ABSTRACT
PD-1 blockade unleashes CD8 T cells1, including those specific for mutation-associated neoantigens (MANA), but factors in the tumour microenvironment can inhibit these T cell responses. Single-cell transcriptomics have revealed global T cell dysfunction programs in tumour-infiltrating lymphocytes (TIL). However, the majority of TIL do not recognize tumour antigens2, and little is known about transcriptional programs of MANA-specific TIL. Here, we identify MANA-specific T cell clones using the MANA functional expansion of specific T cells assay3 in neoadjuvant anti-PD-1-treated non-small cell lung cancers (NSCLC). We use their T cell receptors as a 'barcode' to track and analyse their transcriptional programs in the tumour microenvironment using coupled single-cell RNA sequencing and T cell receptor sequencing. We find both MANA- and virus-specific clones in TIL, regardless of response, and MANA-, influenza- and Epstein-Barr virus-specific TIL each have unique transcriptional programs. Despite exposure to cognate antigen, MANA-specific TIL express an incompletely activated cytolytic program. MANA-specific CD8 T cells have hallmark transcriptional programs of tissue-resident memory (TRM) cells, but low levels of interleukin-7 receptor (IL-7R) and are functionally less responsive to interleukin-7 (IL-7) compared with influenza-specific TRM cells. Compared with those from responding tumours, MANA-specific clones from non-responding tumours express T cell receptors with markedly lower ligand-dependent signalling, are largely confined to HOBIThigh TRM subsets, and coordinately upregulate checkpoints, killer inhibitory receptors and inhibitors of T cell activation. These findings provide important insights for overcoming resistance to PD-1 blockade.
Subject(s)
Antigens, Neoplasm/immunology , Carcinoma, Non-Small-Cell Lung/drug therapy , Gene Expression Regulation , Immune Checkpoint Inhibitors/therapeutic use , Lung Neoplasms/drug therapy , Lung Neoplasms/immunology , Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/metabolism , Antigens, Neoplasm/genetics , CD8-Positive T-Lymphocytes/immunology , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/immunology , Cells, Cultured , Humans , Immunologic Memory , Lung Neoplasms/genetics , Programmed Cell Death 1 Receptor/antagonists & inhibitors , RNA-Seq , Receptors, Interleukin-7/immunology , Single-Cell Analysis , Transcriptome/genetics , Tumor MicroenvironmentABSTRACT
BACKGROUND: Evaluating the complex interplay of cell types in the tissue microenvironment is critical to understanding the origin and progression of diseases in the prostate and potential opportunities for intervention. Mouse models are an essential tool to investigate the molecular and cell-type-specific contributions of prostate disease at an organismal level. While there are well-documented differences in the extent, timing, and nature of disease development in various genetically engineered and exposure-based mouse models in different mouse strains and prostate lobes within each mouse strain, the underlying molecular phenotypic differences in cell types across mouse strains and prostate lobes are incompletely understood. METHODS: In this study, we used single-cell RNA-sequencing (scRNA-seq) methods to assess the single-cell transcriptomes of 6-month-old mouse prostates from two commonly used mouse strains, friend virus B/NIH jackson (FVB/NJ)Ā (N = 2) and C57BL/6J (N = 3). For each mouse, the lobes of the prostate were dissected (anterior, dorsal, lateral, and ventral), and individual scRNA-seq libraries were generated. In situ and pathological analyses were used to explore the spatial and anatomical distributions of novel cell types and molecular markers defining these cell types. RESULTS: Data dimensionality reduction and clustering analysis of scRNA-seq data revealed that basal and luminal cells possessed strain-specific transcriptomic differences, with luminal cells also displaying marked lobe-specific differences. Gene set enrichment analysis comparing luminal cells by strain showed enrichment of proto-Oncogene targets in FVB/NJ mice. Additionally, three rare populations of epithelial cells clustered independently of strain and lobe: one population of luminal cells expressing Foxi1 and components of the vacuolar ATPase proton pump (Atp6v0d2 and Atp6v1g3), another population expressing Psca and other stem cell-associated genes (Ly6a/Sca-1, Tacstd2/Trop-2), and a neuroendocrine population expressing Chga, Chgb, and Syp. In contrast, stromal cell clusters, including fibroblasts, smooth muscle cells, endothelial cells, pericytes, and immune cell types, were conserved across strain and lobe, clustering largely by cell type and not by strain or lobe. One notable exception to this was the identification of two distinct fibroblast populations that we term subglandular fibroblasts and interstitial fibroblasts based on their strikingly distinct spatial distribution in the mouse prostate. CONCLUSIONS: Altogether, these data provide a practical reference of the transcriptional profiles of mouse prostate from two commonly used mouse strains and across all four prostate lobes.
