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Colostrum is the first form of milk produced by the mammary glands of mammals immediately following delivery of the newborn. Most species will begin to generate colostrum just prior to giving birth. Colostrum has an especially high amount of bioactive compounds compared to mature milk to give the newborn the best possible start to life. Specifically, colostrum contains antibodies to protect the newborn against disease and infection, and immune and growth factors and other bioactives that help to activate a newborn’s immune system, jumpstart gut function, and seed a healthy gut microbiome in the first few days of life. The bioactives found in colostrum are essential for a newborn’s health, growth and vitality.
Lactoferrin (LF), also known as lactotransferrin (LTF), is a multifunctional protein of the transferrin family. Lactoferrin is a globular glycoprotein with a molecular mass of about 80 kDa that is widely represented in various secretory fluids, such as milk, saliva, tears, and nasal secretions. Lactoferrin is also present in secondary granules of PMNs and is secreted by some acinar cells. Lactoferrin can be purified from milk or produced recombinantly. Human colostrum has the highest concentration, followed by human milk, then cow milk (150 mg/L).
Defensins are small cysteine-rich cationic proteins across cellular life, including vertebrate and invertebrate animals, plants, and fungi. They are host defense peptides, with members displaying either direct antimicrobial activity, immune signalling activities, or both. They are variously active against bacteria, fungi and many enveloped and nonenveloped viruses. They are typically 18-45 amino acids in length, with three or four highly conserved disulphide bonds.
Antimicrobial peptides (AMPs), also called host defence peptides (HDPs) are part of the innate immune response found among all classes of life. Fundamental differences exist between prokaryotic and eukaryotic cells that may represent targets for antimicrobial peptides. These peptides are potent, broad spectrum antibiotics which demonstrate potential as novel therapeutic agents. Antimicrobial peptides have been demonstrated to kill Gram negative and Gram positive bacteria, enveloped viruses, fungi and even transformed or cancerous cells. Unlike the majority of conventional antibiotics it appears that antimicrobial peptides frequently destabilize biological membranes, can form transmembrane channels, and may also have the ability to enhance immunity by functioning as immunomodulators.
Paneth cells are cells in the small intestine epithelium, alongside goblet cells, enterocytes, and enteroendocrine cells. Some can also be found in the cecum and appendix. They are below the intestinal stem cells in the intestinal glands and the large eosinophilic refractile granules that occupy most of their cytoplasm.
Cathelicidin antimicrobial peptide (CAMP) is a polypeptide that is primarily stored in the lysosomes of macrophages and polymorphonuclear leukocytes (PMNs); in humans, the CAMP gene encodes the peptide precursor CAP-18, which is processed by proteinase 3-mediated extracellular cleavage into the active form LL-37.
Beta-defensin 2 (BD-2) also known as skin-antimicrobial peptide 1 (SAP1) is a peptide that in humans is encoded by the DEFB4 gene.
Beta defensins are a family of mammalian defensins. The beta defensins are antimicrobial peptides implicated in the resistance of epithelial surfaces to microbial colonization.
Defensin, alpha 1 also known as human alpha defensin 1, human neutrophil peptide 1 (HNP-1) or neutrophil defensin 1 is a human protein that is encoded by the DEFA1 gene. Human alpha defensin 1 belongs to the alpha defensin family of antimicrobial peptides.
Beta-defensin 1 is a protein that in humans is encoded by the DEFB1 gene.
Beta-defensin 103 is a protein that in humans is encoded by the DEFB103A gene.
Arthropod defensins are a family defensin proteins found in mollusks, insects, and arachnids. These cysteine-rich antibacterial peptides are primarily active against Gram-positive bacteria and fungi in vitro. However Drosophila fruit flies mutant for the fly defensin were more susceptible to infection by the Gram-negative bacteria Providencia burhodogranariea, and resisted infection against Gram-positive bacteria like wild-type flies. It remains to be seen how in vitro activity relates to in vivo function. Mutants for the defensin-like antimicrobial peptide Drosomycin were more susceptible to fungi, validating a role for defensin-like peptides in anti-fungal defence.
