Project description:Pneumococcal infections cause serious illness and death among older adults. A capsular polysaccharide vaccine PPSV23 (Pneumovax®) and a conjugated polysaccharide vaccine PCV13 (Prevnar®) are used to prevent these infections, yet underlying immunological responses, and baseline predictors remain unknown. We recruited and vaccinated 39 older adults (>60 years) with PPSV23 or PCV13. Both vaccines induced strong antibody responses at day 28 and similar plasmablast transcriptional signatures at day 10, however, their baseline predictors were distinct. Analyses of baseline flow cytometry and RNA-seq data (bulk and single cell) revealed a novel baseline phenotype that is specifically associated with weaker PCV13 responses, characterized by i) increased expression of cytotoxicity-associated genes and increased CD16+ NK frequency; ii) increased Th17 and decreased Th1 cell frequency. Men were more likely to display this cytotoxic phenotype and mounted weaker responses to PCV13 than women. Baseline expression levels of a distinct gene set was predictive of PPSV23 responses. This first precision vaccinology study for pneumococcal vaccine responses of older adults uncovered novel and distinct baseline predictors that might transform vaccination strategies and initiate novel interventions.
Project description:Pneumococcal infections cause serious illness and death among older adults. A capsular polysaccharide vaccine PPSV23 (Pneumovax®) and a conjugated polysaccharide vaccine PCV13 (Prevnar®) are used to prevent these infections, yet underlying immunological responses, and baseline predictors remain unknown. We recruited and vaccinated 39 older adults (>60 years) with PPSV23 or PCV13. Both vaccines induced strong antibody responses at day 28 and similar plasmablast transcriptional signatures at day 10, however, their baseline predictors were distinct. Analyses of baseline flow cytometry and RNA-seq data (bulk and single cell) revealed a novel baseline phenotype that is specifically associated with weaker PCV13 responses, characterized by i) increased expression of cytotoxicity-associated genes and increased CD16+ NK frequency; ii) increased Th17 and decreased Th1 cell frequency. Men were more likely to display this cytotoxic phenotype and mounted weaker responses to PCV13 than women. Baseline expression levels of a distinct gene set was predictive of PPSV23 responses. This first precision vaccinology study for pneumococcal vaccine responses of older adults uncovered novel and distinct baseline predictors that might transform vaccination strategies and initiate novel interventions.
Project description:Analysis of the pulmonary gene expression in two mouse strains BALB/cOlaHsd (BALB/c) and CBA/CaOlaHsd (CBA/Ca) after infection with various serotypes of Streptococcus pneumoniae. BALB/c mice show high resistance to infection with S. pneumoniae strain D39 (serotype 2), while CBA/Ca mice are highly susceptible. The lung samples of BALB/c and CBA/Ca were collected at 6h post-infection with one of the tested pneumococcal serotypes (2, 3, 6B and 19F) and for control animals (PBS-treated). Additionally lung samples from both mouse strains were collected at 12h and 24h post-infection with pneumococcal strain D39. The lists of differentially expressed genes were created by the comparison of infected versus PBS-treated animals and infected BALB/c versus infected CBA/Ca for each pneumococcal strain. The tested hypotheses were: 1) infection with S. pneumoniae will change the pulmonary transcriptomes of both mouse strains 2) The pulmonary gene expression will be specific for mouse strains and for the pneumococcal serotype and 3) The change in the pulmonary gene expression will associate with future clinical outcome of infection or with the type of observed inflammatory responses. Total RNA obtained from lung tissue from BALB/cOlaHsd and CBA/CaOlaHsd mouse strains (Harlan) post intranasal infection with Streptococcus pneumoniae of various serotypes (2, 3, 6B and 19F) dose 5.0E06 CFU or PBS-treated animals
Project description:Analysis of the pulmonary gene expression in two mouse strains BALB/cOlaHsd (BALB/c) and CBA/CaOlaHsd (CBA/Ca) after infection with various serotypes of Streptococcus pneumoniae. BALB/c mice show high resistance to infection with S. pneumoniae strain D39 (serotype 2), while CBA/Ca mice are highly susceptible. The lung samples of BALB/c and CBA/Ca were collected at 6h post-infection with one of the tested pneumococcal serotypes (2, 3, 6B and 19F) and for control animals (PBS-treated). Additionally lung samples from both mouse strains were collected at 12h and 24h post-infection with pneumococcal strain D39. The lists of differentially expressed genes were created by the comparison of infected versus PBS-treated animals and infected BALB/c versus infected CBA/Ca for each pneumococcal strain. The tested hypotheses were: 1) infection with S. pneumoniae will change the pulmonary transcriptomes of both mouse strains 2) The pulmonary gene expression will be specific for mouse strains and for the pneumococcal serotype and 3) The change in the pulmonary gene expression will associate with future clinical outcome of infection or with the type of observed inflammatory responses.
