ABSTRACT
Ovarian cancer (OC) is one of the deadliest gynecological cancers, largely due to the fast development of metastasis and drug resistance. The immune system is a critical component of the OC tumor microenvironment (TME) and immune cells such as T cells, NK cells, and dendritic cells (DC) play a key role in anti-tumor immunity. However, OC tumor cells are well known for evading immune surveillance by modulating the immune response through various mechanisms. Recruiting immune-suppressive cells such as regulatory T cells (Treg cells), macrophages, or myeloid-derived suppressor cells (MDSC) inhibit the anti-tumor immune response and promote the development and progression of OC. Platelets are also involved in immune evasion by interaction with tumor cells or through the secretion of a variety of growth factors and cytokines to promote tumor growth and angiogenesis. In this review, we discuss the role and contribution of immune cells and platelets in TME. Furthermore, we discuss their potential prognostic significance to help in the early detection of OC and to predict disease outcome.
Subject(s)
Blood Platelets , Neoplasms , Ovarian Neoplasms , Female , Humans , Blood Platelets/immunology , Blood Platelets/pathology , Myeloid Cells/metabolism , Neoplasms/metabolism , Ovarian Neoplasms/metabolism , Prognosis , Tumor Microenvironment , Immune System/cytology , Immune System/immunology , Receptor Cross-Talk/immunologyABSTRACT
We examined the role of ATP and high mobility group box 1 (HMGB1) in paclitaxel-induced peripheral neuropathy (PIPN). PIPN in mice was prevented by HMGB1 neutralization, macrophage depletion, and P2X7 or P2X4 blockade. Paclitaxel and ATP synergistically released HMGB1 from macrophage-like RAW264.7 cells, but not neuron-like NG108-15 cells. The paclitaxel-induced HMGB1 release from RAW264.7 cells was accelerated by co-culture with NG108-15 cells in a manner dependent on P2X7 or P2X4. Paclitaxel released ATP from NG108-15 cells, but not RAW264.7 cells. Thus, PIPN is considered to involve acceleration of HMGB1 release from macrophages through P2X7 and P2X4 activation by neuron-derived ATP.
Subject(s)
Adenosine Triphosphate/physiology , HMGB1 Protein/metabolism , Macrophages/metabolism , Neurons/metabolism , Paclitaxel/adverse effects , Peripheral Nervous System Diseases/chemically induced , Peripheral Nervous System Diseases/metabolism , Animals , Male , Mice , Mice, Inbred Strains , Peripheral Nervous System Diseases/immunology , Peripheral Nervous System Diseases/prevention & control , RAW 264.7 Cells , Receptor Cross-Talk/immunology , Receptors, Purinergic P2X4/metabolism , Receptors, Purinergic P2X7/metabolismABSTRACT
Many innate immune receptors function collaboratively to detect and elicit immune responses to pathogens, but the physical mechanisms that govern the interaction and signaling crosstalk between the receptors are unclear. In this study, we report that the signaling crosstalk between Fc gamma receptor (FcγR) and Toll-like receptor (TLR)2/1 can be overall synergistic or inhibitory depending on the spatial proximity between the receptor pair on phagosome membranes. Using a geometric manipulation strategy, we physically altered the spatial distribution of FcγR and TLR2 on single phagosomes. We demonstrate that the signaling synergy between FcγR and TLR2/1 depends on the proximity of the receptors and decreases as spatial separation between them increases. However, the inhibitory effect from FcγRIIb on TLR2-dependent signaling is always present and independent of receptor proximity. The overall cell responses are an integration from these two mechanisms. This study presents quantitative evidence that the nanoscale proximity between FcγR and TLR2 functions as a key regulatory mechanism in their signaling crosstalk.
