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phagocyte images: illustrations and micrographs. All credits and licenses listed. Click a picture to see it large; click it again to open its paper. The pictures by method and the papers by section are in the library.

Micrographs

Pathology from the initial biopsy. The lesion consisted of large neoplastic cells with abundant eosinophilic cytoplasm, eccentrically placed nuclei, and increased mitotic activity. (A) H&E stain (X200), (B) H&E stain (X800).

Li M, et al. Gastric histiocytic sarcoma: a case report and literature review. Front Surg. 2026;13:1884156. PMID: 42609495 · CC BY 4.0

PMID 42609495 · fig. Fig. 1A-B
Immunohistochemical analysis of histiocytic sarcoma. (A) Neoplastic cells positive for CD68 (IHC×200), (B) Ki-67 labeling index was about 30% (IHC×200).

Li M, et al. Gastric histiocytic sarcoma: a case report and literature review. Front Surg. 2026;13:1884156. PMID: 42609495 · CC BY 4.0

PMID 42609495 · fig. Fig. 1C-D
Scanning electron micrograph of a macrophage, colorized in Halloween colors. Stay safe and have a Happy Halloween! Credit: NIAID

NIAID (National Institute of Allergy and Infectious Diseases) · CC BY 2.0

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A macrophage of a mouse forming two processes to phagocytize two smaller particles, possibly pathogens.

Obli (original uploader, English Wikipedia) · CC BY-SA 2.0

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Transmission electron microscope image of thin section cut through an area of mammalian lung tissue. Image shows golgi in the cytoplasm of a macrophage in the alveolus. Golgi is a structure involved in protein transport in the cytoplasm of the cell.

Louisa Howard / Rippel Electron Microscopy Facility, Dartmouth College · Public domain

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Photomicrograph showing alveolus cell types. 1 - Type II alveolar epithelial cell (type II pneumocyte). 2 - Type I alveolar epithelial cell (type I pneumocyte). 3 - Alveolar macrophage (alveolar macrophage; dust cell).

RWhitwam / Michael Hortsch, University of Michigan Medical School, Wikimedia Commons · CC BY-SA 4.0

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Representative morphologic features of alveolar macrophages in healthy controls and sarcoidosis. (A) Representative Diff-Quik®–stained images of alveolar macrophages (AMs) in bronchoalveolar lavage fluid specimens (scale bar = 40 μm, shown in figure). E, extra-large; L, large; M, medium; S, small. (A, left panel) Healthy individual: AM measuring 15–20 μm in diameter, with faintly basophilic cytoplasm and elongated, thin nuclei displaying unevenly distributed chromatin. Occasional cytoplasmic vacuoles are present. (A, right panel) Sarcoidosis patient: AMs enlarged to 20–30 μm with bright basophilic cytoplasm, round nuclei exhibiting relatively uniform chromatin, and prominent nucleoli. Numerous vacuolated AMs and lymphocyte attachment to the AM surface (rosette formation) are also observed. (B) Typical morphological features of sarcoidosis AMs (scale bar = 20 μm, shown in figure).

Ishida M, et al. Enlarged, activated alveolar macrophages as quantitative surrogates of disease activity in pulmonary sarcoidosis. Front Med (Lausanne). 2026;13:1739663. PMID: 41658608 · CC BY 4.0

PMID 41658608 · fig. Fig. 1
Micrograph showing hemosiderin-laden macrophages (also siderophages) in a bronchoalveolar lavage (BAL) specimen.

Librepath, Wikimedia Commons · CC BY-SA 3.0

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Overview of cells found in a bronchoalveolar lavage sample from two healthy cynomolgus macaques. (A) macaque #1, (B) macaque #2. Alveolar macrophages (Mφ) predominate, followed by lymphocytes (L). Neutrophil (N) and occasional ciliated columnar epithelial cells (E) are also present. Modified Giemsa. X50 objective. Oil immersion.

Pavot V, et al. Bronchoalveolar Lavage Fluid Cytology in Healthy Cynomolgus Macaques. Front Vet Sci. 2021;8:679248. PMID: 34113679 · CC BY

PMID 34113679 · fig. Fig. 1
Morphology of cells found in bronchoalveolar lavage samples from healthy cynomolgus macaques. (A) Macrophages, one of them contains a pollen grain (arrow). (B) One lymphocyte (bottom left) and one eosinophil (upper right). (C) Bilobed eosinophil (bottom). (D) One well-preserved neutrophil (bottom left) and a macrophage (upper right). (E) Mast cell. Modified Giemsa. X100 objective. Oil immersion.

Pavot V, et al. Bronchoalveolar Lavage Fluid Cytology in Healthy Cynomolgus Macaques. Front Vet Sci. 2021;8:679248. PMID: 34113679 · CC BY

PMID 34113679 · fig. Fig. 2
Lung tissue showing collections of alveolar macrophages with phagocytosed blackish pigment, carbon, without evoking an inflammatory response in the surrounding tissue. H&E stain 100X.

Department of Pathology, Calicut Medical College · CC BY-SA 4.0

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Activated macrophages with abnormal shapes and cytoplasmic vacuolization. (Original magnification ×1000 oil immersion {A through C}.)