Project description:Streptococcus pneumoniae is a frequent coloniser of the human nasopharynx and a major cause of life-threating invasive infections such as pneumonia, meningitis and sepsis. Over 1 million people die every year due to invasive pneumococcal disease (IPD), mainly in developing countries. Serotype 1 is a common cause of IPD; however, unlike other serotypes, it is rarely found in the carrier state in the nasopharynx, which is often considered a prerequisite for disease. The aim of this study was to understand this dichotomy. We used murine models of carriage and IPD to characterise the pathogenesis of African serotype 1 (Sequence Type 217) pneumococcal strains obtained from the Queen Elizabeth Central Hospital in Blantyre, Malawi. We found that ST217 pneumococcal strains were highly virulent in a mouse model of invasive pneumonia, but in contrast to the generally accepted assumption, can also successfully establish nasopharyngeal carriage. Interestingly, we found that co-colonising serotypes may proliferate in the presence of serotype 1, suggesting that acquisition of serotype 1 carriage could increase the risk of developing IPD by other serotypes. RNAseq analysis confirmed that key virulence genes associated with inflammation and tissue invasiveness were upregulated in serotype 1. These data reveal important new insights into serotype 1 pathogenesis, with implications for carriage potential and risk of invasive disease through interactions with other co-colonising serotypes; an often overlooked factor in transmission and disease progression.
Project description:Streptococcus pneumoniae colonization in the upper respiratory tract is linked to pneumococcal disease development, predominantly affecting young children and older adults. As the global population ages and comorbidities increase, there is a heightened concern about this infection. We investigated the immunological responses of older adults to pneumococcal controlled human infection by analysing the cellular composition and gene expression in the nasal mucosa. Our comparative analysis with data from a concurrent study in younger adults revealed distinct gene expression patterns in older individuals susceptible to colonization, highlighted by neutrophil activation and elevated levels of CXCL9 and CXCL10. Unlike younger adults challenged with pneumococcus, older adults did not show recruitment of monocytes into the nasal mucosa following nasal colonization. However, older adults who were protected from colonization showed increased degranulation of CD8+ T cells, both before and after pneumococcal challenge. These findings suggest age-associated cellular changes, in particular enhanced mucosal inflammation, that may predispose older adults to pneumococcal colonization.
Project description:Analysis of transcript abundance estimates as a function of child soldier status, PTSD symptoms, and psychological resilience. Gene expression profiling was conducted on dried blood spot (DBS) samples collected from community dwelling adolescents and young adults in Nepal. Approximatley half of the sample were former child soldiers in the Nepal People's War and the other half were demographically similiar civilian non-combatants. In addition to basic demographic characteristics (age, sex, ethnic minority status, social caste status, education level), participants were also assessed on syptoms of post-traumatic stress (PTS, assessed by a culturally adapted version of The Child PTSD Symptom Scale; Kohrt BA, et al. (2011) Validation of cross-cultural child mental health and psychosocial research instruments: adapting the Depression Self-Rating Scale and Child PTSD Symptom Scale in Nepal. BMC Psychiatry 11(1):e127, with higher values indicating greater PTSD symptoms) and psychological resilience (assessed by a culturally adapted version of the Resilience Scale; Wagnild GM & Young HM (1993) Development and psychometric evaluation of the Resilience Scale. Journal of Nursing Measurement, with higher values indicating greater resilience). Dichotomous variables were coded 0=no/absent and 1=yes/present. Valid gene expression data are available for 254 samples.
