RESUMO
BACKGROUND: Faecal microbiota transplantation [FMT] shows some efficacy in treating patients with ulcerative colitis [UC], although variability has been observed among donors and treatment regimens. We investigated the effect of FMT using rationally selected donors after pretreatment with budesonide or placebo in active UC. METHODS: Patients ≥18 years old with mild to moderate active UC were randomly assigned to 3 weeks of budesonide [9 mg] or placebo followed by 4-weekly infusions of a donor faeces suspension. Two donors were selected based on microbiota composition, regulatory T cell induction and short-chain fatty acid production in mice. The primary endpoint was engraftment of donor microbiota after FMT. In addition, clinical efficacy was assessed. RESULTS: In total, 24 patients were enrolled. Pretreatment with budesonide did not increase donor microbiota engraftment [pâ =â 0.56] nor clinical response, and engraftment was not associated with clinical response. At week 14, 10/24 [42%] patients achieved [partial] remission. Remarkably, patients treated with FMT suspensions from one donor were associated with clinical response [80% of responders, pâ <â 0.05] but had lower overall engraftment of donor microbiota. Furthermore, differences in the taxonomic composition of the donors and the engraftment of certain taxa were associated with clinical response. CONCLUSION: In this small study, pretreatment with budesonide did not significantly influence engraftment or clinical response after FMT. However, clinical response appeared to be donor-dependent. Response to FMT may be related to transfer of specific strains instead of overall engraftment, demonstrating the need to characterize mechanisms of actions of strains that maximize therapeutic benefit in UC.
Assuntos
Budesonida , Colite Ulcerativa , Transplante de Microbiota Fecal , Humanos , Transplante de Microbiota Fecal/métodos , Budesonida/uso terapêutico , Budesonida/administração & dosagem , Colite Ulcerativa/terapia , Colite Ulcerativa/microbiologia , Feminino , Masculino , Adulto , Projetos Piloto , Pessoa de Meia-Idade , Resultado do Tratamento , Microbioma Gastrointestinal/efeitos dos fármacos , Método Duplo-Cego , Seleção do Doador/métodos , Anti-Inflamatórios/uso terapêutico , Fezes/microbiologiaRESUMO
BACKGROUND: Lactobacillus was described as a keystone bacterial taxon in the human vagina over 100 years ago. Using metagenomics, we and others have characterized lactobacilli and other vaginal taxa across health and disease states, including pregnancy. While shifts in community membership have been resolved at the genus/species level, strain dynamics remain poorly characterized. METHODS: We performed a metagenomic analysis of the complex ecology of the vaginal econiche during and after pregnancy in a large U.S. based longitudinal cohort of women who were initially sampled in the third trimester of pregnancy, then validated key findings in a second cohort of women initially sampled in the second trimester of pregnancy. FINDINGS: First, we resolved microbial species and strains, interrogated their co-occurrence patterns, and probed the relationship between keystone species and preterm birth outcomes. Second, to determine the role of human heredity in shaping vaginal microbial ecology in relation to preterm birth, we performed a mtDNA-bacterial species association analysis. Finally, we explored the clinical utility of metagenomics in detection and co-occurrence patterns for the pathobiont Group B Streptococcus (causative bacterium of invasive neonatal sepsis). CONCLUSIONS: Our highly refined resolutions of the vaginal ecology during and post-pregnancy provide insights into not only structural and functional community dynamics, but highlight the capacity of metagenomics to reveal finer aspects of the vaginal microbial ecologic framework. FUNDING: NIH-NINR R01NR014792, NIH-NICHD R01HD091731, NIH National Children's Study Formative Research, Burroughs Wellcome Fund Preterm Birth Initiative, March of Dimes Preterm Birth Research Initiative, NIH-NIGMS (K12GM084897, T32GM007330, T32GM088129).
Assuntos
Microbiota , Nascimento Prematuro , Bactérias , Criança , Feminino , Humanos , Recém-Nascido , Lactobacillus/genética , Microbiota/genética , Período Pós-Parto , Gravidez , Nascimento Prematuro/microbiologia , RNA Ribossômico 16S/genética , Vagina/químicaRESUMO
The human microbiota includes the trillions of microorganisms living in the human body whereas the human microbiome includes the genes and gene products of this microbiota. Bacteria were historically largely considered to be pathogens that inevitably led to human disease. However, because of advances in both cultivation-based methods and the advent of metagenomics, bacteria are now recognized to be largely beneficial commensal organisms and thus, key to normal and healthy human development. This relatively new area of medical research has elucidated insights into diseases such as inflammatory bowel disease and obesity, as well as metabolic and atopic disorders. However, much remains unknown about the complexity of microbe-microbe and microbe-host interactions. Future efforts aimed at answering key questions pertaining to the early establishment of the microbiome, alongside what defines its dysbiosis, will likely lead to long-term health and mitigation of disease. Here, we review the relevant literature pertaining to modulations in the perinatal and neonatal microbiome, the impact of environmental and maternal factors in shaping the neonatal microbiome, and future questions and directions in the exciting emerging arena of metagenomic medicine.