Subject(s)
Phagosomes/immunology , Receptor Cross-Talk/immunology , Receptors, IgG/immunology , Toll-Like Receptor 1/immunology , Toll-Like Receptor 2/immunology , Animals , Cytokines/metabolism , Immunity, Innate , Immunoglobulin G/immunology , Intracellular Membranes/immunology , Mice , Protein Transport , RAW 264.7 Cells , Signal Transduction , Syk Kinase/physiology , Transcription Factor RelA/metabolismABSTRACT
Introduction: Nonalcoholic fatty liver disease (NAFLD) is the most widespread chronic liver disease in the world. It can evolve into nonalcoholic steatohepatitis (NASH) where inflammation and hepatocyte ballooning are key participants in the determination of this steatotic state.Areas covered: To provide a systematic overview and current understanding of the role of inflammation in NAFLD and its progression to NASH, the function of the cells involved, and the activation pathways of the innate immunity and cell death; resulting in inflammation and chronic liver disease. A PubMed search was made with relevant articles together with relevant references were included for the writing of this review.Expert opinion: Innate and adaptive immunity are the key players in the NAFLD progression; some of the markers presented during NAFLD are also known to be immunity biomarkers. All cells involved in NAFLD and NASH are known to have immunoregulatory properties and their imbalance will completely change the cytokine profile and form a pro-inflammatory microenvironment. It is necessary to fully answer the question of what initiators and metabolic imbalances are particularly important, considering sterile inflammation as the architect of the disease. Due to the shortage of elucidation of NASH progression, we discuss in this review, how inflammation is a key part of this development and we presume the targets should lead to inflammation and oxidative stress treatment.
Subject(s)
Hepatocytes/physiology , Inflammation/physiopathology , Non-alcoholic Fatty Liver Disease/physiopathology , Receptor Cross-Talk/physiology , Adaptive Immunity/immunology , Disease Progression , Hepatocytes/immunology , Humans , Immunity, Innate/immunology , Inflammation/immunology , Kupffer Cells/immunology , Lymphocytes/immunology , Non-alcoholic Fatty Liver Disease/immunology , Oxidative Stress/immunology , Receptor Cross-Talk/immunology , Regulated Cell Death/immunology , Regulated Cell Death/physiologyABSTRACT
OBJECTIVE: The effector T cell and B cell cytokine networks have been implicated in the pathogenesis of systemic autoimmune diseases, but the association of these cytokine networks with the heterogeneity of clinical manifestations and immune profiles has not been carefully examined. This study was undertaken to examine whether cytokine profiles can delineate distinct groups of patients in 4 systemic autoimmune diseases (systemic lupus erythematosus, Sjögren's syndrome, rheumatoid arthritis, and systemic sclerosis). METHODS: A total of 179 patients and 48 healthy volunteers were enrolled in the multicenter cross-sectional PRECISE Systemic Autoimmune Diseases (PRECISESADS) study. Multi-low-dimensional omics data (cytokines, autoantibodies, circulating immune cells) were examined. Coculture experiments were performed to test the impact of the cytokine microenvironment on T cell/B cell cross-talk. RESULTS: A proinflammatory cytokine profile defined by high levels of CXCL10, interleukin-6 (IL-6), IL-2, and tumor necrosis factor characterized a distinct group of patients in the 4 systemic autoimmune diseases. In each disease, this proinflammatory cluster was associated with a specific circulating immune cell signature, more severe disease, and higher levels of autoantibodies, suggesting an uncontrolled proinflammatory Th1 immune response. We observed in vitro that B cells reinforce Th1 differentiation and naive T cell proliferation, leading to the induction of type 1 effector B cells and IgG production. This process was associated with an increase in CXCL10, IL-6, IL-2, and interferon-γ production. CONCLUSION: This composite analysis brings new insights into human B cell functional heterogeneity based on T cell/B cell cross-talk, and proposes a better stratification of patients with systemic autoimmune diseases, suggesting that combined biomarkers would be of great value for the design of personalized treatments.
Subject(s)
Autoantibodies/immunology , Autoimmune Diseases/immunology , B-Lymphocyte Subsets/immunology , Cytokines/immunology , Th1 Cells/immunology , Adult , Arthritis, Rheumatoid/blood , Arthritis, Rheumatoid/immunology , Autoantibodies/blood , Autoimmune Diseases/blood , Biomarkers/blood , Cell Differentiation/immunology , Cell Proliferation , Cellular Microenvironment/immunology , Chemokine CXCL10/blood , Chemokine CXCL10/immunology , Coculture Techniques , Cross-Sectional Studies , Cytokines/blood , Female , Humans , Interferon-gamma/blood , Interferon-gamma/immunology , Interleukin-2/blood , Interleukin-2/immunology , Interleukin-6/blood , Interleukin-6/immunology , Lupus Erythematosus, Systemic/blood , Lupus Erythematosus, Systemic/immunology , Male , Middle Aged , Prospective Studies , Receptor Cross-Talk/immunology , Scleroderma, Systemic/blood , Scleroderma, Systemic/immunology , Sjogren's Syndrome/blood , Sjogren's Syndrome/immunologyABSTRACT
Regulatory T cells (Tregs) have a critical role in maintaining self-tolerance and immune homeostasis. There is much interest in using Tregs as a cell therapy to re-establish tolerance in conditions such as inflammatory bowel disease and type 1 diabetes, with many ongoing clinical studies testing the safety and efficacy of this approach. Manufacturing of Tregs for therapy typically involves ex vivo expansion to obtain sufficient cell numbers for infusion and comes with the risk of altering the activity of key biological processes. However, this process also offers an opportunity to tailor Treg function to maximize in vivo activity. In this review, we focus on the roles of antigen-presenting cells (APCs) in the generation and function of Tregs in humans. In addition to stimulating the development of Tregs, APCs activate Tregs and provide signals that induce specialized functional and homing marker expression. Cross talk between Tregs and APCs is a critical, often under-appreciated, aspect of Treg biology, with APCs mediating the key properties of infectious tolerance and bystander suppression. Understanding the biology of human Treg-APC interactions will reveal new ways to optimize Treg-based therapeutic approaches.
