Paneth cells is also called  Davidoff's Cell,  specialized type of epithelial cell found in the mucous-membrane lining of the small intestine and of the appendix, at the base of tubelike depressions known as Lieberkühn glands. Named for the 19th-century Austrian physiologist Joseph Paneth, the cell has one nucleus at its base and densely packed secretory granules throughout the rest of its body.

Paneth cells provide host defense against microbes in the small intestine. They are functionally similar to neutrophils. When exposed to bacteria or bacterial antigens, Paneth cells secrete a number of antimicrobial molecules into the lumen of the crypt, thereby contributing to maintenance of the gastrointestinal barrier.

alpha-Defensins (cryptdins)

• a major constituent of Paneth cells. PMID: 14715526

Cryptdins

• are antimicrobial peptides of the defensin family that are produced by intestinal Paneth cells. PMID: 7927786, PMID: 11960772
• antimicrobial peptides of the defensin family that are expressed specifically by Paneth cells in small intestinal crypts. PMID: 8760109
• constitute a diverse population of defensins in Paneth cells of intestinal crypts. PMID: 7896294

Cryptdin-1

• a murine Paneth cell defensin, is one of the earliest markers in Paneth cells. PMID: 1618314, PMID: 1500163

Cryptdin-2

• a useful marker of crypt morphogenesis and a valuable tool for conducting gain-of-function or loss-of-function experiments in Paneth cells. PMID: 7937951, PMID: 1500163

Cryptdin-3

• Immunohistochemical localization demonstrated that cryptdin-1, and probably cryptdins 2 and 3, occur exclusively in Paneth cells, where the peptides appear to be associated with cytoplasmic granules. PMID: 1500431

Cryptdin-4

• a mouse paneth cell alpha-defensin. PMID: 15595831, PMID: 14702345
• a differentially expressed mouse paneth cell alpha-defensin. PMID: 10569786

Defensins

• Paneth cell defensins are early markers of crypt ontogeny and are therefore useful in studies of lineage determination in the intestinal epithelium. PMID: 8836041
• In the small intestine, Paneth cells at the base of the crypts of Lieberkuhn secrete alpha-defensins and additional AMPs at high levels in response to cholinergic stimulation and when exposed to bacterial antigens. PMID: 16909916
• The antimicrobial peptide human alpha-defensin 5 (HD5) is expressed in Paneth cells, secretory epithelial cells in the small intestine. PMID: 12021776

Enhancing factor (EF)

• a 14 kDa protein, isolated from mouse small intestines, is a Paneth cell specific growth factor modulator. EF is localized in the Paneth cells of small intestines, is a Paneth cell-specific marker. PMID: 8267767, PMID: 1787109

GM-CSF (granulocyte-macrophage colony-stimulating factor)

• GM-CSF gene is specifically present in Paneth cells, whereas GM-CSF receptor beta-chain mRNA is expressed in Paneth cells and other epithelial cells. There was intense immunohistochemical staining of GM-CSF in Paneth cells but not in other epithelial cells. PMID: 14651956

HD-5 (Human Defensin 5)

• selectively stained Paneth cells of the normal adult small intestine. Immunogold electron microscopy further localized HD-5 to the Paneth cell secretory granules. PMID: 9169779

Lysozyme

• a marker for normal Paneth cells. PMID: 6996310
• immunohistochemically identified as a component of the Paneth cell secretory granule, was evident in the glandular lumina and in degranulated Paneth cells. PMID: 1869451
• the lysozyme of the succus entericus is, at least in part, derived from the Paneth cell, and is probably present in the Paneth cell granules. PMID: 1167179

Matrilysin

• In mouse small intestine, matrilysin colocalized with alpha-defensins (cryptdins) in Paneth cell granules, and in vitro it cleaved the pro segment from cryptdin precursors. PMID: 10506557

PLA2 (group II phospholipase A2)

• a marker of Paneth cell differentiation. PMID: 11469501
• marker of Paneth cell secretion. PMID: 8945560
• PLA2-II was localized by immunohistochemistry in Paneth cells in three patients with areas of intestinal metaplasia of the gastric mucosa and in Paneth cells of duodenal and jejunal mucosa in all patients, but not in any other epithelial cell type of the mucosa of the stomach or the small intestine. Inflammatory cells did not contain PLA2-II. The current results suggest that PLA2-II found in gastric juice is derived from the Paneth cells of the small intestinal mucosa. PMID: 12004927
• PLA2 protein was localized in the Paneth cells of the intestinal mucosa, chondrocytes and the matrix of cartilage, and megakaryocytes in the spleen. By Northern blotting, mRNA of PLA2 was found in the gastrointestinal tract, lung, heart, and spleen. By in situ hybridization, PLA2 mRNA was localized in the Paneth cells of the small intestinal mucosa but in no other cell types. PMID: 11036090
• nonpancreatic group II PLA2 is synthesized and stored by Paneth cells, whereas other cell types of the gastrointestinal tract seem incapable of synthesis of this enzyme. PMID: 7853853
• By immunohistochemistry, syn-PLA2 was localized in Paneth cell secretory granules, chondrocytes, cartilage matrix, and glandular cells of prostate. PMID: 8406689

Trypsin

• By acting as a prodefensin convertase in human Paneth cells, trypsin is involved in the regulation of innate immunity in the small intestine. PMID: 12021776