Kaur G, et al. Morphologic Changes in Circulating Blood Cells of COVID-19 Patients. Cureus. 2021;13:e13416. PMID: 33758711 · CC BY 3.0

PMID 33758711 · fig. Fig. 1
Cytology of a macrophage with typical features. Wright stain. Sample from cerebrospinal fluid.

Mikael Häggström, M.D. · CC0

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Histopathological image of sarcoidosis. Lymph node biopsy. Note epithelioid granuloma. H & E stain.

KGH, Wikimedia Commons · CC BY-SA 3.0

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Histopathological image of sarcoidosis. Lymph node biopsy. Note epithelioid granuloma with asteroid bodies, which appear obscure. H & E stain.

KGH, Wikimedia Commons · CC BY-SA 3.0

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Phenotypic characterization of iPSC-derived macrophages continuously produced in intermediate scale bioreactors. A Number of viable cells harvested from the intermediate scale bioreactor for three different iPSC lines (iPSC line#1: n = 2, iPSC line#2: n = 2, iPSC line#3: n = 1, all individual values with mean +/− SD) over a time span of 7 weeks. Representative brightfield images and cytospin staining for iPSC-derived macrophages (iPSC-Mac) derived from harvest #1b, 3 and 5 for iPSC line#1.

Ackermann M, et al. Standardized generation of human iPSC-derived hematopoietic organoids and macrophages utilizing a benchtop bioreactor platform under fully defined conditions. Stem Cell Res Ther. 2024;15:171. PMID: 38886860 · CC BY 4.0

PMID 38886860 · fig. Fig. 1
Sequential stages of phagosome maturation can also be identified by monitoring rhodopsin in macrophages challenged with POS. J774A.1 macrophages seeded onto Transwell® membrane inserts were challenged with POS for 1 h, washed to remove unbound POS, chased for 2 h at 37°C and processed for cryo-immuno-electron microscopy. Ultrathin sections were double labelled for rhodopsin with antibodies against the C-terminal epitope (1D4; PAG, 10 nm) and N-terminal epitope (RET-P1; PAG, 15 nm). (A) Double-labelled ROS at the plasma membrane. (B) A double-labelled early phagosome (earlyP). (C) A maturing phagosome (matP) containing only very little 1D4 on some discs. (D) A phagolysosome (PL) containing disorganised discs where RET-P1 has started to be degraded. Scale bars: 200 nm (A,C), 100 nm (B,D). Black and white arrows indicate rhodopsin labelling with RET-P1 and 1D4, respectively.

Wavre-Shapton ST, et al. Phagosome maturation during endosome interaction revealed by partial rhodopsin processing in retinal pigment epithelium. J Cell Sci. 2014;127:3852-61. PMID: 25074813 · CC BY 3.0

PMID 25074813 · fig. Fig. 2
Morphological features of human MDMs after 24 h of in vitro treatment with Eucalyptus oil. a-f, phase-contrast microscopy after Wright Giemsa staining: a, d, untreated control; b, e, MDMs stimulated with 0.1 μg/ml of bacterial lipopolysaccharide (LPS); c, f, MDMs treated with 0.016% Eucalyptus oil; a, b, c, original magnification: 20×;d, e, f, original magnification: 40×. g-l, Scanning electron microscopy of untreated (g, j), LPS treated (h, k) and Eucalyptus oil treated MDMs (i, l). Bars: 20 μm.

Serafino A, et al. Stimulatory effect of Eucalyptus essential oil on innate cell-mediated immune response. BMC Immunol. 2008;9:17. PMID: 18423004 · CC BY 2.0

PMID 18423004 · fig. Fig. 1
Effect of M-CSF and GM-CSF on FBGC formation. Percentage of macrophage fusion in response to (A) M-CSF (25–100 ng/mL) and (B) GM-CSF (2.5–10 ng/mL) with stacked bars showing the percentage of nuclei within FBGC containing a total of 2 to 3, 4 to 5, 6 to 10 and/or >10 nuclei/cell. Macrophages were cultured in the absence or presence of IL-4 (10 ng/mL), IL-13 (10 ng/mL) or both IL-4 and IL-13 (5 ng/mL each) for 28 days. Data are means ± SEM of three donors. (C) Macrophages and FBGCs were stained with May-Grünwald and Giemsa. Images are representative of three independent experiments, scale bar 100 μm.

Stewart CL, et al. Cellular and microenvironmental cues that promote macrophage fusion and foreign body response. Front Immunol. 2024;15:1411872. PMID: 39034997 · CC BY 4.0

PMID 39034997 · fig. Fig. 1
Ibrutinib-induced differentiation into fibrocyte-like cells Purified human monocytes were cultured in the presence of 100 ng/mL M-CSF. (A–F) Monocytes were cultured in serum-containing medium in the absence (A, C, E) or presence (B, D, F) of 10 μM Ibrutinib. After 10 days, cells were air-dried, fixed and stained with May-Grunwald and Giemsa solutions for optic microscopy (A, B) or captured unstained for interference microscopy (C–F). Monocytes cultured with only M-CSF (A, C, E) displayed a fried-egg or slightly spindle shape with round nuclei, typical of M-CSF-differentiated cells. Monocytes treated with Ibrutinib (B, D, F) displayed a fibrocyte-like morphology with an elongated shape.

