Project description:Mariana Esther Martinez-Sanchez, Luis Mendoza, Carlos Villarreal & Elena R. Alvarez-Buylla. A Minimal Regulatory Network of Extrinsic and Intrinsic Factors Recovers Observed Patterns of CD4+ T Cell Differentiation and Plasticity. PLOS Computational Biology 11, 6 (2015).
CD4+ T cells orchestrate the adaptive immune response in vertebrates. While both experimental and modeling work has been conducted to understand the molecular genetic mechanisms involved in CD4+ T cell responses and fate attainment, the dynamic role of intrinsic (produced by CD4+ T lymphocytes) versus extrinsic (produced by other cells) components remains unclear, and the mechanistic and dynamic understanding of the plastic responses of these cells remains incomplete. In this work, we studied a regulatory network for the core transcription factors involved in CD4+ T cell-fate attainment. We first show that this core is not sufficient to recover common CD4+ T phenotypes. We thus postulate a minimal Boolean regulatory network model derived from a larger and more comprehensive network that is based on experimental data. The minimal network integrates transcriptional regulation, signaling pathways and the micro-environment. This network model recovers reported configurations of most of the characterized cell types (Th0, Th1, Th2, Th17, Tfh, Th9, iTreg, and Foxp3-independent T regulatory cells). This transcriptional-signaling regulatory network is robust and recovers mutant configurations that have been reported experimentally. Additionally, this model recovers many of the plasticity patterns documented for different T CD4+ cell types, as summarized in a cell-fate map. We tested the effects of various micro-environments and transient perturbations on such transitions among CD4+ T cell types. Interestingly, most cell-fate transitions were induced by transient activations, with the opposite behavior associated with transient inhibitions. Finally, we used a novel methodology was used to establish that T-bet, TGF-β and suppressors of cytokine signaling proteins are keys to recovering observed CD4+ T cell plastic responses. In conclusion, the observed CD4+ T cell-types and transition patterns emerge from the feedback between the intrinsic or intracellular regulatory core and the micro-environment. We discuss the broader use of this approach for other plastic systems and possible therapeutic interventions.
Project description:Martinez-Sanchez2015 - T CD4+ lymphocyte
transcriptional-signaling regulatory network
This model is described in the article:
A Minimal Regulatory Network
of Extrinsic and Intrinsic Factors Recovers Observed Patterns
of CD4+ T Cell Differentiation and Plasticity.
Martinez-Sanchez ME, Mendoza L,
Villarreal C, Alvarez-Buylla ER.
PLoS Comput. Biol. 2015 Jun; 11(6):
e1004324
Abstract:
CD4+ T cells orchestrate the adaptive immune response in
vertebrates. While both experimental and modeling work has been
conducted to understand the molecular genetic mechanisms
involved in CD4+ T cell responses and fate attainment, the
dynamic role of intrinsic (produced by CD4+ T lymphocytes)
versus extrinsic (produced by other cells) components remains
unclear, and the mechanistic and dynamic understanding of the
plastic responses of these cells remains incomplete. In this
work, we studied a regulatory network for the core
transcription factors involved in CD4+ T cell-fate attainment.
