Lactotransferrin human milk

Stephens, S., Dolby, J.M., Montreuil, J., and Spik, G. 1980. Differences in inhibition of the growth of commensal and enteropathogenic strains of Escherichia coli by lactotransferrin and secretory immunoglobulin A isolated from human milk. Immunology 41, 597-603. 

Lactoferrin was first identified as a red protein fraction in human milk (1). The milk protein has been called by various names of red milk protein, ekkrino-siderophilin, and lactotransferrin which is in turn very similar in many respects to transferrin, the ironbinding protein of serum. The concentration of lactoferrin in human milk is unusally rich with a range of 7 mg/ml in colostrum to approximately 1 mg/ml in mature milk (2). However, the bovine colostrum contains lactoferrin at concentrations of 5 mg/ml, which drops very rapidly with stage of lactation to where mature bovine milk contains 20-200 pg/ml of lactroferrin (3). Lactoferrin is also found in various other exocrine secretions of the body such as vaginal, nasal, bronchial and intestinal (4 6). 

Lactoferrin, lactotransferrin. Important component of the human milk bacteriostatic system also found in human and bovine tear proteins. Isoln from human whey by a single chromatographic step L. Blackberg, O. Hernell, FEES... 

Human colostrum and milk contain 6-8 mg ml and 2-4 mg ml lactotransferrin, respectively, representing about 20% of the total protein in the latter bovine colostrum and milk contain about 1 and 0.02-0.35 mg ml respectively. The concentration of lactotransferrin in human milk decreases slightly during lactation but appears to increase slightly in bovine milk and very markedly during the dry period. 

These findings caught the attention of many milk companies since, rightly or wrongly, a nutritional role was suggested for these proteins in iron transport for the mammalian newborn. The discovery of lactotransferrin specific receptors in the brush-border of enterocytes [48] supports this concept. In addition, as suggested by Montreuil et al. [34], human lactotransferrin could intervene in the intestinal defence of breast-fed infants by a... 

In 1963, using immunoelectrophoresis, Biserte et al. [49] demonstrated that lactotransferrin was present in bronchial secretions. This result was confirmed in 1965 by Masson et al. [37] who, in addition, localized the lactotransferrin in human bronchial glands by immuno-histochemistry. Lactotransferrin has been identified, mainly due to the work of Masson, in most mucous secretions, i.e., bronchial and intestinal mucus and in various biological fluids such as saliva, tears, synovial fluid, seminal plasma, pancreatic juice, bile and, in very small amount, in blood plasma. In milk and mucous secretions, lactotransferrin is associated with secretory IgA (sIgA) and lysozyme and we now know that this association represents a powerful system of defence of mucosae (see section 2.3.2.1.2). 

Serotransferrin glycans are generally non-fucosylated except in human cerebrospinal fluid (trace amounts) [246,247], rat (20-30% of the molecules) [221], pig (100% of the molecules) [220] and the serotransferrin-like glycoprotein from mouse milk [218,219] in which this protein co-exists with a lactotransferrin. None of the serotransferrin glycans... 

Fig. 11. Primary structure of the glycans from human leukocyte lactotransferrin (A) [226] and human (B,C,D) [211,227-230], Rhesus monkey (A) [231], sheep (A) [232], goat (B,C) [119,228,232], and mouse (B,C)[119, 218,233] milk lactotransferrins. E, human recombinant lactotransferrin expressed in BHK cells [234],...

Lactotransferrins have been isolated from the milks of several species, including human and bovine, and some have been well characterized, including determination of their amino acid sequence. Some of the isolation procedures have industrial-scale potential the preparations obtained from such procedures usually contain both Lf and LPO. 

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