Model systems to analyze the role of miRNAs and commensal microflora in bovine mucosal immune system development

Epigenetic modifications regulate gene expression for development, immune response, disease, and other processes. A major role of epigenetics is to control the dynamics of chromatin structure, i.e., the condensed packaging of DNA around histone proteins in eukaryotic nuclei. Key epigenetic factors include enzymes for histone modifications and DNA methylation, non-coding RNAs, and prions. Epigenetic modifications are heritable but during embryonic development, most parental epigenetic marks are erased and reset. Interestingly, some epigenetic modifications, that may be resulting from immune response to stimuli, can escape remodeling and transmit to subsequent generations who are not exposed to those stimuli. This phenomenon is called transgenerational epigenetic inheritance if the epigenetic phenotype persists beyond the third generation in female germlines and second generation in male germlines. Although its primary function is likely immune response for survival, its role in the development and functioning of the immune system is not extensively explored, despite studies reporting transgenerational inheritance of stress-induced epigenetic modifications resulting in immune disorders. Hence, this review draws from studies on transgenerational epigenetic inheritance, immune system development and function, high-throughput epigenetics tools to study those phenomena, and relevant clinical trials, to focus on their significance and deeper understanding for future research, therapeutic developments, and various applications.

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Commensal microbiome effects on mucosal immune system development in the ruminant gastrointestinal tract

Animal Health Research Reviews ◽

10.1017/s1466252312000096 ◽

2012 ◽

Vol 13 (1) ◽

pp. 129-141 ◽

Cited By ~ 43

Author(s):

Ryan Taschuk ◽

Philip J Griebel

Keyword(s):

Immune System ◽

Gastrointestinal Tract ◽

Regional Differences ◽

System Development ◽

Mucosal Immune System ◽

Host Interactions ◽

Susceptibility To Infection ◽

Commensal Flora ◽

Mucosal Surfaces ◽

Immune System Development

AbstractCommensal microflora play many roles within the mammalian gastrointestinal tract (GIT) that benefit host physiology by way of direct or indirect interactions with mucosal surfaces. Commensal flora comprises members across all microbial phyla, although predominantly bacterial, with population dynamics varying with host species, genotype, and environmental factors. Little is known, however, about the complex mechanisms regulating host–commensal interactions that underlie this mutually beneficial relationship and how alterations in the microbiome may influence host development and susceptibility to infection. Research into the gut microbiome has intensified as it becomes increasingly evident that symbiont–host interactions have a significant impact on mucosal immunity and health. Furthermore, evidence that microbial populations vary significantly throughout the GIT suggest that regional differences in the microbiome may also influence immune function within distinct compartments of the GIT. Postpartum colonization of the GIT has been shown to have a direct effect on mucosal immune system development, but information is limited regarding regional effects of the microbiome on the development, activation, and maturation of the mucosal immune system. This review discusses factors influencing the colonization and establishment of the microbiome throughout the GIT of newborn calves and the evidence that regional differences in the microbiome influence mucosal immune system development and maturation. The implications of this complex interaction are also discussed in terms of possible effects on responses to enteric pathogens and vaccines.

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Symbiont-induced odorant binding proteins mediate insect host hematopoiesis

eLife ◽

10.7554/elife.19535 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 48

Author(s):

Joshua B Benoit ◽

Aurélien Vigneron ◽

Nichole A Broderick ◽

Yineng Wu ◽

Jennifer S Sun ◽

...

Keyword(s):

Immune System ◽

Molecular Mechanisms ◽

System Development ◽

Model Systems ◽

Tsetse Flies ◽

Immune System Development ◽

Indigenous Microbiota ◽

And Function ◽

Necessary And Sufficient ◽

Odorant Binding

Symbiotic bacteria assist in maintaining homeostasis of the animal immune system. However, the molecular mechanisms that underlie symbiont-mediated host immunity are largely unknown. Tsetse flies (Glossina spp.) house maternally transmitted symbionts that regulate the development and function of their host’s immune system. Herein we demonstrate that the obligate mutualist, Wigglesworthia, up-regulates expression of odorant binding protein six in the gut of intrauterine tsetse larvae. This process is necessary and sufficient to induce systemic expression of the hematopoietic RUNX transcription factor lozenge and the subsequent production of crystal cells, which actuate the melanotic immune response in adult tsetse. Larval Drosophila’s indigenous microbiota, which is acquired from the environment, regulates an orthologous hematopoietic pathway in their host. These findings provide insight into the molecular mechanisms that underlie enteric symbiont-stimulated systemic immune system development, and indicate that these processes are evolutionarily conserved despite the divergent nature of host-symbiont interactions in these model systems.

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