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PubMed2002

Immunocytochemical localization of lysozyme and lactoferrin attached to surface bacteria of the palatine tonsils during infectious mononucleosis.

Bacterial samples were obtained from the tonsillar surfaces of seven patients (four males, three females; median age 18 years, range 15 to 21 years) suffering from acute infectious mononucleosis with concomitant pharyngotonsillitis, and from five healthy controls. By using gold-labelled antiserum to human lysozyme and lactoferrin, micro-organisms on the tonsillar surfaces coated with these antibacterial substances could be identified by tracing the gold particles in the transmission electron microscope. In healthy individuals, most of the bacteria were coated with lysozyme and significantly more bacteria were coated with lysozyme than with lactoferrin (p < 0.01). In patients there was a non-significant reduction in lysozyme-coating of the bacteria, whereas lactoferrin-coating was significantly increased (p < 0.01). Changes in the lysozyme and/or lactoferrin coating of the tonsillar surface bacteria on the palatine tonsils during infectious mononucleosis cannot explain the tendency to immense local bacterial colonization with commensals and proneness to bacterial penetration into the epithelial cells.

Adolescent↗
PubMed2000

Role of basic residues of human lactoferrin in the interaction with B lymphocytes.

We have previously demonstrated that lactoferrin was incorporated into B lymphocytes and that a trypsin treatment for a short period reduced the number of lactoferrin molecules incorporated into B lymphocytes. An N-terminal sequence analysis revealed that the mild trypsin treatment had cleaved the three N-terminal amino acids, Gly1-Arg2-Arg3. Chemical conjugation of lost sequence analogue Gly-Arg-Arg-Gly with the mildly digested lactoferrin recovered the interaction with B lymphocytes, while conjugation of acetyl-Arg-Arg-Gly, a deamino analogue of Gly-Arg-Arg-Gly, did not recover the interaction. This shows that the N-terminal basic region containing N-terminal Gly played an important role in the interaction with B lymphocytes. Acylation of the amino groups of lactoferrin also significantly reduced the interaction with B lymphocytes, and an O-methylisourea treatment of the amino groups, which preserved the positive charge, hardly affected the interaction. These results suggest that both the N-terminal basic region and the basic characteristics of the whole molecule contributed to its interaction with B lymphocytes.

Amino Acid Sequence↗
PubMed2000

Purification of membrane-bound lactoferrin from the human milk fat globule membrane.

Although lactoferrin is known as a basic soluble glycoprotein, the presence of the membrane-bound form of this protein has also been demonstrated in human milk. Membrane-bound lactoferrin was extracted from the human milk fat globule membrane with a detergent mixture of 1% Tween-20, 0.5% C12E8, and 0.5 M KCl in 20 mM Tris-HCl (pH 7.4). Lactoferrin in the detergent-soluble fraction was purified by affinity chromatography with Concanavalin A and by hydrophobic chromatography with phenyl-Superose. The purified protein gave a single band of 80 kDa by SDS-PAGE. Its N-terminal amino acid sequence was consistent with that of human lactoferrin.

Amino Acid Sequence↗
PubMed2002

Purification and quantification of lactoferrin in equine seminal plasma.

Lactoferrin with a molecular mass of 80 kDa was purified from equine seminal plasma by heparin-Agarose affinity chromatography and Sephacryl S-200 gel filtration. Purified lactoferrin was found to be highly homogeneous on the bases of its migration as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and of the monospecificity of rabbit antibodies to the purified protein in immunoblotting of seminal plasma proteins. A sandwich enzyme-linked immunosorbent assay was developed for quantifying lactoferrin in equine seminal plasma. Seminal plasma lactoferrin concentrations in 23 normal stallions ranged from 42 to 453 microg/ml, with a mean value of 157 +/- 118 microg/ml (S.D.).

Animals↗
PubMed2002

Foam fractionation of a dilute solution of bovine lactoferrin.

