Phago Knowledge Base
The phagocyte's permanent record. What it is, what it eats, what it leaves behind. Organized by topic. Every claim sourced. Thin evidence marked thin.
Chronic inflammation, explained from the inside.
Phago. What do you need to know about phagocytes?
Phagocytes are the eaters. Every bacterium that does not make it past your skin ends up, sooner or later, in a phagolysosome: a membrane bag acidified to pH 4.5, flooded with reactive oxygen, staffed by enzymes that dismantle proteins, lipids, and nucleic acids at speed. The same machinery that clears an infection clears apoptotic debris, damaged organelles, and the remnants of old tissue. A macrophage at rest resembles a scout; one responding to a pathogen or a dying cell resembles a furnace. This site is the record: what phagocytes do, what happens when they malfunction, and what the literature currently knows.
Sun B, et al. Macrophage: Biological Functions, Diseases, and Therapeutic Targets. MedComm (2020). 2026;7:e70883. PMID: 42502712
iPSC-macrophages co-cultured with hepatocytes acquire Kupffer cell identity through direct contact; hepatocytes reciprocally mature; demonstrates that KC phenotype is driven by the hepatic niche, not precursor origin alone. 2026.
IFN-gamma drives macrophages into marathon mode via STAT1/ETC/GBP1; sustains skin granulomas without a foreign invader. New therapeutic target.
IKKbeta activated by apoptotic cell uptake; downstream Myc/TET2/PD-L1 drives resolution. Knockout blocks repair in thymic injury and atherosclerosis.
Mtb selects specific macrophage subsets in cynomolgus macaque granulomas. Population structure matters as much as morphology.
By day 11, macrophages shift from acute activation to chronic immune suppression via transcriptional reprogramming; chromatin remodeling and cytokine milieu change drive the transition.
Cancer cells exploit macrophage PRR pathways for immune evasion; proof that the same machinery used for defense can be turned against the host.
Intermediate monocyte fraction decreases in histiocytosis patients without relapse and predicts recurrence risk independent of CRP; potential circulating biomarker. Hematological Oncology 2026.
2026 comprehensive review of macrophage biology across health and disease; current state of the field.
New in vitro efferocytosis assay applicable across research contexts; visualized, quantitative, generalizable. Methods paper.
Oncoimmunology 2026: higher M1-polarized and lower M2-polarized macrophage density correlate with complete pathological response to neoadjuvant therapy in rectal cancer; multiplex marker panel required; M1/M2 balance in tumor-infiltrating macrophages functions as a clinical predictive biomarker for treatment response.
Histopathology 2026: CD71 (transferrin receptor) expression characterises Rosai-Dorfman disease histiocytes and helps distinguish RDD from LCH, ECD/xanthogranuloma, and other histiocytic proliferations with overlapping morphology; proposes CD71 as a practical adjunct IHC marker in challenging differential diagnoses.
Comprehensive methodological review of MDM differentiation protocols; addresses reproducibility gaps and proposes strategies for physiologically relevant in vitro macrophage polarization modeling. Frontiers in Immunology 2025.
Am J Respir Crit Care Med 2026: MMP12 acts as a macrophage-intrinsic inducer of fibrogenic differentiation within cardiac sarcoidosis granulomas; blocking MMP12 disrupts granuloma architecture and reduces myocardial fibrosis in mouse models; identifies MMP12 as a macrophage-driven molecular link between granulomatous inflammation and fibrotic remodeling.
Am J Respir Crit Care Med 2026: editorial commentary on the granuloma-to-fibrosis transition in cardiac sarcoidosis; discusses how macrophage populations and molecular pathways (including MMP12) mechanistically connect granulomatous inflammation to progressive myocardial fibrosis.
Patient-derived organoids with intact TME; anti-CD47 checkpoint blockade stimulates macrophage phagocytosis but reprograms TAMs toward immunosuppressive SPP1+ state; demonstrates a negative feedback loop limiting the benefit of "don't eat me" signal blockade. 2026 preprint.
Comprehensive review of granuloma etiologies on histopath; diagnostic challenges and emerging approaches including molecular profiling.
