CD Markers - CD14

Home Chapter Home Jobs Conferences Fellowships Books

CD Markers

CD14

Reviewers: Nat Pernick, M.D., PathologyOutlines.com (see Reviewers page)
Revised: 6 January 2011, last major update January 2011
Copyright: (c) 2002-2011, PathologyOutlines.com, Inc.

General
=========================================================================

● Pattern recognition receptor that detects antigenic molecules on the surface of various microorganisms

Terminology
=========================================================================

● Also called lipopolysaccharide (LPS) receptor, monocyte differentiation antigen

Physiology
=========================================================================

● 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 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, MD-2 and TLR4 bind to LPS, causing macrophage activation and release of cytokines; overstimulation may cause toxic shock syndrome
● Detection of lipopolysaccharide induces IL-12 production (mediated by CD14), producing interferon gamma, which steers immune system away from allergy driven Thelper2 phenotype, associated with IgE production
● Important for clearance of apoptotic cells (Nature 1998;392:505)
● 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)

Diagrams
=========================================================================

CD14 dependent vs. independent pathways

Toll-like receptor pathways

Recognition of lipopolysaccharide

Membrane bound and serum forms of CD14

Clinical features
=========================================================================

● Mutations can prevent adequate inflammatory response to infection, leading to systemic infections

Uses for pathologists
=========================================================================

● Identify mature monocytes/macrophages

Micro images
=========================================================================

Appendix macrophages and dendritic cells are CD14+

Colon

Hepatic Kuppfer cells and sinusoidal endothelial cells are CD14+

Lymph node (normal)

Various images

Positive stains - normal
=========================================================================

● Macrophages/monocytes (90%), Langerhans cells, dendritic cells, B cells, granulocytes-weak (30%)

Positive stains - disease
=========================================================================

● AML-M4/M5 (50-90%), chronic myelomonocytic leukemia, histiocytic sarcoma

Negative stains
=========================================================================

● Myeloid progenitors, AML M0-M2 (usually), M3, M6, 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

Additional references
=========================================================================

● MIM 158120

End of CD Markers > CD14

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).