Assuntos
Saúde do Lactente/tendências , Metagenoma/fisiologia , Metagenômica/tendências , Microbiota/fisiologia , Feminino , Previsões , Humanos , Recém-Nascido , Metagenômica/métodos , GravidezRESUMO
Previously we have shown that the Japanese macaque gut microbiome differs not by obesity per se, but rather in association with high-fat diet (HFD) feeding. This held true for both pregnant dams, as well as their 1-year-old offspring, even when weaned onto a control diet. Here we aimed to examine the stability of the gut microbiome over time and in response to maternal and postweaning HFD feeding from 6 months of age, and at 1 and 3 years of age. In both cross-sectional and longitudinal specimens, we performed analysis of the V4 hypervariable region of the 16S rRNA gene on anus swabs collected from pregnant dams and their juveniles at age 6 months to 3 years (n = 55). Extracted microbial DNA was subjected to 16S-amplicon-based metagenomic sequencing on the Illumina MiSeq platform. We initially identified 272 unique bacterial genera, and multidimensional scaling revealed samples to cluster by age and diet exposures. Dirichlet multinomial mixture modeling of microbiota abundances enabled identification of two predominant enterotypes to which samples sorted, characterized primarily by Treponema abundance, or lack thereof. Approximating the time of initial weaning (6 months), the Japanese macaque offspring microbiome underwent a significant state type transition which stabilized from 1 to 3 years of age. However, we also found the low abundance Treponema enterotype to be strongly associated with HFD exposure, be it during gestation/lactation or in the postweaning interval. Examination of taxonomic co-occurrences revealed samples within the low Treponema cluster were relatively permissive (allowing for increased interactions between microbiota) whereas samples within the high Treponema cluster were relatively exclusionary (suggesting decreased interactions amongst microbiota). Taken together, these findings suggest that Treponemes are keystone species in the developing gut microbiome of the gut, and susceptible to HFD feeding in their relative abundance.
Assuntos
Dieta/veterinária , Microbioma Gastrointestinal , Macaca fuscata/microbiologia , Fatores Etários , Animais , Bactérias/classificação , Dieta Hiperlipídica/veterinária , Feminino , Genoma Bacteriano , Estudos Longitudinais , Macaca fuscata/crescimento & desenvolvimento , Gravidez , RNA Ribossômico 16S/genética , Treponema , DesmameRESUMO
BACKGROUND: We and others have previously shown that alterations in the mammalian gut microbiome are associated with diet, notably early life exposure to a maternal high fat diet (HFD). Here, we aimed to further these studies by examining alterations in the gut microbiome of juvenile Japanese macaques (Macaca fuscata) that were exposed to a maternal HFD, weaned onto a control diet, and later supplemented with a synbiotic comprised of psyllium seed and Enterococcus and Lactobacillus species. RESULTS: Eighteen month old offspring (n = 7) of 36% HFD fed dams were fed a control (14% fat) diet post weaning, then were synbiotic supplemented for 75 days and longitudinal stool and serum samples were obtained. All stool samples were subjected to 16S rRNA metagenomic sequencing, and microbiome profiles and serum lipids and triglycerides were compared to untreated, healthy age matched and diet matched controls (n = 7). Overall, 16S-based metagenomic analysis revealed that supplementation exerted minimal alterations to the gut microbiome including transient increased abundance of Lactobacillus species and decreased abundance of few bacterial genera, including Faecalibacterium and Anaerovibrio. However, serum lipid analysis revealed significant decreases in triglycerides, cholesterol, and LDL (p < 0.05). Nevertheless, supplemented juveniles challenged 4 months later were not protected from HFD-induced gut dysbiosis. CONCLUSIONS: Synbiotic supplementation is temporally associated with alterations in the gut microbiome and host lipid profiles of juvenile Japanese macaques that were previously exposed to a maternal HFD. Despite these presumptive temporal benefits, a protective effect against later HFD-challenge gut dysbiosis was not observed.
