implications of BTZ combination, we conducted CD3-stimulated PBMC-mediated cytotoxicity assay against H929 MM target cells in a co-culture model. The efficiency of POM or CC-92480 induced PBMC-mediated killing in a dose dependent manner (~65% increase compared to DMSO) were similar at a 100-fold lower dose range of CC-92480 compared to POM, with the effect not being altered by co-treatment with BTZ. These data were replicated with a POM or CC-92480 treated supernatant stimulation of purified NK cells co-culture, which induced an 80% reduction in target cell viability with the BTZ combination having no negative effects on CELMoD-mediated activity. Cytokine analysis on PBMC supernatants treated with either POM or CC-92480 in the absence or presence of BTZ-pulse showed a dose-dependent increase in IL-2 (>2.4-fold) and Granzyme B (>3.1-fold), which were not impacted by BTZ co-treatment.As a secondary readout on activation status, we measured multiple signaling molecules and activation markers on the cell surface of T and NK cell subsets in CD3 stimulated HD PBMCs treated with dose-dependent POM or CC-92480 with or without co-treatment of BTZ. Compared to DMSO controls, elevated expression levels of CD25 (IL2RA), CD278 (ICOS), Granzyme B, CD134 (OX40R) and HLA-DR were observed with both POM and CC-92480 on CD4, CD8 and NK cells demonstrating a CELMoD-mediated increase in immune activation. These effects were not impacted by the co-treatment of BTZ.Examination of peripheral blood samples from MM patients enrolled in the CC-92480-MM-001/002 (NCT03374085/NCT03989414) clinical trials revealed that CC-92480 promoted potent immunomodulation when administered in combination with DEX and with BTZ/DEX. These data included increased numbers of activated and central memory T cells, as well as increased Ki67+ proliferating T and NK cell populations compared to samples collected during the screening period before any drugs had been administered, consistent with earlier observation of POM in combination with BTZ/DEX treated patients.Conclusions: Taken together, these data demonstrate that POM and CC-92480 are potent immunomodulatory agents with enhanced induction of PBMC and NK mediated cell killing of MM tumor cells and activation of T and NK cells, at 100-fold lower concentrations of CC-92480 compared to POM. Additionally, we showed that combination with BTZ in preclinical assays and in the clinical setting did not antagonistically affect the immunostimulatory ability of POM or CC-92480. DisclosuresBjorklund: BMS: Current Employment, Current equity holder in publicly-traded company. Amatangelo: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Chiu: Bristol Myers Squibb: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Kang: BMS: Current equity holder in publicly-traded company. Civardi: Bristol Myers Squibb: Current Employment. Katz: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Maciag: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Hagner: BMS: Current Employment, Current equity holder in publicly-traded company. Pourdehnad: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: No royalty. Bahlis: Pfizer: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Genentech: Consultancy; BMS/Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; GlaxoSmithKline: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria. Richardson: Oncopeptides: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Karyopharm: Consultancy, Research Funding; Protocol Intelligence: Consultancy; Janssen: Consultancy; Sanofi: Consultancy; Secura Bio: Consultancy; GlaxoSmithKline: Consultancy; Regeneron: Consultancy; AstraZeneca: Consultancy; AbbVie: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding. Thakurta: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties.

Metabolomic signature of amino acids in plasma of patients with non-segmental Vitiligo

IntroductionVitiligo pathogenesis is complicated, and several possibilities were suggested. However, it is well-known that the metabolism of pigments plays a significant role in the pathogenicity of the disease.ObjectivesWe explored the role of amino acids in vitiligo using targeted metabolomics.MethodsThe amino acid profile was studied in plasma using liquid chromatography. First, 22 amino acids were derivatized and precisely determined. Next, the concentrations of the amino acids and the molar ratios were calculated in 31 patients and 34 healthy individuals.ResultsThe differential concentrations of amino acids were analyzed and eight amino acids, i.e., cysteine, arginine, lysine, ornithine, proline, glutamic acid, histidine, and glycine were observed differentially. The ratios of cysteine, glutamic acid, and proline increased significantly in Vitiligo patients, whereas arginine, lysine, ornithine, glycine, and histidine decreased significantly compared to healthy individuals. Considering the percentage of skin area, we also showed that glutamic acid significantly has a higher amount in patients with less than 25% involvement compared to others. Finally, cysteine and lysine are considered promising candidates for diagnosing and developing the disorder with high accuracy (0.96).ConclusionThe findings are consistent with the previously illustrated mechanism of Vitiligo, such as production deficiency in melanin and an increase in immune activity and oxidative stress. Furthermore, new evidence was provided by using amino acids profile toward the pathogenicity of the disorder.