Ferrarini I, et al. Monocyte-to-macrophage switch reversibly impaired by Ibrutinib. Oncotarget. 2019;10:1943-1956. PMID: 30956776 · CC BY 3.0

PMID 30956776 · fig. Fig. 1
Histopathological features of STB. Representative H&E images from STB lesions. Panels (A-L) were selected from different STB patients to illustrate recurrent lesion-level pathological patterns observed in the cohort. The annotations indicate representative histopathological features: yellow arrows and asterisks indicate multinucleated/Langhans-type giant cells; white arrows and circles indicate caseous granulomas; and brown-red arrows indicate epithelioid cells.

Liu Q, et al. Integrated histopathology and single-cell transcriptomics reveal distinct pathological features and foamy macrophage characteristics in spinal tuberculosis and brucellar spondylitis. Front Immunol. 2026;17:1909083. PMID: 42698543 · CC BY 4.0

PMID 42698543 · fig. Fig. 1
Tuberculoid granuloma associating epithelioid cells, Langhans' multinucleated giant cells and caseous necrosis (upper right)

Humpath, Wikimedia Commons · CC BY-SA 3.0

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Presiding over a noncaseating granuloma.

Ed Uthman from Houston, TX, USA · CC BY 2.0

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Representative images of lung tissue specimens with (A) hematoxylin eosin staining, (B) alcian blue staining, (C) Elastica van Gieson and (D) Masson-Goldner staining of COVID–/ARDS–, COVID+/ARDS+ and COVID–/ARDS+ patients. Scale bar 100 µm.

Silawal S, et al. A Histological Analysis and Detection of Complement Regulatory Protein CD55 in SARS-CoV-2 Infected Lungs. Life (Basel). 2024;14:1249. PMID: 39337843 · CC BY 4.0

PMID 39337843 · fig. Fig. 1
Macrophage cell in early stages of infection with African swine fever virus, magnified about 1,000x.

Keith Weller, USDA ARS · Public domain

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Cytospin generation and annotation. (A) The cell fraction of bronchoalveolar lavage or sputum was applied to glass slides by centrifugation, stained with May Grumwald Giemsa based solutions and then digitally imaged by microscopy. (B) Representative digital images at × 4 (overview) and × 100 magnification (inset). (C) Average time in seconds for assessors to annotate a × 100 magnification sample image tiles by four separate annotation modalities.

Lee SMW, et al. Differential cell counts using center-point networks achieves human-level accuracy and efficiency over segmentation. Sci Rep. 2021;11:16917. PMID: 34413367 · CC BY 4.0

PMID 34413367 · fig. Fig. 1
Micrograph showing hemosiderin-laden macrophages (also siderophages) in a bronchoalveolar lavage (BAL) specimen.

Librepath, Wikimedia Commons · CC BY-SA 3.0

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Lung tissue showing collections of alveolar macrophages with phagocytosed blackish pigment, carbon, without evoking an inflammatory response in the surrounding tissue. H&E stain 4X.

Department of Pathology, Calicut Medical College · CC BY-SA 4.0

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Kidney - Miliary tuberculosis

Yale Rosen from USA · CC BY-SA 2.0

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Observations of macrophage-fibre interactions. a, After taking up the long silver nanowire of the aged AG-Rods-3170 variant, the macrophage continued to take up a fibre with an extended pseudopod (left panel), initiating bending which results in higher curvature of the fibre (right panel). b, Afterwards, the cell increased its size to ca. 25 μm and the fibre spring extended (left panel). The macrophage attempted to constrain the fibre by decreasing its size to ca. 17 μm (right panel). c, The cell maintained the shape of the fibre spiral while still actively extending pseudopodia.

Broßell D, et al. Macrophages bend long fibres with flexural rigidity lower than 3 mN·nm² to avoid frustrated phagocytosis. Part Fibre Toxicol. 2026;23:21. PMID: 41845490 · CC BY 4.0

PMID 41845490 · fig. Fig. 2
Electron microscopy analysis. Mtb lacking PDIM is much less frequently present in the cytosol. Human lymphatic endothelial cells were infected with Mtb WT, Mtb ΔPDIM or Mtb ΔPDIM::PDIM for 5 + 24 h and fixed. The samples were processed for resin embedding and then transmission electron microscopy was used to look at the subcellular localisation of Mtb. Three potential localisations were considered and classified. a–c Cytosolic (defined as no obvious host membrane surrounding bacteria outside the bacterial capsule-like material visible on the surface). d–f Phagosomal (defined as bacteria enclosed in a single membrane-bound organelle). Most of these are larger (membrane-bound) vacuoles, often with more than one Mtb cell as well as additional irregular membranes and contents in various stages of degradation, typical for phagolysosomes. Arrowheads indicate the phagosomal/phagolysosomal limiting membrane. g–i Autophagic. In this case, the bacteria and surrounding cytoplasm are enclosed by either single or multiple membranes that are mostly poorly preserved. Scale bars are 500 nm.

