CD Markers

Author: Nat Pernick, M.D. (see Authors page)

Revised: 22 December 2015, last major update December 2013

Copyright: (c) 2003-2015,, Inc.

PubMed Search: CD14[title]
Cite this page: CD14. website. Accessed July 21st, 2018.
Definition / general
  • Pattern recognition receptor that detects antigenic molecules on the surface of various microorganisms
  • Also called lipopolysaccharide (LPS) receptor, monocyte differentiation antigen
  • Mutations can prevent adequate inflammatory response to infection, leading to systemic infections
  • References: OMIM #158120
Diagrams / tables

Images hosted on other servers:

Toll-like receptor pathways

Membrane bound and serum forms of CD14

Images hosted on

Independent vs. dependent pathways

Recognition of lipopolysaccharide

  • GPI linked pattern recognition receptor that detects antigenic molecules on the surface of bacteria (lipoteichoic acid on gram positive, lipopolysaccharides on gram negative), myobacteria (glycolipids) and fungi (mannans), as part of the innate (non-adaptive) immune system (adaptive immune system refers to lymphocytes recognizing microorganism proteins via T cell receptors and antibodies)
  • Soluble form of CD14 is secreted by liver and monocytes; in low concentrations it confers LPS responsiveness to cells which are otherwise CD14 negative
  • Macrophages with a multiprotein complex of CD14, MD2 and TLR4 bind to LPS, causing macrophage activation and release of cytokines (Mol Immunol 2014;57:210); overstimulation may cause toxic shock syndrome (Nature 1998;392:505)
  • Detection of lipopolysaccharide induces IL12 production (mediated by CD14), producing interferon gamma, which steers immune system away from allergy driven Th2 phenotype, associated with IgE production
  • Important for clearance of apoptotic cells (Nature 1998;392:505, PLoS One 2013;8:e70691)
  • Early promonocytes express MY4 epitope; mature monocytes express MO2 epitope; neoplastic monocytes also often express MY4 but not MO2 (Am J Clin Pathol 2005;124:930)
Clinical features
Uses by pathologists
  • Identify mature monocytes / macrophages
Microscopic (histologic) images

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Various images

Appendix: macrophages and dendritic cells are CD14+

Bone marrow: normal (fig C)

Bone marrow: acute monoblastic leukemia (fig F)

Bone marrow: acute myelomonocytic leukemia (fig F)

CNS: microglia in Alzheimer patients

Liver: Kuppfer & sinusoidal endothelial cells are CD14+

Liver: biliary atresia

Lymph node (normal)

Positive staining - normal
  • Macrophages / monocytes (90%), Langerhans cells, dendritic cells, B cells and granulocytes-weak (30%)
Positive staining - disease
Negative staining
  • Myeloid progenitors, AML M0-M2 (usually), M3, M6 and M7
  • Sinusoidal histiocytes with phagocytic properties (erythrophagocytosis, anthracosis, tingible body macrophages, Hum Pathol 2006;37:68), Gaucher's macrophages (Hum Pathol 1992;23:1410)
  • Most epithelial and endothelial cells