Modulation Of Immune Function Research Articles

The Role of Trogocytosis in the Modulation of Immune Cell Functions.

Trogocytosis is an active process, in which one cell extracts the cell fragment from another cell, leading to the transfer of cell surface molecules, together with membrane fragments. Recent reports have revealed that trogocytosis can modulate various biological responses, including adaptive and innate immune responses and homeostatic responses. Trogocytosis is evolutionally conserved from protozoan parasites to eukaryotic cells. In some cases, trogocytosis results in cell death, which is utilized as a mechanism for antibody-dependent cytotoxicity (ADCC). In other cases, trogocytosis-mediated intercellular protein transfer leads to both the acquisition of novel functions in recipient cells and the loss of cellular functions in donor cells. Trogocytosis in immune cells is typically mediated by receptor–ligand interactions, including TCR–MHC interactions and Fcγ receptor-antibody-bound molecule interactions. Additionally, trogocytosis mediates the transfer of MHC molecules to various immune and non-immune cells, which confers antigen-presenting activity on non-professional antigen-presenting cells. In this review, we summarize the recent advances in our understanding of the role of trogocytosis in immune modulation.

A Review of Inflammatory Bowel Disease: A Model of Microbial, Immune and Neuropsychological Integration.

Objective: Inflammatory bowel diseases (IBDs) are complex chronic inflammatory disorders of the gastro-intestinal (GI) tract with uncertain etiology. IBDs comprise two idiopathic disorders: Crohn’s disease (CD) and ulcerative colitis (UC). The aetiology, severity and progression of such disorders are still poorly understood but thought to be influenced by multiple factors (including genetic, environmental, immunological, physiological, psychological factors and gut microbiome) and their interactions. The overarching aim of this review is to evaluate the extent and nature of the interrelationship between these factors with the disease course. A broader conceptual and longitudinal framework of possible neuro-visceral integration, core microbiome analysis and immune modulation assessment may be useful in accurately documenting and characterizing the nature and temporal continuity of crosstalk between these factors and the role of their interaction (s) in IBD disease activity. Characterization of these interactions holds the promise of identifying novel diagnostic, interventions, and therapeutic strategies. Material and Methods: A search of published literature was conducted by exploring PubMed, EMBASE, MEDLINE, Medline Plus, CDSR library databases. Following search terms relating to key question were set for the search included: “Inflammatory bowel diseases,” “gut microbiota,” “psychological distress and IBD,” “autonomic reactivity and IBD,” “immune modulation,” “chronic inflammation,” “gut inflammation,” “enteric nervous system,” “gut nervous system,” “Crohn’s disease,” “Ulcerative colitis”, “depression and IBD”, “anxiety and IBD”, “quality of life in IBD patients,” “relapse in IBDs,” “remission in IBDs,” “IBD disease activity,” “brain-gut-axis,” “microbial signature in IBD,” “validated questionnaires in IBD,” “IBD activity indices,” “IBD aetiology,” “IBDs and stress,” “epidemiology of IBDs”, “autonomic nervous system and gut inflammation”, “IBD and environment,” “genetics of IBDs,” “pathways of immune response in IBDs,” “sleep disturbances in IBD,” “hypothalamic-pituitary-adrenal axis (HPA),” “sympatho-adrenal axis,” “CNS and its control of gut function” “mucosal immune response,” “commensal and pathogenic bacteria in the gut,” “innate and adaptive immunity.” Studies evaluating any possible associations between gut microbiome, psychological state, immune modulation, and autonomic function with IBDs were identified. Commonly cited published literatures with high quality research methodology/results and additional articles from bibliographies of recovered papers were examined and included where relevant. Results: Although there is a substantial literature identifying major contributing factors with IBD, there has been little attempt to integrate some factors over time and assess their interplay and relationship with IBD disease activity. Such contributing factors include genetic and environmental factors, gut microbiota composition and function, physiological factors, psychological state and gut immune response. Interdependences are evident across psychological and biological factors and IBD disease activity. Although from the available evidence, it is implausible that a single explanatory model could elucidate the interplay between such factors and the disease course as well as the sequence of the effect during the pathophysiology of IBD. Conclusion: Longitudinal monitoring of IBD patients and integrating data related to the contributing/risk factors including psychological state, physiological conditions, inflammatory/immune modulations, and microbiome composition/function, could help to explain how major factors associate and interrelate leading to exacerbation of symptoms and disease activity. Identifying the temporal trajectory of biological and psychosocial disturbances may also help to assess their effects and interdependence on individuals’ disease status. Moreover, this allows greater insight into understanding the temporal progressions of subclinical events as potential ground for disease severity in IBD. Furthermore, understanding the interaction between these risk factors may help better interventions in controlling the disease, reducing the costs related to disease management, further implications for clinical practice and research approaches in addition to improving patients’ mental health and quality of life.