Lerner TR, et al. Phthiocerol dimycocerosates promote access to the cytosol and intracellular burden of Mycobacterium tuberculosis in lymphatic endothelial cells. BMC Biol. 2018;16:1. PMID: 29325545 · CC BY 4.0

PMID 29325545 · fig. Fig. 4
Histopathology specimen of tuberculous meningitis - HE stain

Jensflorian · CC BY-SA 4.0

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Efferocytic capacity of bone marrow-derived and hepatic Mf from Mdr2-/- mice. (A and B) (A) Representative images, and (B) FACS plots from liver Mf and graphs reporting the frequency of Mdr2+/+ and Mdr2-/- Mf differentiated from the bone marrow (BMDMs) or isolated from the liver (liver Mf), engulfing in vitro apoptotic thymocytes (aT) or apoptotic hepatocytes (aH) upon 45 min or 120 min coculture. Efferocytic Mf are identified as CD11b+ F4/80

Al Jawazneh A, et al. Bile acid retention in efferocytic macrophages shapes their inflammatory status during cholangitis. J Exp Med. 2026;223:e20241384. PMID: 42334420 · CC BY 4.0

PMID 42334420 · fig. Figure S2.
Histopathology of miliary tuberculosis having caused the death of a 82-year-old female. It shows epithelioid granulomas with multinucleated giant cells (H & E stain) from kidney and spleen micronodules (left images) with acid-fast bacilli.

Benjamin Herreros, Isabel Plaza, Rebeca Garcia, Marta Chichon, Carmen Guerrero and Emilio Pintor · CC BY 4.0

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Pulmonary tuberculosis characterized by granulomatous inflammation with necrotizing epithelioid granulomas. H&E stain.

CoRus13 · CC BY-SA 4.0

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Pulmonary tuberculosis characterized by granulomatous inflammation with necrotizing epithelioid granulomas. H&E stain.

CoRus13 · CC BY-SA 4.0

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Kupffer cell with hemosiderin and hepatocyte with lipofuscin, H&E stain

Mikael Häggström, M.D. · CC0 1.0

High magnification micrograph showing Kupffer cells, in the setting of a resolving congestive hepatopathy. Liver biopsy. Trichrome stain.

Nephron (Wikimedia Commons) · CC BY-SA 3.0

Mixed rat brain cultures stained for coronin 1a, found in microglia here in green, and alpha-internexin, in red, found in neuronal processes.

GerryShaw (Wikimedia Commons); antibodies and image by EnCor Biotechnology Inc. · CC BY-SA 3.0

Aging dampens phagocytic activity in monocyte derived macrophages. (A) Experimental design of human MDMs phagocytic activity assay. (B, C) Flow cytometry quantification of pHrodo-E. coli phagocytosis in MDMs from young and elderly donors (n = 6 each). (D, E) Flow cytometry quantification of fluorescence-labeled latex beads phagocytosis in MDMs from young and elderly donors (n = 7 each). (F) Percentage of MDMs phagocytosing 3 or more beads in both group (n = 7 each). (G) Representative confocal microscopy images showing intracellular localization of phagocytosed fluorescence-latex beads in hMDMs. (H) Experimental design of peritoneal macrophage phagocytic activity assay. Peritoneal macrophages were harvested 4 h post-injection of pHrodo-E. coli. (I) Example of large peritoneal macrophages (LPMs, CD11b+, F4/80hi) and small peritoneal macrophages (SPMs, CD11b+, F4/80lo) in flow cytometry assay. (J) Flow cytometry quantification of pHrodo-E. coli containing SPM in young and old mice (n = 5 each). (J) Quantification of pHrodo-E. coli containing LPM in young and old mice (n = 5 each). All data are mean +/- SEM. Two-tailed, unpaired Mann-Whitney-Wilcoxon rank test (C, E, F, J, K): * p < 0.05, ** p < 0.01.

Wang, Xu, Shen et al 2026, Aging Cell · CC BY 4.0

PMID 42298889 · fig. 1
The engulfment and digestion of TNF-alpha in Anti-TNF-alpha CAR-M. (A) Representative confocal images of the colocalization of Cy5-labeled-TNF-alpha (red) and CAR (green) on BMDMs. The BMDMs were transfected with the plasmids of anti-TNF-alpha CAR-M, nsCAR-M for 72 h, after a 2 h-incubation with 20 ng/mL TNF-alpha, cells were labeled with anti-HA antibody. Scale bar represents 5 um. (B) The fluorescence intensity of TNF-alpha and CAR in (A) was quantified by ImageJ software. n = 3. Data are shown as mean +/- S.E.M. (C) Representative confocal images showing TNF-alpha uptake and degradation stages. CAR-M were treated with 20 ng/mL Cy5-TNF-alpha for 12 h and washed with fresh medium after incubation, TNF-alpha and LAMP1 in CAR-M were stained with respective antibodies at different times and imaged by confocal microscopy. Scale bar represents 5 um. (D) TNF-alpha levels in the culture supernatants were measured by ELISA following CQ treatment. n = 3. (E) Flow cytometric measurement of MerTK and TNF-alpha in anti-TNF-alpha CAR-M or nsCAR-M. (F) The activation of Rac1, Cdc42 and RhoA. (G) Quantitative analysis of the results shown in (F). n = 3.

Wang, Zhu, Liu et al 2026, Theranostics · CC BY 4.0

PMID 42708095 · fig. Figure 2
Aa co-distributes with Cellugyrin. TDMWT and TDMCg- were inoculated with Aa (MOI of 1:100) for 1 h and treated as described in the Methods. (A) Representative multi-fluor confocal images showing Aa (pseudocolored-cyan), cellugyrin (red), and nuclei (pseudocolored-cyan) with 2 um by 2 um volumetric reconstruction around Aa. Data in (B) represent raw cellugyrin fluorescence intensity around the Aa. Data in (B) are presented as mean +/- standard error of the mean (5 Aa per each of three biological replicates were analyzed, for n = 15) and analyzed using Student's t-test (****, p < 0.0001).

