Project description:Microbes are an integral component of the tumor microenvironment (TME). However, mechanisms that direct microbial recruitment into tumors and the spatial relationship between intratumoral microbes and host cells remain poorly understood. Here, we show that microbes and immune cells have parallel spatial distribution and that the presence of intratumoral microbes is dependent on T cells. Analysis of human pancreatic ductal adenocarcinomas (PDAC) and lung adenocarcinomas (LUAD) revealed a spatially heterogeneous distribution of lipopolysaccharide (LPS) that is associated with T cell infiltration. Using mouse models of PDAC, we found that microbes were more abundant and diverse in tumors that were enriched in T cells compared to tumors that lacked T cells, despite no significant differences in the fecal microbiome. Consistent with these findings, we detected elevated levels of microbial genes in T cell-enriched tumor nests in human PDAC. Compared to microbe-poor tumor nests, microbe-enriched tumor nests displayed a higher number of myeloid cells, B cells, and plasma cells. Microbe-enriched tumor nests also showed upregulation of immune-related processes, including responses to bacteria, and receptors that mediate mucosal immune responses to microbes. Administration of antibiotics to tumor-bearing mice altered the phenotype and presence of intratumoral myeloid cells and B cells but did not alter T cell infiltration. In contrast, depletion of T cells reduced the presence of intratumoral microbes. Our results identify a novel coupling between microbes and the intratumoral immune landscape, with T cells shaping microbial presence and subsequent microbial-host interactions.
Project description:Solid tumors are composed of cancer cells and host immune cells that are distributed in a non-uniform pattern. Although this spatial heterogeneity may reflect mutational variations in cancer cells, mechanisms that direct the recruitment of immune cells to distinct regions within a tumor remain poorly understood. Here, we show that microbial-host interactions define tumor nests enriched in immune cells, and the distribution of microbes within tumors parallels the spatial heterogeneity of intratumoral lymphoid and myeloid cell populations. Analysis of human solid tumors revealed that the spatial distribution of immune cells, particularly CD8+ T cells, is markedly heterogeneous. Compared to T cell-poor (“cold”) tumor nests, T cell-rich (“hot”) tumor nests displayed a significantly higher number of myeloid cells, B cells, and plasma cells. We performed laser capture microdissection (LCM) followed by RNA sequencing to identify unique gene signatures that define tumor epithelium and stroma of cold and hot tumor nests. Cold tumor nests expressed genes that promote tumor proliferation and fibrosis, whereas hot tumor stroma and epithelium showed upregulation of immune-related processes, including responses to bacteria, and receptors that mediate mucosal immune responses to microbes, respectively. Consistent with these findings, we detected elevated levels of microbes within hot tumor nests in human pancreatic and lung cancers. Our data implicate host immune responses to microbes in defining intratumoral immune heterogeneity and highlight a potential role for crosstalks between microbes, cancer cells, and the host immune system in regulating cancer immunogenicity.
Project description:Solid tumors are composed of cancer cells and host immune cells that are distributed in a non-uniform pattern. Although this spatial heterogeneity may reflect mutational variations in cancer cells, mechanisms that direct the recruitment of immune cells to distinct regions within a tumor remain poorly understood. Here, we show that microbial-host interactions define tumor nests enriched in immune cells, and the distribution of microbes within tumors parallels the spatial heterogeneity of intratumoral lymphoid and myeloid cell populations. Analysis of human solid tumors revealed that the spatial distribution of immune cells, particularly CD8+ T cells, is markedly heterogeneous. Compared to T cell-poor (“cold”) tumor nests, T cell-rich (“hot”) tumor nests displayed a significantly higher number of myeloid cells, B cells, and plasma cells. We performed laser capture microdissection (LCM) followed by RNA sequencing to identify unique gene signatures that define tumor epithelium and stroma of cold and hot tumor nests. Cold tumor nests expressed genes that promote tumor proliferation and fibrosis, whereas hot tumor stroma and epithelium showed upregulation of immune-related processes, including responses to bacteria, and receptors that mediate mucosal immune responses to microbes, respectively. Consistent with these findings, we detected elevated levels of microbes within hot tumor nests in human pancreatic and lung cancers. Our data implicate host immune responses to microbes in defining intratumoral immune heterogeneity and highlight a potential role for crosstalks between microbes, cancer cells, and the host immune system in regulating cancer immunogenicity.
Project description:Solid tumors are composed of cancer cells and host immune cells that are distributed in a non-uniform pattern. Although this spatial heterogeneity may reflect mutational variations in cancer cells, mechanisms that direct the recruitment of immune cells to distinct regions within a tumor remain poorly understood. Here, we show that microbial-host interactions define tumor nests enriched in immune cells, and the distribution of microbes within tumors parallels the spatial heterogeneity of intratumoral lymphoid and myeloid cell populations. Analysis of human solid tumors revealed that the spatial distribution of immune cells, particularly CD8+ T cells, is markedly heterogeneous. Compared to T cell-poor (“cold”) tumor nests, T cell-rich (“hot”) tumor nests displayed a significantly higher number of myeloid cells, B cells, and plasma cells. We performed laser capture microdissection (LCM) followed by RNA sequencing to identify unique gene signatures that define tumor epithelium and stroma of cold and hot tumor nests. Cold tumor nests expressed genes that promote tumor proliferation and fibrosis, whereas hot tumor stroma and epithelium showed upregulation of immune-related processes, including responses to bacteria, and receptors that mediate mucosal immune responses to microbes, respectively. Consistent with these findings, we detected elevated levels of microbes within hot tumor nests in human pancreatic and lung cancers. Our data implicate host immune responses to microbes in defining intratumoral immune heterogeneity and highlight a potential role for crosstalks between microbes, cancer cells, and the host immune system in regulating cancer immunogenicity.