Subject(s)
Antigen-Presenting Cells/immunology , T-Lymphocytes, Regulatory/immunology , Cell Differentiation , Humans , Immune Tolerance , Immunological Synapses , Immunotherapy, Adoptive , Lymphocyte Activation , Models, Immunological , Receptor Cross-Talk/immunology , Receptors, Lymphocyte Homing/immunology , Self Tolerance , Synthetic Biology , T-Lymphocytes, Regulatory/cytology , Thymus Gland/cytology , Thymus Gland/immunologyABSTRACT
Abnormal pattern recognition receptor (PRR) signaling plays an important role in gastric mucosal damage caused by stomach microbiota; however, the underlying molecular mechanisms remain obscure. Here, we show that DC-SIGN, a surface phenotype marker of dendritic cells, is overexpressed in gastric epithelial cells facing LPS stimulation. NLRP3 expression in gastric epithelial cells are significantly increased and related to the degree of LPS stimulation. Furthermore, DC-SIGN could interact with TLR4, promote NLRP3 and related genes expression via MyD88-independent signaling pathway and regulate the secretion of IL-1ß and IL-18 in gastric epithelial cells. The results of flow cytometry analysis show that DC-SIGN primarily mediates Th1 differentiation when co-cultured with gastric epithelial cells. These results reveal that LPS-induced DC-SIGN expression modulates NLRP3 inflammasomes formation via MyD88-independent TLR4 signaling in gastric epithelial cell, and induces a Th1-predominant host immune response,these findings may indicate a new function of DC-SIGN in non-immune cells, and elucidate the diversity role of gastric epithelial cells in mechanism of immune damage caused by microbial flora.
Subject(s)
Cell Adhesion Molecules/genetics , Gastric Mucosa/immunology , Gastritis/genetics , Lectins, C-Type/genetics , Myeloid Differentiation Factor 88/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Receptors, Cell Surface/genetics , Toll-Like Receptor 4/genetics , Animals , Cell Adhesion Molecules/immunology , Cell Line , Child , Child, Preschool , Dendritic Cells/immunology , Dendritic Cells/pathology , Epithelial Cells/drug effects , Epithelial Cells/immunology , Epithelial Cells/pathology , Female , Gastric Mucosa/drug effects , Gastric Mucosa/pathology , Gastritis/immunology , Gastritis/pathology , Gene Expression Regulation , Humans , Inflammasomes/genetics , Inflammasomes/immunology , Interleukin-18/genetics , Interleukin-18/immunology , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Lectins, C-Type/immunology , Lipopolysaccharides/pharmacology , Male , Mice, Inbred C57BL , Myeloid Differentiation Factor 88/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Primary Cell Culture , Receptor Cross-Talk/immunology , Receptors, Cell Surface/immunology , Signal Transduction , Th1 Cells/immunology , Th1 Cells/pathology , Toll-Like Receptor 4/immunologyABSTRACT
In this review, we summarize the evidence against direct stimulation of insulin-like growth factor 1 receptors (IGF1Rs) by autoantibodies in Graves' orbitopathy (GO) pathogenesis. We describe a model of thyroid-stimulating hormone (TSH) receptor (TSHR)/IGF1R crosstalk and present evidence that observations indicating IGF1R's role in GO could be explained by this mechanism. We evaluate the evidence for and against IGF1R as a direct target of stimulating IGF1R antibodies (IGF1RAbs) and conclude that GO pathogenesis does not involve directly stimulating IGF1RAbs. We further conclude that the preponderance of evidence supports TSHR as the direct and only target of stimulating autoantibodies in GO and maintain that the TSHR should remain a major target for further development of a medical therapy for GO in concert with drugs that target TSHR/IGF1R crosstalk.