Multi-omics analysis of respiratory specimen characterizes baseline molecular determinants associated with SARS-CoV-2 outcome

SummaryRapid diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection still remains a major challenge. A multi-omic approach was adopted to analyze the respiratory specimens of 20 SARS-CoV-2-positive, 20 negative and 15 H1N1 pdm 2009 positive cases. Increased basal level of MX1 (MX dynamin-like GTPase 1) and WARS (tryptophan-tRNA ligase) correlated with SARS-CoV-2 infection and its outcome. These markers were further validated in 200 suspects. MX1>30pg/ml and WARS>25ng/ml segregated virus positives [AUC = 94% CI: (0.91–0.97)] and severe patients [AUC>0.85%]. Our results documented significant increase in immune activation; metabolic reprograming and decrease in oxygen transport, wound healing and others linked proteins and metabolites in patients with coronavirus disease 2019 (COVID-19). Multi-omics profiling correlated with viremia and segregated asymptomatic patients with COVID-19. Additionally, we identified increased respiratory pathogens (Burkholderiales, Klebsiella pneumonia) and decreased lactobacillus salivarius (FDR<0.05) in COVID-19 specimens. In conclusion, increased basal MX1 and WARS levels correlates with SARS-CoV-2 infection and could aid in the identification of patient's predisposed to higher severity.

Who Rules Over Immunology? Seasonal Variation in Body Temperature, Steroid Hormones, and Immune Variables in a Tegu Lizard.

Multiple factors can influence the immune response of ectothermic vertebrates, including body temperature (Tb), gonadal steroids, and seasonality, in ways that are thought to reflect trade-offs between energetic investment in immunity versus reproduction. Hibernating tegu lizards (Salvator merianae) are a unique model to investigate how immunocompetence might be influenced by different factors during their annual cycle. We assessed immunological measures (plasma bacterial killing ability, total and differential leukocyte count), plasma hormone levels (testosterone in males, estradiol and progesterone in females, and corticosterone [CORT] in both sexes), Tb, and body condition from adult tegus during each stage of their annual cycle: reproduction, post-reproduction/preparation for hibernation, and hibernation. Our hypothesis that immune traits present higher values during the reproductive phase, and a sharp decrease during hibernation, was partially supported. Immune variables did not change between life history stages, except for total number of leukocytes, which was higher at the beginning of the reproductive season (September) in both males and females. Average Tb of the week prior to sampling was positively correlated with number of eosinophils, basophils, monocytes, and azurophils, corroborating other studies showing that when animals maintain a high Tb, there is an increase in immune activity. Surprisingly, no clear relationship between immune traits and gonadal steroids or CORT levels was observed, even when including life history stage in the model. When gonadal hormones peaked in males and females, heterophil: lymphocyte ratio (which often elevates during physiological stress) also increased. Additionally, we did not observe any trade-off between reproduction and immunity traits, sex differences in immune traits, or a correlation between body condition and immune response. Our results suggest that variation in patterns of immune response and correlations with body condition and hormone secretion across the year can depend upon the specific hormone and immune trait, and that experienced Tb is an important variable determining immune response in ectotherms.