Project description:The association between soil microbes and plant roots is present in all natural and agricultural environments. Microbes can be beneficial, pathogenic, or neutral to the host plant development and adaptation to abiotic or biotic stresses. Progress in investigating the functions and changes in microbial communities in diverse environments have been rapidly developing in recent years, but the changes in root function is still largely understudied. The aim of this study was to determine how soil bacteria influence maize root transcription and microRNAs (miRNAs) populations in a controlled inoculation of known microbes over a defined time course. At each time point after inoculation of the maize inbred line B73 with ten bacterial isolates, DNA and RNA were isolated from roots. The V4 region of the 16S rRNA gene was amplified from the DNA and sequenced with the Illumina MiSeq platform. Amplicon sequencing of the 16S rRNA gene indicated that most of the microbes successfully colonized maize roots. The colonization was dynamic over time and varied with the specific bacterial isolate. Small RNA sequencing and mRNA-Seq was done to capture changes in the root transcriptome from 0.5 to 480 hours after inoculation. The transcriptome and small RNA analyses revealed epigenetic and transcriptional changes in roots due to the microbial inoculation. This research provides the foundational data needed to understand how plant roots interact with bacterial partners and will be used to develop predictive models for root response to bacteria.
Project description:Solid tumors are composed of cancer cells and host immune cells that are distributed in a non-uniform pattern. Growing evidence shows that intratumoral microbes are associated with immune microenvironments in cancer. However, mechanisms that direct the recruitment of microbes to tumors remain poorly understood. Here, we show that intratumoral infiltration of immune cells and microbes are heterogeneous, and the distribution of microbes within tumors are orchestrated by the spatial heterogeneity of intratumoral lymphoid populations. Analysis of human solid tumors revealed that the spatial distribution of immune cells, particularly CD8+ T cells, is markedly heterogeneous. Compared to T cell-poor (“cold”) tumor nests, T cell-rich (“hot”) tumor nests displayed a significantly higher number of myeloid cells, B cells, and plasma cells. We performed laser capture microdissection (LCM) followed by RNA sequencing to identify unique gene signatures that define tumor epithelium and stroma of cold and hot tumor nests. Cold tumor nests expressed genes that promote tumor proliferation and fibrosis, whereas hot tumor stroma and epithelium showed upregulation of immune-related processes, including responses to bacteria, and receptors that mediate mucosal immune responses to microbes, respectively. Consistent with these findings, we detected elevated levels of microbes within hot tumor nests in human pancreatic and lung cancers as well as in mouse models of pancreatic cancer. Intratumoral T cell infiltration plays a causal role in spatial distribution of bacteria in tumor. Our data implicate intratumoral immune heterogeneity in defining microbial spatial distribution and highlight a potential role for crosstalks between microbes, cancer cells, and the host immune system in shaping constituents of the tumor microenvironment (TME).
Project description:The transition to parasitism is a drastic shift in lifestyle, involving rapid changes in gene structure, function, and expression. Evolutionarily 'young' parasites are ideal models for the elucidation of the early steps of this transition. After the establishment of an antagonistic relationship, parasite and host co-evolve through reciprocal adaptations resulting in an evolutionary arms-race. Repeated evolution of social parasitism and slavery among Temnothorax ants allows us to examine gene expression patterns characterizing slavemaker raiding and reciprocal host defensive behavior. Previous studies of Temnothorax provide evidence for co-evolving adaptations between parasites and hosts, as well as diverging raiding strategies between slavemakers. However, under parasite pressure, host defense portfolios shift similarly, suggesting diverging evolution of defensive traits. Through comparative gene expression analyses, we find that slavemaker raiding behavior is characterized by a down-regulation of numerous genes relative to their non-raiding state. Moreover, only a small number of genes shared expression between slavemaking species. In contrast, hosts possess a higher ratio of commonly-to-privately over-expressed genes and metabolic pathways during raids, suggesting that genes of similar function control defensive behavior. Additionally, a number of candidate genes were identified, each potentially playing a major role in shaping slavemaker- and host-specific behaviors. Finally, in two slavemaking species, functional enrichment analyses indicate that genes over-expressed during raiding behavior are associated with ribosomal structure, oxidation-reduction, and metabolic processes. Overall, our analysis revealed evidence for divergent evolution among closely-related ant species, where species-specific gene expression characterize raiding and defensive behavior.
Project description:The composition of the resident microbiota changes and diversifies as its host develops. Enrichment of specific taxa early in life is important for immune system development and maturation, but the impact of early life commensals on other host developmental processes is little studied. Here, we describe a critical window of postnatal life when specific microbes are necessary to establish an adequate supply of insulin-producing tissue for lifelong metabolic homeostasis of the host.
Project description:This study examines the role of early exposure to gut microbes and poor diet on microglial function in mice. Groups = control (CON), malnourished (MAL), and malnourished + microbial exposure (E/MALBG). CD11b+ cells (microglial enrichment) were isolated from whole mouse brains (Adult Brain Disruption Kit, Miltenyi Biotec). After sample quality control (Agilent 2100 Bioanalyzer), qualifying samples were sent for RNA-Seq (Illumina NextSeq 500 with Paired End 42bp × 42bp reads; demultiplexed: Illumina's bcl2fastq2). Following alignment against mouse reference genes (STAR aligner), DEG analyses was conducted using the DESeq2 pipeline.