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PloS One 2021Homotypic or heterotypic internalization of another, either living or necrotic cell is currently in the center of research interest. The active invasion of a living cell...
Homotypic or heterotypic internalization of another, either living or necrotic cell is currently in the center of research interest. The active invasion of a living cell called entosis and cannibalism of cells by rapidly proliferating cancers are prominent examples. Additionally, normal healthy tissue cells are capable of non-professional phagocytosis. This project studied the relationship between non-professional phagocytosis, individual proliferation and cell cycle progression. Three mesenchymal and two epithelial normal tissue cell lines were studied for homotypic non-professional phagocytosis. Homotypic dead cells were co-incubated with adherent growing living cell layers. Living cells were synchronized by mitotic shake-off as well as Aphidicolin-treatment and phagocytotic activity was analyzed by immunostaining. Cell cycle phases were evaluated by flow cytometry. Mesenchymal and epithelial normal tissue cells were capable of internalizing dead cells. Epithelial cells had much higher non-professional phagocytotic rates than mesenchymal cells. Cells throughout the entire cell cycle were able to phagocytose. The phagocytotic rate significantly increased with progressing cell cycle phases. Mitotic cells regularly phagocytosed dead cells, this was verified by Nocodazole and Colcemid treatment. Taken together, our findings indicate the ability of human tissue cells to phagocytose necrotic neighboring cells in confluent cell layers. The origin of the cell line influences the rate of cell-in-cell structure formation. The higher cell-in-cell structure rates during cell cycle progression might be influenced by cytoskeletal reorganization during this period or indicate an evolutionary anchorage of the process. Recycling of nutrients during cell growth might also be an explanation.
Topics: Cell Cycle; Cell Division; Cell Line; Entosis; Epithelial Cells; Humans; Mesenchymal Stem Cells; Neoplasms; Phagocytosis
PubMed: 33544774
DOI: 10.1371/journal.pone.0246402 -
Microbial Pathogenesis Aug 2023Candida tropicalis is among the most prevalent human pathogenic yeast species. Switch states of C. tropicalis differ in virulence traits. Here, we evaluate the effect of...
BACKGROUND AND OBJECTIVE
Candida tropicalis is among the most prevalent human pathogenic yeast species. Switch states of C. tropicalis differ in virulence traits. Here, we evaluate the effect of phenotypic switching on phagocytosis and yeast-hyphae transition in C. tropicalis.
METHODS
C. tropicalis morphotypes included a clinical strain and two switch strains (rough variant and rough revertant). In vitro, phagocytosis assay was performed using peritoneal macrophages and hemocytes. The proportion of hyphal cells was ascertained by scoring morphology using optical microscopy. Expression of the WOR1 (White-opaque regulator 1) and EFG1 (Enhanced filamentous growth protein 1) was determined by quantitative PCR.
RESULTS
The rough variant was more resistant to in vitro phagocytosis by peritoneal macrophages than that observed for the clinical strain, while hemocytes phagocytosed clinical and rough variant to the same extent. The rough revertant was more phagocytosed than the clinical strain by both phagocytes. During co-incubation with phagocytic cells, the clinical strain of C. tropicalis exists mainly as blastoconidia. The co-culture of the rough variant with macrophages resulted in a higher percentage of hyphae than blastoconidia cells, while in co-culture with hemocytes, no differences were observed between the percentage of hyphae and blastoconidia. The expression levels of WOR1 in the rough variant co-cultured with phagocytes were significantly higher than they were in the clinical strain.
CONCLUSIONS
Differences on phagocytosis and hyphal growth between switch states cells of C. tropicalis co-cultured with phagocytic cells were observed. The pronounced hyphal growth may affect the complex host-pathogen relationship and favor the pathogen to escape phagocytosis. The pleiotropic effects of phenotypic switching suggest that this event may contribute to the success of infection associated with C. tropicalis.