MODL-29. EVALUATING TUMOR-IMMUNE INTERACTIONS IN MOUSE MODELS OF DIFFUSE INTRINSIC PONTINE GLIOMA

BACKGROUNDWhile adult gliomas show some level of immune cell infiltration, diffuse intrinsic pontine glioma (DIPG) is characterized as having an “immune cold” state. We have developed new immunocompetent mouse models of DIPG. These models faithfully recapitulate the pathological hallmarks of DIPG and provides a unique platform to investigate immune modulatory therapies and potential therapeutic benefits of check point inhibitor combination therapies.METHODSTo evaluate the effects of CDK4/6 inhibition (CDK4/6i) on cell proliferation and immune interactions we performed a series of in vitro and in vivo studies using DIPG mouse models. In vitro assays included dose response curves, transcriptional profiling, and MHC1 expression. In vivo preclinical studies treated mouse models with CDK4/6i with or without immune check-point inhibitors (ICI). We also examined other candidate immune modulatory therapies in vitro.RESULTSCDK4/6i (Abemeciclib) reduced proliferation of DIPG cells derived from mouse models, and displayed a modest increase in immune activation by MHC1 expression and transcriptome. Pilot in vivo preclinical studies did not show any significant changes in DIPG proliferation or immune changes with CDK4/6i treatment, ICI treatment, or the combination of CDK4/6i + ICI. In vitro testing of other immune-modulatory drugs identified additional candidates that can be tested in vivo.CONCLUSIONCDK4/6i displayed in vitro action, but lacked efficacy in DIPG mouse models in vivo. Further use of spontaneous DIPG mouse models will provide a rapid preclinical platform to evaluate in vivo tumor-immune interactions, drug efficacy, and mechanisms of resistance.

Multi-Omics Analysis of Respiratory Specimen Characterizes Baseline Molecular Determinants Associated with COVID-19 Diagnosis and Outcome

Rapid diagnosis and outcome prediction of SARS-CoV-2 infection remains a major challenge. A multi-omic approach was adopted, and in the discovery phase, respiratory specimens of 20 SARS-CoV-2 positive, 20 negative and 5 H1N1 positive cases were subjected to global proteomics, metaproteomics and metabolomics. We identified MX1 (MX Dynamin like GTPase 1) and WARS (Tryptophan--tRNA ligase) as clues to viral diagnosis and outcome which was validated in 200 SARS-CoV-2 suspects. MX1>30pg/ml and WARS>25ng/ml distinctly segregated virus positives [AUC=94%CI(0.91-0.97)], severe and symptomatic patients [AUC>0.85%]. SARS-CoV-2 infection mediated a distinct increase in immune activation, metabolic reprograming and decrease in oxygen transport, wound healing, vitamin and steroid metabolism. Multi-omics profiling correlated with viraemia and segregated asymptomatic COVID-19 patients. Additionally, we identified increased respiratory pathogens [Burkholderiales, Klebsiella-pneumonia] and decreased lactobacillus salivarius (FDRConclusion: Baseline levels of MX1 and WARS can reliably diagnose SARS-CoV-2 infection and identify patient’s predisposed to higher severity.FundIng: The work was supported from project DST (DST-SERB) (EMR/2016/004829).Conflict of Interest: All authors have declared no conflict of interest.

Effect of Opioid Use on Immune Activation and HIV Persistence on ART.

While there is an emerging consensus that engagement of the Mu opioid receptor by opioids may modulate various stages the HIV life cycle (e.g.: increasing cell susceptibility to infection, promoting viral transcription, and depressing immune responses to virally-infected cells), the overall effect on latency and viral reservoirs remains unclear. Importantly, the hypothesis that the increase in immune activation observed in chronic opioid users by direct or indirect mechanisms (i.e., microbial translocation) would lead to a larger HIV reservoir after ART-suppression has not been supported to date. The potential for a subsequent decrease in reservoirs after ART-suppression has been postulated and is supported by early reports of opioid users having lower latent HIV burden. Here, we review experimental data supporting the link between opioid use and HIV modulation, as well as the scientific premise for expecting differential changes in immune activation and HIV reservoir between different medications for opioid use disorder. A better understanding of potential changes in HIV reservoirs relative to the engagement of the Mu opioid receptor and ART-mediated immune reconstitution will help guide future cure-directed studies in persons living with HIV and opioid use disorder. Graphical Abstract Review. HIV replication, immune activation and dysbiosis: opioids may affect immune reconstitution outcomes despite viral suppression.

Heat stress negatively affects the transcriptome related to overall metabolism and milk protein synthesis in mammary tissue of midlactating dairy cows.