Assuntos
Bactérias/classificação , Bactérias/metabolismo , Dieta Hiperlipídica , Microbioma Gastrointestinal/fisiologia , Primatas/microbiologia , Simbióticos , Animais , Bactérias/genética , Disbiose/microbiologia , Enterococcus/fisiologia , Faecalibacterium , Fezes/microbiologia , Feminino , Firmicutes , Microbioma Gastrointestinal/genética , Lactobacillus/fisiologia , Lipídeos/sangue , Macaca/microbiologia , Masculino , Redes e Vias Metabólicas , Metagenômica , Probióticos , Psyllium , RNA Ribossômico 16S/genética , Especificidade da Espécie , Triglicerídeos/sangueRESUMO
Human microbial communities are characterized by their taxonomic, metagenomic and metabolic diversity, which varies by distinct body sites and influences human physiology. However, when and how microbial communities within each body niche acquire unique taxonomical and functional signatures in early life remains underexplored. We thus sought to determine the taxonomic composition and potential metabolic function of the neonatal and early infant microbiota across multiple body sites and assess the effect of the mode of delivery and its potential confounders or modifiers. A cohort of pregnant women in their early third trimester (n = 81) were prospectively enrolled for longitudinal sampling through 6 weeks after delivery, and a second matched cross-sectional cohort (n = 81) was additionally recruited for sampling once at the time of delivery. Samples across multiple body sites, including stool, oral gingiva, nares, skin and vagina were collected for each maternal-infant dyad. Whole-genome shotgun sequencing and sequencing analysis of the gene encoding the 16S rRNA were performed to interrogate the composition and function of the neonatal and maternal microbiota. We found that the neonatal microbiota and its associated functional pathways were relatively homogeneous across all body sites at delivery, with the notable exception of the neonatal meconium. However, by 6 weeks after delivery, the infant microbiota structure and function had substantially expanded and diversified, with the body site serving as the primary determinant of the composition of the bacterial community and its functional capacity. Although minor variations in the neonatal (immediately at birth) microbiota community structure were associated with the cesarean mode of delivery in some body sites (oral gingiva, nares and skin; R2 = 0.038), this was not true for neonatal stool (meconium; Mann-Whitney P > 0.05), and there was no observable difference in community function regardless of delivery mode. For infants at 6 weeks of age, the microbiota structure and function had expanded and diversified with demonstrable body site specificity (P < 0.001, R2 = 0.189) but without discernable differences in community structure or function between infants delivered vaginally or by cesarean surgery (P = 0.057, R2 = 0.007). We conclude that within the first 6 weeks of life, the infant microbiota undergoes substantial reorganization, which is primarily driven by body site and not by mode of delivery.
Assuntos
Cesárea , Parto Obstétrico , Microbioma Gastrointestinal/genética , RNA Ribossômico 16S/genética , Adulto , Estudos Transversais , Feminino , Gengiva/microbiologia , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Mecônio/microbiologia , Metagenômica , Mucosa Nasal/microbiologia , Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Pele/microbiologia , Adulto JovemRESUMO
Evidence supporting the Developmental Origins of Health and Disease Hypothesis indicates that maternal nutrition in pregnancy has a significant impact on offspring disease risk later in life, likely by modulating developmental processes in utero. Gut microbiota have recently been explored as a potential mediating factor, as dietary components strongly influence microbiota abundance, function and its impact on host physiology. A growing body of evidence has additionally indicated that the intrauterine environment is not sterile as once presumed, indicating that maternal-fetal transmission of microbiota may occur during pregnancy. In this article, we will review the body of literature that supports this emerging hypothesis, as well as highlight the work in relevant animal models demonstrating associations with maternal gestational nutrition and the offspring gut microbiome that may influence offspring physiology and susceptibility to disease.