Topics: Humans; Candida tropicalis; Coculture Techniques; Phagocytosis; Macrophages, Peritoneal; Morphogenesis; Candida albicans
PubMed: 37269878
DOI: 10.1016/j.micpath.2023.106186 -
American Journal of Physiology. Cell... Jul 2018Chitin particles have been used to understand host response to chitin-containing pathogens and allergens and are known to induce a wide range of polarized macrophage...
Chitin particles have been used to understand host response to chitin-containing pathogens and allergens and are known to induce a wide range of polarized macrophage activations, depending, at least in part, on particle size. Nonphagocytosable particles larger than a macrophage induce tissue repair M2 activation. In contrast, phagocytosable chitin microparticles (CMPs, 1-10 μm diameters) induce M1 macrophages that kill intracellular microbes and damage tissues. However, chitosan (deacetylated) microparticles (de-CMPs, 1-10 µm) induce poor M1 activation. Toll-like receptor 2 (TLR2) and associated coreceptors in macrophages appear to be required for the M1 activation. To understand the exact mechanism of phagocytosis-mediated M1 activation by chitin, we isolated macrophage proteins that bind to CMPs during early phagocytosis and determined that TLR1, TLR2, CD14, late endosomal/lysosomal adaptor MAPK and mechanistic target of rapamycin activator 1 (LAMTOR1), Lck/Yes novel tyrosine kinase (Lyn), and β-actin formed phagosomal CMP-TLR2 clusters. These proteins were also detected in TLR2 phagosomal clusters in macrophages phagocytosing de-CMPs, but at relatively lower levels than in the CMP-TLR2 clusters. Importantly, CMP-TLR2 clusters further recruited myeloid differentiation primary response gene 88 (MyD88) and Toll-IL-1 receptor-containing adaptor protein (TIRAP) and phosphorylated Lyn, whereas neither the adaptors nor phosphorylated Lyn was detected in the de-CMP clusters. The results indicate that the acetyl group played an obligatory, phagocytosis-dependent role in the initiation of an integrated signal for TLR2-mediated M1 activation.
Topics: Adaptor Proteins, Signal Transducing; Animals; Cell Differentiation; Chitin; Chitosan; Macrophage Activation; Macrophages; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Myeloid Differentiation Factor 88; Phagocytosis; Phosphorylation; Protein-Tyrosine Kinases; Toll-Like Receptor 2
PubMed: 29719169
DOI: 10.1152/ajpcell.00268.2017 -
Journal of Controlled Release :... Mar 2022Humans are exposed to numerous synthetic foreign particles in the form of drug delivery systems and diagnostic agents. Specialized immune cells (phagocytes) clear these...
Humans are exposed to numerous synthetic foreign particles in the form of drug delivery systems and diagnostic agents. Specialized immune cells (phagocytes) clear these particles by phagocytosing and attempting to degrade them. The process of recognition and internalization of the particles may trigger changes in the function of phagocytes. Some of these changes, especially the ability of a particle-loaded phagocyte to take up and neutralize pathogens, remains poorly studied. Herein, we demonstrate that the uptake of non-stimulatory cargo-free particles enhances the phagocytic ability of monocytes, macrophages and neutrophils. The enhancement in phagocytic ability was independent of particle properties, such as size or the base material constituting the particle. Additionally, we show that the increased phagocytosis was not a result of cellular activation or cellular heterogeneity but was driven by changes in cell membrane fluidity and cellular compliance. A consequence of the enhanced phagocytic activity was that particulate-laden immune cells neutralize Escherichia coli (E. coli) faster in culture. Moreover, when administered in mice as a prophylactic, particulates enable faster clearance of E. coli and Staphylococcus epidermidis. Together, we demonstrate that the process of uptake induces cellular changes that favor additional phagocytic events. This study provides insights into using non-stimulatory cargo-free particles to engineer immune cell functions for applications involving faster clearance of phagocytosable abiotic and biotic material.