Lactoferrin (Lf), a protein found in human and bovine milk, tears, blood, and other secretory fluids, has been used to prevent infection from potential microbial pathogens by its ability to bind with iron (Fe3+). Currently, bovine lactoferrin can be purified from milk using ion exchange resin, which is a costly procedure making lactoferrin expensive. The purpose of this work was to investigate a low-cost foam fractionation process as the first step in separating lactoferrin from milk.

Animals↗
PubMed1983

Lysozyme and lactoferrin quantitation in the crevicular fluid.

This study was designed to determine if quantitation of lysosomal products in crevicular fluid may be useful as a diagnostic test to evaluate clinical status in periodontal disease. Levels of lysozyme and lactoferrin were quantitated in crevicular fluid from patients with gingivitis, generalized adult periodontitis, localized juvenile periodontitis and normals. Crevicular fluid (CF) was collected from each patient by standardized filter paper strips and evaluated for lysozyme and lactoferrin by rocket immunoelectrophoresis. Levels of lysozyme (micrograms of protein per microliter of CF) were significantly higher in localized juvenile periodontitis patients as compared to gingivitis and adult periodontitis. On the other hand, levels of lactoferrin (micrograms of protein per microliter of CF) did not show significant differences between gingivitis, adult periodontitis and localized juvenile periodontitis. These results indicate that a lysozyme to lactoferrin ratio could be of value as a diagnostic test for localized juvenile periodontitis patients.

Adolescent↗
PubMed2002

Serum lactoferrin concentrations in colostrum-fed calves.

OBJECTIVE: To determine serum lactoferrin concentrations (SLFC) in neonatal calves before and after ingestion of colostrum and to develop models that predict SLFC as a function of colostral lactoferrin concentrations (CLFC) in calves. ANIMALS: 13 Holstein calves. PROCEDURE: Calves were fed 4 L of colostrum via oroesophageal feeder within 3 hours after birth. Serum samples were collected before ingestion of colostrum (day 0) and 2, 4, 6, and 7 days after birth. Colostrum and serum IgG concentrations were measured by use of radial immunodiffusion. The CLFC and SLFC were determined by use of an ELISA. RESULTS: Mean +/- SD SLFC on days 0, 2, 4, 6, and 7 were 2.5+/-1.6 (range 0.47 to 71), 6.0+/-3.0 (range 2.0 to 16.6), 12.0+/-12.4 (range 0.0 to 43.5), 171+/-13.6 (range 2.2 to 39.4), and 13.6+/-16.4 (range 0.0 to 43.8) mg/ml, respectively. The SLFC on days 6 and 7 differed significantly from SLFC on day 0. The model that best estimated SLFC on day 6 predicted that (SLFC)2 was a function of the logarithm of relative efficiency of passive transfer (REPT) and ([CLFC]2 x [REPT]2), where R2 = 0.4. The model for SLFC on day 7 predicted that (SLFC)2 was a function of log(REPT), where R2 = 0.44. CONCLUSIONS AND CLINICAL RELEVANCE: Definitive evidence for passive transfer of lactoferrin via colostrum is lacking, because SLFC on day 2 or 4 were not significantly different than day 0. Relative efficiency of lactoferrin absorption was directly related to SLFC on day 6 but inversely related to SLFC on day 7.

Animals↗
PubMed2006

Effect of lactoferrin on the growth performance, intestinal morphology, and expression of PR-39 and protegrin-1 genes in weaned piglets.