Assuntos
Desenvolvimento Fetal , Microbioma Gastrointestinal , Fenômenos Fisiológicos da Nutrição Materna , Animais , Feminino , Humanos , Lactação , Masculino , Troca Materno-Fetal , GravidezRESUMO
BACKGROUND: Emerging evidence suggests that the in utero environment is not sterile as once presumed. Work in the mouse demonstrated transmission of commensal bacteria from mother to fetus during gestation, though it is unclear what modulates this process. We have previously shown in the nonhuman primate that, independent of obesity, a maternal high-fat diet during gestation and lactation persistently shapes the juvenile gut microbiome. We therefore sought to interrogate in a population-based human longitudinal cohort whether a maternal high-fat diet similarly alters the neonatal and infant gut microbiome in early life. METHODS: A representative cohort was prospectively enrolled either in the early third trimester or intrapartum (n = 163), with a subset consented to longitudinal sampling through the postpartum interval (n = 81). Multiple body site samples, including stool and meconium, were collected from neonates at delivery and by 6 weeks of age. A rapid dietary questionnaire was administered to estimate intake of fat, added sugars, and fiber over the past month (National Health and Examination Survey). DNA was extracted from each infant meconium/stool sample (MoBio) and subjected to 16S rRNA gene sequencing and analysis. RESULTS: On average, the maternal dietary intake of fat ranged from 14.0 to 55.2 %, with an average intake of 33.1 % (σ = 6.1 %). Mothers whose diets significantly differed from the mean (±1 standard deviation) were separated into two distinct groups, a control group (n = 13, µ = 24.4 %) and a high-fat group (n = 13, µ = 43.1 %). Principal coordinate analysis revealed that the microbiome of the neonatal stool at birth (meconium) clustered differently by virtue of maternal gestational diet (PERMANOVA p = 0.001). LEfSe feature selection identified several taxa that discriminated the groups, with a notable relative depletion of Bacteroides in the neonates exposed to a maternal high-fat gestational diet (Student's t-test, p < 0.05) that persisted to 6 weeks of age. CONCLUSIONS: Similar to the primate, independent of maternal body mass index, a maternal high-fat diet is associated with distinct changes in the neonatal gut microbiome at birth which persist through 4-6 weeks of age. Our findings underscore the importance of counseling pregnant mothers on macronutrient consumption during pregnancy and lactation.
Assuntos
Dieta Hiperlipídica , Gorduras na Dieta/administração & dosagem , Microbioma Gastrointestinal/efeitos dos fármacos , Mecônio/microbiologia , RNA Ribossômico 16S/genética , Feminino , Microbioma Gastrointestinal/genética , Humanos , Lactente , Recém-Nascido , Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality and is not uncommonly associated with chorioamnionitis. We recently have demonstrated that the placenta harbors a unique microbiome with similar flora to the oral community. We also have shown an association of these placental microbiota with PTB, history of antenatal infection, and excess maternal weight gain. On the basis of these previous observations, we hypothesized that the placental membranes would retain a microbiome community that would vary in association with preterm birth and chorioamnionitis. OBJECTIVE: In the current study, we aimed to examine the differences in the placental membrane microbiome in association with PTB in both the presence and absence of chorioamnionitis and/or funisitis using state-of-the-science whole-genome shotgun metagenomics. STUDY DESIGN: This was a cross-sectional analysis with 6 nested spontaneous birth cohorts (n = 9-15 subjects/cohort): Term gestations without chorioamnionitis, term with chorioamnionitis, preterm without chorioamnionitis, preterm with mild chorioamnionitis, preterm with severe chorioamnionitis, and preterm with chorioamnionitis and funisitis. Histologic analysis was performed with Redline's criteria, and inflammatory cytokines were analyzed in the cord blood. DNA from placental membranes was extracted from sterile swabs collected at delivery, and whole-genome shotgun sequencing was performed on the Illumina HiSeq platform. Filtered microbial DNA sequences were annotated and analyzed with MG-RAST (ie, Metagenomic Rapid Annotations using Subsystems Technology) and R. RESULTS: Subjects were assigned to cohorts on the basis of gestational age at delivery and independent scoring of histologic chorioamnionitis. We found that preterm subjects with severe chorioamnionitis and funisitis had increases in cord blood inflammatory cytokines. Of interest, although the placental membrane microbiome was altered in association with severity of histologic chorioamnionitis (permutational multivariate analysis of variance P = .005), there was no observable impact with either betamethasone or antibiotic treatment. In preterm subjects with chorioamnionitis, we found a high abundance of both urogenital and oral commensal bacteria. These alterations in the microbiome were accompanied by significant variation (P < .05) in microbial metabolic pathways important in the glucose-fed pentose phosphate pathway (term subjects), or glycerophopholipid metabolism, and the biosynthesis of the siderophore group nonribosomal peptides (preterm subjects). CONCLUSION: Consistent with ours and others previous findings, women who experienced spontaneous PTB harbor placental microbiota that further differed by severity of chorioamnionitis. Integrative metagenomic analysis revealed significant variation in distinct bacterial metabolic pathways, which we speculate may contribute to risk of preterm birth with and without severe chorioamnionitis.