A Timely Review of Cross-Kingdom Regulation of Plant-Derived MicroRNAs.

MicroRNAs (miRNAs) belong to a class of non-coding RNAs that suppress gene expression by complementary oligonucleotide binding to the sites in target messenger RNAs. Numerous studies have demonstrated that miRNAs play crucial role in virtually all cellular processes of both plants and animals, such as cell growth, cell division, differentiation, proliferation and apoptosis. The study of rice MIR168a has demonstrated for the first time that exogenous plant MIR168a influences cholesterol transport in mice by inhibiting low-density lipoprotein receptor adapter protein 1 expression. Inspired by this finding, the cross-kingdom regulation of plant-derived miRNAs has drawn a lot of attention because of its capability to provide novel therapeutic agents in the treatment of miRNA deregulation-related diseases. Notably, unlike mRNA, some plant miRNAs are robust because of their 3′ end modification, high G, C content, and the protection by microvesicles, miRNAs protein cofactors or plant ingredients. The stability of these small molecules guarantees the reliability of plant miRNAs in clinical application. Although the function of endogenous miRNAs has been widely investigated, the cross-kingdom regulation of plant-derived miRNAs is still in its infancy. Herein, this review summarizes the current knowledge regarding the anti-virus, anti-tumor, anti-inflammatory, anti-apoptosis, immune modulation, and intestinal function regulation effects of plant-derived miRNAs in mammals. It is expected that exploring the versatile role of plant-derived miRNAs may lay the foundation for further study and application of these newly recognized, non-toxic, and inexpensive plant active ingredients.

IL-27 enhances cytokine secretion by TIGIT+ HIVGag-specific T cells

Abstract In chronic HIV infection, HIV-specific T cells have diminished effector function and fail to control/eliminate the viral reservoirs. HIV-specific T cells and latently HIV infected T cells express checkpoint receptors suggesting that therapeutic strategies improving T cell function and targeting the reservoir will be required to treat HIV infection. IL-27, a member of the IL-6/IL-12 cytokine superfamily, can be considered as such agent because of its anti-viral properties and immune modulatory functions. IL-27 signaling activates mainly Signal Transducer and Activator of Transcription (STAT) 1 and 3. IL-27 can inhibit HIV replication, however, its immunomodulatory functions in T cells are largely unknown. In this study, we hypothesized that IL-27 promotes pro-inflammatory properties enhancing HIV-specific T cell immunity. We found that IL-27 enhanced STAT1 activation in T cell subsets from people living with HIV (PLWH). Moreover, the RNA-Seq analysis showed that IL-27 stimulation induced global transcriptional changes that overlapped with both IFNα and IL-6 signaling. We also determined that the T cells response to IL-27 stimulation were enriched in genes associated with IFN/STAT1 signaling pathways in PLWH and healthy donors. In addition, overnight in vitro stimulation with IL-27 upregulated expression of CD69 and T-bet in CD4 and CD8 T cells. Accordingly, IL-27 increased IFN-ɣ and TNF-αsecretion by TIGIT+ HIVGag specific CD4 and CD8 T cells. The previously described anti-viral properties and these newly immunomodulatory features of IL-27 in HIV-specific T cell function suggest its potential therapeutic use in HIV cure strategies.

Experimental infection with the hookworm, Necator americanus, is associated with stable gut microbial diversity in human volunteers with relapsing multiple sclerosis

BackgroundHelminth-associated changes in gut microbiota composition have been hypothesised to contribute to the immune-suppressive properties of parasitic worms. Multiple sclerosis is an immune-mediated autoimmune disease of the central nervous system whose pathophysiology has been linked to imbalances in gut microbial communities.ResultsIn the present study, we investigated, for the first time, qualitative and quantitative changes in the faecal bacterial composition of human volunteers with remitting multiple sclerosis (RMS) prior to and following experimental infection with the human hookworm, Necator americanus (N+), and following anthelmintic treatment, and compared the findings with data obtained from a cohort of RMS patients subjected to placebo treatment (PBO). Bacterial 16S rRNA high-throughput sequencing data revealed significantly decreased alpha diversity in the faecal microbiota of PBO compared to N+ subjects over the course of the trial; additionally, we observed significant differences in the abundances of several bacterial taxa with putative immune-modulatory functions between study cohorts. Parabacteroides were significantly expanded in the faecal microbiota of N+ individuals for which no clinical and/or radiological relapses were recorded at the end of the trial.ConclusionsOverall, our data lend support to the hypothesis of a contributory role of parasite-associated alterations in gut microbial composition to the immune-modulatory properties of hookworm parasites.

