scholarly journals Symbiont-induced odorant binding proteins mediate insect host hematopoiesis

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Joshua B Benoit ◽  
Aurélien Vigneron ◽  
Nichole A Broderick ◽  
Yineng Wu ◽  
Jennifer S Sun ◽  
...  

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.

Blood ◽  
2002 ◽  
Vol 99 (9) ◽  
pp. 3350-3359 ◽  
Author(s):  
Peter I. Chuang ◽  
Samantha Morefield ◽  
Chien-Ying Liu ◽  
Stephen Chen ◽  
John M. Harlan ◽  
...  

Abstract Decisions about cell survival or death are central components of adaptive immunity and occur at several levels in immune system development and function. The Bcl-2 family of homologous proteins plays an important role in these decisions in lymphoid cells. Bcl-2, Bcl-xL, and A1 are differentially expressed during B- and T-cell development, and they have shared and distinct roles in regulating cell death. We sought to gain insight into the role of A1 in immune system development and function. A murine A1-a transgene was expressed under the control of the Eμ enhancer, and mice with A1 overexpression in B- and T-cell lineages were derived. Thymocytes and early B cells in Eμ-A1 mice showed extended survival. B-lineage development was altered, with expansion of the pro–B cell subset at the expense of pre–B cells, suggesting an impairment of the pro– to pre–B-cell transition. This early B-cell phenotype resembled Eμ–Bcl-xL mice but did not preferentially rescue cells with completed V(D)J rearrangements of the immunoglobulin heavy chain. In contrast to Eμ–Bcl-2 transgenes, A1 expression in pro–B cells did not rescue pre–B-cell development in SCID mice. These studies indicate that A1 protects lymphocytes from apoptosis in vitro but that it has lineage- and stage-specific effects on lymphoid development. Comparison with the effects of Bcl-2 and Bcl-xL expressed under similar control elements supports the model that antiapoptotic Bcl-2 homologs interact differentially with intracellular pathways affecting development and apoptosis in lymphoid cells.


2021 ◽  
Vol 9 (2) ◽  
pp. 20
Author(s):  
Rwik Sen ◽  
Christopher Barnes

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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