ABSTRACT
The latest vaccination campaign has actualized the potential impact of antigenic stimuli on reproductive functions. To address this, we mimicked vaccination's effects by administering keyhole limpet hemocyanin (KLH ) to CD1 male mice and used their sperm for in vitro fertilization (IVF). Two-cell embryos after IVF with spermatozoa from control (C) or KLH-treated (Im) male mice were transferred to surrogate mothers mated with vasectomized control (C) or KLH-treated (Im) male mice, resulting in four experimental groups: C-C, Im-C, C-Im, and Im-Im. The pre-implantation losses were significantly lower in the Im-C group than in the C-Im group. At the same time, the resorption rates reduced markedly in the C-Im compared to the Im-C group. Embryo and placenta weights were significantly higher in the Im-Im group. Although the GM-CSF levels were lower in the amniotic fluid of the gestating surrogate mothers in the Im-Im group, they were strongly correlated with embryo mass. The number-size trade-off was only significant in the Im-Im group. This suggests a positive, cooperative effect of spermatozoa and seminal fluid from immune-primed males on embryo growth and the optimal distribution of surrogate mother maternal resources despite the negative impact of males' antigenic challenge on the IVF success rate.
Subject(s)
Adjuvants, Immunologic/administration & dosage , Embryo Transfer/methods , Embryonic Development/immunology , Fertilization in Vitro/methods , Hemocyanins/administration & dosage , Semen/immunology , Spermatozoa/immunology , Vaccination/methods , Animals , Antibodies/blood , Blastocyst/immunology , Blastocyst/metabolism , Cell Division/immunology , Embryo Implantation/immunology , Female , Hemocyanins/immunology , Immunoglobulin G/blood , Male , Mice , Pregnancy , Vasectomy/methodsABSTRACT
The selection of B cells (BCs) in germinal centers (GCs) is pivotal to the generation of high-affinity antibodies and memory BCs, but it lacks global understanding. Based on the idea of a single Tfh-cell signal that controls BC selection and division, experiments appear contradictory. Here, we use the current knowledge on the molecular pathways of GC BCs to develop a theory of GC BC selection and division based on the dynamics of molecular factors. This theory explains the seemingly contradictory experiments by the separation of signals for BC fate decision from signals controlling the number of BC divisions. Three model variants are proposed and experiments are predicted that allow one to distinguish those. Understanding information processing in molecular BC states is critical for targeted immune interventions, and the proposed theory implies that selection and division can be controlled independently in GC reactions.
Subject(s)
B-Lymphocytes/immunology , Cell Division/immunology , Clonal Selection, Antigen-Mediated , Germinal Center/immunology , Models, Immunological , Signal Transduction/immunology , Antibodies/immunology , Antibody Affinity , Humans , T-Lymphocytes, Helper-Inducer/immunologyABSTRACT
Changes in stem cell activity may underpin aging. However, these changes are not completely understood. Here, we combined single-cell profiling with machine learning and in vivo functional studies to explore how hematopoietic stem cell (HSC) divisions patterns evolve with age. We first trained an artificial neural network (ANN) to accurately identify cell types in the hematopoietic hierarchy and predict their age from single-cell gene-expression patterns. We then used this ANN to compare identities of daughter cells immediately after HSC divisions and found that the self-renewal ability of individual HSCs declines with age. Furthermore, while HSC cell divisions are deterministic and intrinsically regulated in young and old age, they are variable and niche sensitive in mid-life. These results indicate that the balance between intrinsic and extrinsic regulation of stem cell activity alters substantially with age and help explain why stem cell numbers increase through life, yet regenerative potency declines.