Inadequate dry matter intake only partially accounts for the decrease in milk protein synthesis during heat stress (HS) in dairy cows. Our hypothesis is that reduced milk protein synthesis during HS in dairy cows is also caused by biological changes within the mammary gland. The objective of this study was to assess the hypothesis via RNA-Seq analysis of mammary tissue. Herein, four dairy cows were used in a crossover design where HS was induced for 9 days in environmental chambers. There was a 30-day washout between periods. Mammary tissue was collected via biopsy at the end of each environmental period (HS or pair-fed and thermal neutral) for transcriptomic analysis. RNA-Seq analysis revealed HS affected >2,777 genes (false discovery rate-adjusted P value < 0.05) in mammary tissue. Expression of main milk protein-encoding genes and several key genes related to regulation of protein synthesis and amino acid and glucose transport were downregulated by HS. Bioinformatics analysis revealed an overall decrease of mammary tissue metabolic activity by HS (especially carbohydrate and lipid metabolism) and an increase in immune activation and inflammation. Network analysis revealed a major role of TNF, IFNG, S100A8, S100A9, and IGF-1 in inducing/controlling the inflammatory response, with a central role of NF-κB in the process of immunoactivation. The same analysis indicated an overall inhibition of PPARγ. Collectively, these data suggest HS directly controls milk protein synthesis via reducing the transcription of metabolic-related genes and increasing inflammation-related genes.

Exposure to artificial light at night increases innate immune activity during development in a precocial bird

Humans have greatly altered Earth's night-time photic environment via the production of artificial light at night (ALAN; e.g. street lights, car traffic, billboards, lit buildings). ALAN is a problem of growing importance because it may significantly disrupt the seasonal and daily physiological rhythms and behaviors of animals. There has been considerable interest in the impacts of ALAN on health of humans and other animals, but most of this work has centered on adults and we know comparatively little about effects on young animals. We exposed 3-week-old king quail (Excalfactoria chinensis) to a constant overnight blue-light regime for 6 weeks and assessed weekly bactericidal activity of plasma against Escherichia coli – a commonly employed metric of innate immunity in animals. We found that chronic ALAN exposure significantly increased bactericidal activity and that this elevation in immune performance manifested at different developmental time points in males and females. Whether this short-term increase in immune activity can be extended to wild animals, and whether ALAN-mediated increases in immune activity have positive or negative fitness effects, are unknown and will provide interesting avenues for future studies.

TSR-033, a Novel Therapeutic Antibody Targeting LAG-3, Enhances T-Cell Function and the Activity of PD-1 Blockade In Vitro and In Vivo.

Progressive upregulation of checkpoints on tumor-infiltrating lymphocytes promotes an immunosuppressive tumor microenvironment, severely compromising tumor immunity. Lymphocyte activation gene-3 (LAG-3) is a coinhibitory receptor associated with impaired T-cell function and is frequently coexpressed with programmed cell death protein-1 (PD-1) in the context of human cancers. Targeting LAG-3 in conjunction with PD-1 thus represents a strategy to amplify and broaden the therapeutic impact of PD-1 blockade alone. We have generated a high affinity and selective humanized monoclonal IgG4 antibody, TSR-033, which binds human LAG-3 and serves as a functional antagonist, enhancing in vitro T-cell activation both in mixed lymphocyte reactions and staphylococcal enterotoxin B-driven stimulation assays. In a humanized mouse non-small cell lung carcinoma model, TSR-033 boosted the antitumor efficacy of PD-1 monotherapy, with a concomitant increase in immune activation. Analogous studies in a murine syngeneic tumor model using surrogate antibodies demonstrated significant synergy between LAG-3 and PD-1 blockade-combination treatment led to a marked improvement in therapeutic efficacy, increased T-cell proliferation, IFNγ production, and elicited durable immunologic memory upon tumor rechallenge. Taken together, the pharmacologic activity of TSR-033 demonstrates that it is a potent anti-LAG-3 therapeutic antibody and supports its clinical investigation in cancer patients.

Regenerative Effects of Heme Oxygenase Metabolites on Neuroinflammatory Diseases.

