Project description:Infants and young children are more susceptible to common respiratory pathogens compared to adults, but can fare better against novel pathogens like SARS-CoV-2. The mechanisms by which infants and young children mount effective responses to respiratory pathogens are unknown. Here, we demonstrate through study of lungs and lung-associated lymph nodes (LLN) from infant and pediatric organ donors, aged 0-13 years, that bronchus-associated lymphoid tissue (BALT), develops in lungs during the first year of life. BALT structures, consisting of B cell follicles and T cell zones, increase in numbers in the early years, and subsequently decrease over childhood coincident with accumulation of memory T cells in the lung. Early life BALT contains germinal centers and supports B cell differentiation, clonal expansion, somatic hypermutation, and immunoglobulin class switching. High dimensional flow cytometry reveals seeding of lungs by newly formed B cells (transitional cells) during infancy coincident with the timing of maximal BALT formation. We further demonstrate increased lung-localized B cell responses during respiratory virus infection in infants. Together, our findings provide novel evidence for BALT as an early life adaptation for mobilizing in situ immune protection to the diverse respiratory challenges during this formative life stage.
Project description:<p><b>Public health importance</b>: Babies born preterm, approximately 1 out of every 9 live births in the United States, have significant respiratory morbidity over the first two years of life, exacerbated by respiratory viral infections. Many (<50%) return to pediatricians, emergency rooms and pulmonologists with symptoms of respiratory dysfunction (SRD): intermittent or chronic wheezing, poor growth and an excess of upper and lower respiratory tract infections (LRTI). SRD correlate inversely with gestational age and weight at birth and is more common in those with chronic lung disease of prematurity, yet its incidence and severity varies widely among both the prematurely born and those born at term. There is evidence from clinical studies and animal models that risks of LRTI and recurrent wheezing is influenced by gut and respiratory flora and by T cell responses to infection. Information gained from this study will be used to identify characteristics, risk factors and potential mechanisms for early and persistent lung disease in children born at term and born preterm.</p> <p>This Clinical Research Study will investigate the relationships between sequential respiratory viral infections, patterns of intestinal and respiratory bacterial colonization, and adaptive cellular immune phenotypes which are associated with increased susceptibility to respiratory infections and long term respiratory morbidity in preterm and full term infants. We hypothesize that the timing and acquisition of specific viral infections and bacterial species are directly related to respiratory morbidity in the first year of life as defined by SRD and by measures of pulmonary function. We hypothesize that cellular and molecular immuno-maturity are altered due to factors presented by premature birth in such a way as to promote chronic inflammatory and cytotoxic damage to the lung, with subsequent enhanced, damaging responses to infectious agents and environmental irritants. Our preliminary studies demonstrate both feasibility and expertise in mutiparameter immunophenotyping of small volume peripheral blood samples obtained from premature infants including gene expression arrays of flow cytometry sorted cells. We will use new technologies for known viral identification, as well as high-throughput metagenome sequencing of RNA and DNA virus like particles (VLP) to be used for viral discovery in infant respiratory sample and use of high-throughput pyrosequencing (454T) of bacterial 16S rRNA to determine shifts in bacterial community structure, occurring in pre-term (PT) as compared to full term (FT) infants, over the first year of life. Finally, we present statistical approaches to stratify disease risk predictors using multivariate logistic regression modeling approaches. We propose to evaluate T cell phenotypic and functional profiles relative to viral and predominant bacterial exposures according to highly complementary, but independent, Specific Objectives.</p> <p><b>Objective 1</b>: To determine if viral respiratory infections and patterns of respiratory and gut bacterial community structure (microbiome) in prematurely born babies predict the rate and degree of immunologic maturation, and pulmonary dysfunction, measured from birth to 36 weeks corrected gestational age (CGA).</p> <p><b>Objective 2</b>: To determine the relationship between respiratory viral infections and disease severity up to one year CGA, and the lymphocyte (Lc) phenotypes documented at term gestation (birth for term infants and 36 wks/NICU discharge in preterm infants) and at one year CGA. Three secondary outcomes of this objective will be to a) relate the quantity, type and severity of viral infections with pulmonary function at one and three years of life, b) relate the viral community structure to severity of viral infections and c) to seek evidence of modulation of viral susceptibility by bacterial respiratory and gut community structure (microbiome). The relationship of colonization with known and non-identified bacterial species in both the respiratory tract and the gut will be evaluated. </p>
Project description:Background: Farm exposures in early life reduce the risks for childhood allergic diseases and asthma. There is less information about how farm exposures relate to respiratory illnesses and mucosal immune development. Objective: We hypothesized that children raised in farm environments have a lower incidence of viral illnesses over the first two years of life than non-farm children. We also analyzed between farm exposures or respiratory illnesses were related to patterns of nasal cell gene expression. Methods: The Wisconsin Infant Study Cohort (WISC) birth cohort enrolled farm and non-farm pregnant women from central Wisconsin. Parents reported prenatal farm and other environmental exposures. Illness frequency and severity were assessed using illness diaries and periodic surveys. Nasopharyngeal cell gene expression at age two years was compared to farm exposure and respiratory illness history. Results: There was a higher rate of respiratory illnesses in the non-farm vs. farm group (rate ratio 0.82 [0.69,0.97], p=0.020), but no significant differences in wheezing illnesses. There was a stepwise reduction in rates of respiratory illnesses in children exposed at least weekly to 0, 1, or ≥2 animals (p=0.006). In analyzing nasal cell gene expression, farm exposures and preceding respiratory illnesses were positively related to gene signatures for mononuclear cells and innate and antimicrobial responses. Conclusions: Children exposed to farms and farm animals had lower rates of respiratory illnesses over the first two years of life. Both farm exposures and preceding respiratory illnesses were associated with increased innate immune responses, suggesting that these exposures stimulate mucosal immune responses to reduce subsequent illness frequency.