Subject(s)
Aging/immunology , Cell Differentiation/immunology , Cell Division/immunology , Machine Learning/standards , Hematopoietic Stem Cells/metabolism , HumansABSTRACT
Over the last decades, cancer immunotherapies such as checkpoint blockade and adoptive T cell transfer have been a game changer in many aspects and have improved the treatment for various malignancies considerably. Despite the clinical success of harnessing the adaptive immunity to combat the tumor, the benefits of immunotherapy are still limited to a subset of patients and cancer types. In recent years, neutrophils, the most abundant circulating leukocytes, have emerged as promising targets for anti-cancer therapies. Traditionally regarded as the first line of defense against infections, neutrophils are increasingly recognized as critical players during cancer progression. Evidence shows the functional plasticity of neutrophils in the tumor microenvironment, allowing neutrophils to exert either pro-tumor or anti-tumor effects. This review describes the tumor-promoting roles of neutrophils, focusing on their myeloid-derived suppressor cell activity, as well as their role in tumor elimination, exerted mainly via antibody-dependent cellular cytotoxicity. We will discuss potential approaches to therapeutically target neutrophils in cancer. These include strategies in humans to either silence the pro-tumor activity of neutrophils, or to activate or enhance their anti-tumor functions. Redirecting neutrophils seems a promising approach to harness innate immunity to improve treatment for cancer patients.
Subject(s)
Neoplasms/immunology , Neutrophil Activation , Neutrophils/immunology , Adaptive Immunity , Animals , Antibody-Dependent Cell Cytotoxicity , Cell Division/immunology , Cell Movement/immunology , Humans , Immunity, Innate , Immunotherapy/methods , Mice , Myeloid-Derived Suppressor Cells/immunology , Neoplasm Invasiveness/immunology , Neoplasm Metastasis/immunology , Neoplasms/blood supply , Neoplasms/therapy , Neoplasms, Experimental/immunology , Neoplasms, Experimental/therapy , Neovascularization, Pathologic/immunology , Tumor Microenvironment/immunologyABSTRACT
The roles distinct B cell subsets play in clonal expansion, isotype switching, and memory B cell differentiation in response to T cell-independent type 2 Ags (TI-2 Ags) has been understudied. Using sorted B cells from VHB1-8 knock-in mice, we evaluated B-1b, marginal zone, and follicular B cell responses to the TI-2 Ag, NP-Ficoll. All subsets extensively divided in response to NP-Ficoll. Nonetheless, B-1b cells exhibited significantly increased IgG switching and differentiation into Ab-secreting cells (ASC)-a finding that coincided with increased AgR signaling capacity and Blimp1 expression by B-1b cells. All subsets formed memory cells and expressed markers previously identified for T cell-dependent memory B cells, including CD80, PDL2, and CD73, although B-1b cells generated the greatest number of memory cells with higher frequencies of IgG- and CD80-expressing cells. Despite memory formation, secondary immunization 4 wk after primary immunization did not increase NP-specific IgG. However, boosting occurred in B-1b cell-recipient mice when IgG levels declined. CD80+ memory B-1b cells divided, class switched, and differentiated into ASC in response to Ag in vivo, but this was inhibited in the presence of NP-specific IgG. Furthermore, CD80 blockade significantly increased memory B-1b cell division and differentiation to ASC upon Ag restimulation. Collectively, these findings demonstrate B-1b, marginal zone B, and follicular B subsets significantly contribute to the TI-2 Ag-specific memory B cell pool. In particular, we show B-1b cells generate a functional CD80-regulated memory population that can be stimulated to divide and differentiate into ASC upon Ag re-encounter when Ag-specific IgG levels decline.