A total of 90 weaned female pigs (Duroc x Landrace x Yorkshire) were used in a 15-d growth experiment to investigate the effect of lactoferrin on growth performance, intestinal morphology, and expression of PR-39 and protegrin-1 genes. The pigs were allocated on the basis of BW and litter to 3 dietary treatments in a randomized complete block design. There were 3 replicate pens per treatment, and the pigs were grouped with 10 pigs per pen. The dietary treatments were (1) basal diet; (2) basal diet + 20 mg of flavomycin/kg + 110 mg of aureomycin/kg; (3) basal diet + 1.0 g of lactoferrin/kg. Six pigs, randomly selected from each treatment (2 piglets/pen) were slaughtered for intestinal morphology and expression of PR-39 and protegrin-1 genes at the end of the experiment. Supplementation with lactoferrin improved growth performance; it increased ADG by 41.80% (P < 0.01) and efficiency of gain (G:F) by 17.20% (P < 0.05). Intestinal villus height was increased by 15.30% (P < 0.05), and crypt depth was decreased by 9.60% (P < 0.05). Supplemental lactoferrin increased the relative abundance of mRNA for PR-39 and protegrin-1 by 143% (P < 0.01) and 217% (P < 0.01), respectively. The use of lactoferrin as an additive to improve nonspecific immunity and strengthen host defenses would be good a method of defending weaned pigs from infections and weanling stress.

Actins↗
PubMed1984

Isolation of lactoferrin and its concentration in sows' colostrum and milk during a 21-day lactation.

Levels of lactoferrin, an Fe-binding protein with bacteriostatic properties, were determined in the colostrum and milk of Yorkshire sows during a 21-d lactation. Lactoferrin levels averaged 1,100 to 1,300 micrograms/ml near the time of farrowing, then declined sharply during the first week of lactation. Concentration of lactoferrin showed considerable variation among sows, but not among teat positions (anterior to posterior). A method for isolating high purity swine lactoferrin is described.

Animals↗
PubMed1986

Serum lactoferrin and C-reactive protein in mother and newborn after preterm rupture of membranes.

Eleven of 15 serum lactoferrin (S-LF) values and all 16 C-reactive protein (CRP) values were significantly elevated in cases of premature rupture of the amniotic membranes (PROM). There was no correlation between values of C-reactive protein and lactoferrin in either mothers or their newborn. The difference in C-reactive protein between mothers and their newborn was significant, but this was not the case with serum lactoferrin. This suggest that there is no transplacental transfer of C-reactive protein, even in preterm rupture of the membranes, and this is probably also the case with lactoferrin.

C-Reactive Protein↗
PubMed1986

Duodenal output and concentration of lactoferrin in chronic pancreatitis: correlation to amylase secretion and duct morphology.

To evaluate the clinical value of lactoferrin determination in duodenal contents in patients with chronic pancreatitis, three different studies were performed. No significant difference in meal stimulated output or secretion pattern was found between seven patients with chronic pancreatitis and six controls. After a meal test in 88 patients suspected for pancreatitis no correlation between concentration of lactoferrin and amylase was found. No correlation was found between degree of obstruction at endoscopic retrograde pancreaticography and duodenal concentration of lactoferrin. We conclude that the diagnostic value of lactoferrin determinations in chronic pancreatitis is doubtful.

Adult↗
PubMed1995

Interleukin-6, C-reactive protein, lactoferrin and white blood cell count in patients with S. aureus septicemia.

In a prospective study of 65 patients with S. aureus septicemia, the clinical value of measuring serum IL-6 and lactoferrin levels was assessed and compared with CRP levels and WBC count. 20/65 (31%) patients had a CRP value < or = 100 mg/l on admission and 10 (50%) and 11 (55%) of these had serum levels of IL-6 > 100 pg/ml or lactoferrin > 2.0 mg/l, respectively. 41/64 (64%) patients had a WBC count < or = 15.0 x 10(9)/l and the corresponding figures for increased IL-6 and lactoferrin values were 29 (71%) and 21 (51%) patients, respectively. The high concentrations of IL-6 and lactoferrin on admission decreased rapidly during the hospital stay, better reflecting the clinical course than CRP and WBC count. Patients with endocarditis showed higher IL-6 levels and body temperatures both on admission and during the first days of hospitalization compared with patients without endocarditis.