We first show that this core is not sufficient to recover
common CD4+ T phenotypes. We thus postulate a minimal Boolean
regulatory network model derived from a larger and more
comprehensive network that is based on experimental data. The
minimal network integrates transcriptional regulation,
signaling pathways and the micro-environment. This network
model recovers reported configurations of most of the
characterized cell types (Th0, Th1, Th2, Th17, Tfh, Th9, iTreg,
and Foxp3-independent T regulatory cells). This
transcriptional-signaling regulatory network is robust and
recovers mutant configurations that have been reported
experimentally. Additionally, this model recovers many of the
plasticity patterns documented for different T CD4+ cell types,
as summarized in a cell-fate map. We tested the effects of
various micro-environments and transient perturbations on such
transitions among CD4+ T cell types. Interestingly, most
cell-fate transitions were induced by transient activations,
with the opposite behavior associated with transient
inhibitions. Finally, we used a novel methodology was used to
establish that T-bet, TGF-? and suppressors of cytokine
signaling proteins are keys to recovering observed CD4+ T cell
plastic responses. In conclusion, the observed CD4+ T
cell-types and transition patterns emerge from the feedback
between the intrinsic or intracellular regulatory core and the
micro-environment. We discuss the broader use of this approach
for other plastic systems and possible therapeutic
interventions.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000593.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Inoculation of endophyte-free (E-) Theobroma cacao leaves with Colletotrichum tropicale (E+), the dominant foliar fungal endophyte in healthy T. cacao, induced significant changes in the expression of hundreds of host genes. Further, E+ leaves exhibit enhanced pathogen resistance, increased lignin and cellulose content, reduced maximum rates of photosynthesis (Amax), and enrichment of nitrogen-15 and carbon-13 isotopes that all correspond to the changes in expression of specific functional genes in related pathways. Moreover, a cacao gene highly up-regulated in E+ leaves increases pathogen resistance apart from any direct endophyte effects. Thus, benefits of increased pathogen resistance in E+ plants are partially due to enhanced induction of intrinsic host defense pathways, and potential costs include reduced photosynthetic capacity and endophyte metabolism of host tissues. Similar effects are likely to be properties of most plant-endophyte interactions, suggesting general relevance to the design and interpretation of studies of genetic and phenotypic expression in plants. The objective of this experiment was to identify Theobroma cacao genes that are differentially expressed between leaves inoculated with fungal endophyte Colletotrichum tropicale (E+ leaves) and control un-inoculated leaves (E- leaves) 3 days post endophyte inoculation. The experiment was conducted in a Percival growth chamber (model I35LL, 115 volts, 1/4 Hp, series: 8503122.16, Percival Scientific, Inc., Perry IA) with 12/12 h light/dark photoperiod and temperatures of 30M-BM-:C and 26M-BM-:C respectively. Inoculation was done by aspersion of endophyte spores (2X10^6 spore/ml) to a group of T. cacao seedlings and a second group of seedlings were maintained as control un-inoculated (E- leaves). Then three biological replicates (each one consisting of one leaf from different plants) per treatment E+ and four leaves per treatment E- leaves) were collected and processed for a two color oligo microarray analysis.
Project description:Inoculation of endophyte-free (E-) Theobroma cacao leaves with Colletotrichum tropicale (E+), the dominant foliar fungal endophyte in healthy T. cacao, induced significant changes in the expression of hundreds of host genes. Further, E+ leaves exhibit enhanced pathogen resistance, increased lignin and cellulose content, reduced maximum rates of photosynthesis (Amax), and enrichment of nitrogen-15 and carbon-13 isotopes that all correspond to the changes in expression of specific functional genes in related pathways. Moreover, a cacao gene highly up-regulated in E+ leaves increases pathogen resistance apart from any direct endophyte effects. Thus, benefits of increased pathogen resistance in E+ plants are partially due to enhanced induction of intrinsic host defense pathways, and potential costs include reduced photosynthetic capacity and endophyte metabolism of host tissues. Similar effects are likely to be properties of most plant-endophyte interactions, suggesting general relevance to the design and interpretation of studies of genetic and phenotypic expression in plants.
Project description:Inoculation of endophyte-free (E-) Theobroma cacao leaves with Colletotrichum tropicale (E+), the dominant foliar fungal endophyte in healthy T. cacao, induced significant changes in the expression of hundreds of host genes. Further, E+ leaves exhibit enhanced pathogen resistance, increased lignin and cellulose content, reduced maximum rates of photosynthesis (Amax), and enrichment of nitrogen-15 and carbon-13 isotopes that all correspond to the changes in expression of specific functional genes in related pathways. Moreover, a cacao gene highly up-regulated in E+ leaves increases pathogen resistance apart from any direct endophyte effects. Thus, benefits of increased pathogen resistance in E+ plants are partially due to enhanced induction of intrinsic host defense pathways, and potential costs include reduced photosynthetic capacity and endophyte metabolism of host tissues. Similar effects are likely to be properties of most plant-endophyte interactions, suggesting general relevance to the design and interpretation of studies of genetic and phenotypic expression in plants.