Eradication of specific donor-dependent variations of mesenchymal stem cells in immunomodulation to enhance therapeutic values

Mesenchymal stem cells (MSCs) are one of the most widely clinically trialed stem cells, due to their abilities to differentiate into multiple cell lineages, to secrete regenerative/rejuvenative factors, and to modulate immune functions, among others. In this study, we analyzed human umbilical-cord-derived MSCs from 32 donors and revealed donor-dependent variations in two non-correlated properties, (1) cell proliferation, and (2) immune modulatory functions in vitro and in vivo, which might explain inconsistent clinical efficacies of MSCs. Through unbiased transcriptomic analyses, we discovered that IFN-γ and NF-κB signaling were positively associated with immune modulatory function of MSCs. Activation of these two pathways via IFN-γ and TNF-α treatment eradicated donor-dependent variations. Additional transcriptomic analyses revealed that treatment with these two factors, while having abolished donor-dependent variations in immune modulatory function, did not overall make different donor-derived MSCs the same at whole transcriptomic levels, demonstrating that the cells were still different in many other biological perspectives, and may not perform equally for therapeutic purposes other than immune modulation. Pre-selection or pre-treatment to eradicate MSC variations in a disease-treatment-specific manner would therefore be necessary to ensure clinical efficacies. Together this study provided novel insights into the quality control perspective of using different-donor-derived MSCs to treat inflammation-related clinical conditions and/or autoimmune diseases.

SnapShot: The microbiota-gut-brain axis

Animals have co-evolved with a vast diversity of microorganisms, collectively named the microbiome, which are important modulators of host gastrointestinal, immune, metabolic, and behavioral functions. In this SnapShot, we provide an overview of the neurodevelopmental and functional influence of host-microbial interactions in the "microbiota-gut-brain axis," which refers to the bidirectional communication between the central nervous system and the gastrointestinal microbiome. To view this SnapShot, open or download the PDF.

Anticancer activity of milk fat rich in conjugated linoleic acid against Ehrlich ascites carcinoma cells in female Swiss albino mice.

Background and Aim:The major conjugated linoleic acid (CLA) isomers have anticancer effect, especially breast cancer cells, inhibits cell growth and induces cell death. Also, CLA has several health benefits in vivo, including antiatherogenesis, antiobesity, and modulation of immune function. The present study aimed to assess the safety and anticancer effects of milk fat CLA against in vivo Ehrlich ascites carcinoma (EAC) in female Swiss albino mice. This was based on acute toxicity study, detection of the tumor growth, life span of EAC bearing hosts, and simultaneous alterations in the hematological, biochemical, and histopathological profiles.Materials and Methods:One hundred and fifty adult female mice were equally divided into five groups. Groups (1-2) were normal controls, and Groups (3-5) were tumor transplanted mice (TTM) inoculated intraperitoneally with EAC cells (2×106/0.2 mL). Group (3) was (TTM positive control). Group (4) TTM fed orally on balanced diet supplemented with milk fat CLA (40 mg CLA/kg body weight). Group (5) TTM fed orally on balanced diet supplemented with the same level of CLA 28 days before tumor cells inoculation. Blood samples and specimens from liver and kidney were collected from each group. The effect of milk fat CLA on the growth of tumor, life span of TTM, and simultaneous alterations in the hematological, biochemical, and histopathological profiles were examined.Results:For CLA treated TTM, significant decrease in tumor weight, ascetic volume, viable Ehrlich cells accompanied with increase in life span were observed. Hematological and biochemical profiles reverted to more or less normal levels and histopathology showed minimal effects.Conclusion:The present study proved the safety and anticancer efficiency of milk fat CLA and provides a scientific basis for its medicinal use as anticancer attributable to the additive or synergistic effects of its isomers.

A Differential Immune Modulating Role of Vitamin D in Urinary Tract Infection.

ABSTRACT Vitamin D is known as an important modulator of numerous immune functions. We aimed to investigate the association of 25-hydroxyvitamin D [25(OH)D] with several humoral mediators of the immune system in the patients with urinary tract infection (UTI) caused by uropathogenic E. coli (UPEC). Serum levels of 25(OH)D, cytokines (interferon (IFN)-γ, interleukin (IL)–4, IL-6, IL–10, IL-17A, Tumor necrosis factor (TNF)–α, and transforming growth factor (TGF)–β, immunoglobulin (Ig) isotypes (IgG, IgM, and IgA), complement proteins (C3 and C4) with hemolytic activities (CH50 and AP50), and nitric oxide (NO) were evaluated in 65 patients, compared to 45 age- and sex-matched healthy controls. An insignificant decrease in 25(OH)D levels was observed in patients, compared to controls. In the patient group, elevated levels of IFN-γ, IL-17A, and IL-10 had a significant association with the serum levels of 25(OH)D, while the levels of TGF-β, IL-6, and TNF-α showed an insignificant association. The levels of IgG, C3, and NO also displayed such a statistically significant association with serum 25(OH)D levels. The AP50 levels which had significant difference were found to be not associated with serum 25(OH)D levels. Vitamin D might mediate a link between the innate and adaptive immune responses via the induction of Th1/Th17 polarization of cytokine responses and isotype regulation of antibody production, along with the maintenance of the capacity of the alternative complement pathway, in response to a UPEC infection. However, further studies are needed to validate the defined nature of the host immune response.

