Red blood cells are produced by terminal erythroid differentiation, which involves the dramatic morphological transformation of erythroblasts into enucleated reticulocytes. Microtubules are important for enucleation, but it is not known if the centrosome, a key microtubule-organizing center, is required as well. Mice lacking the conserved centrosome component, CDK5RAP2, are likely to have defective erythroid differentiation because they develop macrocytic anemia. Here, we show that fetal liver-derived, CDK5RAP2-deficient erythroid progenitors generate fewer and larger reticulocytes, hence recapitulating features of macrocytic anemia. In erythroblasts, but not in embryonic fibroblasts, loss of CDK5RAP2 or pharmacological depletion of centrosomes leads to highly aberrant spindle morphologies. Consistent with such cells exiting mitosis without chromosome segregation, tetraploidy is frequent in late-stage erythroblasts, thereby giving rise to fewer but larger reticulocytes than normal. Our results define a critical role for CDK5RAP2 and centrosomes in spindle formation specifically during blood production. We propose that disruption of centrosome and spindle function could contribute to the emergence of macrocytic anemias, for instance, due to nutritional deficiency or exposure to chemotherapy.
© 2022 The Authors. Published under the terms of the CC BY 4.0 license.

Alterations in intestinal MUC2 mucin and microbial diversity are closely linked with important intestinal pathologies; however, their impact on each other and on intestinal pathogenesis has been vaguely characterized. Therefore, it was of interest in this study to delineate distinct and cooperative function of commensal microbiota and the Muc2 mucus barrier in maintaining intestinal epithelial barrier function.
Muc2 mucin deficient (Muc2-/-) and sufficient (Muc2+/+) littermates were used as a model for assessing the role of Muc2. To quantify the role of the microbiota in disease pathogenesis, Muc2+/+ and Muc2-/- littermates were treated with a cocktail of antibiotics that reduced indigenous bacteria, and then fecal transplanted with littermate stool and susceptibility to dextran sulphate sodium (DSS) quantified.
Although, Muc2+/+ and Muc2-/- littermates share similar phyla distribution as evidenced by 16S sequencing they maintain their distinctive gastrointestinal phenotypes. Basally, Muc2-/- showed low-grade colonic inflammation with high populations of inflammatory and tolerogenic immune cells that became comparable to Muc2+/+ littermates following antibiotic treatment. Antibiotics treatment rendered Muc2+/+ but not Muc2-/- littermates highly susceptibility to DSS-induced colitis that was ILC3 dependent. Muc2-/- microbiota was colitogenic to Muc2+/+ as it worsened DSS-induced colitis. Microbiota dependent inflammation was confirmed by bone-marrow chimera studies, as Muc2-/- receiving Muc2+/+ bone marrow showed no difference in their susceptibility toward DSS induced colitis. Muc2-/- microbiota exhibited presence of characteristic OTUs of specific bacterial populations that were transferrable to Muc2+/+ littermates.
These results highlight a distinct role for Muc2 mucin in maintenance of healthy microbiota critical in shaping innate host defenses to promote intestinal homeostasis.
Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

The incidence of oral cancer in the United States is increasing, especially in young people and women. Patients with oral cancer report severe functional pain. Using a patient cohort accrued through the New York University Oral Cancer Center and immune-competent mouse models, we identify a sex difference in the prevalence and severity of oral cancer pain. A neutrophil-mediated endogenous analgesic mechanism is present in male mice with oral cancer. Local naloxone treatment potentiates cancer mediator-induced orofacial nociceptive behavior in male mice only. Tongues from male mice with oral cancer have significantly more infiltrating neutrophils compared to female mice with oral cancer. Neutrophils isolated from the cancer-induced inflammatory microenvironment express beta-endorphin and met-enkephalin. Furthermore, neutrophil depletion results in nociceptive behavior in male mice. These data suggest a role for sex-specific, immune cell-mediated endogenous analgesia in the treatment of oral cancer pain.

The relation between B2 cells and commensal microbes during atherosclerosis remains largely unexplored. Here we show that under hyperlipidemic conditions intestinal microbiota resulted in recruitment and ectopic activation of B2 cells in perivascular adipose tissue, followed by an increase in circulating IgG, promoting disease development. In contrast, disruption of the intestinal microbiota by a broad-spectrum antibiotic cocktail (AVNM) led to the attenuation of atherosclerosis by suppressing B2 cells, despite the persistence of serum lipid abnormalities. Furthermore, pharmacological depletion of B2 cells with an anti-B2-cell surface CD23 antibody also attenuated commensal microbe-induced atherosclerosis. Moreover, expression analysis of TLR-signaling-related genes in the activated B2 cell subsets, assessed using the Toll-Like Receptor Signaling Pathway RT2 Profiler PCR Array, confirmed activation of the B2-cell autoantibody-production axis, which was associated with an increased capacity of B2 cells to bind to intestinal microbiota. Together, our findings reveal the critical role of commensal microbe-specific activation of B2 cells in the development of atherogenesis through lipid metabolism-independent mechanisms.
Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Antibodies are critical for defense against a variety of microbes, but they may also be pathogenic in some autoimmune diseases. Many effector functions of antibodies are mediated by Fcγ receptors (FcγRs), which are found on most immune cells, including dendritic cells (DCs)-important antigen-presenting cells that play a central role in inducing antigen-specific tolerance or immunity. Following antigen acquisition in peripheral tissues, DCs migrate to draining lymph nodes via the lymphatics to present antigen to T cells. Here we demonstrate that FcγR engagement by IgG immune complexes (ICs) stimulates DC migration from peripheral tissues to the paracortex of draining lymph nodes. In vitro, IC-stimulated mouse and human DCs showed greater directional migration in a chemokine (C-C) ligand 19 (CCL19) gradient and increased chemokine (C-C) receptor 7 (CCR7) expression. Using intravital two-photon microscopy, we observed that local administration of IC resulted in dermal DC mobilization. We confirmed that dermal DC migration to lymph nodes depended on CCR7 and increased in the absence of the inhibitory receptor FcγRIIB. These observations have relevance to autoimmunity because autoantibody-containing serum from humans with systemic lupus erythematosus (SLE) and from a mouse model of SLE also increased dermal DC migration in vivo, suggesting that this process may occur in lupus, potentially driving the inappropriate localization of autoantigen-bearing DCs.