Special Issue: The Immune System in Development and Regeneration
Summary: Intestinal organoid co-cultures with immune cells are meeting their potential as a robust tool for modelling the bi-directional interactions between epithelial and immune cells in mediating development and regeneration.
Summary: This Spotlight discusses non-traditional roles of immune and non-immune-like cells, and their interactions with other cells to carry out functions during tissue repair and homeostasis.
DEVELOPMENT AT A GLANCE
Summary: This Meeting Review summarizes the recent findings presented at the recent symposium ‘Stem Cells & the Immune System: At the Crossroads of Regeneration’ held on 3rd November 2021.
Summary: This Review summarizes the crucial role of microglia – brain-specific, yolk sac-derived macrophages – in neural development, highlighting temporal and spatial heterogeneity in their interactions with neuronal and non-neuronal cells to support brain development and regeneration.
Summary: This Review summarizes recent developments in our understanding of the embryonic origin of osteoclasts and their interactions with the immune environment, highlighting their role in the regulation of normal and pathological bone development, homeostasis and repair.
Summary: This Review summarises the array of signals that influence regenerative neurogenesis in the central nervous system of zebrafish, indicating possible avenues for activation of similar signalling pathways in non-regenerating mammals.
Derivation of extra-embryonic and intra-embryonic macrophage lineages from human pluripotent stem cells
Summary: Generation of intra-embryonic-like and extra-embryonic-like macrophages from human pluripotent stem cells reveals intrinsic differences in macrophages generated through distinct hematopoietic pathways.
Summary: Mass cytometry is used to identify a complex and diverse immune profile in the healthy mid-gestation human placenta at single-cell resolution.
Summary: This study provides versatile tools for the isolation, phenotyping and expansion of human fetal skin T cells, enabling the study of their complexity and heterogeneity allowing new research in skin development and immunity.
STEM CELLS AND REGENERATION
Avian auditory hair cell regeneration is accompanied by JAK/STAT-dependent expression of immune-related genes in supporting cells
Summary: Gene expression changes in the facultative stem cells of the avian inner ear after ototoxic drug-induced hair cell loss in vivo.
MyD88-dependent TLR signaling oppositely regulates hematopoietic progenitor and stem cell formation in the embryo
Summary: Toll-like receptor signaling in endothelial cells restricts the number of hematopoietic stem cells but increases the number of committed progenitors and intra-arterial hematopoietic cluster cells, and promotes their proliferation.
IL7Rα, but not Flk2, is required for hematopoietic stem cell reconstitution of tissue-resident lymphoid cells
Summary: Tissue-resident lymphoid cells develop via IL7Rα-positive progenitors and are repopulated by transplanted adult hematopoietic stem cells; however, such TLC lymphopoiesis cannot be fully rescued in IL7Rα−/− recipient mice.
Toll signalling promotes blastema cell proliferation during cricket leg regeneration via insect macrophages
Summary: Toll2-2, one of 11 Toll-related receptors expressed in insect macrophages, induces cytokine expression and promotes cell proliferation during Gryllus bimaculatus leg regeneration.
Selective Cdk9 inhibition resolves neutrophilic inflammation and enhances cardiac regeneration in larval zebrafish
Summary: This study is the first to show that resolving neutrophilic inflammation using a clinically approved immunomodulatory drug (AT7519) improves heart regeneration in zebrafish.
Summary: Feto-placental macrophages called Hofbauer cells are functionally distinct from maternal placenta macrophages, originate from yolk-sac erythro-myeloid progenitors and are controlled by Pu.1 in a dose-dependent manner.
Elevated numbers of infiltrating eosinophils accelerate the progression of Duchenne muscular dystrophy pathology in mdx mice
Summary: Hyper-eosinophilia has an adverse effect on muscle repair, resulting in strong collagen deposition and eventually death, and could be a marker of poor outcomes in Duchenne muscular dystrophy.
Retinal ganglion cell survival after severe optic nerve injury is modulated by crosstalk between Jak/Stat signaling and innate immune responses in the zebrafish retina
Summary: Jak/Stat pathway activity mediates crosstalk between macrophages/microglia and retinal ganglion cells to regulate retinal ganglion cell survival after injury in zebrafish.
Laser-mediated osteoblast ablation triggers a pro-osteogenic inflammatory response regulated by reactive oxygen species and glucocorticoid signaling in zebrafish
Summary: Laser-mediated osteoblast ablation induces recruitment of tissue-resident macrophages, which are required for osteoblasts to repopulate the lesion site, through glucocorticoid signaling and by a release of reactive oxygen species.
The immune environment of the mammary gland fluctuates during post-lactational regression and correlates with tumour growth rate
Summary: Mammary gland involution is associated with dynamic changes in immune cell types and numbers at different stages that correlates with the initial rate of growth of implanted tumour cells.
Summary: Cellular reprogramming is inefficient in vivo partly because natural killer (NK) cells eliminate cells undergoing reprogramming; transient depletion of NK cells facilitates reprogramming and the emergence of cells with high organoid-formation capacity, which could be important for tissue repair applications.
A kinase-dead Csf1r mutation associated with adult-onset leukoencephalopathy has a dominant inhibitory impact on CSF1R signalling
Summary:Csf1r mutation negatively impacts CSF1R signalling in postnatal development and growth factor responsiveness of macrophage-lineage cells in mice, mirroring the phenotype of adult-onset leukoencephalopathy associated with dominant human CSF1R mutations.
Blood progenitor redox homeostasis through olfaction-derived systemic GABA in hematopoietic growth control in Drosophila
Summary: Ablation of olfactory receptor neurons reveals that odor-sensing and GABA are involved in myeloid reactive oxygen species regulation and hematopoietic growth control.
Summary: The expression of MyD88 and IL10 in B cells is essential for appropriate in utero development and protects against LPS-induced preterm birth.