Ruxolitinib Inhibits IFNγ Licensing of Human Bone Marrow Derived Mesenchymal Stromal Cells

Ruxolitinib is a JAK2/JAK1 inhibitor that blocks the inflammatory JAK-STAT signaling pathway. Ruxolitinib has been demonstrated to be effective in the treatment of steroid-resistant acute graft-versus-host disease (GVHD). Ruxolitinib's effect on inflammatory cells of hematopoietic origin is known. However, its effect on nonhematopoietic cell types with immune-modulating and antigen-presenting cell competency plausibly involved in pathogenesis of GVHD has not been explored. Mesenchymal stromal cells (MSCs) are CD45- nonhematopoietic cells of the bone marrow with immune modulatory functions in vivo. MSCs' immunobiology largely depends on their responsiveness to IFNγ. We aimed to define the effect of ruxolitinib on the immunobiology of MSCs that are modulated by IFNγ. Human bone marrow derived MSCs, peripheral blood mononuclear cells (PBMCs), and primary bone marrow aspirates were analyzed for their sensitivity to ruxolitinib-mediated blocking of IFNγ-induced STAT-1 phosphorylation and downstream effector molecules, utilizing Western blot, flow cytometry, secretome analysis, and phosflow techniques. IFNγ-induced cytostatic effects on MSCs are reversed by ruxolitinib. Ruxolitinib inhibits IFNγ and secretome of activated peripheral PBMC-induced STAT-1 phosphorylation on human bone marrow derived MSCs. In addition, ruxolitinib inhibits IFNγ-induced pro-GVHD pathways on MSCs, which includes HLAABC(MHCI), HLADR(MHCII), CX3CL1, and CCL2. IFNγ-induced immunosuppressive molecules IDO and PDL-1 were also inhibited by ruxolitinib on MSCs. Comparative analysis with PBMCs has demonstrated that MSCs are as equal as to HLADR+ PBMC populations in responding to ruxolitinib-mediated inhibition of IFNγ-induced STAT-1 phosphorylation. Ex vivo analysis of human marrow aspirates has demonstrated that ruxolitinib blocks IFNγ-induced STAT-1 phosphorylation in CD45+/-HLADR+/- populations at different levels, which is depending on their sensitivity to IFNγ responsiveness. These results inform the hypothesis that ruxolitinib's immune-modulatory effects in vivo may pharmacologically involve marrow and tissue-resident MSCs. Ruxolitinib affects the immunobiology of MSCs equivalent to professional HLADR+ antigen presenting cells, which collectively mitigate GVHD.

Immune monitoring in mesothelioma patients identifies novel immune-modulatory functions of gemcitabine associating with clinical response.

BackgroundGemcitabine is a frequently used chemotherapeutic agent but its effects on the immune system are incompletely understood. Recently, the randomized NVALT19-trial revealed that maintenance gemcitabine after first-line chemotherapy significantly prolonged progression-free survival (PFS) compared to best supportive care (BSC) in malignant mesothelioma. Whether these effects are paralleled by changes in circulating immune cell subsets is currently unknown. These analyses could offer improved mechanistic insights into the effects of gemcitabine on the host and guide development of effective combination therapies in mesothelioma.MethodsWe stained peripheral blood mononuclear cells (PBMCs) and myeloid-derived suppressor cells (MDSCs) at baseline and 3 weeks following start of gemcitabine or BSC treatment in a subgroup of mesothelioma patients included in the NVALT19-trial. In total, 24 paired samples including both MDSCs and PBMCs were included. We performed multicolour flow-cytometry to assess co-inhibitory and-stimulatory receptor- and cytokine expression and matched these parameters with PFS and OS.FindingsGemcitabine treatment was significantly associated with an increased NK-cell- and decreased T-regulatory cell proliferation whereas the opposite occurred in control patients. Furthermore, myeloid-derived suppressor cells (MDSCs) frequencies were lower in gemcitabine-treated patients and this correlated with increased T-cell proliferation following treatment. Whereas gemcitabine variably altered co-inhibitory receptor expression, co-stimulatory molecules including ICOS, CD28 and HLA-DR were uniformly increased across CD4+ T-helper, CD8+ T- and NK-cells. Although preliminary in nature, the increase in NK-cell proliferation and PD-1 expression in T cells following gemcitabine treatment was associated with improved PFS and OS.InterpretationGemcitabine treatment was associated with widespread effects on circulating immune cells of mesothelioma patients with responding patients displaying increased NK-cell and PD-1 + T-cell proliferation. These exploratory data provide a platform for future on treatment-biomarker development and novel combination treatment strategies.