Subject(s)
Graves Ophthalmopathy/pathology , Receptor, IGF Type 1/immunology , Receptors, Thyrotropin/metabolism , Autoantibodies/immunology , Graves Ophthalmopathy/immunology , Humans , Hyaluronic Acid/metabolism , Receptor Cross-Talk/immunology , Receptor, IGF Type 1/metabolism , Receptors, Somatomedin , Receptors, Thyrotropin/immunologyABSTRACT
Infected or damaged tissues release multiple "alert" molecules such as alarmins and damage-associated molecular patterns (DAMPs) that are recognized by innate immune receptors, and induce tissue inflammation, regeneration, and repair. Recently, an extract from inflamed rabbit skin inoculated with vaccinia virus (Neurotropin®, NTP) was found to induce infarct tolerance in mice receiving permanent ischemic attack to the middle cerebral artery. Likewise, we report herein that NTP prevented the neurite retraction in PC12 cells by nerve growth factor (NGF) deprivation. This effect was accompanied by interaction of Fyn with high-affinity NGF receptor TrkA. Sucrose density gradient subcellular fractionation of NTP-treated cells showed heretofore unidentified membrane fractions with a high-buoyant density containing Trk, B subunit of cholera toxin-bound ganglioside, flotillin-1 and Fyn. Additionally, these new membrane fractions also contained Toll-like receptor 4 (TLR4). Inhibition of TLR4 function by TAK-242 prevented the formation of these unidentified membrane fractions and suppressed neuroprotection by NTP. These observations indicate that NTP controls TrkA-mediated signaling through the formation of clusters of new membrane microdomains, thus providing a platform for crosstalk between neurotrophic and innate immune receptors. Neuroprotective mechanisms through the interaction with innate immune systems may provide novel mechanism for neuroprotection.
Subject(s)
Immunity, Innate/drug effects , Polysaccharides/metabolism , Receptor Cross-Talk/drug effects , Animals , Gangliosides/metabolism , Immunity, Innate/immunology , Immunity, Innate/physiology , Membrane Microdomains/metabolism , Membrane Proteins/metabolism , Nerve Growth Factor/metabolism , Neurites/metabolism , Neuroprotection/drug effects , Neuroprotective Agents/metabolism , PC12 Cells , Phosphorylation/drug effects , Polysaccharides/immunology , Proto-Oncogene Proteins c-fyn/metabolism , Rats , Receptor Cross-Talk/immunology , Receptor Cross-Talk/physiology , Receptor, trkA/immunology , Receptor, trkA/metabolism , Signal Transduction/drug effectsABSTRACT
Recent advances have identified a growing array of roles played by lymphatics in the tumor microenvironment, from providing a route of metastasis to immune modulation. The tumor microenvironment represents an exceptionally complex, dynamic niche comprised of a diverse mixture of cancer cells and normal host cells termed the stroma. This review discusses our current understanding of stromal elements and how they regulate lymphatic growth and functional properties in the tumor context.
Subject(s)
Lymphatic System/immunology , Neoplasms/pathology , Tumor Microenvironment/immunology , Cancer-Associated Fibroblasts/immunology , Endothelial Cells/immunology , Extracellular Matrix/immunology , Humans , Lymphatic Vessels/pathology , Models, Biological , Neovascularization, Pathologic/immunology , Receptor Cross-Talk/immunologyABSTRACT
Mounting an effective immune response relies critically on the coordinated interactions between adaptive and innate compartments. How and where immune cells from these different compartments interact is still poorly understood. Here, we demonstrate that the cross-talk between invariant natural killer T cells (iNKT) and CD8+ T cells in the spleen, essential for initiating productive immune responses, is biphasic and occurs at 2 distinct sites. Codelivery of antigen and adjuvant to antigen-presenting cells results in: 1) initial short-lived interactions (0 to 6 h), between CD8+ T cells, dendritic cells (DCs), and iNKT cells recruited outside the white pulp; 2) followed by long-lasting contacts (12 to 24 h) between iNKT cells, DCs, and CD8+ T cells occurring in a 3-way interaction profile within the white pulp. Both CXCR3 and CCR4 are essential to orchestrate this highly dynamic process and play nonredundant in T cell memory generation. While CXCR3 promotes memory T cells, CCR4 supports short-lived effector cell generation. We believe our work provides insights into the initiation of T cell responses in the spleen and their consequences for T cell differentiation.