Adolescent↗
PubMed1993

Nitric oxide interaction with lactoferrin and its production by macrophage cells studied by EPR and spin trapping.

The production of nitrate (NO3-) and nitrite (NO2-) from macrophage-derived NO was studied using EPR and spin trapping. The formation of NO3- was determined via EPR in reactions involving the iron-binding protein, lactoferrin. The formation of NO2- was determined via EPR/spin trapping in the reaction between NO2- and H2O2. Dissolved nitric oxide (NO.) was reacted with lactoferrin yielding an EPR spectrum (77 degrees K) different from the normal EPR spectrum obtained for lactoferrin, suggesting that NO. interacts with the ferric ions bound to lactoferrin forming a ferric-nitrosyl type complex. The EPR spectrum (77 degrees K) of this ferric-nitrosyl type complex was also observed in the supernatant fluid of macrophage cell suspensions following their stimulation with lipopolysaccharide (LPS). During LPS stimulation of macrophages, these cells generate NO. which in turn produces NO3- and NO2-. The ferric-nitrosyl type complex is formed in a reaction mixture containing apolactoferrin and bicarbonate following the reaction of Fe+2 with NO3-, generated from macrophage-derived NO(.), to produce Fe+3 and NO(.). Furthermore, in an acidic medium, NO2- reacts with H2O2 forming peroxynitrous acid (HOONO) which rapidly decomposes into hydroxyl radicals (.OH) and the nitrogen dioxide (NO2.) radical. In the supernatant fluid of LPS-stimulated macrophage suspensions, the production of .OH was verified by spin trapping using 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) as the spin trap and ethanol as the .OH scavenger. The EPR spectra corresponding to the DMPO-OH and the DMPO-hydroxyethyl adducts were identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

Amoebicidal activity of milk, apo-lactoferrin, sIgA and lysozyme.

OBJECTIVES: To identify amoebicidal components in human milk and the effect of iron on the amoebicidal activity. DESIGN: Investigation in axenic cultures of Entamoeba histolytica trophozoites. METHODS: Amoebas were treated with 5%-20% of human, bovine and swine milk, with 10% of human milk fractions (i.e., casein, proteins except casein and fat) or with 1 mg/ml of human milk apo-lactoferrin, human secretory immunoglobulin type A (sIgA) and chicken egg-white lysozyme (i.e., purified proteins). Milk proteins were detected using immunoblot. Confocal microscopy was used to define the interaction of milk proteins (100 microM each) and amoebas. Experiments were done at least three times in triplicate, and mean and standard deviations were calculated. RESULTS: Human and bovine milk were amoebicidal showing a concentration-dependent effect. The amoebicidal effect was increased in the absence of iron. Milk protein fractions, with the exception of casein, were the components responsible for the amoebicidal activity found. Apo-lactoferrin, sIgA and lysozyme were identified in the amoebicidal milk protein fraction. Apo-lactoferrin showed the major amoebicidal effect. These proteins, either alone or in combination, showed a killing effect on the trophozoites. They bound to the amoebic membrane causing cell rounding, lipid disruption and damage. CONCLUSIONS: Milk proteins such as apo-lactoferrin, sIgA and lysozyme are able to kill Entamoeba histolytica trophozoites. This study confirms the importance of feeding breast milk to newborns.

Amebicides↗
PubMed2002

Lactoferrin supplementation to dairy calves.

Twenty-one Holstein calves (12 bulls, 9 heifers) were used to evaluate the effects of supplemental lactoferrin (0, 1, and 10 g/d) added to colostrum, milk, and milk replacer in a 56-d study. Calves fed lactoferrin (LF) weighed more during wk 2, 3, 4, 5, and 6 than control calves. Calves fed LF had increased preweaning daily weight gains and heart girth gains compared with calves not fed lactoferrin. Calves fed 1 g/d LF had a greater preweaning average daily gain than calves fed 10 g/d of lactoferrin. Hematocrit and serum Fe were unaffected by treatments. Calves were weaned when they had consumed 0.7 kg of calf starter grain for 2 consecutive d and were at least 28 d of age. All calves were weaned by 35 d of age, regardless of starter intake. Calves fed LF consumed more calf starter grain during the preweaning period and met weaning criteria at a younger age. This study indicates that supplementing calf diets with LF is advantageous to calf performance.