RDD can mimic BRAF+ histiocytosis on molecular testing. Emperipolesis on H&E remains the morphologic anchor. Never skip the H&E.
Full text of the genomics review; BRAF, MAP2K1, KRAS, ALK frequency tables across LCH/ECD/RDD.
Leishmania subverts macrophage immunometabolism to survive intracellularly; review covers resistance mechanisms and next-generation therapeutics targeting this interface.
eLife 2026: complement C3 enhances trained immune responses in alveolar macrophages through C3aR signaling, boosting glycolytic activity and inflammatory cytokine production on secondary stimulation; C3-deficient macrophages show impaired phagocytosis and reduced ROS generation; positions complement as a modulator of macrophage innate memory formation.
Pharmacol Res 2026: dioscin reprograms macrophages via AMPK activation, suppressing M1 polarization and IL-1beta production; macrophage depletion abolishes the protective effect; AMPK-driven macrophage metabolic reprogramming as the required intermediary between a plant compound and intestinal stem cell recovery.
Med Oncol 2026: oxidized LDL receptor 1 activates NF-kB in tumor-associated macrophages and shifts them toward immunosuppressive M2 polarization, supporting cancer cell proliferation and migration; OLR1/NF-kB as a macrophage-intrinsic axis linking lipid sensing to immunosuppressive state in the tumor microenvironment.
J Mol Histol 2026: adverse lipid conditions increase CD36 while suppressing ABCA1 in macrophages, driving foam cell formation and atherosclerotic inflammation; HDL rescue restores macrophage cholesterol efflux; CD36/ABCA1 balance as the macrophage lipid-handling checkpoint in diabetic atherosclerosis.
Tissue Barriers 2026: review positions cathepsin D, a lysosomal aspartyl protease, as a key regulator of macrophage phenotype and matrix remodeling during tissue repair; its activity shapes inflammatory macrophage responses and ECM degradation essential for barrier recovery in chronic wound contexts.
Pexidartinib + chemotherapy: decreased tumor growth kinetics and pulmonary metastases by CD8+ T cell-dependent mechanism; CD8 cells do the work, but the macrophage was in the way.
Corticosteroids suppress macrophage activation in sarcoidosis. Methotrexate spares steroids. Anti-TNF biologics (infliximab, adalimumab) for refractory disease; dissolve granulomas by removing the TNF survival signal.
J Mater Chem B 2026: Mn-doped ceria nanoparticles scavenge intracellular ROS in macrophages and promote M2-like polarization with elevated IL-10; polarized macrophages then drive osteogenesis and angiogenesis via BMP-2 and VEGF paracrine signals; redox regulation of macrophage state as an engineering handle for bone repair.
Adv Healthc Mater 2026: apoptotic body-mimetic nanoparticles carrying antioxidants target macrophages and drive anti-inflammatory reprogramming via MAPK and metabolic pathway modulation in diabetic wounds; mimicking the phosphatidylserine signal of apoptotic cells as an engineering strategy to trigger macrophage efferocytic programs for wound resolution.
Frontiers in Medicine 2026 review: corticosteroids remain first-line; steroid-sparing agents (methotrexate, azathioprine) and biologics (anti-TNF) reviewed against a backdrop of sarcoidosis heterogeneity; individualized treatment based on organ involvement and symptom severity. July 2026.
Int Immunopharmacol 2026: engineered nanoparticles including antioxidant nanozymes and extracellular vesicle systems reprogram macrophages toward tissue-repair phenotypes in diabetic foot ulcers; reviews multifunctional nanotherapeutic platforms modulating macrophage polarization to break chronic wound chronicity.
The phagocyte's permanent record. What it is, what it eats, what it leaves behind. Organized by topic. Every claim sourced. Thin evidence marked thin.
Six macrophage populations, each tied to the organ they inhabit. Lineage is from mouse fate-mapping unless noted; human equivalents exist for all.
Core surface and intracellular markers. "Expressed on" covers the predominant macrophage context; expression in other cell types is not listed here.
Granulomas are organized aggregates of macrophages, formed when the macrophage cannot resolve a stimulus. They are chronic by definition. A granuloma that just formed still took weeks.