Subject(s)
B-Lymphocyte Subsets/immunology , Immunologic Memory/immunology , T-Lymphocytes/immunology , Animals , Antigens, T-Independent/immunology , B7-1 Antigen/immunology , Cell Differentiation/immunology , Cell Division/immunology , Immunoglobulin Class Switching/immunology , Immunoglobulin G/immunology , Lymphocyte Activation/immunology , Mice , Mice, Inbred C57BL , Signal Transduction/immunologyABSTRACT
The processes governing lymphocyte fate (division, differentiation, and death), are typically assumed to be independent of cell age. This assumption has been challenged by a series of elegant studies which clearly show that, for murine cells in vitro, lymphocyte fate is age-dependent and that younger cells (i.e., cells which have recently divided) are less likely to divide or die. Here we investigate whether the same rules determine human T cell fate in vivo. We combined data from in vivo stable isotope labeling in healthy humans with stochastic, agent-based mathematical modeling. We show firstly that the choice of model paradigm has a large impact on parameter estimates obtained using stable isotope labeling i.e., different models fitted to the same data can yield very different estimates of T cell lifespan. Secondly, we found no evidence in humans in vivo to support the model in which younger T cells are less likely to divide or die. This age-dependent model never provided the best description of isotope labeling; this was true for naïve and memory, CD4+ and CD8+ T cells. Furthermore, this age-dependent model also failed to predict an independent data set in which the link between division and death was explored using Annexin V and deuterated glucose. In contrast, the age-independent model provided the best description of both naïve and memory T cell dynamics and was also able to predict the independent dataset.
Subject(s)
Models, Theoretical , T-Lymphocytes/immunology , Cell Death/immunology , Cell Differentiation/immunology , Cell Division/immunology , HumansABSTRACT
Infections caused by multi-drug resistance Acinetobacter baumannii are increasing worldwide. Discovery of the vaccine against this bacterium as a cost-effective and preventive strategy seems necessary. This study has introduced 11 new putative vaccine candidates against A. baumannii using the reverse vaccinology method. We considered 33 genomes of A. baumannii strains and selected the outer membrane and secreted proteins as putative vaccine candidates using Vaxign web tool. Finally, 11 proteins were confirmed as promising vaccine candidates. These targets belonged to proteins involved in cell division (NlpD), fimbria or pili assembly (FimA, PapC, and PapC associated with usher system), iron acquisition (FhuA, BfnH, FatA-like protein, and IutA), DcaP-like protein and two novel hypothetical proteins (HP-1 and HP-2). The analysis of linear and conformational B-cell epitopes showed that the outer membrane proteins including DcaP-like protein and HP-2 had high conserved surface-exposed epitopes that they can consider as excellent putative vaccine targets in the upcoming immunological assays.
Subject(s)
Acinetobacter Infections/prevention & control , Acinetobacter baumannii/immunology , Bacterial Vaccines/immunology , Acinetobacter Infections/immunology , Acinetobacter baumannii/genetics , Bacterial Proteins/immunology , Bacterial Vaccines/genetics , Cell Division/immunology , Epitopes/immunology , Fimbriae, Bacterial/immunology , Humans , Vaccinology/methodsABSTRACT
Zinc oxide nanoparticles (ZnO NPs) are used in many applications; however, their interactions with cells, immune cells in particular, and potential health risk(s) are not fully known. In this manuscript, we have demonstrated the potential of ZnO NPs to cross the gut barrier in an invertebrate model, Bombyx mori, and that they can reach the hemolymph where they interact with and/or are taken up by immune-competent cells resulting in various toxic responses like decline in hemocyte viability, ROS generation, morphological alterations, apoptotic cell death, etc. Exposure to these NPs also resulted in alteration of hemocyte dynamics including an immediate increase in THC, possibly due to the release of these hemocytes either from enhanced rate of cell divisions or from attached hemocyte populations, and decline in percentage of prohemocytes and increase in percentage of two professional phagocytes, i.e., granulocytes and plasmatocytes, possibly due to the differentiation of prohemocytes into phagocytes in response to a perceived immune challenge posed by these NPs. Taken together, our data suggest that ZnO NPs have the potential to cross gut barrier and cause various toxic effects that could reverse and the insects could return to normal physiological states as there is restoration and repair of various systems and their affected pathways following the clearance of these NPs from the insect body. Our study also indicates that B. mori has the potential to serve as an effective alternate animal model for biosafety, environmental monitoring and screening of NPs, particularly to evaluate their interactions with invertebrate immune system.