Kim, Schneider, Defreitas et al 2026, Pathogens · CC BY 4.0

PMID 42198631 · fig. Figure 1
ANXA2-dependent phagocytosis drives the generation of AR+ TAMs. (A) Representative confocal microscopy images showing the uptake of GFP-labeled tumor cells by macrophages (stained with F4/80, red; nuclei stained with DAPI, blue). White arrows indicate engulfed cells. Scale bar = 20 um. (B) Representative flow cytometry plots identifying GFP+ cells gated from F4/80+ macrophages, defining the TCNPMs and TCPMs. (C) WB analysis evaluating the protein levels of AR, CLTC, LIPA, LAPTM5, and LAMP2 in TCNPMs and TCPMs. (D) Mass spectrometry spectrum identifying ANXA2. (E) Flow cytometry analysis of GFP+ cells within the F4/80+ gate following ANXA2 knockdown (KD-1 and KD-2) versus negative control (NC). (F) Quantification of the percentage of GFP+ cells from (E). (G) Confocal microscopy images visualizing macrophage phagocytic capacity in NC and ANXA2-deficient groups. Staining included GFP (green), F4/80 (red), and DAPI (blue), with white arrows pointing to internalized cells. Scale bar = 40 um. (H) Quantification of phagocytosing macrophage populations per microscopic field. (I) WB analysis of ANXA2, AR, and phagocytosis-associated proteins (CLTC, LIPA, LAPTM5, LAMP2) in macrophages subjected to ANXA2 knockdown.

Luo, Luo, Li et al 2026, Advanced Science · CC BY 4.0

PMID 41990247 · fig. FIGURE 2
Scanning electron microscopy of J774A.1 cells secreting PEVs. The J774A.1 cell line was stimulated with a small amount of E. coli SBMF stabilized with FN, distributed as a substrate on the cell culture surface, for 2 h of interaction. ( A ) The results occasionally show cells with a normal or unstimulated appearance; this result suggests that those cells that did not come into contact with the substrate showed fewer PEVs, indicated by arrows. ( B - D ) Cells that came into contact with the substrate generally changed their morphology and exhibited PEVs. ( E - H ) Stimulated J774A.1 PEVs. Scale bar ( A - H ) 1 um. ( I ) Schematic image illustrates a biopsy of a submandibular lymph node, erased by metastatic histiocytic sarcoma, large scale 20 um and short scale 1 um, based on Purzycka et al. 2020.

Sierra-López, Bernardo-Hernández, Baylón-Pacheco et al 2026, International Journal of Molecular Sciences · CC BY 4.0

PMID 42278472 · fig. Figure 3
Macrophages and their subtypes in PV lesional tissues. Representative confocal microscopic images of M1 and M2 macrophages in control and PV tissue. (a) M1 phenotypic cells are shown as cells which are CD68+ (green) and iNOS+ (red). Tissue sections were stained with primary antibody CD68 conjugated with anti-mouse FITC labelled secondary antibody (green), primary antibody iNOS conjugated with anti-rabbit Alexa fluor 550 labelled secondary antibody (red) and DAPI mounting media =blue. The dilution used for CD68 was standardised at 1:100 and for iNOS at 1:200. Images were captured at 40x magnification. Scale bar= 50 um. (b) M2 phenotypic cells are shown as cells which are CD68+ (green) and CD163+ (red). Tissue sections were stained with primary antibody CD68 conjugated with anti-mouse FITC labelled secondary antibody (green), primary antibody CD163 conjugated with anti-rabbit Alexa fluor 550 labelled secondary antibody (red) and DAPI mounting media =blue. The dilution used for CD163 was standardised at 1:200. Images were captured at 60x magnification. Scale bar= 100 um. (c-e) Column bar graph representing MFI (mean fluorescent intensity) of macrophages and their subtypes calculated using ImageJ software. ***p<0.001, **p<0.005, *p<0.05, n= 10.

Hooda, Singh, Khandpur et al 2026, Frontiers in Immunology · CC BY 4.0

PMID 42183286 · fig. Figure 4
Ultrastructural analysis of M. abscessus infection in THP-1 cells. Transmission electron microscopy (TEM) analysis of THP-1 cells differentiated with PMA and infected with M. abscessus smooth morphotype (S form) at a multiplicity of infection of 10:1. (A) Uninfected THP-1 cell showing a few extracellular bacilli. (B) At 4 h post-infection, M. abscessus S bacilli are enclosed within phagosomes characterized by tightly apposed phagosomal membranes and close association with mitochondria. (C) At 24 h post-infection, phagosomal membranes occasionally display irregularities or partial breaks, suggesting potential phagosome-cytosol communication. Nevertheless, most bacilli remain enclosed within phagosomal compartments, and some exhibit signs of intracellular division. An electron-translucent zone (ETZ), characteristic of the smooth morphotype and associated with surface glycopeptidolipids (GPLs), is observed surrounding the bacilli.