Heme oxygenase (HO) catabolizes heme to produce HO metabolites, such as carbon monoxide (CO) and bilirubin (BR), which have gained recognition as biological signal transduction effectors. The neurovascular unit refers to a highly evolved network among endothelial cells, pericytes, astrocytes, microglia, neurons, and neural stem cells in the central nervous system (CNS). Proper communication and functional circuitry in these diverse cell types is essential for effective CNS homeostasis. Neuroinflammation is associated with the vascular pathogenesis of many CNS disorders. CNS injury elicits responses from activated glia (e.g., astrocytes, oligodendrocytes, and microglia) and from damaged perivascular cells (e.g., pericytes and endothelial cells). Most brain lesions cause extensive proliferation and growth of existing glial cells around the site of injury, leading to reactions causing glial scarring, which may act as a major barrier to neuronal regrowth in the CNS. In addition, damaged perivascular cells lead to the breakdown of the blood-neural barrier, and an increase in immune activation, activated glia, and neuroinflammation. The present review discusses the regenerative role of HO metabolites, such as CO and BR, in various vascular diseases of the CNS such as stroke, traumatic brain injury, diabetic retinopathy, and Alzheimer’s disease, and the role of several other signaling molecules.

Novel immune signatures associated with dysplastic naevi and primary cutaneous melanoma in human skin.

Dysplastic naevi (DN) are benign lesions with atypical features intermediate between that of common melanocytic naevi (CMN) and malignant melanoma (MM). Debate remains over whether DN represent progressive lesions from CMN. Through gene expression profiling and analysis of molecular gene signatures, our study revealed progressive increases in immune activation and regulation, along with pathways implicated in melanomagenesis, from CMN to DN to MM. Using criteria of 1.5-fold change and false discovery rate ≤0.05, we found differential expression of 7186 probes (6370 unique genes) with the largest difference detected between DN and MM from the standpoint of genomic melanoma progression. Despite progressive increases in the T-helper type 1 (Th1)-inducing gene (IL-12), RT-PCR indicated impaired Th1 or cytotoxic T-cell response (decreased IFN-γ) in MM. Concordantly, our results indicated progressive increases in molecular markers associated with regulatory T cells, exhausted T cells and tolerogenic dendritic cells, including detection of increased expression of suppressor of cytokine signalling 3 (SOCS3) in dendritic cells associated with MM. All together, our findings suggest that the increased immunosuppressive microenvironment of melanoma may contribute to unhampered proliferation of neoplastic cells. In addition, the detection of increased markers associated with tolerogenic dendritic cells in MM suggests that targeting these suppressive immune cell types may represent an alternative avenue for future immunotherapy.

Immune Response Modulation of Conjugated Agonists with Changing Linker Length.

We report immune response modulation with linked Toll-like receptor (TLR) agonists. Conjugating two agonists of synergistic TLRs induce an increase in immune activity compared to equal molarity of soluble agonists. Additionally, varying the distance between the agonists by changing the linker length alters the level of macrophage NF-κB activity as well as primary bone marrow derived dendritic cell IL-6 production. This modulation is effected by the size of the agonists and the pairing of the stimulated TLRs. The sensitivity of linker-length-dependent immune activity of conjugated agonists provides the potential for developing application specific therapeutics.

Tumor-infiltrating dendritic cells in cancer pathogenesis.

Dendritic cells (DCs) play a pivotal role in the tumor microenvironment, which is known to affect disease progression in many human malignancies. Infiltration by mature, active DCs into the tumors confers an increase in immune activation and recruitment of disease-fighting immune effector cells and pathways. DCs are the preferential target of infiltrating T cells. However, tumor cells have means of suppressing DC function or of altering the tumor microenvironment in such a way that immune-suppressive DCs are recruited. Advances in understanding these changes have led to promising developments in cancer-therapeutic strategies targeting tumor-infiltrating DCs to subdue their immunosuppressive functions and enhance their immune-stimulatory capacity.

Effect of probiotics (Saccharomyces boulardii) on microbial translocation and inflammation in HIV-treated patients: a double-blind, randomized, placebo-controlled trial.