Assuntos
Corioamnionite/microbiologia , Microbiota , Placenta/microbiologia , Nascimento Prematuro , Butiratos/metabolismo , Estudos Transversais , DNA Bacteriano/genética , Feminino , Glicerofosfolipídeos/metabolismo , Humanos , Metagenômica , Via de Pentose Fosfato , Gravidez , Riboflavina/metabolismo , Análise de Sequência de DNA , Índice de Gravidade de Doença , Nascimento a TermoRESUMO
The human microbiome, the collective genome of the microbial community that is on and within us, has recently been mapped. The initial characterization of healthy subjects has provided investigators with a reference population for interrogating the microbiome in metabolic, intestinal, and reproductive health and disease states. Although it is known that bacteria can colonize the vagina, recent metagenomic studies have shown that the vaginal microbiome varies among reproductive age women. Similarly, the richness and diversity of intestinal microbiota also naturally fluctuate among gravidae in both human and nonhuman primates, as well as mice. Moreover, recent evidence suggests that microbiome niches in pregnancy are not limited to maternal body sites, as the placenta appears to harbor a low biomass microbiome that is presumptively established in early pregnancy and varies in association with a remote history of maternal antenatal infection as well as preterm birth. In this article, we will provide a brief overview on metagenomics science as a means to investigate the microbiome, observations pertaining to both variation and the presumptive potential role of a varied microbiome during pregnancy, and how future studies of the microbiome in pregnancy may lend to a better understanding of human biology, reproductive health, and parturition.
Assuntos
Metagenômica/métodos , Microbiota/fisiologia , Complicações Infecciosas na Gravidez/microbiologia , Vagina/microbiologia , Animais , DNA Bacteriano/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Camundongos , Microbiota/genética , Placenta/microbiologia , Gravidez , Saúde ReprodutivaRESUMO
T cell development in the thymus produces multiple lineages of cells, including innate T cells such as γδ TCR(+) cells, invariant NKT cells, mucosal-associated invariant T cells, and H2-M3-specific cells. Although innate cells are generally a minor subset of thymocytes, in several strains of mice harboring mutations in T cell signaling proteins or transcriptional regulators, conventional CD8(+) T cells develop as innate cells with characteristics of memory T cells. Thus, in Itk-deficient mice, mature CD4(-)CD8(+) (CD8 single-positive [SP]) thymocytes express high levels of the transcription factor eomesodermin (Eomes) and are dependent on IL-4 being produced in the thymic environment by a poorly characterized subset of CD4(+) thymocytes expressing the transcriptional regulator promyelocytic leukemia zinc finger. In this study, we show that a sizeable proportion of mature CD4(+)CD8(-) (CD4SP) thymocytes in itk(-/-) mice also develop as innate Eomes-expressing T cells. These cells are dependent on MHC class II and IL-4 signaling for their development, indicating that they are conventional CD4(+) T cells that have been converted to an innate phenotype. Surprisingly, neither CD4SP nor CD8SP innate Eomes(+) thymocytes in itk(-/-) or SLP-76(Y145F) mice are dependent on γδ T cells for their development. Instead, we find that the predominant population of Eomes(+) innate itk(-/-) CD4SP thymocytes is largely absent in mice lacking CD1d-specific invariant NKT cells, with no effect on innate itk(-/-) CD8SP thymocytes. In contrast, both subsets of innate Eomes(+)itk(-/-) T cells require the presence of a novel promyelocytic leukemia zinc finger-expressing, SLAM family receptor adapter protein-dependent thymocyte population that is essential for the conversion of conventional CD4(+) and CD8(+) T cells into innate T cells with a memory phenotype.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Proteínas Tirosina Quinases/imunologia , Transdução de Sinais/imunologia , Animais , Antígenos CD1d/imunologia , Antígenos CD1d/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Proliferação de Células , Citometria de Fluxo , Interleucina-15/deficiência , Interleucina-15/genética , Interleucina-15/imunologia , Interleucina-4/imunologia , Interleucina-4/metabolismo , Fatores de Transcrição Kruppel-Like/imunologia , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Proteína com Dedos de Zinco da Leucemia Promielocítica , Proteínas Tirosina Quinases/deficiência , Proteínas Tirosina Quinases/genética , Ratos , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Transdução de Sinais/genética , Proteínas com Domínio T/imunologia , Proteínas com Domínio T/metabolismo , Timócitos/imunologia , Timócitos/metabolismoRESUMO