Singh, Berdal, Deflandre et al 2026, EMBO Reports · CC BY 4.0

PMID 42315648 · fig. Figure 2
Phagocytosis assay of macrophages with different phenotypes and their co-culture with neurons. (A) Representative fluorescence images showing microsphere uptake by bone marrow-derived macrophages (BMDMs) with different phenotypes (M0, M1, M2, and Mi). Scale bar = 100 um. (B) Quantification of phagocytic activity based on mean fluorescence intensity of engulfed microspheres. (C) Schematic illustration of the macrophage-neuron co-culture assay. Differently induced BMDMs were co-cultured with primary neurons for 24 h. (D) Representative confocal images of primary neurons after co-culture with macrophages under the indicated conditions. Neurons were immunostained for MAP2 (red). Scale bar = 100 um. (E) Quantitative analysis of relative MAP2 immunofluorescence intensity and number of neurons demonstrated significantly reduced levels in the M1 macrophage group compared to the other groups. In contrast, neurons co-cultured with Mi (LPS/IL-4/TGF-beta-stimulated) macrophages exhibited MAP2 immunointensity and number of neurons comparable to the M0 and M2 groups, with no significant decrease in neuronal preservation observed in the Mi group. Data are expressed as mean +/- SD (n = 5/group; one-way ANOVA followed by Bonferroni post hoc test. ns: not significant, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001).

Zha, Zheng, Wang et al 2026, Journal of Orthopaedic Translation · CC BY 4.0

PMID 42740843 · fig. Fig. 4
mcr-3-modified E. coli impair phagolysosomal maturation. (A-B) Growth of 299 and mcr-3 strains in LB adjusted to pH 1-7 for 12 h. Cultures were adjusted to a McFarland standard of 0.5, diluted 1:100, and incubated at the indicated pH; bacterial viability was determined by serial dilution plating (n = 4 independent experiments). (C) Heatmap of DEGs related to phagolysosomal maturation in infected macrophages (n = 3 independent experiments). (D-G) RAW264.7 cells infected with 299 or mcr-3 (MOI = 1:20, 6 h) were analyzed by confocal microscopy for colocalization of bacteria with EEA1 (early endosome marker) or LAMP1 (lysosome marker) (n = 18 cells per group from three independent experiments). Scale bar, 10 um. (H-I) Western blot analysis of P65 and p-P65 expression in RAW264.7 cells infected with 299 or mcr-3 at an MOI of 1:20 for 1 h; extracellular bacteria removed by gentamicin, and cell lysates were collected at 12 h post-gentamicin treatment for immunoblotting, with GAPDH used as the loading control (n = 3 independent experiments). Data are shown as the mean +/- SEM.

Tan, Yin, Sun et al 2026, PLOS Pathogens · CC BY 4.0

PMID 42447151 · fig. Fig 5
P. gingivalis infection impairs the intracellular bacteria clearance in macrophages through MCU-mediated Ca2+ overload. (A) Representative fluorescence images showing the levels of the cytosolic Ca2+ (Fluo-4 AM, green) in control and P. gingivalis-infected macrophages. (B) Quantification of Fluo-4 AM MFI. (C) The changes of Fluo-4 AM levels in control and P. gingivalis-infected macrophages over a 50-min period. (D) Representative fluorescence images showing the levels of the mitochondrial Ca2+ (Rhod-2, red) in control and P. gingivalis-infected macrophages. (E) Quantification of Rhod-2 MFI. (F) The changes of Rhod-2 AM levels in control and P. gingivalis-infected macrophages over a 50-min period. (G) The MCU gene expression in macrophages between control, P. gingivalis, and P. gingivalis + MCU-i4 (MCU inhibitor, 10 uM) group. (H) Representative IF images showing the intracellular survival of P. gingivalis in macrophages between P. gingivalis and P. gingivalis + MCU-i4 groups. (I) Quantification of P. gingivalis MFI. (J) Quantification of phagocytic activity (OD 540 nm) in macrophages between P. gingivalis and P. gingivalis + MCU-i4 groups.

Deng, Su, Zhang et al 2026, Cell Proliferation · CC BY 4.0

PMID 42790879 · fig. FIGURE 3
Ultrastructural features of MNP-containing vacuoles and associated remodeling of degradative vacuolar hubs with autophagic features. (A-F) Representative TEM images of human monocytes exposed to MNPs at 24 or 72 h. (A) MNP-containing phagosome surrounded by multilamellar membrane structures (lamellar whorls; arrow). (B) Multiple intracellular MNP-containing vacuoles (arrows), displaying heterogeneous morphology and electron density. (C) Prominent multilamellar body (arrow) adjacent to MNP-containing compartments. (D) Coexistence of MNP-containing phagosomes (arrows) with vacuolar structures of variable size and content, including early and late phagolysosomal compartments. (E) Giant degradative vacuolar compartment (arrow) resembling an autolysosome/phagolysosome, containing heterogeneous material including organelles and electron-dense debris. (F) Overview of a cell displaying extensive accumulation of MNP-containing vacuoles (arrows) and enlarged vacuolar compartments. Red asterisks indicate MNPs; N, nuclei.