Microbial translocation has been associated with an increase in immune activation and inflammation in HIV infection despite effective highly active antiretroviral therapy. It has been shown that some probiotics have a beneficial effect by reducing intestinal permeability and, consequently, microbial translocation. To assess changes in microbial translocation and inflammation after treatment with probiotics (Saccharomyces boulardii) in HIV-1-infected patients with virologic suppression. A double-blind, randomized, placebo-controlled trial was conducted in 44 nonconsecutive HIV-1-infected patients with viral load of <20 copies per milliliter for at least 2 years. Patients were randomized to oral supplementation with probiotics or placebo during 12 weeks. Markers of microbial translocation (lipopolysaccharide-binding protein [LBP] and soluble CD14), inflammation (interleukin 6 [IL-6], tumor necrosis factor alpha, interferon gamma, high-sensitivity C-reactive protein), and immunological and clinical data were determined before and after the intervention and 3 months after treatment discontinuation. Quantitative variables were compared using the Mann-Whitney U test, and categorical variables were compared using the Fisher exact test. After 12 weeks of treatment, differences between the probiotic arm and the placebo arm were observed in LBP values (-0.30 vs +0.70 pg/mL) and IL-6 (-0.60 vs +0.78 pg/mL). These differences were also noted at 3 months after treatment withdrawal. Qualitative analysis was performed, defining a variable as "decreased" or "increased" from baseline LBP. A significant decrease of LBP at 12 weeks of treatment was observed (57.9% patients in the probiotic group vs 6.2% in the placebo group, P = 0.002). Treatment with S. boulardii decreases microbial translocation (LBP) and inflammation parameters (IL-6) in HIV-1-infected patients with long-term virologic suppression.

Behavioural, Mucosal and Systemic Immune Parameters in HIV-infected and Uninfected Injection Drug Users.

ObjectiveInjection drug use (IDU) remains a major risk factor for HIV-1 acquisition. The complex interplay between drug use, non-sterile injection, and Hepatitis C remains poorly understood. We conducted a pilot study to determine the effect of IDU on immune parameters among HIV-uninfected and -infected individuals. We hypothesized that IDU could further augment immunological changes associated with HIV-1 infection, which could in turn affect HIV pathogenesisMethodsHIV-uninfected and -infected subjects with IDU, and non-IDU controls were recruited to obtain socio-demographic and drug-related behaviours. Blood (PBMC) and mucosal (MMC) mononuclear cells were analysed for cellular markers of immune activation (CD38 and Ki67). Serum ELISA was performed to determine levels of soluble CD14, a marker of immune activation.ResultsNo significant quantitative differences in CD4+ and CD8+ T cell levels were observed between IDU and non-IDU subjects when accounting for the presence of HIV-1 infection. However, increased levels of cellular and soluble markers of immune activation were documented in cells and plasma of HIV-uninfected IDU subjects compared to non-injectors. Additionally, sharing of injection paraphernalia was related to immune activation among HIV-uninfected IDU subjects.ConclusionIDU, with or without HIV-1 infection, results in a significant increase in immune activation in both the peripheral blood and the GI tract. This may have significant impact on HIV transmission, pathogenesis, and immunologic responses to combination antiviral therapy. This study provides compelling preliminary results which in turn support larger studies to better define the relationship between IDU, infection with HIV-1, co-infection with Hepatitis C and immunity.

Early HIV-1 infection is associated with reduced frequencies of cervical Th17 cells.

The hallmark of HIV infection is progressive but variable rates of systemic and mucosal CD4 depletion, leading to immunodeficiency. The impact of early HIV infection on cervical CD4 T-cell populations in humans remains poorly described. We analyzed cytobrush-derived immune cells by flow cytometry and cytokines in cervicovaginal lavage from participants in early HIV (<6 months postinfection), chronic HIV, and HIV-uninfected controls. CD4:CD8 ratios declined rapidly in both the cervix and the blood following HIV infection. In contrast, absolute cervical CD4 T-cell counts in early HIV were comparable to HIV-uninfected participants, declining only in chronic infection. Early HIV infection was associated with increases in RANTES and MIP3a in cervicovaginal fluids. Concurrently, slight increases in activated cells (CD38HLA-DR) and higher levels of CTLA4 expression on Tregs in the cervix were observed. Although study groups did not differ with respect to levels of CCR5, integrin B7, or CD69, the frequencies of Th17 cells (defined as CCR6CCR10) was reduced by >10-fold in early HIV infection and Th1 cells (defined as CCR6CXCR3) were reduced by >2-fold. Although CCR6CCR10 cells did not differ in HIV receptor expression, these cells produced higher levels of interferon gamma and interleukin 17. These data support the model of initial CD4 T-cell depletion followed by overall T-cell influx in response to infection and concomitant increases in immune activation, inflammation, and regulatory markers. These data are among the earliest characterization of the cellular milieu in the female genital tract following male-to-female HIV transmission.