A Case-control Study of Urinary Tract Infection, 25‑hydroxyvitamin D Status and Associated Inflammatory and Regulatory Responses

Background: Vitamin D plays a key role in the modulation of numerous immune functions against infectious agents. We aimed to explore the association between serum 25‑hydroxyvitamin D (25[OH] D) levels and cytokine responses, along with hematological changes, in patients with urinary tract infection (UTI). Materials and Methods: Vitamin D level, cytokines (interferon [IFN]−γ, interleukin [IL]−4, IL−6, IL–10, IL−17A, tumor necrosis factor [TNF]−α, and transforming growth factor [TGF]−β), hematological indices (neutrophil-to-lymphocyte ratio [NLR], monocyte-to-lymphocyte ratio [MLR], neutrophil-to-monocyte ratio [NMR], platelet-to-lymphocyte ratio [PLR], and mean platelet volume [MPV]), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were evaluated in a case-control human study included 65 patients and 45 controls. Results: Among the enhanced cytokine levels in patients, the cytokines IFN-γ, IL-17A, and IL-10 had a significant association with 25(OH)D, but not IL-6, TNF-α, and TGF-β. The IL-4 levels remained unchanged. By comparing hematological indices, we found the association of increased NLR and MLR with 25(OH)D and the cytokines IFN-γ and IL-17A, along with a decrease in the PLR without showing such an association. The NMR did not show any significant difference. The platelet count showed an association with IL-6, IL-17A, and TGF-β, but the association of MPV with 25(OH)D was significant. The ESR results exhibited statistically non-significant differences. CRP elevation was directly associated with IL-6 and IL-17A, but not with 25(OH)D. Conclusion: 25(OH)D-mediated inflammatory cytokine milieu might alter the proportion and function of peripheral blood cells in a regulated manner to support bacterial clearance which needs further studies to be validated.

Gold digging: Searching for gut microbiota that enhancesantitumor immunity.

Programmed cell death protein-1/programmed cell death-ligand 1and cytotoxic T-lymphocyte antigen-4are two immune checkpoint inhibitors (ICIs), exhibiting significant antitumor effects on multiple types of cancers in clinical practice. However, only some patients respond to ICI agents, which limits their widespread application. Recent findings revealed that the gut microbiota is relevant to host health through the modulation of host physical and immune functions. Therefore, the modulation of gut microbiota to achieve the desired taxa may be a potential strategy to improve the efficacy of immunotherapies. In this review, we classified the relative microbes according to their taxonomic information and aimed to clarify their modulatory functions and potent effects on ICI immunotherapyby focusing on recent trials investigating the relationships between the gut microbiota and ICIs.

Peripheral blood mononuclear cells preferentially activate 11-oxygenated androgens.

ObjectiveAndrogens are important modulators of immune cell function. The local generation of active androgens from circulating precursors is an important mediator of androgen action in peripheral target cells or tissues. We aimed to characterize the activation of classic and 11-oxygenated androgens in human peripheral blood mononuclear cells (PBMCs).MethodsPBMCs were isolated from healthy male donors and incubated ex vivo with precursors and active androgens of the classic and 11-oxygenated androgen pathways. Steroids were quantified by liquid chromatography-tandem mass spectrometry. The expression of genes encoding steroid-metabolizing enzymes was assessed by quantitative PCR.ResultsPBMCs generated eight-fold higher amounts of the active 11-oxygenated androgen 11-ketotestosterone than the classic androgen testosterone from their respective precursors. We identified the enzyme AKR1C3 as the major reductive 17β-hydroxysteroid dehydrogenase in PBMCs responsible for both conversions and found that within the PBMC compartment natural killer cells are the major site of AKRC13 expression and activity. Steroid 5α-reductase type 1 catalyzed the 5α-reduction of classic but not 11-oxygenated androgens in PBMCs. Lag time prior to the separation of cellular components from whole blood increased serum 11-ketotestosterone concentrations in a time-dependent fashion, with significant increases detected from two hours after blood collection.Conclusions11-Oxygenated androgens are the preferred substrates for androgen activation by AKR1C3 in PBMCs, primarily conveyed by natural killer cell AKR1C3 activity, yielding 11-ketotestosterone the major active androgen in PBMCs. Androgen metabolism by PBMCs can affect the results of serum 11-ketotestosterone measurements, if samples are not separated in a timely fashion.Significance statementWe show that human peripheral blood mononuclear cells (PBMCs) preferentially activate 11-ketotestosterone rather than testosterone when incubated with precursors of both the classic and the adrenal-derived 11-oxygenated androgen biosynthesis pathways. We demonstrate that this activity is catalyzed by the enzyme AKR1C3, which we found to primarily reside in natural killer cells, major contributors to the anti-viral immune defense. This potentially links intracrine 11-oxygenated androgen generation to the previously observed decreased NK cell cytotoxicity and increased infection risk in primary adrenal insufficiency. In addition, we show that PBMCs continue to generate 11-ketotestosterone if the cellular component of whole blood samples is not removed in a timely fashion, which could affect measurements of this active androgen in routine clinical biochemistry.