Pezzana, Broggiato, Limanaqi et al 2026, Frontiers in Immunology · CC BY 4.0

PMID 42718517 · fig. Figure 3
RAB5c depletion impairs LAP. ( A ) mCh-RAB5c MFI at phagosomes (n = 12) of RAW264.7 cells fed Op-zym (see movie S1). ( B ) CLEM analysis of Op-zym+ phagosome in RAW264.7-mCh-RAB5c cells. Left: Fluorescence image. Middle: overlay (bottom) and corresponding TEM cross section (top). Right: Magnified inset; arrows indicate single membrane. Scale bars, 5 um (left and middle) and 1 um (right). ( C ) Confocal images of RAW264.7-mCh-RAB5c cells stimulated with Op-zym, IgG-beads, or BSA-beads for 5 min. Insets fluorescence intensity (show as RAINBOW LUT). Scale bar, 5 um. DIC, differential interference contrast. ( D and E ) Confocal images (D) and mCh-LC3B MFI at phagosomes (E) for RAW264.7 cells expressing scrambled shRNA (sh_Ctrl) or indicated shRNAs (#1; #2) fed Op-zym. Scale bar, 5 um. ( F to H ) Confocal images (F) and MFI of LC3 at phagosomes for RAW264.7 cells (G) and BMDMs (H) expressing sh_Ctrl or sh_Rab5c fed Op-zym. Scale bars, 5 um. ( I ) Immunoblot of LC3A/B, RAB5a/b/c, EEA1, UNC93B1 (loading control), and GM130 (purification control) in IgG-bead- or BSA-bead-containing phagosomes purified from RAW264.7 cells expressing sh_Ctrl or sh_Rab5c. Mr, relative molecular mass. ( J and K ) Confocal images (shown as FIRE LUT) (J) and LAMP1 MFI at phagosomes (K) for RAW264.7 cells fed Op-zym. Scale bar, 10 um. ( L and M ) MFI (L) and percentage (M) of Op-pHrodo-zym in RAW264.7 cells analyzed by flow cytometry. ( N ) MFI of opsonized DQ-BSA-coated beads in RAW264.7 cells. Colored symbols [(A), (E), (G), (H), and (K)] or bars [(L) to (N)] represent means of biological replicates, each indicated as a gray (phagosome) or white (sample) object. Shaded area (A) or error bars, +/-SEM. Statistical comparison between groups are unpaired Student's t test. Data are pooled from two (A) or three [(E), (G), (H), and (K)] independent experiments or are representative of four (I), three [(L) and (M)], or two (N) independent experiments. *, phagosomes; N, nuclei.

Freitas-Filho, Zaidan, Alzamora-Terrel et al 2025, Science Advances · CC BY 4.0

PMID 42102192 · fig. Fig. 1
RAB5c depletion impairs LAP. (A) mCh-RAB5c MFI at phagosomes (n = 12) of RAW264.7 cells fed Op-zym (see movie S1). (B) CLEM analysis of Op-zym+ phagosome in RAW264.7-mCh-RAB5c cells. Left: Fluorescence image. Middle: overlay (bottom) and corresponding TEM cross section (top). Right: Magnified inset; arrows indicate single membrane. Scale bars, 5 um (left and middle) and 1 um (right). (C) Confocal images of RAW264.7-mCh-RAB5c cells stimulated with Op-zym, IgG-beads, or BSA-beads for 5 min. Insets fluorescence intensity (show as RAINBOW LUT). Scale bar, 5 um. DIC, differential interference contrast. (D and E) Confocal images (D) and mCh-LC3B MFI at phagosomes (E) for RAW246.7 cells expressing scrambled shRNA (sh_Ctrl) or indicated shRNAs (#1; #2) fed Op-zym. Scale bar, 5 um. (F to H) Confocal images (F) and MFI of LC3 at phagosomes for RAW264.7 cells (G) and BMDMs (H) expressing sh_Ctrl or sh_Rab5c fed Op-zym. Scale bars, 5 um. (I) Immunoblot of LC3A/B, RAB5a/b/c, EEA1, UNC93B1 (loading control), and GM130 (purification control) in IgG-bead or BSA-bead-containing phagosomes purified from RAW264.7 cells expressing sh_Ctrl or sh_Rab5c. Mr, relative molecular mass. (J and K) Confocal images (shown as FIRE LUT) (J) and LAMP1 MFI at phagosomes (K) for RAW264.7 cells fed Op-zym. Scale bar, 10 um.

Freitas-Filho, Zaidan, Alzamora-Terrel et al 2026, Science Advances · CC BY 4.0

PMID 42102192 · fig. Fig. 1
RAB5c depletion impairs LAP. (A) mCh-RAB5c MFI at phagosomes (n = 12) of RAW264.7 cells fed Op-zym. (B) CLEM analysis of Op-zym+ phagosome in RAW264.7-mCh-RAB5c cells. Left: Fluorescence image. Middle: overlay (bottom) and corresponding TEM cross section (top). Right: Magnified inset; arrows indicate single membrane. Scale bars, 5 um (left and middle) and 1 um (right). (C) Confocal images of RAW264.7-mCh-RAB5c cells stimulated with Op-zym, IgG-beads, or BSA-beads for 5 min. Scale bar, 5 um. DIC, differential interference contrast. (D and E) Confocal images (D) and mCh-LC3B MFI at phagosomes (E) for RAW246.7 cells expressing scrambled shRNA (sh_Ctrl) or indicated shRNAs (#1; #2) fed Op-zym. Scale bar, 5 um. (F to H) Confocal images (F) and MFI of LC3 at phagosomes for RAW264.7 cells (G) and BMDMs (H) expressing sh_Ctrl or sh_Rab5c fed Op-zym. Scale bars, 5 um. (J and K) Confocal images (shown as FIRE LUT) (J) and LAMP1 MFI at phagosomes (K) for RAW264.7 cells fed Op-zym. Scale bar, 10 um. Error bars, +/-SEM. *, phagosomes; N, nuclei.