Project description:Human respiratory syncytial virus (HRSV) is the main cause of bronchiolitis during the first year of life, but other viruses such as rhinovirus also occur and are clinically indistinguishable. In hospitalized infants with bronchiolitis, the analysis of the peripheral blood mononuclear cells (PBMC) gene expression might be useful for identification the etiologies caused by HRSV and human rhinovirus (HRV) and to the development of future tests, as well as to elucidate the pathogenic mechanisms triggered by different viral agents and new therapeutic possibilities. In this study, we conducted a comparative global gene expression analysis of infants with acute viral bronchiolitis infected by HRSV (HRSV group) or HRV (HRV group).
Project description:The prevalence of atopic diseases has increased with atopic dermatitis (AD) as the earliest manifestation. We assessed if molecular risk factors in atopic mothers influence their offsprings’ susceptibility to an atopic disease. Pairs of pregnant women and their infants with or without parental atopy were followed over the first 2 years of life. Global DNA methylation and differentially methylated regions (DMR) were determined in atopic and non-atopic mothers. During the first 2 years of life, AD was more prevalent in children of atopic compared to non-atopic mothers with an increase in food sensitization in children with AD. 165 DMRs distinguished atopic from non-atopic mothers. Maternal atopy combined with DMRs increased the offsprings’ predicted risk to develop AD from an odds ratio of 2.56 to 4.26.
Project description:91 preterm infant gut metaproteomes measured in technical duplicate using an eleven salt pulse 2D-LC-MS/MS method. Samples represent 17 preterm infants over the first several weeks of life, of which 6 preterm infants eventually developed necrotizing enterocolitis.
| MSV000086096 | MassIVE
Project description:Infant gut microbiome over the first 2 years of life in the BLOSOM cohort
Project description:Introduction: Early pulmonary vascular disease in preterm infants is associated with the subsequent development of bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH), however, mechanisms that contribute to or identify infants with increased susceptibility for BPD and/or PH are incompletely understood. Therefore, we tested if changes in circulating angiogenic peptides during the first week of life are associated with the later development of BPD and/or PH. We further sought to determine alternate peptides and related signalling pathways with the risk for BPD or PH. Methods: We prospectively enrolled infants with gestational age <34 weeks gestation and collected blood samples during their first week of life. BPD and PH were assessed at 36 weeks postmenstrual age. Samples were assayed for each of the 1121 peptides included in the SOMAscanTM technology, with subsequent pathway analysis. Results: Of 102 study infants, 82 had BPD and 13 had PH. Multiple angiogenic proteins (PF-4, VEGF121, ANG-1, BMP10, HGF, ANG2) were associated with the subsequent diagnosis of BPD, and FGF-19, PF-4, CTAP-III and PDGF-AA levels were associated with BPD severity. Early increases in BMP10 was strongly associated with the late risk for BPD and PH. Conclusion: We found that early alterations of circulating angiogenic peptides and others were associated with the subsequent development of BPD. We further identified peptides that were associated with BPD severity and BPD-associated PH, including BMP10. We speculate that proteomic biomarkers during the first week of life may identify infants at risk for BPD and/or PH to enhance care and research.
Project description:Analysis of influenza A and respiratory synctial virus infections in cultured nasal epithelial cells at the air-liquid interface (ALI) of adult, term, and preterm infants.