Subject(s)
Endothelial Cells , Prostate , Male , Animals , Mice , Prostate/pathology , Mice, Inbred C57BL , Epithelial Cells , Disease Models, Animal , Forkhead Transcription Factors/metabolismABSTRACT
We report heterozygous mutations in the genes encoding either type I or type II transforming growth factor beta receptor in ten families with a newly described human phenotype that includes widespread perturbations in cardiovascular, craniofacial, neurocognitive and skeletal development. Despite evidence that receptors derived from selected mutated alleles cannot support TGFbeta signal propagation, cells derived from individuals heterozygous with respect to these mutations did not show altered kinetics of the acute phase response to administered ligand. Furthermore, tissues derived from affected individuals showed increased expression of both collagen and connective tissue growth factor, as well as nuclear enrichment of phosphorylated Smad2, indicative of increased TGFbeta signaling. These data definitively implicate perturbation of TGFbeta signaling in many common human phenotypes, including craniosynostosis, cleft palate, arterial aneurysms, congenital heart disease and mental retardation, and suggest that comprehensive mechanistic insight will require consideration of both primary and compensatory events.
Subject(s)
Activin Receptors, Type I/genetics , Bone Development/genetics , Cardiovascular System/growth & development , Cognition Disorders/genetics , Face , Mutation , Receptors, Transforming Growth Factor beta/genetics , Skull/growth & development , Amino Acid Sequence , Child, Preschool , Female , Humans , Male , Molecular Sequence Data , Phenotype , Protein Serine-Threonine Kinases , Receptor, Transforming Growth Factor-beta Type I , Receptor, Transforming Growth Factor-beta Type II , Sequence Homology, Amino Acid , SyndromeABSTRACT
PURPOSE: The new ultra-short-acting benzodiazepine, remimazolam, offers a pharmacokinetic and pharmacodynamic advantage over commonly used procedural sedation medication. This retrospective study explored the real-world utilization of remimazolam during procedural sedation to support the development of a nurse sedation protocol. The primary outcome was to identify associations between recovery time, adverse reactions, and dose-response in expanded patient populations. METHODS: This study reviewed charts of 292 adult patients from 3 hospitals within one institution who received remimazolam during procedural sedation between June 1, 2021 and December 31, 2021. Data were analyzed using logistic and linear regression. FINDINGS: The median time to alert in patients receiving remimazolam alone was 12 minutes (interquartile range 10, 17) and increased when additional sedation medications were utilized. Receiving additional sedative medication significantly increased the odds of hypoxia (OR 2.77, 95% CI 1.30-5.91, P = 0.008) after adjusting for body mass index (BMI), American Society of Anesthesiologists physical status (ASA-PS), and total remimazolam dose. There was a 25% increase in odds of experiencing hypoxia for every 5 kg/m2 increase in BMI (95% CI 1.01-1.54, P = 0.037). IMPLICATIONS: Remimazolam presents as a promising option for nurse procedural sedation, offering minimal impact on hemodynamics and respirations, quick recovery, and no residual sedative effects.