The entities below (LCH, ECD, RDD, ALK+ histiocytosis) now have a dedicated home at histo.site. What follows is the reference snapshot that was here when phago.site covered them; new work on those diseases is tracked at histo.site.
Kupffer cells (KCs) are the liver's resident macrophage population, strategically placed in hepatic sinusoids to intercept portal blood. They are not a single fixed type. Metabolic state, infectious challenge, and injury context all reshape them; the shift can happen within days. The monocyte-derived liver macrophage adds a second layer that expands under stress and does not always behave like its residential predecessor.
Diseases where the macrophage is not bystander but mechanism. Each entry is a named entity with a macrophage at its center.
Substance-effect-dose table. Doses are from fetched abstract text; rows without an open-access abstract dose are withheld. "Osteoclasts" are macrophage-lineage cells.
| substance | effect | dose | species | method | cite |
|---|---|---|---|---|---|
| LPS (low, M1 co-stimulus) | M1 polarization; IL-6/IL-1β production; ferroportin downregulation | 10 pg/ml (with IFN-gamma 20 ng/ml) | human monocyte-derived macrophages | in vitro M1 polarization assay | Cutone A, et al. Lactoferrin Efficiently Counteracts the Inflammation-Induced Changes of the Iron Homeostasis System in Macrophages. Front Immunol. 2017;8:705. PMID: 28663751 |
| IFN-gamma | M1 polarization (pure M1 protocol with low LPS) | 20 ng/ml (with LPS 10 pg/ml) | human monocyte-derived macrophages | in vitro M1 polarization assay | Cutone A, et al. Lactoferrin Efficiently Counteracts the Inflammation-Induced Changes of the Iron Homeostasis System in Macrophages. Front Immunol. 2017;8:705. PMID: 28663751 |
| LPS (high dose) | pro-inflammatory cytokine production; ferroportin and transferrin receptor 1 downregulation; IL-10 upregulation | 1 µg/ml | human macrophages | in vitro cytokine and iron homeostasis assay | Cutone A, et al. Lactoferrin Efficiently Counteracts the Inflammation-Induced Changes of the Iron Homeostasis System in Macrophages. Front Immunol. 2017;8:705. PMID: 28663751 |
| LPS (mid dose) | M1 polarization of RAW264.7; NF-κB p65 phosphorylation | 100 ng/ml | mouse RAW264.7 | in vitro M1 polarization assay | Wang WT, et al. Syringic acid attenuates acute lung injury by modulating macrophage polarization in LPS-induced mice. Phytomedicine. 2024;129:155591. PMID: 38692075 |
| IL-4 | M2 polarization; CD206, Arg1, IL-10 expression | 20 ng/mL | mouse RAW264.7 | in vitro M2 polarization assay | Yang L, et al. Interleukin-37 ameliorates periodontitis development by inhibiting NLRP3 inflammasome activation and modulating M1/M2 macrophage polarization. J Periodontal Res. 2024;59:128-139. PMID: 37947055 |
| IL-4 (combined with IL-13) | M2 polarization (M2 protocol with IL-13) | 40 ng/mL each | mouse RAW264.7 | in vitro M2 polarization assay | Zhao Q, et al. TNFAIP3 in M2 Macrophage Attenuates Subretinal Fibrosis in Laser-Induced Murine Model. Invest Ophthalmol Vis Sci. 2026;67:25. PMID: 42126158 |
| Dexamethasone | M2 morphotype; CD163 upregulation; prevents LPS/IFN-gamma-induced CD163 downregulation | 100 nM | human monocyte-derived macrophages | in vitro macrophage activation assay | Tedesco S, et al. Phenotypic activation and pharmacological outcomes of spontaneously differentiated human monocyte-derived macrophages. Immunobiology. 2015;220:545-54. PMID: 25582402 |
| Clodronate liposomes | depletion of hepatic and splenic macrophages | 200 µL i.v. per mouse | mouse (strain not stated) | in vivo macrophage depletion | Nieuwenhuijzen GA, et al. Macrophage elimination increases bacterial translocation and gut-origin septicemia but attenuates symptoms and mortality rate in a model of systemic inflammation. Ann Surg. 1993;218:791-9. PMID: 8257230 |
| PLX5622 (CSF1R inhibitor) | 70-80% microglia depletion; peripheral monocyte and macrophage depletion | 1200 ppm in diet for 7 days | mouse C57BL/6 | in vivo dietary CSF1R inhibition | Mein N, et al. Low-dose PLX5622 treatment prevents neuroinflammatory and neurocognitive sequelae after sepsis. J Neuroinflammation. 2023;20:289. PMID: 38041192 |