T cell development in the thymus produces multiple lineages of cells, including innate T cells. Studies in mice harboring alterations in TCR signaling proteins or transcriptional regulators have revealed an expanded population of CD4(+) innate T cells in the thymus that produce IL-4 and express the transcription factor promyelocytic leukemia zinc finger (PLZF). In these mice, IL-4 produced by the CD4(+)PLZF(+) T cell population leads to the conversion of conventional CD8(+) thymocytes into innate CD8(+) T cells resembling memory T cells expressing eomesodermin. The expression of PLZF, the signature invariant NKT cell transcription factor, in these innate CD4(+) T cells suggests that they might be a subset of αß or γδ TCR(+) NKT cells or mucosal-associated invariant T (MAIT) cells. To address these possibilities, we characterized the CD4(+)PLZF(+) innate T cells in itk(-/-) mice. We show that itk(-/-) innate PLZF(+)CD4(+) T cells are not CD1d-dependent NKT cells, MR1-dependent MAIT cells, or γδ T cells. Furthermore, although the itk(-/-) innate PLZF(+)CD4(+) T cells express αß TCRs, neither ß2-microglobulin-dependent MHC class I nor any MHC class II molecules are required for their development. In contrast to invariant NKT cells and MAIT cells, this population has a highly diverse TCRα-chain repertoire. Analysis of peripheral tissues indicates that itk(-/-) innate PLZF(+)CD4(+) T cells preferentially home to spleen and mesenteric lymph nodes owing to increased expression of gut-homing receptors, and that their expansion is regulated by commensal gut flora. These data support the conclusion that itk(-/-) innate PLZF(+)CD4(+) T cells are a novel subset of innate T cells.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Proliferação de Células , Fatores de Transcrição Kruppel-Like/imunologia , Proteínas Tirosina Quinases/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Animais , Antígenos CD1d/imunologia , Antígenos CD1d/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Citometria de Fluxo , Expressão Gênica/imunologia , Antígenos H-2/genética , Antígenos H-2/imunologia , Antígenos H-2/metabolismo , Interleucina-4/genética , Interleucina-4/imunologia , Interleucina-4/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Linfonodos/imunologia , Linfonodos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína com Dedos de Zinco da Leucemia Promielocítica , Proteínas Tirosina Quinases/deficiência , Proteínas Tirosina Quinases/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/imunologia , Baço/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Timócitos/imunologia , Timócitos/metabolismo , Microglobulina beta-2/imunologia , Microglobulina beta-2/metabolismoRESUMO
The causes of preterm birth are multifactorial, but its association with infection has been well-established. The predominant paradigm describes an ascending infection from the lower genital tract through the cervix and into the presumably sterile fetal membranes and placenta. Thus, an evaluation of the role of the vaginal microbiome in preterm birth is implicated. However, emerging fields of data described in this review suggest that the placenta might not be sterile, even in the absence of clinical infection. We thus propose an additional mechanism for placental colonization and infection: hematogenous spread. When considered in the context of decades of evidence demonstrating a strong risk of recurrence for preterm birth, studies on parturition are ideal for applying the rapidly expanding field of metagenomics and analytic pipelines. The translational implications toward identification of innovative treatments for the prevention of preterm birth are further discussed. In sum, exciting advances in understanding the role of both host and microbiota in parturition and preterm birth are on the horizon.
Assuntos
Microbiota/imunologia , Parto/imunologia , Complicações Infecciosas na Gravidez , Nascimento Prematuro , Infecções do Sistema Genital/imunologia , Animais , Feminino , Humanos , Gravidez , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/microbiologia , Nascimento Prematuro/imunologia , Nascimento Prematuro/microbiologiaRESUMO
In response to acute virus infections, CD8(+) T cells differentiate to form a large population of short-lived effectors and a stable pool of long-lived memory cells. The characteristics of the CD8(+) T cell response are influenced by TCR affinity, Ag dose, and the inflammatory cytokine milieu dictated by the infection. To address the mechanism by which differences in TCR signal strength could regulate CD8(+) T cell differentiation, we investigated the transcription factor, IFN regulatory factor 4 (IRF4). We show that IRF4 is transiently upregulated to differing levels in murine CD8(+) T cells, based on the strength of TCR signaling. In turn, IRF4 controls the magnitude of the CD8(+) T cell response to acute virus infection in a dose-dependent manner. Modest differences in IRF4 expression dramatically influence the numbers of short-lived effector cells at the peak of the infection, but have no impact on the kinetics of the infection or on the rate of T cell contraction. Furthermore, the expression of key transcription factors such as T cell factor 1 and Eomesodermin are highly sensitive to graded levels of IRF4. In contrast, T-bet expression is less dependent on IRF4 levels and is influenced by the nature of the infection. These data indicate that IRF4 is a key component that translates the strength of TCR signaling into a graded response of virus-specific CD8(+) T cells.