Subject(s)
Biological Transport/immunology , Bombyx/immunology , Immune System/immunology , Invertebrates/immunology , Metal Nanoparticles/administration & dosage , Zinc Oxide/immunology , Animals , Apoptosis/immunology , Cell Differentiation/immunology , Cell Division/immunology , Hemocytes/immunology , Hemolymph/immunology , Nanoparticles , Phagocytes/immunology , Reactive Oxygen Species/immunologyABSTRACT
INTRODUCTION: The aim of this study was to give quantitative insight into the number of cytokine molecules needed to activate a target cell and relate this to the physiological consequences of the amounts of cytokines typically detectable in humans. As a model system blood interleukin-6 (IL-6) was chosen since this cytokine is one of the most studied and clinically monitored cytokines, and because of the tools for the present investigations such as fully bioactive iodinated recombinant IL-6, cellular cytokine binding assays, and bioassays have been thoroughly validated. METHODS: The key intermediates of the basic equilibrium principles that govern cytokine binding and exchange were deduced and applied on concrete estimations of cellular and extracellular IL-6 binding in the bloodstream based on experimental binding data and data from the literature. In parallel, in vitro cellular IL-6 binding data was substantiated by paired measurements of IL-6 bioactivity on IL-6 sensitive B9 hybridoma cells. RESULTS: Blood leucocytes and B9 cells expressed 50 to 300, 10 to 20 picomolar affinity, IL-6 binding sites per cell and at physiological concentrations of IL-6 less than 10 IL-6 molecules seemed to be bound to blood cells. Nonetheless, binding off as few as four IL-6 molecules per cell seemed to result in statistically significant bioactivity, whereas binding of 16 IL-6 molecules triggered extensive cellular responses. CONCLUSION: Together, the estimations and the measurements support the notion that target cells with more than 100 bioactive cytokine receptors per cell, such as T cells and hepatocytes, are likely to be under steady and substantial cytokine-induced endocrine activation.
Subject(s)
Biological Assay/methods , Interleukin-6/analysis , Animals , Biological Assay/statistics & numerical data , Cell Division/drug effects , Cell Division/immunology , Cell Line , Cytokines/pharmacology , Humans , Interleukin-6/biosynthesis , Interleukin-6/pharmacology , Mice , Sensitivity and Specificity , Signal TransductionABSTRACT
Brucella abortus is a stealthy intracellular bacterial pathogen of animals and humans. This bacterium promotes the premature cell death of neutrophils (PMN) and resists the killing action of these leukocytes. B. abortus-infected PMNs presented phosphatidylserine (PS) as "eat me" signal on the cell surface. This signal promoted direct contacts between PMNs and macrophages (MÏs) and favored the phagocytosis of the infected dying PMNs. Once inside MÏs, B. abortus replicated within MÏs at significantly higher numbers than when MÏs were infected with bacteria alone. The high levels of the regulatory IL-10 and the lower levels of proinflammatory TNF-α released by the B. abortus-PMN infected MÏs, at the initial stages of the infection, suggested a non-phlogistic phagocytosis mechanism. Thereafter, the levels of proinflammatory cytokines increased in the B. abortus-PMN-infected MÏs. Still, the efficient bacterial replication proceeded, regardless of the cytokine levels and MÏ type. Blockage of PS with Annexin V on the surface of B. abortus-infected PMNs hindered their contact with MÏs and hampered the association, internalization, and replication of B. abortus within these cells. We propose that B. abortus infected PMNs serve as "Trojan horse" vehicles for the efficient dispersion and replication of the bacterium within the host.