Importance of omega 3 fatty acids in health

Omega 3 fatty acids are polyunsaturated fatty acids, essential since the human body does not produce them and they are obtained mainly from the diet. They confer flexibility, fluidity and selective permeability to the membranes, which favors cardiovascular health, reduces the risk of deficiencies in vision and neural development in infants and children, and dementia in older adults; some of them are precursors in the synthesis of prostaglandins. Some effects have also been seen in the prevention and treatment of coronary heart disease, hypertension, diabetes, arthritis, inflammation, autoimmune disorders, and cancer. These effects can be explained through the specific actions of each of them. Dietary fat influences the modulation of immune functions and inflammatory processes; most of the impact is attributed to long-chain polyunsaturated fatty acids (LCPUFA). The EPA exerts: hypotriglyceridemic effect at LDL and VLDL level; hypocholesterolemic effect due to increase in bile efflux and reverse cholesterol transport; antithrombotic effect due to the formation of Series 3 eicosanoids. DHA: increases the fluidity of neuronal, glial, and cone and rod membranes; decreases neuronal apoptosis; facilitates the recycling of neurotransmitters; regulates the expression of enzymes involved in lipid metabolism as a ligand for PPARs; inhibits insulin resistance to muscle and fat tissues. The intake recommendations are: 6 polyunsaturated fatty acids: 2.5-9% of energy intake/daily, and ω3 polyunsaturated fatty acids: 0.6-2.0% of energy intake/daily. Key words: omega-3 fatty acids; food sources; immune system; pathologies.

The impact of salinity and dissolved oxygen regimes on transcriptomic immune responses to oil in early life stage Fundulus grandis

Understanding the effects of oil exposure on early life stage fish species is critical to fully assessing the environmental impacts of oil spills. Oil released from the 2010 Deepwater Horizon spill reached habitats where estuarine fish routinely spawn. In addition, estuaries are highly dynamic environments, therefore, fish in these areas are routinely exposed to varying salinity and dissolved oxygen (DO) levels, each of which are known to modulate transcriptional responses. Fish exposed to oil often display altered immune competence, and several studies have shown that Deepwater Horizon oil in particular causes modulation of various immune functions. However, few studies have directly examined how environmental parameters may affect oil-induced immunomodulation, particularly in early life stage fishes when the immune system is still developing. To this end, we examined transcriptional patterns of immune genes and pathways in Fundulus grandis larvae to various oil (0, 15 μg/L), salinity (3, 30 ppt), and DO (2.5, 6 mg/L) regimes in a fully factorial design. Our results suggest that immune pathways are generally activated in all treatment groups with the exception of the Low Salinity/No Oil/Hypoxia treatment where immune pathways are largely suppressed, and the High Salinity/No Oil/Hypoxia treatment where pathways are unchanged. The High Salinity/Oil/Hypoxia treatment had the largest number of enriched immune pathways (44 as defined by IPA and 43 as defined by ConsensusPathDB), indicating that oil under certain environmental conditions has the potential to further modulate immune-related genes, pathways, and responses in fish.

A Novel HGF/SF Receptor (MET) Agonist Transiently Delays the Disease Progression in an Amyotrophic Lateral Sclerosis Mouse Model by Promoting Neuronal Survival and Dampening the Immune Dysregulation.

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease with no effective treatment. The Hepatocyte Growth Factor/Scatter Factor (HGF/SF), through its receptor MET, is one of the most potent survival-promoting factors for motor neurons (MN) and is known as a modulator of immune cell function. We recently developed a novel recombinant MET agonist optimized for therapy, designated K1K1. K1K1 was ten times more potent than HGF/SF in preventing MN loss in an in vitro model of ALS. Treatments with K1K1 delayed the onset of muscular impairment and reduced MN loss and skeletal muscle denervation of superoxide dismutase 1 G93A (SOD1G93A) mice. This effect was associated with increased levels of phospho-extracellular signal-related kinase (pERK) in the spinal cord and sciatic nerves and the activation of non-myelinating Schwann cells. Moreover, reduced activated microglia and astroglia, lower T cells infiltration and increased interleukin 4 (IL4) levels were found in the lumbar spinal cord of K1K1 treated mice. K1K1 treatment also prevented the infiltration of T cells in skeletal muscle of SOD1G93A mice. All these protective effects were lost on long-term treatment suggesting a mechanism of drug tolerance. These data provide a rational justification for further exploring the long-term loss of K1K1 efficacy in the perspective of providing a potential treatment for ALS.