Subject(s)
CD8-Positive T-Lymphocytes/immunology , Chemokine CCL17/metabolism , Interleukin-4/metabolism , Natural Killer T-Cells/immunology , Spleen/immunology , Animals , Cell Differentiation , Chemokine CXCL9/metabolism , Dendritic Cells/immunology , Homeodomain Proteins/genetics , Immunologic Memory/immunology , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptor Cross-Talk/immunology , Receptor Cross-Talk/physiology , Receptors, CCR4/metabolism , Receptors, CXCR3/metabolism , Spleen/cytologyABSTRACT
During the last decade, the dynamics of the cellular crosstalk have highlighted the significance of the host vs. tumor interaction. This resulted in the development of novel immunotherapeutic strategies in order to modulate/inhibit the mechanisms leading to escape of tumor cells from immune surveillance. Different monoclonal antibodies directed against immune checkpoints, e.g., the T lymphocyte antigen 4 and the programmed cell death protein 1/ programmed cell death ligand 1 have been successfully implemented for the treatment of cancer. Despite their broad activity in many solid and hematologic tumor types, only 20-40% of patients demonstrated a durable treatment response. This might be due to an impaired T cell tumor interaction mediated by immune escape mechanisms of tumor and immune cells as well as alterations in the composition of the tumor microenvironment, peripheral blood, and microbiome. These different factors dynamically regulate different steps of the cancer immune process thereby negatively interfering with the T cell -mediated anti-tumoral immune responses. Therefore, this review will summarize the current knowledge of the different players involved in inhibiting tumor immunogenicity and mounting resistance to checkpoint inhibitors with focus on the role of tumor T cell interaction. A better insight of this process might lead to the development of strategies to revert these inhibitory processes and represent the rational for the design of novel immunotherapies and combinations in order to improve their efficacy.
Subject(s)
Neoplasms/immunology , Receptor Cross-Talk/immunology , T-Lymphocytes/immunology , Tumor Escape/immunology , Tumor Microenvironment/immunology , Animals , Antineoplastic Agents, Immunological/immunology , Humans , Immunotherapy/methodsABSTRACT
Antigen-presenting cells (APCs) such as dendritic cells (DCs) are crucial for initiation of adequate inflammatory responses, which critically depends on the cooperated engagement of different receptors. In addition to pattern recognition receptors (PRRs), Fc gamma receptors (FcγRs) have recently been identified to be important in induction of inflammation by DCs. FcγRs that recognize IgG immune complexes, which are formed upon opsonization of pathogens, induce pro-inflammatory cytokine production through cross-talk with PRRs such as Toll-like receptors (TLRs). While the physiological function of FcγR-TLR cross-talk is to provide protective immunity against invading pathogens, undesired activation of FcγR-TLR cross-talk, e.g., by autoantibodies, also plays a major role in the development of chronic inflammatory disorders such as rheumatoid arthritis (RA). Yet, the molecular mechanisms of FcγR-TLR cross-talk are still largely unknown. Here, we identified that FcγR-TLR cross-talk-induced cytokine production critically depends on activation of the transcription factor interferon regulatory factor 5 (IRF5), which results from induction of two different pathways that converge on IRF5 activation. First, TLR stimulation induced phosphorylation of TBK1/IKKε, which is required for IRF5 phosphorylation and subsequent activation. Second, FcγR stimulation induced nuclear translocation of IRF5, which is essential for gene transcription by IRF5. We identified that IRF5 activation by FcγR-TLR cross-talk amplifies pro-inflammatory cytokine production by increasing cytokine gene transcription, but also by synergistically inducing glycolytic reprogramming, which is another essential process for induction of inflammatory responses by DCs. Combined, here we identified IRF5 as a pivotal component of FcγR-TLR cross-talk in human APCs. These data may provide new potential targets to suppress chronic inflammation in autoantibody-associated diseases that are characterized by undesired or excessive FcγR-TLR cross-talk, such as RA, systemic sclerosis, and systemic lupus erythematous.