| Zoledronate (bisphosphonate) | osteoclast apoptosis; inhibits bone resorption; reduces osteoclast count | 500 nM | murine osteoclasts (macrophage-lineage) | in vitro dentine disk resorption assay | Manzano-Moreno FJ, et al. Influence of pH on osteoclasts treated with zoledronate and alendronate. Clin Oral Investig. 2019;23:813-820. PMID: 29876664 |
| Emactuzumab (anti-CSF1R mAb) | TAM depletion; clinical responses in diffuse-type giant cell tumour (CSF1R-overexpressing macrophage-lineage neoplasm); dose-dependent decrease in CD68+ macrophages | 1000 mg IV every 2 weeks | human | phase I clinical trial, diffuse-type giant cell tumour | Cassier PA, et al. CSF1R inhibition with emactuzumab in locally advanced diffuse-type tenosynovial giant cell tumours of the soft tissue: a dose-escalation and dose-expansion phase 1 study. Lancet Oncol. 2015;16:949-56. PMID: 26179200 |
| Pexidartinib (PLX3397, oral CSF1R inhibitor) | CSF1R inhibition; 39% objective response rate in tenosynovial giant cell tumour (CSF1-overexpressing macrophage-lineage neoplasm); depletion of CSF1R+ macrophage-lineage cells | loading 1000 mg/day orally x 2 weeks, then 800 mg/day x 22 weeks | human | phase 3 RCT (ENLIVEN), TGCT | Tap WD, et al. Pexidartinib versus placebo for advanced tenosynovial giant cell tumour (ENLIVEN): a randomised phase 3 trial. Lancet. 2019;394:478-487. PMID: 31229240 |
| 2026 | Mathematical model quantifies when phagocytosis confers competitive advantage; engulfment rate is the key determinant; a primitive phagocytoser can outperform the ancestor in a range of situations | https://pubmed.ncbi.nlm.nih.gov/42842363/ | primary literature | | 2026 | Macrophages employ distinct actin strategies depending on target: tight membrane cups for apoptotic cells alone, protrusive extensions for bacteria-laden apoptotic cells; most phagosomes contain one target type; active sorting, not indiscriminate engulfment | https://pubmed.ncbi.nlm.nih.gov/42842582/ | primary literature | | 2026 | Inducible human yolk sac myeloid progenitors transplanted in vivo acquire organ-specific tissue-resident macrophage identities: microglia, Kupffer cells, border-associated macrophages, cardiac and renal macrophages | https://pubmed.ncbi.nlm.nih.gov/42838060/ | primary literature | | 2026 | GPR18 induced by inflammatory stimuli via NFkB p65 and IRF1; myeloid Gpr18-knockout mice accumulate Ly6Chi monocytes in hypersensitivity responses; GPR18 participates in inflammatory macrophage subtype specification | https://pubmed.ncbi.nlm.nih.gov/42848422/ | primary literature | | 2026 | Macrophage LAMTOR2 required for TFR1 lysosomal trafficking and iron recycling from aged erythrocytes; LAMTOR2 loss causes TFR1 shift to hyperacidified lysosomes, iron-restricted erythropoiesis, and compensatory extramedullary hematopoiesis | https://pubmed.ncbi.nlm.nih.gov/42845059/ | primary literature | | 2026 | AML leukemic cells transfer mitochondria to macrophages via tunneling nanotubes; metabolic rewiring shifts macrophages toward OXPHOS, impairs phagocytosis, and promotes immune escape in pediatric AML | https://pubmed.ncbi.nlm.nih.gov/42855473/ | primary literature | | 2026 | Early DNase activity present at the nascent phagocytic cup before closure; membrane-bound DNaseX constitutively recruited to the cup; F-actin correlates with DNaseX at the cup; macrophages degrade extracellular DNA in bacterial biofilms by direct contact without internalisation; species: various macrophage types (not named in abstract); method: fluorescent DNase sensor | https://pubmed.ncbi.nlm.nih.gov/42848625/ Pyne A, Pandey V, et al. eLife 2026 | primary literature | | 2026 | Inflammatory TBK1+CASP1+ Kupffer cell state identified in steatotic liver disease by scRNA-seq; cell-type-specific TBK1 functions in Kupffer cells vs hepatocytes are separable; inflammatory KC state correlates with fibrosis | https://pubmed.ncbi.nlm.nih.gov/42764693/ | primary literature |
Efferocytosis is the macrophage's quiet second job. Find, engulf, reset. When the machinery jams, debris accumulates and inflammation does not resolve.
