Howard G. Smith MD, AM on Instagram: "Obesity Cripples Anti-Bacterial Immunity Obesity due to consistent ingestion of a high-fat diet limits that ability of your white blood cells to effectively fight bacterial infections. Pediatric researchers at the University of Michigan studied this phenomenon in a mouse model and now report their findings in The Journal of Immunology. Obesity was induced with a sustained, 16 week, high fat diet. The bacteria-fighting lymphocytes, so-called neutrophils, generated by these obese mice produce diminished bactericidal secretions, are less capable of ingesting or phagocytosing these pathogens, and lack normal regenerative capabilities in comparison to those neutrophils found in control mice with normal weights. This study adds yet another reason for obese persons to cut out fats in their diets and normalize their body weights. Besides reducing the risk of heart attacks and alleviating the burdens their joints and backs must bear, they will repower their immune systems to protect them against serious and often life-threatening bacterial disease. https://academic.oup.com/jimmunol/advance-article/doi/10.1093/jimmun/vkaf024/8081674 #obesity #fattydiet #bacteria #immunity #neutrophils #phagocytosis"

0 likes, 0 comments - drhowardsmithreports on April 2, 2025: "Obesity Cripples Anti-Bacterial Immunity Obesity due to consistent ingestion of a high-fat diet limits that ability of your white blood cells to effectively fight bacterial infections. Pediatric researchers at the University of Michigan studied this phenomenon in a mouse model and now report their findings in The Journal of Immunology. Obesity was induced with a sustained, 16 week, high fat diet. The bacteria-fighting lymphocytes, so-called neutrophils, generated by these obese mice produce diminished bactericidal secretions, are less capable of ingesting or phagocytosing these pathogens, and lack normal regenerative capabilities in comparison to those neutrophils found in control mice with normal weights. This study adds yet another reason for obese persons to cut out fats in their diets and normalize their body weights. Besides reducing the risk of heart attacks and alleviating the burdens their joints and backs must bear, they will repower their immune systems to protect them against serious and often life-threatening bacterial disease. https://academic.oup.com/jimmunol/advance-article/doi/10.1093/jimmun/vkaf024/8081674 #obesity #fattydiet #bacteria #immunity #neutrophils #phagocytosis".

Movie - Neutrophil chasing bacteria - Embryology

Study finds widespread 'cell cannibalism' and related phenomena across tree of life

In a new review paper, Carlo Maley and Arizona State University colleagues describe cell-in-cell phenomena in which one cell engulfs and sometimes consumes another. The study shows that cases of this behavior, including cell cannibalism, are widespread across the tree of life.

Identification of methylation-regulated genes modulating microglial phagocytosis in hyperhomocysteinemia-exacerbated Alzheimer’s disease - Alzheimer's Research & Therapy

Background Hyperhomocysteinemia (HHcy) has been linked to development of Alzheimer’s disease (AD) neuropathologically characterized by the accumulation of amyloid β (Aβ). Microglia (MG) play a crucial role in uptake of Aβ fibrils, and its dysfunction worsens AD. However, the effect of HHcy on MG Aβ phagocytosis remains unstudied. Methods We isolated MG from the cerebrum of HHcy mice with genetic cystathionine-β-synthase deficiency (Cbs−/−) and performed bulk RNA-seq. We performed meta-analysis over transcriptomes of Cbs−/− mouse MG, human and mouse AD MG, MG Aβ phagocytosis model, human AD methylome, and GWAS AD genes. Results HHcy and hypomethylation conditions were identified in Cbs−/− mice. Through Cbs−/− MG transcriptome analysis, 353 MG DEGs were identified. Phagosome formation and integrin signaling pathways were found suppressed in Cbs−/− MG. By analyzing MG transcriptomes from 4 AD patient and 7 mouse AD datasets, 409 human and 777 mouse AD MG DEGs were identified, of which 37 were found common in both species. Through further combinatory analysis with transcriptome from MG Aβ phagocytosis model, we identified 130 functional-validated Aβ phagocytic AD MG DEGs (20 in human AD, 110 in mouse AD), which reflected a compensatory activation of Aβ phagocytosis. Interestingly, we identified 14 human Aβ phagocytic AD MG DEGs which represented impaired MG Aβ phagocytosis in human AD. Finally, through a cascade of meta-analysis of transcriptome of AD MG, functional phagocytosis, HHcy MG, and human AD brain methylome dataset, we identified 5 HHcy-suppressed phagocytic AD MG DEGs (Flt1, Calponin 3, Igf1, Cacna2d4, and Celsr) which were reported to regulate MG/MΦ migration and Aβ phagocytosis. Conclusions We established molecular signatures for a compensatory response of Aβ phagocytosis activation in human and mouse AD MG and impaired Aβ phagocytosis in human AD MG. Our discoveries suggested that hypomethylation may modulate HHcy-suppressed MG Aβ phagocytosis in AD.

Phagocytosis

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Samuel Lab

Large vesicle extrusions from C. elegans neurons are consumed and stimulated by glial-like phagocytosis activity of the neighboring cell

Giant neuron derived vesicles called exophers are processed by phagocytosis in neighboring skin cells, and the phagocytic interaction promotes exopher production.

MafB-restricted local monocyte proliferation precedes lung interstitial macrophage differentiation - Nature Immunology

Marichal and colleagues use a model of niche depletion and refilling to show that engrafted Ly6C+ classical monocytes proliferate locally in a Csf1 receptor-dependent manner before differentiating into lung interstitial macrophages.