Project description:Inoculation of endophyte-free (E-) Theobroma cacao leaves with Colletotrichum tropicale (E+), the dominant foliar fungal endophyte in healthy T. cacao, induced significant changes in the expression of hundreds of host genes. Further, E+ leaves exhibit enhanced pathogen resistance, increased lignin and cellulose content, reduced maximum rates of photosynthesis (Amax), and enrichment of nitrogen-15 and carbon-13 isotopes that all correspond to the changes in expression of specific functional genes in related pathways. Moreover, a cacao gene highly up-regulated in E+ leaves increases pathogen resistance apart from any direct endophyte effects. Thus, benefits of increased pathogen resistance in E+ plants are partially due to enhanced induction of intrinsic host defense pathways, and potential costs include reduced photosynthetic capacity and endophyte metabolism of host tissues. Similar effects are likely to be properties of most plant-endophyte interactions, suggesting general relevance to the design and interpretation of studies of genetic and phenotypic expression in plants.
Project description:Longissimus muscle samples were collected from lambs exposed in utero to mycotoxins (E-, endophyte-free tall fescue seed without ergot alkaloids or E+, endophyte-infected tall fescue seed containing ergot alkaloids) during mid-gestation (MID; E+/E-; N) or late-gestation (LATE; E-/E+; T) harvested at two developmental stages (FETAL, gestational d133) or (MKT, near maturity, 250 d of age). Muscle samples were examined to determine the impact of in utero mycotoxin exposure on skeletal muscle fiber hypertrophy and the miRNA transcriptome at FETAL and MKT.
Project description:Inoculation of endophyte-free (E-) Theobroma cacao leaves with Colletotrichum tropicale (E+), the dominant foliar fungal endophyte in healthy T. cacao, induced significant changes in the expression of hundreds of host genes. Further, E+ leaves exhibit enhanced pathogen resistance, increased lignin and cellulose content, reduced maximum rates of photosynthesis (Amax), and enrichment of nitrogen-15 and carbon-13 isotopes that all correspond to the changes in expression of specific functional genes in related pathways. Moreover, a cacao gene highly up-regulated in E+ leaves increases pathogen resistance apart from any direct endophyte effects. Thus, benefits of increased pathogen resistance in E+ plants are partially due to enhanced induction of intrinsic host defense pathways, and potential costs include reduced photosynthetic capacity and endophyte metabolism of host tissues. Similar effects are likely to be properties of most plant-endophyte interactions, suggesting general relevance to the design and interpretation of studies of genetic and phenotypic expression in plants. The objective of this experiment was to identify Theobroma cacao genes that are differentially expressed between leaves inoculated with fungal endophyte Colletotrichum tropicale (E+ leaves) and control un-inoculated leaves (E- leaves) 14 days post last endophyte inoculation. The experiment was conducted in a Percival growth chambers (model I35LL, 115 volts, 1/4 Hp, series: 8503122.16, Percival Scientific, Inc., Perry IA) with 12/12 h light/dark photoperiod and temperatures of 30M-BM-:C and 26M-BM-:C respectively. A total of four endophyte spore inoculations (1X10^6 spore/ml) were made by aspersion to a group of T. cacao seedlings and a second group of seedlings were maintained as un-inoculated. Then six biological replicates per treatment (E+ leaves and six E- leaves) each one belonging from a different seedling were collected and processed for a two color oligo microarray analysis. A total of six arrays were processed, each one hybridized to an inoculated and a control un-inoculated sample in a dye swap design.
Project description:Regulated host cell death is part of a plant defense strategy against pathogens but it is also involved in accommodating certain beneficial root microbes. We have identified extracellular metabolites and intracellular metabolic signals that contribute to beneficial root fungal endophyte colonization, and uncovered a conserved cell death mechanism likely co-opted for establishing plant-endophyte symbiosis.