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Proliferação de Células , Vírus da Influenza A/imunologia , Fatores Reguladores de Interferon/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Infecções por Orthomyxoviridae/imunologia , Doença Aguda , Animais , Linfócitos T CD8-Positivos/patologia , Diferenciação Celular/genética , Vírus da Influenza A/genética , Fatores Reguladores de Interferon/genética , Coriomeningite Linfocítica/genética , Vírus da Coriomeningite Linfocítica/genética , Camundongos , Camundongos Knockout , Infecções por Orthomyxoviridae/genética , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Regulação para Cima/genética , Regulação para Cima/imunologiaRESUMO
The intestinal microbiome is a unique ecosystem and an essential mediator of metabolism and obesity in mammals. However, studies investigating the impact of the diet on the establishment of the gut microbiome early in life are generally lacking, and most notably so in primate models. Here we report that a high-fat maternal or postnatal diet, but not obesity per se, structures the offspring's intestinal microbiome in Macaca fuscata (Japanese macaque). The resultant microbial dysbiosis is only partially corrected by a low-fat, control diet after weaning. Unexpectedly, early exposure to a high-fat diet diminished the abundance of non-pathogenic Campylobacter in the juvenile gut, suggesting a potential role for dietary fat in shaping commensal microbial communities in primates. Our data challenge the concept of an obesity-causing gut microbiome and rather provide evidence for a contribution of the maternal diet in establishing the microbiota, which in turn affects intestinal maintenance of metabolic health.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Disbiose/etiologia , Intestinos/microbiologia , Microbiota , Efeitos Tardios da Exposição Pré-Natal/etiologia , Animais , Dieta com Restrição de Gorduras , Disbiose/microbiologia , Feminino , Macaca , Gravidez , Efeitos Tardios da Exposição Pré-Natal/microbiologia , DesmameRESUMO
Whole genome shotgun sequencing (WGS) has been increasingly recognized as the most comprehensive and robust approach for metagenomics research. When compared with 16S-based metagenomics, it offers the advantage of identification of species level taxonomy and the estimation of metabolic pathway activities from human and environmental samples. Several large-scale metagenomic projects have been recently conducted or are currently underway utilizing WGS. With the generation of vast amounts of data, the bioinformatics and computational analysis of WGS results become vital for the success of a metagenomics study. However, each step in the WGS data analysis, including metagenome assembly, gene prediction, taxonomy identification, function annotation, and pathway analysis, is complicated by the shear amount of data. Algorithms and tools have been developed specifically to handle WGS-generated metagenomics data with the hope of reducing the requirement on computational time and storage space. Here, we present an overview of the current state of metagenomics through WGS sequencing, challenges frequently encountered, and up-to-date solutions. Several applications that are uniquely applicable to microbiome studies in reproductive and perinatal medicine are also discussed.
Assuntos
Genoma Humano/genética , Metagenoma/genética , Metagenômica , Microbiota/genética , Microbiota/fisiologia , Bactérias/classificação , Biologia Computacional/métodos , Bases de Dados Genéticas , Feminino , Expressão Gênica/genética , Expressão Gênica/fisiologia , Humanos , Gravidez , Medicina ReprodutivaRESUMO
Dysbiosis of the microbiome has been associated with type II diabetes mellitus, obesity, inflammatory bowel disorders, and colorectal cancer, and recently, the Human Microbiome Project Consortium has helped to define a healthy microbiome. Now research has begun to investigate how the microbiome is established, and in this article, we will discuss the maternal influences on the establishment of the microbiome. The inoculation of an individual's microbiome is highly dependent on the maternal microbiome, and changes occur in the maternal microbiome during pregnancy that may help to shape the neonatal microbiome. Further, we consider how mode of delivery may shape the developing microbiome of a neonate, and we end by discussing how the microbiome may impact preterm birth and the possibility of bacterial colonization of the placenta. Although the current literature demonstrates that the transformation of the maternal microbiome during pregnancy effects the establishment of the neonatal microbiome, further research is needed to explore how the microbiome shapes our metabolism and developing immune system.