Defensin, alpha 5 (DEFA5) also known as human alpha defensin 5 (HD5) is a protein that in humans is encoded by the DEFA5 gene. DEFA5 is expressed in the Paneth cells of the ileum.
Beta-defensin 106 is a protein that in humans is encoded by the DEFB106A gene.
Protegrins are small peptides containing 16-18 amino acid residues. Protegrins were first discovered in porcine leukocytes and were found to have antimicrobial activity against bacteria, fungi, and some enveloped viruses. The amino acid composition of protegrins contains six positively charged arginine residues and four cysteine residues. Their secondary structure is classified as cysteine-rich β-sheet antimicrobial peptides, AMPs, that display limited sequence similarity to certain defensins and tachyplesins. In solution, the peptides fold to form an anti-parallel β-strand with the structure stabilized by two cysteine bridges formed among the four cysteine residues. Recent studies suggest that protegrins can bind to lipopolysaccharide, a property that may help them to insert into the membranes of gram-negative bacteria and permeabilize them.
Hypothiocyanite is the anion [OSCN]− and the conjugate base of hypothiocyanous acid (HOSCN). It is an organic compound part of the thiocyanates as it contains the functional group SCN. It is formed when an oxygen is singly bonded to the thiocyanate group. Hypothiocyanous acid is a fairly weak acid; its acid dissociation constant (pKa) is 5.3.
Michael A. Zasloff is an American physician, medical researcher, and entrepreneur. Zasloff is primarily known for his work on antimicrobial peptides.
Brilacidin, an investigational new drug (IND), is a polymer-based antibiotic currently in human clinical trials, and represents a new class of antibiotics called host defense protein mimetics, or HDP-mimetics, which are non-peptide synthetic small molecules modeled after host defense peptides (HDPs). HDPs, also called antimicrobial peptides, some of which are defensins, are part of the innate immune response and are common to most higher forms of life. As brilacidin is modeled after a defensin, it is also called a defensin mimetic.
Drosomycin is an antifungal peptide from Drosophila melanogaster and was the first antifungal peptide isolated from insects. Drosomycin is induced by infection by the Toll signalling pathway, while expression in surface epithelia like the respiratory tract is instead controlled by the immune deficiency pathway (Imd). This means that drosomycin, alongside other antimicrobial peptides (AMPs) such as cecropins, diptericin, drosocin, metchnikowin and attacin, serves as a first line defence upon septic injury. However drosomycin is also expressed constitutively to a lesser extent in different tissues and throughout development.
References
- ↑ Huttner KM, Brezinski-Caliguri DJ, Mahoney MM, Diamond G (February 1998). "Antimicrobial peptide expression is developmentally regulated in the ovine gastrointestinal tract". The Journal of Nutrition. 128 (2 Suppl): 297S–299S. doi: 10.1093/jn/128.2.297s . PMID 9478010.
- ↑ Schonwetter BS, Stolzenberg ED, Zasloff MA (March 1995). "Epithelial antibiotics induced at sites of inflammation". Science. 267 (5204): 1645–8. Bibcode:1995Sci...267.1645S. doi:10.1126/science.7886453. PMID 7886453. S2CID 85415552.
- ↑ Stolzenberg ED, Anderson GM, Ackermann MR, Whitlock RH, Zasloff M (August 1997). "Epithelial antibiotic induced in states of disease". Proceedings of the National Academy of Sciences of the United States of America. 94 (16): 8686–90. Bibcode:1997PNAS...94.8686S. doi: 10.1073/pnas.94.16.8686 . PMC 23078 . PMID 9238038.
- ↑ Isobe N, Nakamura J, Nakano H, Yoshimura Y (June 2009). "Existence of functional lingual antimicrobial peptide in bovine milk". Journal of Dairy Science. 92 (6): 2691–5. doi: 10.3168/jds.2008-1940 . PMID 19448002.
- ↑ Mak P, Wójcik K, Thogersen IB, Dubin A (November 1996). "Isolation, antimicrobial activities, and primary structures of hamster neutrophil defensins". Infection and Immunity. 64 (11): 4444–9. doi:10.1128/IAI.64.11.4444-4449.1996. PMC 174396 . PMID 8890190.
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