Subject(s)
Benzodiazepines , Hypnotics and Sedatives , Adult , Humans , Retrospective Studies , Benzodiazepines/therapeutic use , Hypnotics and Sedatives/adverse effects , Hypoxia/chemically inducedABSTRACT
OBJECTIVE: We aimed to reduce the time interval between an infant's admission to the Neonatal Intensive Care Unit (NICU) and first maternal interaction. METHODS: We identified three key drivers: 1. Collaboration with Labor and Delivery, 2. Education of staff and parents, and 3. Improved documentation of maternal presence. We measured the time interval from NICU admission to the initial maternal presence. We followed length of stay as a balancing measure to assay whether use of remote televisitation impeded efficient parental teaching and delayed discharge. RESULTS: We reduced the time interval from an average of 19.7 h in February 2020 to 12.3 h in June 2021. We expanded an already existing televisitation program as a surrogate to in-person interaction during COVID-19 pandemic. Televisitation did not affect in-person parental presence or LOS. CONCLUSION: Our multidisciplinary efforts resulted in a significantly accelerated time to initial maternal presence and did not prolong LOS.
Subject(s)
Intensive Care Units, Neonatal , Quality Improvement , Infant, Newborn , Infant , Humans , Pandemics/prevention & control , Parents , HospitalizationABSTRACT
How prostate cancer cells and their precursors mediate changes in the tumor microenvironment (TME) to drive prostate cancer progression is unclear, in part due to the inability to longitudinally study the disease evolution in human tissues. To overcome this limitation, we perform extensive single-cell RNA-sequencing (scRNA-seq) and molecular pathology of the comparative biology between human prostate cancer and key stages in the disease evolution of a genetically engineered mouse model (GEMM) of prostate cancer. Our studies of human tissues reveal that cancer cell-intrinsic activation of MYC signaling is a common denominator across the well-known molecular and pathological heterogeneity of human prostate cancer. Cell communication network and pathway analyses in GEMMs show that MYC oncogene-expressing neoplastic cells, directly and indirectly, reprogram the TME during carcinogenesis, leading to a convergence of cell state alterations in neighboring epithelial, immune, and fibroblast cell types that parallel key findings in human prostate cancer.
Subject(s)
Prostatic Neoplasms , Proto-Oncogene Proteins c-myc , Tumor Microenvironment , Male , Tumor Microenvironment/genetics , Humans , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Prostatic Neoplasms/metabolism , Animals , Mice , Proto-Oncogene Proteins c-myc/metabolism , Proto-Oncogene Proteins c-myc/genetics , Gene Expression Regulation, Neoplastic , Signal Transduction , Single-Cell Analysis , Disease Models, Animal , Cell Communication , Carcinogenesis/genetics , Carcinogenesis/pathology , Mice, Transgenic , RNA-SeqABSTRACT
Premature termination codons induce rapid transcript degradation in eukaryotic cells through nonsense-mediated mRNA decay (NMD). This pathway can modulate phenotypes arising from nonsense or frameshift mutations, but little is known about the physiologic role of NMD in higher eukaryotes. To address this issue, we examined expression profiles in mammalian cells depleted of Rent1 (also called hUpf1), a factor essential for NMD. Upregulated transcripts included those with upstream open reading frames in the 5' untranslated region, alternative splicing that introduces nonsense codons or frameshifts, introns in the 3' untranslated region or selenocysteine codons. Transcripts derived from ancient transposons and endogenous retroviruses were also upregulated. These RNAs are unified by the presence of a spliced intron at least 50 nucleotides downstream of a termination codon, a context sufficient to initiate NMD. Consistent with direct regulation by NMD, representative upregulated transcripts decayed more slowly in cells deficient in NMD. In addition, inhibition of NMD induced by amino acid starvation upregulated transcripts that promote amino acid homeostasis. These results document that nonsense surveillance is a crucial post-transcriptional regulatory event that influences the expression of broad classes of physiologic transcripts, has been functionally incorporated into essential homeostatic mechanisms and suppresses expression of evolutionary remnants.