Project description:Background: Pneumococcal secondary infection following influenza A virus (IAV) pneumonia is a synergistic complication with high mortality. While varying invasiveness of pneumococcal serotypes is an important pathogenic factor, serotype-specifc immediate-early transcriptional responses of the IAV-perturbed alveolar epithelium have not been adressed. We comprehensively analyzed gene transcription in alveolar type II epithelial cells (AECII) isolated from mice infected with IAV and/or S. pneumoniae (S.pn.) serotypes 4, 7F and 19F. Results: IAV, 14 days post infection, rendered the lung susceptible to invasive secondary S.pn. infection with serotypes 4 and 7F but not 19F. Only secondary 7F infection induced exacerbated cytokine/chemokine responses. IAV/7F infection induced superior protein expression of type I and II interferons, acesserbated expression in IAV/serotype 4 infection. Inference of a scale-free-like ARACNE gene co-expression network revealed interferon-response network modules in AECII and network-mapping unfolded S.pn. serotype-specific transcriptional network responses/usage. Secondary S.pn. infection abrogated the IAV-induced pneumocyte proliferative configuration and preceeding IAV infection rendered the transcriptional response to 7F infection comparable to that towards serotype 4. This related especially to network genes correlating with the expression of two master regulators of interferon responses: Irf7 and Stat1. Epigenetic ATAC-seq analysis of AECII in resolved IAV infection identified enhanced expression of ARACNE network genes Hist1h2bf, Igtp, Mki67, Rasl10b, H2-Q6 and H2-Q7 to be associated with increased chromatin accessability at promoter regions. Conclusions: We show that AECII sustainably retain an IAV-associated transcriptional configuration with epigenetic involvement, that serotype-specifically affects proliferation and accelerates and enhances the AECII transcriptional response, mainly to interferons, in secondary S.pn. infection.
Project description:Typical enteropathogenic Escherichia coli (EPEC) O55:H7 is regarded as the closest relative of enterohemorrhagic E. coli (EHEC) O157:H7. Both serotypes usually express the γ1 intimin subclass and trigger actin polymerazation by the Tir-TccP pathway. However, atypical O55:H7 strains capable of triggering actin polymerization via the Tir-Nck pathway have recently been identified. In this study, we investigated the genotypic differences and phylogenetic relationships between typical and atypical O55:H7 strains. We show that the atypical O55:H7 strains, which express the θ intimin subclass and lack both tccP and tccP2, belong to an E. coli lineage distinct from the typical O55:H7 and from the EPEC O55:H6, which also uses the Tir-Nck actin polymerization pathway. We conducted genomic comparisons of the chromosomal regions covering the O-antigen gene cluster and its flanking regions between the three O55 lineages by restriction fragment length polymorphism analysis of PCR products and DNA sequencing analysis of about 65-kb chromosomal regions. This unexpectedly revealed that horizontal transfer of large fragments (⥠40 kb) encoding the O55-antigen gene cluster and part of neighboring colanic acid gene cluster is involved in the emergence of the three O55 E. coli lineages. The data provide new insights into the mechanisms involved in the generation of a wide variety of O-serotypes in Gram-negative bacteria. Keywords: comparative genomic hybridization Total 8 test samples were analyzed. Genomic DNA from each test strain and a reference strain (O157 Sakai) were labeled with Cy3 and Cy5, respectively, and were cohybridized on a single array. Labeling and hybridization were performed twice independently.