Animal Feed↗
PubMed1989

Enzyme-linked immunosorbent assays of bovine lactoferrin and a 39-kilodalton protein found in mammary secretions during involution.

Enzyme-linked immunosorbent assays were developed for two proteins found in mammary secretions during the non-lactating period: lactoferrin and a 39-kdal protein. Minimum detectable concentrations were .12 ng/ml for lactoferrin and .0037 ng/ml for the 39-kdal protein. Standard curves were linear in the ranges of .4 to 100 ng/ml for lactoferrin and 2.4 to 30 ng/ml for the 39-kdal protein. The immunoassays were used to measure concentrations of the proteins in mammary secretions during involution. From the last day of milking to d 30 of involution, mean concentrations of lactoferrin and the 39-kdal protein increased from .82 +/- .35 to 78.5 +/- 12.43 mg/ml and from 11.8 +/- 3.8 to 84.4 +/- 21.1 micrograms/ml, respectively. The immunoassays described will be valuable for further studies on the synthesis and secretion of these proteins during mammary involution.

Animals↗
PubMed1989

Lactoferrin and lysozyme in milk during acute mastitis and their inhibitory effect in Delvotest P.

Microbiological methods for detection of antibiotic residues in milk give no explanations regarding the identity of the inhibitory substance(s). Natural antibacterial substances, present at higher concentrations in mastitic milk and in colostrum, occasionally cause false positive results in antibiotic assays. In an earlier investigation, lysozyme and lactoferrin were shown to inhibit the growth of Bacillus stearothermophilus var. calidolactis spores, used as test organism in Delvotest P. To study the effect of high lysozyme and lactoferrin concentrations in milk on the Delvotest P, cows were subjected to acute experimental mastitis by infusion of Salmonella typhimurium SH 4809 endotoxin. Milk samples were collected up to 11 h postinfusion. Concentrations of lactoferrin and lysozyme, somatic cell count, and effect on Delvotest P were determined. A positive reaction in the Delvotest correlated well with an increase in lactoferrin and lysozyme concentrations. The nature of the inhibitory effect is briefly discussed.

Acute Disease↗
PubMed1994

Effect of twinning and supplemental iron-saturated lactoferrin on iron status of newborn calves.

Data from 53 calves by embryo transfer were collected to determine the effect of twinning and supplemental Fe-saturated lactoferrin or FeSO4 for 5 d after parturition on iron status of calves. Blood hematocrit and hemoglobin of multiple calves born from multiparous cows at d 1 postpartum were lower than those of single calves born from multiparous cows, although those of their dams were not different. Plasma Ca, inorganic P, Mg, Zn, and Cu were similar for single and multiple calves or for calves born from primiparous and multiparous cows. Blood hematocrit and hemoglobin of untreated calves decreased from 1 to 6 d postpartum. Blood hematocrit of calves treated with 40 mg of Fe/d as FeSO4 increased from 1 to 10 d postpartum, and blood hemoglobin of calves treated with 20 or 40 mg of Fe/d as ferrous Fe increased from 1 to 10 d postpartum. Blood hematocrit and hemoglobin of calves treated with 20 mg of Fe/d as Fe-saturated lactoferrin remained nearly constant for 10 d postpartum. Serum Fe of calves increased immediately after the treatment with 20 or 40 mg of Fe as FeSO4, but serum Fe of calves treated with lactoferrin was not affected. Thus, ferrous Fe may be more effective than Fe-saturated lactoferrin in elevating blood hematocrit and hemoglobin in newborn calves.

Animal Feed↗