Topics: Animals; Escherichia coli; Macrophages; Mice; Monocytes; Neutrophils; Phagocytes; Phagocytosis
PubMed: 35085696
DOI: 10.1016/j.jconrel.2022.01.030 -
The Journal of Cell Biology Dec 1965The addition of latex particles to native (no anticoagulant) or citrated human platelet-rich plasma (PRP), or to a once-washed platelet suspension causes platelet...
The addition of latex particles to native (no anticoagulant) or citrated human platelet-rich plasma (PRP), or to a once-washed platelet suspension causes platelet aggregation. This aggregation is associated with phagocytosis of the latex particles by the platelets and appears to be due to release of adenosine diphosphate (ADP) from the platelets. Adenosine and adenosine monophosphate, which are known to inhibit platelet aggregation induced by ADP, also block that induced by latex. These compounds do not prevent the phagocytosis of latex particles by the platelet. The addition of iodoacetate and 2,4-dinitrophenol in appropriate concentrations to the PRP, prior to the addition of the latex, blocks platelet aggregation and phagocytosis. This is also true for the chelating agent ethylenediaminetetraacetate (EDTA). Platelets left in contact with latex for a sufficient period of time show loss of their granules. Leucocytes phagocytose both latex and platelets that had themselves phagocytosed latex. It is concluded that phagocytosis of latex particles by platelets resembles that by white cells, and that in both processes metabolic changes appear to be involved.
Topics: Adenine Nucleotides; Blood Platelets; Carbon; Dinitrophenols; Edetic Acid; Humans; In Vitro Techniques; Iodoacetates; Latex; Microscopy, Electron; Microspheres; Phagocytosis
PubMed: 4957257
DOI: 10.1083/jcb.27.3.531 -
Reproduction (Cambridge, England).... 2001For successful conception, fertilization-competent spermatozoa must be present at the site of fertilization in adequate numbers until ovulation has taken place. In pigs,... (Review)
Review
For successful conception, fertilization-competent spermatozoa must be present at the site of fertilization in adequate numbers until ovulation has taken place. In pigs, a large volume of semen is delivered into the uterus. Most, if not all, of the inseminated liquid is voided from the vulva within a few hours after insemination and approximately 45% of the spermatozoa are lost. Large numbers of spermatozoa are also lost due to phagocytosis by polymorphonuclear leukocytes (PMNs). In pigs, the recruitment of PMNs to the uterine lumen appears to be triggered by insemination of a volume of liquid, rather than by specific components of that liquid or by spermatozoa or seminal plasma. However, persistence of large numbers of PMNs in the uterine lumen at > 12 h after insemination appears to depend on the presence of spermatozoa in the inseminate. In vitro studies have indicated that damaged, killed or capacitated spermatozoa are not phagocytosed preferentially, but that capacitation treatment strongly reduced phagocytosis of spermatozoa. Recent studies have also shown that PMN recruitment and phagocytosis of spermatozoa in vivo can be reduced by addition of caffeine plus CaCl2 to the inseminate, which appeared to have positive consequences for the longer term availability of spermatozoa at the site of fertilization.
Topics: Animals; Caffeine; Calcium Chloride; Cells, Cultured; Edetic Acid; Female; Insemination, Artificial; Male; Neutrophil Activation; Neutrophils; Phagocytosis; Sperm Capacitation; Sperm Transport; Spermatozoa; Swine; Uterus
PubMed: 11980184
DOI: No ID Found -
Developmental Dynamics : An Official... Oct 2014Programmed cell death (PCD), together with cell proliferation, cell migration, and cell differentiation, is an essential process during development of the vertebrate... (Review)
Review
Programmed cell death (PCD), together with cell proliferation, cell migration, and cell differentiation, is an essential process during development of the vertebrate nervous system. The visual system has been an excellent model on which to investigate the mechanisms involved in ontogenetic cell death. Several phases of PCD have been reported to occur during visual system ontogeny. During these phases, comparative analyses demonstrate that dying cells show similar but not identical spatiotemporally restricted patterns in different vertebrates. Additionally, the chronotopographical coincidence of PCD with the entry of specialized phagocytes in some regions of the developing vertebrate visual system suggests that factors released from degenerating cells are involved in the cell migration of macrophages and microglial cells. Contradicting this hypothesis however, in many cases the cell corpses generated during degeneration are rapidly phagocytosed by neighboring cells, such as neuroepithelial cells or Müller cells. In this review, we describe the occurrence and the sites of PCD during the morphogenesis and differentiation of the retina and optic pathways of different vertebrates, and discuss the possible relationship between PCD and phagocytes during ontogeny.