Subject(s)
Brucella abortus/immunology , Cell Communication/immunology , Macrophages/immunology , Phagocytosis/immunology , Animals , Brucella abortus/cytology , Brucella abortus/physiology , Brucellosis/immunology , Brucellosis/metabolism , Brucellosis/microbiology , Cell Death/immunology , Cell Division/immunology , Host-Pathogen Interactions/immunology , Humans , Inflammation Mediators/immunology , Inflammation Mediators/metabolism , Interleukin-10/immunology , Interleukin-10/metabolism , Macrophages/metabolism , Macrophages/microbiology , Neutrophils/immunology , Neutrophils/microbiology , Phosphatidylserines/immunology , Phosphatidylserines/metabolism , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Activation of naive CD8 T-cells can lead to the generation of multiple effector and memory subsets. Multiple parameters associated with activation conditions are involved in generating this diversity that is associated with heterogeneous molecular contents of activated cells. Although naive cell polarisation upon antigenic stimulation and the resulting asymmetric division are known to be a major source of heterogeneity and cell fate regulation, the consequences of stochastic uneven partitioning of molecular content upon subsequent divisions remain unclear yet. Here we aim at studying the impact of uneven partitioning on molecular-content heterogeneity and then on the immune response dynamics at the cellular level. To do so, we introduce a multiscale mathematical model of the CD8 T-cell immune response in the lymph node. In the model, cells are described as agents evolving and interacting in a 2D environment while a set of differential equations, embedded in each cell, models the regulation of intra and extracellular proteins involved in cell differentiation. Based on the analysis of in silico data at the single cell level, we show that immune response dynamics can be explained by the molecular-content heterogeneity generated by uneven partitioning at cell division. In particular, uneven partitioning acts as a regulator of cell differentiation and induces the emergence of two coexisting sub-populations of cells exhibiting antagonistic fates. We show that the degree of unevenness of molecular partitioning, along all cell divisions, affects the outcome of the immune response and can promote the generation of memory cells.
Subject(s)
CD8-Positive T-Lymphocytes/immunology , Cell Differentiation/immunology , Animals , Cell Division/immunology , Immunologic Memory/immunology , Mice , Mice, Inbred C57BL , Mice, TransgenicABSTRACT
Lymphatic endothelial cells (LECs) form the structure of the lymphatic vessels and the sinuses of the lymph nodes, positioning them to be key players in many different aspects of the immune response. Following an inflammatory stimulus, LECs produce chemokines that recruit immune cells to the lymph nodes. The recruitment of immune cells aids in the coordination of both LEC and lymph node expansion and contraction. More recent data has demonstrated that to coordinate LEC division and death, cell surface molecules, such as PD-L1 and interferon receptors, are required. During homeostasis, LECs use PD-L1 to maintain peripheral tolerance by presenting specific peripheral tissue antigens in order to eliminate tissue specific responses. LECs also have the capacity to acquire, present, and exchange foreign antigens following viral infection or immunization. Here we will review how lymph node LECs require immune cells to expand and contract in response to an immune stimulus, the factors involved and how direct LEC-immune cell interactions are important for programming immunity.
Subject(s)
Endothelial Cells/immunology , Immunity, Cellular/immunology , Lymph Nodes/immunology , Antigen Presentation/immunology , Apoptosis/immunology , B7-H1 Antigen/metabolism , Cell Communication/immunology , Cell Division/immunology , Cell Proliferation , Endothelial Cells/cytology , Humans , Inflammation/immunology , Lymphatic Vessels/cytology , Platelet Factor 4/metabolism , Receptors, Interferon/metabolismABSTRACT
CD4 T cell memory is fundamental for long-lasting immunity and effective secondary responses following infection or vaccination. We have previously found that memory CD4 T cells specific for systemic antigens preferentially reside in the bone marrow (BM) and arise from splenic CD49b+T-bet+ CD4 T cells. However, how BM-homing memory precursors are generated during an immune reaction is unknown. We show here that BM memory precursors are generated via augmented rates of cell division throughout a primary immune response. Treatment with the cytostatic drug cyclophosphamide or blockade of the CD28/B7 co-stimulatory pathway at the beginning of the contraction phase abrogates the generation of BM memory precursors. We determine that, following a critical number of cell divisions, memory precursors downregulate CCR7 and upregulate IL-2Rß, indicating that loss of CCR7 and gain of IL-2 signal are required for the migration of memory precursors toward the BM.