Subject(s)
Gene Expression Regulation , Amino Acids/metabolism , Codon, Nonsense/genetics , Frameshift Mutation , HeLa Cells , Humans , Molecular Sequence Data , RNA Helicases , RNA Processing, Post-Transcriptional , RNA Stability , RNA, Messenger/genetics , RNA, Messenger/metabolism , Trans-Activators/geneticsABSTRACT
Introduction: Early development of broadly neutralizing antibodies (bNAbs) targeting the hepatitis C virus (HCV) envelope glycoprotein E2 is associated with spontaneous clearance of infection, so induction of bNAbs is a major goal of HCV vaccine development. However, the molecular antibody features important for broad neutralization are not known. Methods: To identify B cell repertoire features associated with broad neutralization, we performed RNA sequencing of the B cell receptors (BCRs) of HCV E2-reactive B cells of HCV-infected individuals with either high or low plasma neutralizing breadth. We then produced a monoclonal antibody (mAb) expressed by pairing the most abundant heavy and light chains from public clonotypes identified among clearance, high neutralization subjects. Results: We found distinctive BCR features associated with broad neutralization of HCV, including long heavy chain complementarity determining region 3 (CDRH3) regions, specific VH gene usage, increased frequencies of somatic hypermutation, and particular VH gene mutations. Most intriguing, we identified many E2-reactive public BCR clonotypes (heavy and light chain clones with the same V and J-genes and identical CDR3 sequences) present only in subjects who produced highly neutralizing plasma. The majority of these public clonotypes were shared by two subjects who cleared infection. A mAb expressing the most abundant public heavy and light chains from these clearance, high neutralization subjects had features enriched in high neutralization clonotypes, such as increased somatic hypermutation frequency and usage of IGHV1-69, and was cross-neutralizing. Discussion: Together, these results demonstrate distinct BCR repertoires associated with high plasma neutralizing capacity. Further characterization of the molecular features and function of these antibodies can inform HCV vaccine development.
Subject(s)
Hepacivirus , Hepatitis C , Humans , Broadly Neutralizing Antibodies , Antibody Formation , Antibodies, Neutralizing , Antibodies, Monoclonal , Complementarity Determining Regions/geneticsABSTRACT
[This corrects the article DOI: 10.3389/fimmu.2023.1135841.].
ABSTRACT
The tissue microenvironment in prostate cancer is profoundly altered. While such alterations have been implicated in driving prostate cancer initiation and progression to aggressive disease, how prostate cancer cells and their precursors mediate those changes is unclear, in part due to the inability to longitudinally study the disease evolution in human tissues. To overcome this limitation, we performed extensive single-cell RNA-sequencing (scRNA-seq) and rigorous molecular pathology of the comparative biology between human prostate cancer and key time points in the disease evolution of a genetically engineered mouse model (GEMM) of prostate cancer. Our studies of human tissues, with validation in a large external data set, revealed that cancer cell-intrinsic activation of MYC signaling was the top up-regulated pathway in human cancers, representing a common denominator across the well-known molecular and pathological heterogeneity of human prostate cancer. Likewise, numerous non-malignant cell states in the tumor microenvironment (TME), including non-cancerous epithelial, immune, and fibroblast cell compartments, were conserved across individuals, raising the possibility that these cell types may be a sequelae of the convergent MYC activation in the cancer cells. To test this hypothesis, we employed a GEMM of prostate epithelial cell-specific MYC activation in two mouse strains. Cell communication network and pathway analyses suggested that MYC oncogene-expressing neoplastic cells, directly and indirectly, reprogrammed the TME during carcinogenesis, leading to the emergence of cascading cell state alterations in neighboring epithelial, immune, and fibroblast cell types that paralleled key findings in human prostate cancer. Importantly, among these changes, the progression from a precursor-enriched to invasive-cancer-enriched state was accompanied by a cell-intrinsic switch from pro-immunogenic to immunosuppressive transcriptional programs with coinciding enrichment of immunosuppressive myeloid and Treg cells in the immune microenvironment. These findings implicate activation of MYC signaling in reshaping convergent aspects of the TME of prostate cancer as a common denominator across the otherwise well-documented molecular heterogeneity of human prostate cancer.