Subject(s)
Dendritic Cells/immunology , Interferon Regulatory Factors/genetics , Interferon Regulatory Factors/metabolism , Receptors, IgG/metabolism , Toll-Like Receptors/metabolism , Tumor Necrosis Factor-alpha/biosynthesis , Active Transport, Cell Nucleus , Dendritic Cells/metabolism , Glycolysis/immunology , Humans , I-kappa B Kinase/immunology , I-kappa B Kinase/metabolism , In Vitro Techniques , Inflammation/immunology , Macrophages/immunology , Macrophages/metabolism , Models, Immunological , Monocytes/immunology , Monocytes/metabolism , Phosphorylation , Protein Serine-Threonine Kinases/immunology , Protein Serine-Threonine Kinases/metabolism , Receptor Cross-Talk/immunology , Transcription, GeneticABSTRACT
BACKGROUND: Heparanase (HPSE) is an endo-beta-glucuronidase that degrades heparan sulfate (HS) chains on proteoglycans. The oligosaccharides generated by HPSE promote angiogenesis, tumor growth and metastasis. Heparanase-2 (HPSE2), a close homolog of HPSE, does not exhibit catalytic activity. Previous studies have demonstrated that serum or plasma from breast cancer patients showed increased expression of both heparanases in circulating lymphocytes. The aim of this study was to better understand the mechanisms involved in the upregulation of heparanases in circulating lymphocytes. METHODS: Lymphocytes collected from healthy women were incubated in the presence of MCF-7 breast cancer cells (co-culture) to stimulate HPSE and HPSE2 overexpression. The protein level of heparanases was evaluated by immunocytochemistry, while mRNA expression was determined by quantitative RT-PCR. RESULTS: The medium obtained from co-culture of MCF-7 cells and circulating lymphocytes stimulated the expression of HPSE and HPSE2. Previous treatment of the co-culture medium with an anti-heparan sulfate proteoglycan antibody or heparitinase II inhibited the upregulation of heparanases in circulating lymphocytes. The addition of exogenous heparan sulfate (HS) enhanced the expression of both heparanases. Moreover, the co-cultured cells, as well as MCF-7 cells, secreted a higher number of exosomes expressing an increased level of HS compared to that of the exosomes secreted by circulating lymphocytes from women who were not affected by cancer. CONCLUSIONS: The results revealed that HS is likely responsible for mediating the expression of heparanases in circulating lymphocytes. HS secreted by tumor cells might be carried by exosome particles, confirming the key role of tumor cells, as well as secreted HS, in upregulating the expression of heparanases, suggesting a possible mechanism of crosstalk between tumor cells and circulating lymphocytes.
Subject(s)
Breast Neoplasms/genetics , Cell Communication/physiology , Glucuronidase/genetics , Lymphocytes/physiology , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Communication/drug effects , Cells, Cultured , Coculture Techniques , Culture Media, Conditioned/pharmacology , Female , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Glucuronidase/metabolism , Heparitin Sulfate/metabolism , Heparitin Sulfate/physiology , Humans , Lymphocyte Activation/genetics , Lymphocytes/metabolism , MCF-7 Cells , Receptor Cross-Talk/drug effects , Receptor Cross-Talk/immunologyABSTRACT
T helper type 2 (Th2) cells are important regulators of mammalian adaptive immunity and have relevance for infection, autoimmunity, and tumor immunology. Using a newly developed, genome-wide retroviral CRISPR knockout (KO) library, combined with RNA-seq, ATAC-seq, and ChIP-seq, we have dissected the regulatory circuitry governing activation and differentiation of these cells. Our experiments distinguish cell activation versus differentiation in a quantitative framework. We demonstrate that these two processes are tightly coupled and are jointly controlled by many transcription factors, metabolic genes, and cytokine/receptor pairs. There are only a small number of genes regulating differentiation without any role in activation. By combining biochemical and genetic data, we provide an atlas for Th2 differentiation, validating known regulators and identifying factors, such as Pparg and Bhlhe40, as part of the core regulatory network governing Th2 helper cell fates.