Subject(s)
Bone Marrow/immunology , CD4-Positive T-Lymphocytes/immunology , Cell Division/immunology , Cell Movement/immunology , Immunologic Memory , Animals , CD28 Antigens/genetics , CD28 Antigens/immunology , CD4-Positive T-Lymphocytes/cytology , Cell Division/genetics , Integrin alpha2/genetics , Integrin alpha2/immunology , Interleukin-2/genetics , Interleukin-2/immunology , Interleukin-2 Receptor beta Subunit/genetics , Interleukin-2 Receptor beta Subunit/immunology , Mice , Mice, Knockout , Receptors, CCR7/genetics , Receptors, CCR7/immunology , T-Box Domain Proteins/genetics , T-Box Domain Proteins/immunologyABSTRACT
Understanding how the strength of an effector T cell response is regulated is a fundamental problem in immunology with implications for immunity to pathogens, autoimmunity, and immunotherapy. The initial magnitude of the T cell response is determined by the sum of independent signals from antigen, co-stimulation and cytokines. By applying quantitative methods, the contribution of each signal to the number of divisions T cells undergo (division destiny) can be measured, and the resultant exponential increase in response magnitude accurately calculated. CD4+CD25+Foxp3+ regulatory T cells suppress self-reactive T cell responses and limit pathogen-directed immune responses before bystander damage occurs. Using a quantitative modeling framework to measure T cell signal integration and response, we show that Tregs modulate division destiny, rather than directly increasing the rate of death or delaying interdivision times. The quantitative effect of Tregs could be mimicked by modulating the availability of stimulatory co-stimuli and cytokines or through the addition of inhibitory signals. Thus, our analysis illustrates the primary effect of Tregs on the magnitude of effector T cell responses is mediated by modifying division destiny of responding cell populations.
Subject(s)
Cell Division/immunology , Cytokines/immunology , Homeostasis/immunology , Lymphocyte Activation/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Cells, Cultured , Mice , Mice, Inbred C57BL , Signal Transduction/immunologyABSTRACT
Adult hematopoiesis has been studied in terms of progenitor differentiation potentials, whereas its kinetics in vivo is poorly understood. We combined inducible lineage tracing of endogenous adult hematopoietic stem cells (HSCs) with flow cytometry and single-cell RNA sequencing to characterize early steps of hematopoietic differentiation in the steady-state. Labeled cells, comprising primarily long-term HSCs and some short-term HSCs, produced megakaryocytic lineage progeny within 1 wk in a process that required only two to three cell divisions. Erythroid and myeloid progeny emerged simultaneously by 2 wk and included a progenitor population with expression features of both lineages. Myeloid progenitors at this stage showed diversification into granulocytic, monocytic, and dendritic cell types, and rare intermediate cell states could be detected. In contrast, lymphoid differentiation was virtually absent within the first 3 wk of tracing. These results show that continuous differentiation of HSCs rapidly produces major hematopoietic lineages and cell types and reveal fundamental kinetic differences between megakaryocytic, erythroid, myeloid, and lymphoid differentiation.