ABSTRACT
Testosterone is the canonical growth factor of prostate cancer but can paradoxically suppress its growth when present at supraphysiological levels. We have previously demonstrated that the cyclical administration of supraphysiological androgen (SPA), termed bipolar androgen therapy (BAT), can result in tumor regression and clinical benefit for patients with castration-resistant prostate cancer. However, predictors and mechanisms of response and resistance have been ill defined. Here, we show that growth inhibition of prostate cancer models by SPA required high androgen receptor (AR) activity and were driven in part by downregulation of MYC. Using matched sequential patient biopsies, we show that high pretreatment AR activity predicted downregulation of MYC, improved clinical response, and prolonged progression-free and overall survival for patients on BAT. BAT induced strong downregulation of AR in all patients, which is shown to be a primary mechanism of acquired resistance to SPA. Acquired resistance was overcome by alternating SPA with the AR inhibitor enzalutamide, which induced adaptive upregulation of AR and resensitized prostate cancer to SPA. This work identifies high AR activity as a predictive biomarker of response to BAT and supports a treatment paradigm for prostate cancer involving alternating between AR inhibition and activation.
Subject(s)
Prostatic Neoplasms, Castration-Resistant , Receptors, Androgen , Male , Humans , Receptors, Androgen/metabolism , Androgens/pharmacology , Prostatic Neoplasms, Castration-Resistant/metabolism , Androgen Receptor Antagonists/pharmacology , Androgen Receptor Antagonists/therapeutic use , Nitriles , Testosterone/pharmacology , Drug Resistance, Neoplasm , Cell Line, TumorABSTRACT
This study compared two instructional and evaluation methods for teaching advanced cardiac life support (ACLS) to health care professionals who were taking the ACLS course for the first time. Outcomes of the instruction were measured on completion of the course and at 3 months and 6 months postinstruction to identify differences in participants' knowledge retention, skills competency, and self-efficacy in performing ACLS. In addition, satisfaction with the teaching method was evaluated. The two methods of teaching and evaluating competencies for ACLS were (1) traditional classroom instruction plus practice and evaluation with monitors (low-fidelity simulation); and (2) classroom instruction plus practice with high-fidelity patient simulators. Participants in the study were 148 health care professionals or health care students who were novices in ACLS preparation. Participants were recruited from a large Midwest school of nursing and school of medicine, a Midwest physicians' assistant program, and a not-for-profit hospital. The findings showed no significant differences in ACLS knowledge, skills, self-efficacy, or learner satisfaction immediately after instruction or at 3 to 9 months posttraining. Retention of ACLS knowledge and skills competency over time was low in both groups; recommendations and interventions are discussed based on the study results.
Subject(s)
Advanced Cardiac Life Support , Education, Nursing, Continuing/methods , Education, Nursing, Continuing/trends , Nursing Staff, Hospital/education , Advanced Cardiac Life Support/education , Advanced Cardiac Life Support/methods , Advanced Cardiac Life Support/trends , Competency-Based Education/methods , Competency-Based Education/trends , Educational Measurement , Humans , Nursing Evaluation ResearchABSTRACT
OBJECTIVE: To increase the usage rate of mothers' own milk (MOM) among neonates with prenatal opioid exposure from a baseline average of 47% to an average of 75% over two years. STUDY DESIGN: Between October 2018 and December 2020, we implemented various Plan-Do-Study-Act cycles that involved engaging providers in postpartum counseling for mothers with opioid dependence, using electronic medical records to track the rate of counseling, providing NAS educational materials to parents, and establishing a rooming-in unit. Our outcome measure was the provision of MOM to eligible neonates, while our process measure was the rate of postpartum counseling. RESULTS: During this initiative, we witnessed a special cause variation with an increase in the usage rate of MOM from a baseline of 47% to a 27-month average of 85% by December 2020. CONCLUSION: A series of quality improvement efforts resulted in increased usage of MOM among infants at risk of NAS.