Topics: Animals; Apoptosis; Cell Death; Eye; Humans; Morphogenesis; Neurons; Ocular Physiological Phenomena; Phagocytosis; Vertebrates; Visual Pathways
PubMed: 25130286
DOI: 10.1002/dvdy.24174 -
Journal of Visualized Experiments : JoVE Dec 2019Invasive pulmonary infection by the mold Aspergillus fumigatus poses a great threat to immunocompromised patients. Inhaled fungal conidia (spores) are cleared from the...
Invasive pulmonary infection by the mold Aspergillus fumigatus poses a great threat to immunocompromised patients. Inhaled fungal conidia (spores) are cleared from the human lung alveoli by being phagocytosed by innate monocytes and/or neutrophils. This protocol offers a fast and reliable measurement of phagocytosis by flow cytometry using fluorescein isothiocyanate (FITC)-labeled conidia for co-incubation with human leukocytes and subsequent counterstaining with an anti-FITC antibody to allow discrimination of internalized and cell-adherent conidia. Major advantages of this protocol are its rapidness, the possibility to combine the assay with cytometric analysis of other cell markers of interest, the simultaneous analysis of monocytes and neutrophils from a single sample and its applicability to other cell wall-bearing fungi or bacteria. Determination of percentages of phagocytosing leukocytes provides a means to microbiologists for evaluating virulence of a pathogen or for comparing pathogen wildtypes and mutants as well as to immunologists for investigating human leukocyte capabilities to combat pathogens.
Topics: Aspergillus fumigatus; Flow Cytometry; Humans; Leukocytes; Phagocytosis; Spores, Fungal
PubMed: 31868176
DOI: 10.3791/60397 -
Produits Pharmaceutiques Feb 1959
Topics: Humans; Phagocytosis
PubMed: 13634245
DOI: No ID Found -
Cell Reports Nov 2023Microglia are the primary phagocytes in the central nervous system and clear dead cells generated during development or disease. The phagocytic process shapes the...
Microglia are the primary phagocytes in the central nervous system and clear dead cells generated during development or disease. The phagocytic process shapes the microglia phenotype, which affects the local environment. A unique population of microglia resides in the ventricular-subventricular zone (V-SVZ) of neonatal mice, but how they influence the neurogenic niche is not well understood. Here, we demonstrate that phagocytosis contributes to a pro-neurogenic microglial phenotype in the V-SVZ and that these microglia phagocytose apoptotic cells via the engulfment receptor Jedi-1. Deletion of Jedi-1 decreases apoptotic cell clearance, triggering a neuroinflammatory microglia phenotype that resembles dysfunctional microglia in neurodegeneration and aging and that reduces neural precursor proliferation via elevated interleukin-1β signaling; interleukin-1 receptor inhibition rescues precursor proliferation in vivo. Together, these results reveal a critical role for Jedi-1 in connecting microglial phagocytic activity to the maintenance of a pro-neurogenic phenotype in the developing V-SVZ.
Topics: Animals; Mice; Lateral Ventricles; Microglia; Phagocytes; Phagocytosis; Signal Transduction
PubMed: 37952151
DOI: 10.1016/j.celrep.2023.113423