CD14
Cluster of differentiation 14 also known as CD14 is a human gene.[1][2]
The protein encoded by this gene is a component of the innate immune system. CD14 exists in two forms. Either it is anchored into the membrane by a glycosylphosphatidylinositol tail (mCD14) or it appears in a soluble form (sCD14). Soluble CD14 either appears after shedding of mCD14 (48 KDa) or is directly secreted from intracellular vesicles (56 KDa).[3]
CD14 takes its name from its inclusion in the cluster of differentiation group of cell surface marker proteins.
CD14 was the first described pattern recognition receptor.
Function
CD14 acts as a co-receptor (along with the Toll-like receptor TLR 4 and MD-2) for the detection of bacterial lipopolysaccharide (LPS).[4][5] CD14 can bind LPS only in the presence of lipopolysaccharide-binding protein (LBP). Although LPS is considered its main ligand, CD14 also recognizes other pathogen-associated molecular patterns.
Tissue distribution
CD14 is expressed mainly by macrophages and (at 10 times lesser extent) by neutrophil granulocytes. It is also expressed by dendritic cells. A soluble form sCD14 is secreted by the liver and monocytes and is sufficient in low concentrations to confer LPS-responsiveness to cells that otherwise do not express CD14. sCD14 is also present in human milk, where it is believed to regulate microbial growth in the infant gut.
Differentiation
CD14+ cells are monocytes that can differentiate into a host of different cells. (A '+' sign refers to the presence of the CD14 protein on a cell. )
One type of cell is the dendritic cell, where differentiation is encouraged by cytokines. Examples of cytokines that will cause dendritic cell differentiation includes GM-CSF and IL-4.
Interactions
CD14 has been shown to interact with Lipopolysaccharide-binding protein.[6][7]
References
- ^ Setoguchi M, Nasu N, Yoshida S, Higuchi Y, Akizuki S, Yamamoto S (July 1989). "Mouse and human CD14 (myeloid cell-specific leucine-rich glycoprotein) primary structure deduced from cDNA clones". Biochim. Biophys. Acta 1008 (2): 213–22. doi:10.1016/0167-4781(80)90012-3. PMID 2472171.
- ^ Simmons DL, Tan S, Tenen DG, Nicholson-Weller A, Seed B (1 January 1989). "Monocyte antigen CD14 is a phospholipid anchored membrane protein". Blood 73 (1): 284–9. PMID 2462937. http://www.bloodjournal.org/cgi/pmidlookup?view=long&pmid=2462937.
- ^ Kirkland TN, Viriyakosol S (1998). "Structure-function analysis of soluble and membrane-bound CD14". Prog. Clin. Biol. Res. 397: 79–87. PMID 9575549.
- ^ Kitchens RL (2000). "Role of CD14 in cellular recognition of bacterial lipopolysaccharides". Chem. Immunol.. Chemical Immunology and Allergy 74: 61–82. doi:10.1159/000058750. ISBN 3-8055-6917-3. PMID 10608082.
- ^ Tapping RI, Tobias PS (2000). "Soluble CD14-mediated cellular responses to lipopolysaccharide". Chem. Immunol.. Chemical Immunology and Allergy 74: 108–21. doi:10.1159/000058751. ISBN 3-8055-6917-3. PMID 10608084.
- ^ Thomas, Celestine J; Kapoor Mili, Sharma Shilpi, Bausinger Huguette, Zyilan Umit, Lipsker Dan, Hanau Daniel, Surolia Avadhesha (Nov. 2002). "Evidence of a trimolecular complex involving LPS, LPS binding protein and soluble CD14 as an effector of LPS response". FEBS Lett. (Netherlands) 531 (2): 184–8. doi:10.1016/S0014-5793(02)03499-3. ISSN 0014-5793. PMID 12417309.
- ^ Yu, B; Wright S D (1995). "LPS-dependent interaction of Mac-2-binding protein with immobilized CD14". J. Inflamm. (UNITED STATES) 45 (2): 115–25. ISSN 1078-7852. PMID 7583357.
External links
Further reading
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CD1 ( a-c, 1A, 1D, 1E) · CD2 · CD3 ( γ, δ, ε) · CD4 · CD5 · CD6 · CD7 · CD8 ( a) · CD9 · CD10 · CD11 ( a, b, c) · CD13 · CD14 · CD15 · CD16 ( A, B) · CD18 · CD19 · CD20 · CD21 · CD22 · CD23 · CD24 · CD25 · CD26 · CD27 · CD28 · CD29 · CD30 · CD31 · CD32 ( A, B) · CD33 · CD34 · CD35 · CD36 · CD37 · CD38 · CD39 · CD40 · CD41 · CD42 ( a, b, c, d) · CD43 · CD44 · CD45 · CD46 · CD47 · CD48 · CD49 ( a, b, c, d, e, f) · CD50
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| 51-100 |
CD51 · CD52 · CD53 · CD54 · CD55 · CD56 · CD57 · CD58 · CD59 · CD61 · CD62 ( E, L, P) · CD63 · CD64 ( A, B, C) · CD66 ( a, b, c, d, e, f) · CD68 · CD69 · CD70 · CD71 · CD72 · CD73 · CD74 · CD78 · CD79 ( a, b) · CD80 · CD81 · CD82 · CD83 · CD84 · CD85 ( a, d, e, h, j, k) · CD86 · CD87 · CD88 · CD89 · CD90 · CD91- CD92 · CD93 · CD94 · CD95 · CD96 · CD97 · CD98 · CD99 · CD100
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CD151 · CD152 · CD153 · CD154 · CD155 · CD156 ( a, b, c) · CD157 · CD158 ( a, d, e, i, k) · CD159 ( a, c) · CD160 · CD161 · CD162 · CD163 · CD164 · CD166 · CD167 ( a, b) · CD168 · CD169 · CD170 · CD171 · CD172 ( a, b, g) · CD174 · CD177 · CD178 · CD179 ( a, b) · CD181 · CD182 · CD183 · CD184 · CD185 · CD186 · CD191 · CD192 · CD193 · CD194 · CD195 · CD196 · CD197 · CDw198 · CDw199 · CD200
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| Lymphoid |
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| Myeloid |
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| Stem cell |
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cell/phys (coag, heme, immu, gran), csfs
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rbmg/mogr/tumr/hist, sysi/epon, btst
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drug (B1/2/3+5+6), btst, trns
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cell/phys/auag/auab/comp, igrc
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| Receptor |
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| Other external |
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| Internal |
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B trdu: iter (nrpl/grfl/cytl/horl), csrc (lgic, enzr, gprc, igsr, intg, nrpr/grfr/cytr), itra (adap, gbpr, mapk), calc, lipd; path (hedp, wntp, tgfp+mapp, notp, jakp, fsap, hipp, tlrp)
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