Subject(s)
Adult Stem Cells/immunology , Cell Differentiation/immunology , Cell Division/immunology , Hematopoietic Stem Cells/immunology , Adult Stem Cells/cytology , Animals , Dendritic Cells/cytology , Dendritic Cells/immunology , Granulocytes/cytology , Granulocytes/immunology , Hematopoietic Stem Cells/cytology , Kinetics , Megakaryocytes/cytology , Megakaryocytes/immunology , Mice , Mice, Transgenic , Monocytes/cytology , Monocytes/immunologyABSTRACT
Epigenetic memory for signal-dependent transcription has remained elusive. So far, the concept of epigenetic memory has been largely limited to cell-autonomous, preprogrammed processes such as development and metabolism. Here we show that IFNß stimulation creates transcriptional memory in fibroblasts, conferring faster and greater transcription upon restimulation. The memory was inherited through multiple cell divisions and led to improved antiviral protection. Of â¼2,000 IFNß-stimulated genes (ISGs), about half exhibited memory, which we define as memory ISGs. The rest, designated nonmemory ISGs, did not show memory. Surprisingly, mechanistic analysis showed that IFN memory was not due to enhanced IFN signaling or retention of transcription factors on the ISGs. We demonstrated that this memory was attributed to accelerated recruitment of RNA polymerase II and transcription/chromatin factors, which coincided with acquisition of the histone H3.3 and H3K36me3 chromatin marks on memory ISGs. Similar memory was observed in bone marrow macrophages after IFNγ stimulation, suggesting that IFN stimulation modifies the shape of the innate immune response. Together, external signals can establish epigenetic memory in mammalian cells that imparts lasting adaptive performance upon various somatic cells.
Subject(s)
Bone Marrow Cells/immunology , Cell Division/immunology , Epigenesis, Genetic/immunology , Immunity, Innate , Interferon-beta/immunology , Macrophages/immunology , Signal Transduction/immunology , Transcription, Genetic/immunology , Animals , Bone Marrow Cells/cytology , Cell Division/genetics , Chromatin/genetics , Chromatin/immunology , Histones/genetics , Histones/immunology , Interferon-beta/genetics , Macrophages/cytology , Mice , Mice, Mutant Strains , RNA Polymerase II/genetics , RNA Polymerase II/immunology , Signal Transduction/genetics , Transcription Factors/genetics , Transcription Factors/immunologyABSTRACT
We recently showed that 2B4 expression on memory T cells in human renal transplant recipients was associated with reduced rates of rejection. To investigate whether 2B4 functionally underlies graft acceptance during transplantation, we established an experimental model in which 2B4 was retrogenically expressed on donor-reactive murine CD8+ T cells (2B4rg), which were then transferred into naive recipients prior to skin transplantation. We found that constitutive 2B4 expression resulted in significantly reduced accumulation of donor-reactive CD8+ T cells following transplantation and significantly prolonged graft survival following transplantation. This marked reduction in alloreactivity was due to reduced proliferation of CD8+ Thy1.1+ 2B4rg cells as compared with control cells, underpinned by extracellular flux analyses demonstrating that 2B4-deficient (2B4KO) CD8+ cells activated in vitro exhibited increased glycolytic capacity and upregulation of gene expression profiles consistent with enhanced glycolytic machinery as compared with wild type controls. Furthermore, 2B4KO CD8+ T cells primed in vivo exhibited significantly enhanced ex vivo uptake of a fluorescent glucose analogue. Finally, the proliferative advantage associated with 2B4 deficiency was only observed in the setting of glucose sufficiency; in glucose-poor conditions, 2B4KO CD8+ T cells lost their proliferative advantage. Together, these data indicate that 2B4 signals function to alter T cell glucose metabolism, thereby limiting the proliferation and accumulation of CD8+ T cells. Targeting 2B4 may therefore represent a novel therapeutic strategy to attenuate unwanted CD8+ T cell responses.
Subject(s)
CD8-Positive T-Lymphocytes/immunology , Cell Division/immunology , Glycolysis/immunology , Graft Survival/immunology , Lymphocyte Activation , Signal Transduction/immunology , Signaling Lymphocytic Activation Molecule Family/immunology , Skin Transplantation , Animals , Cell Division/genetics , Glycolysis/genetics , Graft Survival/genetics , Mice , Mice, Knockout , Signal Transduction/genetics , Signaling Lymphocytic Activation Molecule Family/geneticsABSTRACT
Although cigarette smoke is known to alter immune responses, whether and how CD4 T cells are affected is not well-described. We aimed to characterize how exposure to cigarette smoke extract impacts CD4 T cell effector generation in vitro under Th1-polarizing conditions. Our results demonstrate that cigarette smoke directly acts on CD4 T cells to impair effector expansion by decreasing division and increasing apoptosis. Furthermore, cigarette smoke enhances Th1-associated cytokine production and increases expression of the transcription factor T-bet, the master regulator of Th1 differentiation. Finally, we show that exposure to cigarette smoke extract during priming impairs the ability of effectors to form memory cells. Our findings thus demonstrate that cigarette smoke simultaneously enhances effector functions but promotes terminal differentiation of CD4 T cell effectors. This study may be relevant to understanding how smoking can both aggravate autoimmune symptoms and reduce vaccine efficacy.