Subject(s)
Mothers , Neonatal Abstinence Syndrome , Breast Feeding , Female , Humans , Infant , Infant, Newborn , Infant, Premature , Intensive Care Units, Neonatal , Milk, Human , Neonatal Abstinence Syndrome/epidemiology , Plant Extracts , Pregnancy , Quality ImprovementABSTRACT
BACKGROUND: In cancers, maintenance of telomeres often occurs through activation of the catalytic subunit of telomerase, encoded by TERT. Yet, most cancers show only modest levels of TERT gene expression, even in the context of activating hotspot promoter mutations (C228T and C250T). The role of epigenetic mechanisms, including DNA methylation, in regulating TERT gene expression in cancer cells is as yet not fully understood. METHODS: Here, we have carried out the most comprehensive characterization to date of TERT promoter methylation using ultra-deep bisulfite sequencing spanning the CpG island surrounding the core TERT promoter in 96 different human cell lines, including primary, immortalized and cancer cell types, as well as in control and reference samples. RESULTS: In general, we observed that immortalized and cancer cell lines were hypermethylated in a region upstream of the recurrent C228T and C250T TERT promoter mutations, while non-malignant primary cells were comparatively hypomethylated in this region. However, at the allele-level, we generally found that hypermethylation of promoter sequences in cancer cells is associated with repressed expression, and the remaining unmethylated alleles marked with open chromatin are largely responsible for the observed TERT expression in cancer cells. CONCLUSIONS: Our findings suggest that hypermethylation of the TERT promoter alleles signals transcriptional repression of those alleles, leading to attenuation of TERT activation in cancer cells. This type of fine tuning of TERT expression may account for the modest activation of TERT expression in most cancers.
Subject(s)
Alleles , DNA Methylation/genetics , Neoplasms/genetics , Promoter Regions, Genetic , Telomerase/genetics , Base Sequence , Cell Line, Tumor , CpG Islands/genetics , Genes, Reporter , HEK293 Cells , Humans , Mutation/geneticsABSTRACT
T cells on activation differentiate into different subsets (Th1 or Th2) with distinct effector functions. These T cell subsets are primarily differentiated on the basis of the cytokines that they produce, however, we have identified a novel gene family called TIM (T cell, immunoglobulin, mucin domain-containing molecules), whose members are differentially expressed on Th1 and Th2 cells. Three of the family members (Tim-1, Tim-3, and Tim-4) are conserved between mouse and man. Genomic association of the TIM family and polymorphisms in both Tim-1 and Tim-3 in different immune-mediated diseases suggest that the family may have an important role in regulating immunity, both in terms of normal immune responses and in diseases like autoimmunity and asthma.
Subject(s)
Immunity, Innate/genetics , Membrane Proteins/genetics , Animals , Genetic Predisposition to Disease , Humans , Immune System Diseases/genetics , Immune Tolerance , Mice , T-Lymphocytes/immunologyABSTRACT
Butyric acid and trichostatin A (TSA) are anti-cancer compounds that cause the upregulation of genes involved in differentiation and cell cycle regulation by inhibiting histone deacetylase (HDAC) activity. In this study we have synthesized and evaluated compounds that combine the bioavailability of short-chain fatty acids, like butyric acid, with the bidentate binding ability of TSA. A series of analogs were made to examine the effects of chain length, simple aromatic cap groups, and substituted hydroxamates on the compounds' ability to inhibit rat-liver HDAC using a fluorometric assay. In keeping with previous structure-activity relationships, the most effective inhibitors consisted of longer chains and hydroxamic acid groups. It was found that 5-phenylvaleric hydroxamic acid and 4-benzoylbutyric hydroxamic acid were the most potent inhibitors with IC50's of 5 microM and 133 microM respectively.
Subject(s)
Enzyme Inhibitors/chemistry , Fatty Acids/chemistry , Histone Deacetylase Inhibitors , Hydroxamic Acids/chemistry , Animals , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Fatty Acids/chemical synthesis , Fatty Acids/pharmacology , Histone Deacetylases/metabolism , Hydroxamic Acids/chemical synthesis , Hydroxamic Acids/pharmacology , Inhibitory Concentration 50 , RatsABSTRACT
We examined, by enzyme-linked immunosorbent assay and Western blot analysis, the host immune response to 2 heat-shock proteins (hsps) in a patient and mice previously infected with Burkholderia mallei. The patient was the first reported human glanders case in 50 years in the United States. The expression of the groEL and dnaK operons appeared to be dependent upon a sigma(32) RNA polymerase as suggested by conserved heat-shock promoter sequences, and the groESL operon may be negatively regulated by a controlling invert repeat of chaperone expression (CIRCE) site. In the antisera, the GroEL protein was found to be more immunoreactive than the DnaK protein in both a human patient and mice previously infected with B. mallei. Examination of the supernatant of a growing culture of B. mallei showed that more GroEL protein than DnaK protein was released from the cell. This may occur similarly within an infected host causing an elevated host immune response to the B. mallei hsps.