Subject(s)
Receptor Cross-Talk/immunology , Th2 Cells/immunology , Th2 Cells/metabolism , Animals , CRISPR-Cas Systems/genetics , Cell Differentiation/genetics , Cell Differentiation/immunology , Chromatin , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , Genome , High-Throughput Nucleotide Sequencing , Humans , Lymphocyte Activation/genetics , Lymphocyte Activation/immunology , Mice , Mice, Inbred C57BL , T-Lymphocytes, Helper-Inducer/metabolism , Transcription Factors/metabolismABSTRACT
Dendritic cells (DCs), natural killer (NK) cells, and T cells play critical roles during primary HIV-1 exposure at the mucosa, where the viral particles become coated with complement fragments and mucosa-associated antibodies. The microenvironment together with subsequent interactions between these cells and HIV at the mucosal site of infection will determine the quality of immune response that ensues adaptive activation. Here, we investigated how complement and immunoglobulin opsonization influences the responses triggered in DCs and NK cells, how this affects their cross talk, and what T cell phenotypes are induced to expand following the interaction. Our results showed that DCs exposed to complement-opsonized HIV (C-HIV) were less mature and had a poor ability to trigger IFN-driven NK cell activation. In addition, when the DCs were exposed to C-HIV, the cytotolytic potentials of both NK cells and CD8 T cells were markedly suppressed. The expression of PD-1 as well as co-expression of negative immune checkpoints TIM-3 and LAG-3 on PD-1 positive cells were increased on both CD4 as well as CD8 T cells upon interaction with and priming by NK-DC cross talk cultures exposed to C-HIV. In addition, stimulation by NK-DC cross talk cultures exposed to C-HIV led to the upregulation of CD38, CXCR3, and CCR4 on T cells. Together, the immune modulation induced during the presence of complement on viral surfaces is likely to favor HIV establishment, dissemination, and viral pathogenesis.
Subject(s)
Complement System Proteins/immunology , Dendritic Cells/immunology , HIV Infections/immunology , HIV-1/immunology , Killer Cells, Natural/immunology , T-Lymphocytes/immunology , Cytotoxicity, Immunologic , Humans , Lymphocyte Activation/immunology , Programmed Cell Death 1 Receptor/biosynthesis , Programmed Cell Death 1 Receptor/immunology , Receptor Cross-Talk/immunology , Receptors, CCR4/biosynthesis , Receptors, CCR4/immunology , Receptors, CXCR3/biosynthesis , Receptors, CXCR3/immunology , Up-RegulationABSTRACT
Expression of the membrane-bound form of the immunoglobulin (Ig) as part of the antigen receptor is indispensable for both the development and the effector function of B cells. Among five known isotypes, IgM and IgD are the common B cell antigen receptors (BCRs) that are co-expressed in naïve B cells. Despite having identical antigen specificity and being associated with the same signaling heterodimer Igα/Igß (CD79a/CD79b), IgM and IgD-BCR isotypes functionally differ from each other in the manner of antigen binding, the formation of isolated nanoclusters and in their interaction with co-receptors such as CD19 and CXCR4 on the plasma membrane. With recent developments in experimental techniques, it is now possible to investigate the nanoscale organization of the BCR and better understand early events of BCR engagement. Interestingly, the cytoskeleton network beneath the membrane controls the BCR isotype-specific organization and its interaction with co-receptors. BCR triggering results in reorganization of the cytoskeleton network, which is further modulated by isotype-specific signals from co-receptors. For instance, IgD-BCR is closely associated with CXCR4 on mature B cells and this close proximity allows CXCR4 to employ the BCR machinery as signaling hub. In this review, we discuss the functional specificity and nanocluster assembly of BCR isotypes and the consequences of cross-talk between CXCR4 and IgD-BCR. Furthermore, given the role of BCR and CXCR4 signaling in the development and survival of leukemic B cells, we discuss the consequences of the cross-talk between CXCR4 and the BCR for controlling the growth of transformed B cells.
Subject(s)
B-Lymphocytes/immunology , Cytoskeleton/immunology , Receptor Cross-Talk/immunology , Receptors, Antigen, B-Cell/metabolism , Receptors, CXCR4/metabolism , B-Lymphocytes/metabolism , Cytoskeleton/metabolism , Humans , Immunoglobulin Isotypes/immunology , Immunoglobulin Isotypes/metabolism , Receptors, Antigen, B-Cell/immunology , Receptors, CXCR4/immunology , Signal Transduction/immunologyABSTRACT
The detection of microbial pathogens relies on the recognition of highly conserved microbial structures by the membrane sensor Toll-like receptors (TLRs) and cytosolic sensor NOD-like receptors (NLRs). Upon detection, these sensors trigger innate immune responses to eradicate the invaded microbial pathogens. However, it is unclear whether TLR and NOD signaling are both critical for innate immunity to initiate inflammatory and antimicrobial responses against microbial infection. Here we report that activation of both TLR and NOD signaling resulted in an augmented inflammatory response and the crosstalk between TLR and NOD led to an amplified downstream NF-κB activation with increased nuclear transactivation of p65 at both TNF-α and IL-6 promoters. Furthermore, co-stimulation of macrophages with TLR and NOD agonists maximized antimicrobial activity with accelerated phagosome maturation. Importantly, administration of both TLR and NOD agonists protected mice against polymicrobial sepsis-associated lethality with increased serum levels of inflammatory cytokines and accelerated clearance of bacteria from the circulation and visceral organs. These results demonstrate that activation of both TLR and NOD signaling synergizes to induce efficient inflammatory and antimicrobial responses, thus conferring protection against microbial infection.