| 2026 | SILAC-DIA proteomics identifies CD97 (Adgre5) as a novel efferocytosis-associated receptor; CD97 facilitates apoptotic cell uptake in mouse, human, and Drosophila models; potential MerTK co-receptor; expands the known efferocytosis receptor repertoire | https://pubmed.ncbi.nlm.nih.gov/42811049/ | primary literature | | 2026 | CD74 accumulates in lysosomes when cathepsin S is blocked; accumulated CD74 reduces myosin II activity, impairing the cytoskeletal mechanics of efferocytosis; CD74 overexpression worsens atherosclerotic plaque formation in mice | https://pubmed.ncbi.nlm.nih.gov/42833529/ | primary literature | | 2026 | MERTK inhibition suppresses macrophage M2 polarisation via PI3K/Akt and reduces osteopontin secretion; improves lung function in pulmonary fibrosis models even when started during active fibrosis development | https://pubmed.ncbi.nlm.nih.gov/42836432/ | primary literature | | 2026 | Monotropein raises miR-495, reduces SIRPalpha expression, and derepresses macrophage efferocytosis of foam cells in atherosclerotic plaque; SIRPalpha as a pharmacologically tractable efferocytosis brake | https://pubmed.ncbi.nlm.nih.gov/42828303/ | primary literature |
The granuloma section earned its own address.
Last updated: 2026-09-14 (scan). Topics: 18 sections. Running total: 294 feed rows.
Am J Respir Crit Care Med 2026: MMP12 acts as a macrophage-intrinsic inducer of fibrogenic differentiation within cardiac sarcoidosis granulomas; blocking MMP12 disrupts granuloma architecture and reduces myocardial fibrosis in mouse models; identifies MMP12 as a macrophage-driven molecular link between granulomatous inflammation and fibrotic remodeling.
Am J Respir Crit Care Med 2026: editorial commentary on the granuloma-to-fibrosis transition in cardiac sarcoidosis; discusses how macrophage populations and molecular pathways (including MMP12) mechanistically connect granulomatous inflammation to progressive myocardial fibrosis.
Dairy bacterial exopolysaccharides boost macrophage killing via IL-12 and macrophage-NK cell crosstalk; a dietary route to macrophage activation.
TREM2+ macrophages occupy spatially distinct kidney compartments; their distribution predicts protection against diabetic nephropathy. Tissue macrophage heterogeneity with functional consequence.
Leishmania subverts macrophage immunometabolism to survive intracellularly; review covers resistance mechanisms and next-generation therapeutics targeting this interface.
A cardiac macrophage-specific circular RNA (circHIPK2) regulates post-infarction inflammation and remodeling; tissue-resident macrophage identity encoded in non-coding RNA.
Patient-derived organoids with intact TME; anti-CD47 checkpoint blockade stimulates macrophage phagocytosis but reprograms TAMs toward immunosuppressive SPP1+ state; demonstrates a negative feedback loop limiting the benefit of "don't eat me" signal blockade. 2026 preprint.
iPSC-macrophages co-cultured with hepatocytes acquire Kupffer cell identity through direct contact; hepatocytes reciprocally mature; demonstrates that KC phenotype is driven by the hepatic niche, not precursor origin alone. 2026.