Assuntos
Desenvolvimento Infantil/fisiologia , Microbiota/fisiologia , Mães , Feminino , Humanos , Recém-Nascido , Placenta/microbiologia , Gravidez , Nascimento PrematuroRESUMO
Activation of self-reactive T cells and their trafficking to target tissues leads to autoimmune organ destruction. Mice lacking the co-inhibitory receptor cytotoxic T lymphocyte antigen-4 (CTLA-4) develop fatal autoimmunity characterized by lymphocytic infiltration into nonlymphoid tissues. Here, we demonstrate that the CD28 co-stimulatory pathway regulates the trafficking of self-reactive Ctla4(-/-) T cells to tissues. Concurrent ablation of the CD28-activated Tec family kinase ITK does not block spontaneous T cell activation but instead causes self-reactive Ctla4(-/-) T cells to accumulate in secondary lymphoid organs. Despite excessive spontaneous T cell activation and proliferation in lymphoid organs, Itk(-/-); Ctla4(-/-) mice are otherwise healthy, mount antiviral immune responses and exhibit a long lifespan. We propose that ITK specifically licenses autoreactive T cells to enter tissues to mount destructive immune responses. Notably, ITK inhibitors mimic the null mutant phenotype and also prevent pancreatic islet infiltration by diabetogenic T cells in mouse models of type 1 diabetes, highlighting their potential utility for the treatment of human autoimmune disorders.
Assuntos
Antígenos CD28/fisiologia , Quimiotaxia de Leucócito/genética , Proteínas Tirosina Quinases/fisiologia , Linfócitos T/fisiologia , Animais , Células CHO , Antígeno CTLA-4/genética , Células Cultivadas , Cricetinae , Cricetulus , Feminino , Homeostase/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Transdução de Sinais/fisiologiaRESUMO
The Tec family tyrosine kinase, Itk, regulates signaling downstream of the TCR. The absence of Itk in CD4(+) T cells results in impaired Th2 responses along with defects in maturation, cytokine production, and survival of iNKT cells. Paradoxically, Itk(-/-) mice have spontaneously elevated serum IgE levels, resulting from an expansion of the Vγ1.1(+)Vδ6.3(+) subset of γδ T cells, known as γδ NKT cells. Comparisons between γδ NKT cells and αß iNKT cells showed convergence in the pattern of cell surface marker expression, cytokine profiles, and gene expression, suggesting that these two subsets of NKT cells undergo similar differentiation programs. Hepatic γδ NKT cells have an invariant TCR and are derived predominantly from fetal progenitors that expand in the thymus during the first weeks of life. The adult thymus contains these invariant γδ NKT cells plus a heterogeneous population of Vγ1.1(+)Vδ6.3(+) T cells with diverse CDR3 sequences. This latter population, normally excluded from the liver, escapes the thymus and homes to the liver when Itk is absent. In addition, Itk(-/-) γδ NKT cells persistently express high levels of Zbtb16 (PLZF) and Il4, genes that are normally downregulated in the most mature subsets of NKT cells. These data indicate that Itk signaling is required to prevent the expansion of γδ NKT cells in the adult thymus, to block their emigration, and to promote terminal NKT cell maturation.
Assuntos
Diferenciação Celular/imunologia , Senescência Celular/imunologia , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Proteínas Tirosina Quinases/fisiologia , Receptores de Antígenos de Linfócitos T gama-delta/biossíntese , Timo/enzimologia , Timo/imunologia , Animais , Inibição de Migração Celular/imunologia , Movimento Celular/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/citologia , Timo/citologiaRESUMO
CD8(+) T-cell development in the thymus generates a predominant population of conventional naive cells, along with minor populations of "innate" T cells that resemble memory cells. Recent studies analyzing a variety of KO or knock-in mice have indicated that impairments in the T-cell receptor (TCR) signaling pathway produce increased numbers of innate CD8(+) T cells, characterized by their high expression of CD44, CD122, CXCR3, and the transcription factor, Eomesodermin (Eomes). One component of this altered development is a non-CD8(+) T cell-intrinsic role for IL-4. To determine whether reduced TCR signaling within the CD8(+) T cells might also contribute to this pathway, we investigated the role of the transcription factor, IFN regulatory factor 4 (IRF4). IRF4 is up-regulated following TCR stimulation in WT T cells; further, this up-regulation is impaired in T cells treated with a small-molecule inhibitor of the Tec family tyrosine kinase, IL-2 inducible T-cell kinase (ITK). In contrast to WT cells, activation of IRF4-deficient CD8(+) T cells leads to rapid and robust expression of Eomes, which is further enhanced by IL-4 stimulation. In addition, inhibition of ITK together with IL-4 increases Eomeso up-regulation. These data indicate that ITK signaling promotes IRF4 up-regulation following CD8(+) T-cell activation and that this signaling pathway normally suppresses Eomes expression, thereby regulating the differentiation pathway of CD8(+) T cells.