Subject(s)
Bacterial Infections/immunology , Immunity, Innate , Macrophages/immunology , NLR Proteins/metabolism , Toll-Like Receptors/metabolism , Animals , Bacteria/immunology , Bacterial Infections/microbiology , Cell Membrane/immunology , Cell Membrane/metabolism , Cytosol/immunology , Cytosol/metabolism , Disease Models, Animal , Gene Expression Regulation/immunology , Host-Pathogen Interactions/immunology , Humans , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , NLR Proteins/genetics , NLR Proteins/immunology , Primary Cell Culture , Receptor Cross-Talk/immunology , Signal Transduction/immunology , Toll-Like Receptors/genetics , Toll-Like Receptors/immunologyABSTRACT
Roundabout4 (Robo4) is an endothelial cell-specific receptor that stabilizes vasculature in pathological angiogenesis. Previous studies have shown that Robo4 is a potential therapeutic target for inflammatory diseases, but its precise roles in inflammation remain unclear. To investigate physiological Robo4 functions in inflammation, we performed a loss-of-function study in vitro and in vivo using lipopolysaccharide (LPS)-induced endotoxemia models. Subcutaneous injection of LPS into Robo4-knockout mice reduced circulating IL-6 levels. siRNA-mediated Robo4 knockdown suppressed IL-6 production induced by LPS, IL-1ß, and TNFα, in human umbilical vein endothelial cells (HUVECs). Coculture experiments with HUVECs and a monocytic cell line, U937 cells, demonstrated that Robo4 knockdown suppresses IL-6 production by both endothelial cells and U937 cells. Further coculture experiments demonstrated that Robo4 knockdown inhibited a novel IL-6 amplification mechanism mediated by crosstalk between endothelial cells and U937 cells via direct interactions and two mediators, GM-CSF and IL-1ß. Taken together, we demonstrated novel Robo4 functions in inflammation, i.e., it promotes IL-6 production by endothelial cells and immune cells via crosstalk.
Subject(s)
Cell Communication/immunology , Endothelial Cells/immunology , Inflammation/immunology , Interleukin-6/immunology , Monocytes/immunology , Receptor Cross-Talk/immunology , Receptors, Cell Surface/immunology , Animals , Cell Line , Humans , Inflammation/pathology , Mice , Mice, Knockout , Monocytes/pathologyABSTRACT
Klebsiella pneumoniae is a significant cause of nosocomial pneumonia and an alarming pathogen owing to the recent isolation of multidrug resistant strains. Understanding of immune responses orchestrating K. pneumoniae clearance by the host is of utmost importance. Here we show that type I interferon (IFN) signaling protects against lung infection with K. pneumoniae by launching bacterial growth-controlling interactions between alveolar macrophages and natural killer (NK) cells. Type I IFNs are important but disparate and incompletely understood regulators of defense against bacterial infections. Type I IFN receptor 1 (Ifnar1)-deficient mice infected with K. pneumoniae failed to activate NK cell-derived IFN-γ production. IFN-γ was required for bactericidal action and the production of the NK cell response-amplifying IL-12 and CXCL10 by alveolar macrophages. Bacterial clearance and NK cell IFN-γ were rescued in Ifnar1-deficient hosts by Ifnar1-proficient NK cells. Consistently, type I IFN signaling in myeloid cells including alveolar macrophages, monocytes and neutrophils was dispensable for host defense and IFN-γ activation. The failure of Ifnar1-deficient hosts to initiate a defense-promoting crosstalk between alveolar macrophages and NK cell was circumvented by administration of exogenous IFN-γ which restored endogenous IFN-γ production and restricted bacterial growth. These data identify NK cell-intrinsic type I IFN signaling as essential driver of K. pneumoniae clearance, and reveal specific targets for future therapeutic exploitations.