Subject(s)
Antibodies, Bacterial/blood , Burkholderia mallei/immunology , Chaperonin 60/immunology , Glanders/immunology , HSP70 Heat-Shock Proteins/immunology , Immunoglobulin G/blood , Animals , Burkholderia mallei/genetics , Burkholderia mallei/metabolism , Chaperonin 60/genetics , Chaperonin 60/metabolism , Gene Expression Regulation, Bacterial , Glanders/microbiology , HSP70 Heat-Shock Proteins/genetics , HSP70 Heat-Shock Proteins/metabolism , Humans , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Operon , Sequence Analysis, DNAABSTRACT
The recently identified TIM gene family encodes cell-surface receptors that are involved in the regulation of Th1- and Th2-cell-mediated immunity. Tim-3 protein is specifically expressed on Th1 cells and negatively regulates Th1 responses, whereas Tim-2 is preferentially expressed in Th2 cells. Tim-1, previously identified as the hepatitis A virus receptor, co-stimulates T-cell expansion and cytokine production. Tim-4, which is preferentially expressed on mature dendritic cells, is the ligand for Tim-1. In mouse models of asthma and multiple sclerosis, affecting the function of Tim molecules altered disease phenotype. Because TIM molecules are differentially expressed on effector Th1 and Th2 cells, further understanding of the mechanisms by which they regulate Th1- and Th2-effector functions will probably provide opportunities for the therapeutic modulation of immune-mediated diseases.
Subject(s)
Immune System Diseases/therapy , Membrane Glycoproteins/genetics , Receptors, Virus/genetics , Th1 Cells/immunology , Th2 Cells/immunology , Animals , Cytokines/genetics , Gene Expression Regulation , Hepatitis A Virus Cellular Receptor 1 , Hepatitis A Virus Cellular Receptor 2 , Humans , Membrane Glycoproteins/immunology , Membrane Proteins/genetics , Membrane Proteins/immunology , Mice , Receptors, Virus/immunology , Respiratory HypersensitivityABSTRACT
BACKGROUND: A novel therapeutic option for the treatment of acute myocardial infarction involves the use of mesenchymal stem cells (MSCs). The purpose of this study was to investigate whether implantation of autologous MSCs results in sustained engraftment, myogenic differentiation, and improved cardiac function in a swine myocardial infarct model. METHODS: MSCs were isolated and expanded from bone marrow aspirates of 14 domestic swine. A 60-minute left anterior descending artery occlusion was used to produce anterior wall infarction. Piezoelectric crystals were placed within the ischemic region for measurement of regional wall thickness and contractile function. Two weeks later animals autologous, Di-I-labeled MSCs (6 x 10(7)) were implanted into the infarct by direct injection. Hemodynamic and functional measurements were obtained weekly until the time of sacrifice. Immunohistochemistry was used to assess MSC engraftment and myogenic differentiation. RESULTS: Microscopic analysis showed robust engraftment of MSCs in all treated animals. Expression of muscle-specific proteins was seen as early as 2 weeks and could be identified in all animals at sacrifice. The degree of contractile dysfunction was significantly attenuated at 4 weeks in animals implanted with MSCs (5.4% +/- 2.2% versus -3.37% +/- 2.7% in control). In addition, the extent of wall thinning after myocardial infarction was markedly reduced in treated animals. CONCLUSIONS: Mesenchymal stem cells are capable of engraftment in host myocardium, demonstrate expression of muscle specific proteins, and may attenuate contractile dysfunction and pathologic thinning in this model of left ventricular wall infarction. MSC cardiomyoplasty may have significant clinical potential in attenuating the pathology associated with myocardial infarction.