Freitas-Filho, Zaidan, Alzamora-Terrel et al 2026, Science Advances · CC BY 4.0

PMID 42102192 · fig. Fig. 1.
RAB5c depletion impairs PI(3)P production and stable assembly of NOX2 machinery on phagosomes but increases phagosome ROS production. RAW264.7 cells or BMDMs expressing sh_Ctrl or sh_Rab5c. (A) Immunoblot of class III PI(3)K complex in BSA-bead- or IgG-bead-containing phagosomes from RAW264.7 cells. (B and C) Confocal images (shown as SMART LUT) (B) and p40phox-PX-Venus MFI at phagosomes (n = 18) (C) in RAW264.7-p40phox-PX-Venus cells fed Op-zym. *, phagosomes. (D and E) Immunoblot (D) and quantification (E) of LC3A/B-II in RAW246.7 cells +/- Op-zym (25 min), C8 (2 uM; 25 min), DMXAA (50 ug/ml; 1 hour), and PP242 (1 uM; 2 hours). Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), loading control. NS, nonstimulated. (F) Immunoblot of NOX2 components in IgG-bead- or BSA-bead-containing phagosomes from RAW264.7 cells. (G to I) NBT assay in macrophages fed Op-zym. DIC images (G) and percentage of NBT+ phagosomes in RAW264.7 cells (H) and BMDMs (I). Arrowheads, NBT+ (red) or NBT- (yellow). (J to L) Confocal images (J) and p-p47phox MFI at phagosomes in RAW264.7 cells fed Op-zym for 15 (K) or 40 (L) min. (M and N) Confocal images (M) and MFI (N) of p-ERK1/2 in RAW264.7 cells fed Op-zym (15 min). (O) Percentage of NBT+ phagosomes in RAW264.7 cells +/- ERK1/2 inhibitor (100 uM) for 10 min before Op-zym. Scale bars, 10 um.

Freitas-Filho, Zaidan, Alzamora-Terrel et al 2026, Science Advances · CC BY 4.0

PMID 42102192 · fig. Fig. 2.
Representative confocal images of PMA-differentiated THP-1 cells in serum-supplemented medium. (A) Control, unexposed PMA-differentiated cells. (B,C) PMA-differentiated cells (condition 1 and condition 2 respectively) exposed to NM-401 for 24 h. NM-401 particles are shown in white (reflectance). Blue indicates the nuclei (stained with Hoechst 33342), and in green the cell membrane (stained with Rhodamine Phalloidin), in red the lysosomes (stained with Lysotracker). Images are acquired on Zeiss LSM 880 (x63 objective). Scale bar: 10 um.

Attar, Rajabli, Chary et al 2026, Frontiers in Toxicology · CC BY 4.0

PMID 42453305 · fig. FIGURE 6
TREM2-deficient macrophages have increased parasite burden and decreased LAMP1 expression. Bone marrow-derived macrophages (BMDMs) from naive C57BL/6 (WT) and TREM2 KO mice were infected with T. gondii at a MOI of 2. A) Representative 63X confocal images of WT and TREM2 KO BMDM infected with GFP+ T. gondii (green) for 1 hr or 6 hr and stained with DAPI (blue). B) Quantification of T. gondii parasites per 100 cells from the experiments in (A). C) Percent of BMDM with at least 1 parasite/cell from the experiments in (D). D) Representative 63X images of WT and TREM2 KO BMDMs infected over time with tdTomato+ T. gondii at a MOI of 2. E) Image of HFF plaque assay using parasites isolated from T. gondii-infected WT and TREM2 KO BMDM at 24 hpi. F) Percent of plaque area from the experiments in (E). G) Phagocytic index of WT or TREM2 KO BMDM as determined by the ratio of cells containing 4-BPB-treated parasites (phagocytosis) relative to vehicle-treated parasites (invasion). H) Confocal microscopy of F4/80 (blue), T. gondii (green), and LAMP1 (red) in 40X images of WT or TREM2 KO BMDMs incubated with 4-BPB-treated T. gondii (MOI = 10) for 1 hr. I) Quantification of LAMP1 mean fluorescence intensity (MFI) within F4/80 signal from WT or TREM2 KO BMDM incubated with vehicle- or 4-BPB-treated T. gondii.

Debray, Cheng, Ayala et al 2026, PLOS Pathogens · CC BY 4.0

PMID 42555664 · fig. Fig 4
Bronchoalveolar lavage cytospin from a healthy volunteer showing predominantly alveolar macrophages with abundant pale cytoplasm and bean-shaped nuclei. Occasional lymphocytes visible as expected in normal BAL differential.

Tsitoura E 2021, Frontiers in immunology · CC BY 4.0

PMID 34867934

Illustrations

Phagocytosis: five steps from recognition to digestion. Labeled illustration.

phago.site · original

Multinucleated giant cell variants: epithelioid histiocyte, foreign-body type (scattered nuclei), and Langhans type (peripheral nuclei). Labeled illustration.

phago.site · original

Tissue-resident macrophage subtypes: six named variants with tissue location and key markers.

phago.site · original