Lipopolysaccharide-induced innate immune responses are exacerbated by Prohibitin 1 deficiency and mitigated by S-adenosylmethionine in murine macrophages.

Prohibitin 1 (Phb1) is a pleiotropic protein with multiple functions in mammalian cells including cell cycle regulation and mitochondrial protein stabilization. It has been proposed as a potential therapeutic target for a variety of diseases including inflammatory diseases. In this study, we investigated the potential immune-modulatory functions of Phb1 and anti-inflammatory properties of S-adenosylmethionine (SAMe) using macrophages, which play a major role in the innate immune system. The results showed that expressions of Phb1 mRNA and protein were reduced in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells (p<0.05). Phb1 knockdown further ameliorated the mRNA expression of pro- and anti-inflammatory cytokines such as TNF-α, IL-1α, IL-1β, IL-6, and IL10 in LPS-stimulated RAW 264.7 cells. SAMe significantly attenuated LPS-induced inflammatory responses such as IL-1β, IL-10, Nos2, and NO production in the presence of siPhb1. Luciferase reporter assay was conducted to determine the mechanisms underlying the effects of Phb1 and SAMe on the immune system. The luciferase activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) was significantly increased in LPS-treated RAW 264.7 cells. In addition, the luciferase reporter assay showed increased NF-κB activation in Phb1 knockdown RAW 264.7 cells (p<0.1) and SAMe treatment attenuated the NF-κB luciferase activity in Phb1 knockdown RAW 264.7 cells. Based on the results, we concluded that Phb1 possibly modulates the inflammatory response whereas SAMe has an anti-inflammatory effect on Phb1 knockdown macrophage cells. Furthermore, Phb1 expression level has potential properties of affecting on innate immune system by modulating the NF-κB signaling pathway.

Siglec-15 Is a Novel Immunomodulatory Protein and Therapeutic Target in Childhood Leukemia

Despite advances that have greatly improved the overall survival of pediatric B cell acute lymphoblastic leukemia (B-ALL), it remains one of the leading causes of cancer-related death in children. Immunotherapy has shown efficacy in treatment of refractory disease, highlighting the need for greater understanding of the immune evasion mechanisms underlying this disease so that additional immune modulating therapeutic strategies can be developed. Siglec-15 (Sig15) was recently reported to have immune modulatory functions in the context of solid tumors. We have found that SIGLEC15 is overexpressed at the RNA level in primary B cell acute lymphoblastic leukemia (B-ALL), acute myelogenous leukemia (AML), and diffuse large B cell lymphoma as compared to healthy donor controls. As compared to healthy donor PBMCs, we have confirmed higher expression of Sig15 at the RNA and protein levels through RT-qPCR, immunoblotting, and flow cytometry across a panel of human B-ALL, AML, DLBCL, and T cell acute lymphoblastic leukemia (T-ALL) cell lines. Knockout of Sig15 expression in a BCR-ABL1+ murine model of B-ALL engrafted in immunocompetent and Rag1-/- immunodeficient recipients resulted in leukemia clearance in immunocompetent, but not immunodeficient, recipients and 100% survival (Figure 1). These data suggest a prominent role for Sig15 in the suppression of adaptive immune response to B-ALL as well as other hematological malignancies. Additional studies suggest that SIGLEC15 expression is positively regulated by NFκB signaling, which is known to be constitutively activated in certain B-ALL subsets. Importantly, we have observed release of a soluble form of Sig15 (sSig15) from B-ALL cells, which is regulated by PKC and calcineurin-mediated signaling. To discover translational application, we measured sSig15 in the plasma of both healthy and pediatric leukemia patients and found significantly higher levels of sSig15 as compared to healthy individuals (Figure 2; LLD = 5 pg/ml; **P&amp;lt;0.01). Together, these results suggest Siglec-15 is a novel and potent immunosuppressive molecule active in leukemia that may be targeted therapeutically to activate lymphocytes against leukemia cells. Disclosures Abukharma: NextCure, Inc.: Current Employment. Liu:NextCure, Inc.: Current Employment.