Subject(s)
CD4-Positive T-Lymphocytes/immunology , Immunologic Memory/immunology , Lymphocyte Activation/immunology , Nicotiana/chemistry , Smoke , Th1 Cells/immunology , Animals , Apoptosis/immunology , CD4-Positive T-Lymphocytes/metabolism , Cell Differentiation/immunology , Cell Division/immunology , Cytokines/immunology , Cytokines/metabolism , Humans , Mice, Inbred BALB C , Mice, Transgenic , Th1 Cells/metabolismABSTRACT
Adoptive cell therapy (ACT) of autologous tumor-infiltrating lymphocytes (TILs) has shown an effect on mediating tumor regression in some patients with highly advanced, refractory metastatic malignancy. Here, the in vitro generation of TILs isolated from malignant pleural effusion and ascites was compared with which using engineered cells for costimulatory enhancement (ECCE) and 3 common γ-chain cytokines, interleukin (IL)-2, IL-7, and IL-15, alone or in combination. We showed the robust clinical-scale production of TILs with a less differentiated 'young' phenotype by expansion in the presence of ECCE combined with IL-2/7/15. Furthermore, a major fraction of the TILs generated in this fashion was shown to produce much more IFN-γ and TNF-α, and displayed cytolytic activity against target cells expressing the relevant antigens. To our knowledge, this is the first time that the combination of ECCE and IL-2/7/15 has been applied for the generation of TILs isolated from malignant pleural effusion and ascites.
Subject(s)
Ascites/immunology , Lymphocyte Activation/immunology , Lymphocytes, Tumor-Infiltrating/immunology , Pleural Effusion, Malignant/immunology , 4-1BB Ligand/genetics , 4-1BB Ligand/immunology , 4-1BB Ligand/metabolism , Adult , Aged , Ascites/pathology , Cell Division/immunology , Cells, Cultured , Female , Humans , Immunotherapy, Adoptive/methods , Interleukin-15/genetics , Interleukin-15/immunology , Interleukin-15/metabolism , Interleukin-2/genetics , Interleukin-2/immunology , Interleukin-2/metabolism , Interleukin-7/genetics , Interleukin-7/immunology , Interleukin-7/metabolism , K562 Cells , Lymphocytes, Tumor-Infiltrating/metabolism , Male , Middle Aged , Neoplasms/immunology , Neoplasms/pathology , Neoplasms/therapy , Pleural Effusion, Malignant/pathologyABSTRACT
Unequal partitioning of the molecular content at cell division has been shown to be a source of heterogeneity in a cell population. We propose to model this phenomenon with the help of a scalar, nonlinear impulsive differential equation (IDE). To study the effect of molecular partitioning at cell division on the effector/memory cell-fate decision in a CD8 T-cell lineage, we study an IDE describing the concentration of the protein Tbet in a CD8 T-cell, where impulses are associated to cell division. We discuss how the degree of asymmetry of molecular partitioning can affect the process of cell differentiation and the phenotypical heterogeneity of a cell population. We show that a moderate degree of asymmetry is necessary and sufficient to observe irreversible differentiation. We consider, in a second part, a general autonomous IDE with fixed times of impulse and a specific form of impulse function. We establish properties of the solutions of that equation, most of them obtained under the hypothesis that impulses occur periodically. In particular, we show how to investigate the existence of periodic solutions and their stability by studying the flow of an autonomous differential equation. Then we apply those properties to prove the results presented in the first part.