Hodgkin Lymphoma Reed-Sternberg Cells Induce Immunosuppressive and Pro-Angiogenic Phenotype of Tumor-Associated Macrophages in a Paracrine Manner

Increased frequency of tumor-associated macrophages (TAMs) predicts shortened survival of patients with classical Hodgkin lymphoma (cHL), suggesting their protumoral role in the disease. In vitro, malignant cells of cHL (Reed-Sternberg cells, RS) produce humoral factors that convert macrophages into TAMs capable of suppressing T-cell proliferation and exhibiting matrix remodeling activity that fosters lymphoma cell dissemination. Despite these features, phenotype and tumor-supportive activities of cHL-TAMs still remain to be elucidated. Herein, using an in vitro model of cHL-TAMs (RS-conditioned macrophages; RS-M), we provide more comprehensive insights into the biology of macrophages in cHL. To confirm the ability of RS cells to polarize macrophages, THP1 cells and donor-derived CD14+ monocytes were first differentiated into M0 macrophages(Mϕ-0) using PMA and CSF-1, respectively. Obtained Mϕ-0 were nest cocultured for five days with L428 or L1236 RS cells under conditions prohibiting direct contacts (transwell system) and the expression of established M1/M2 polarization markers was assessed by flow cytometry. In comparison to control Mϕ-0, RS-M (L428- and L1236-conditioned: L428-M and L1236-M) exhibited increased surface levels of PD-L1 and M2-associated markers: CD163, CD206 and CD209, but failed to induce M1-specific expression of HLA-DR, indicating that RS cells alter macrophage phenotype in a paracrine manner. Next, using phospho-protein kinase arrays, we studied RS cell-triggered intracellular signaling in conditioned macrophages (L1236-M). In comparison to Mϕ-0, L1236-M exhibited increased phosphorylation levels of M2-specific transcription factors (TFs) and signaling intermediates (CREB1, AKT, STAT-3/6), M1/M2 TF cJun, but also exhibited elevated activity of the M1-specific STAT1 TF. To determine whether M1/M2 states exist within RS-M, we profiled transcriptomes of THP1 and CD14+-derived Mϕ-0 and RS-M by RNAseq, and performed Gene Set Enrichment Analysis (GSEA) using known M1/M2-macrophage signatures. Surprisingly, RS-M showed enrichment for both M1- and M2-signatures, indicating that RS-M phenotype is more complex and cannot be unequivocally classified as M1 or M2 state. Consistent with the transcriptional profiles of RS-M, THP1-derived L1236-M exhibited both enhanced glycolysis (typical for M1 macrophages) and oxidative phosphorylation (typical for M2). To look for genes and processes overrepresented in RS-M, we performed Gene Ontology Enrichment analysis, and found that THP1- and CD14+-derived RS-M similarly induced expression of genes involved in chemotaxis/immunomodulation (CCLs: 2, 5, 7, 8, 13, 17, 18 and 24), extracellular matrix organization (TGM2 and MMP-1, -7, -9 and -12), T cell repression (PD-L1) and angiogenesis (VEGFA, PDGFB, TIMP1, CHI3L1 and -2). Consistently, THP-1-derived L1236-M secreted higher levels of CCL-2, -5, -7 and -17, VEGF and CHI3L1 than Mϕ-0, as determined using cytokine arrays. Furthermore, L1236-M produced additional pro-angiogenic factors, Angiogenin and IL8, suggesting that cHL-TAMs support tumor growth by fostering angiogenesis. To verify this hypothesis, we incubated HUVEC endothelial cells in medium supplemented with VEGFA (10ng/ml), or THP1-derived Mϕ-0- or L1236-M-conditioned media and assessed blood vessel formation in a matrigel assay. In comparison to HUVEC cells grown in Mϕ-0-conditioned medium, addition of VEGFA (10ng/ml) increased number of master junctions by 169%, whereas L1236-M-conditioned medium by 187%, indicating that RS cells induce pro-angiogenic function in macrophages. Together, our data indicate that RS cells determine TAM phenotype in a paracrine manner. Proteomic, transcriptional and metabolic profiles of the in vitro-generated cHL-conditioned TAMs indicate that these macrophages cannot be categorized into one of the two extreme M1/M2 polarization states. On the contrary, our data identify unique and disease-specific phenotype of cHL-TAMs, characterized by elevated expression of molecules involved in the recruitment and modulation of immune cell function, T-cell suppression, extracellular matrix remodeling and angiogenesis. Study supported by National Centre of Science Poland grants: 2017/26/D/NZ5/00561, 2016/22/M/NZ5/00668 and 2018/31/N/NZ5/03214 Disclosures Zaucha: Cellgene: Other: travel, accomodations, expenses; Abbvie: Honoraria; Sandoz: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Other: travel, accomodations, expenses; Takeda: Consultancy, Honoraria, Other: travel, accomodations, expenses; BMS: Consultancy; Novartis: Consultancy. Juszczynski:Ryvu Therapeutics: Other: member of advisory board.