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PubMed1997

Relationship between antibacterial activity and cell surface binding of lactoferrin in species of genus Micrococcus.

Human lactoferrin was bactericidal in vitro for Micrococcus luteus but not for other Micrococcus species (M. radiophilus, M. roseus and M. varians). A correlation between the binding of lactoferrin to the bacterial surface and the antimicrobial action was observed. Viability assays showed that ferric, but not ferrous, salts prevented binding and consequently M. luteus was not killed. The unsaturated form of lactoferrin showed a greater affinity than that of the iron-saturated molecule for lipomannan, a lipoglycan present on the cell wall of M. luteus, supporting the role for lipomannan as one of the possible binding sites of lactoferrin on M. luteus.

Anti-Bacterial Agents↗
PubMed1999

Cationic amphipathic peptides, derived from bovine and human lactoferrins, with antimicrobial activity against oral pathogens.

Peptides derived from the N-terminal domain that comprises an amphipathic alpha-helix in human lactoferrin (LFh 18-31 and LFh 20-38) and bovine lactoferrin (LFb 17-30 and LFb 19-37) were chemically synthesised. Since many positively charged amphipathic alpha-helices contain antimicrobial activity, the peptides were tested for their antimicrobial activity against various oral pathogens. Both peptides from bovine lactoferrin had more potent antimicrobial activities than the human equivalents. Peptide LFb 17-30, containing the largest number of positively charged amino acids, showed the highest antimicrobial activity to both Gram-positive and Gram-negative bacteria. Since native lactoferrin molecules had no killing activity, release of these peptides from the native protein should be investigated to explore the use in oral care products.

Amino Acid Sequence↗
PubMed2004

Lactoferrin and other markers from gingival crevicular fluid and saliva before and after periodontal treatment.

OBJECTIVES: The aim of the study was to verify (i) if crevicular fluid defence variables reflect the changes after surgical periodontal treatment and (ii) if they are in correspondence with changes of these variables in the unstimulated and stimulated whole saliva. MATERIAL AND METHODS: For 12 male and 13 female volunteers with chronic periodontitis lactoferrin concentration as well as the lysozyme and peroxidase activities were determined in crevicular fluid as well as in unstimulated and stimulated saliva before and 14 days after surgical periodontal treatment by a minimal invasive flap technique. RESULTS: The lactoferrin concentrations decreased significantly in the crevicular fluid eluting solution from 1.63 to 1.23 mg/l reflecting a decrease in the total amount collected, in unstimulated saliva from 10.54 to 8.96 mg/l, and in stimulated saliva from 9.00 to 7.11 mg/l after treatment. No significant change could be found for lysozyme. Peroxidase activity was significantly reduced from 269.06 to 186.15 U/l only in the crevicular fluid. CONCLUSION: The results of this study suggest that (i) the defence factor lactoferrin is suitable for monitoring of periodontal treatment results and (ii) changes of the lactoferrin concentration in crevicular fluid are related with significant changes in unstimulated and stimulated saliva.

Biomarkers↗
PubMed1979

Serum and plasma myeloperoxidase, elastase and lactoferrin content in acute myeloid leukaemia.

Myeloperoxidase (MPO) and elastase, restricted to azurophil granules of neutrophils, as well as lactoferrin, restricted to specific granules of neutrophils, were determined in plasma and serum from patients with acute myeloid leukaemia (AML). Highly sensitive radio immuno assays were developed for detection of these proteins. Serum MPO was increased in 12/35 and decreased in 2/35 patients without correlation to WBC or neutrophil counts; these levels may reflect an abnormal production by leukaemic blasts or ineffective granulopoiesis in the bone marrow. Serum elastase was increased in 6/22 patients. Serum lactoferrin was decreased in 12/25 patients without correlation to neutrophil counts probably reflecting abnormal production. Serum elastase and MPO showed a covariation in chronic myeloid leukaemia but not in AML; the latter finding may indicate that the synthesis of these two proteins is not synchronized in AML-cells. Sequential studies of patients with AML demonstrated fluctuations of serum MPO and lactoferrin during remission most likely because of chemotherapeutic pertubation. Although a limited number of patients has been studied it is suggested that serum lactoferrin may be of help for prediction of relapse in AML.

Antineoplastic Agents↗
PubMed1980

Sequential studies on serum-levels of lysozyme, lactoferrin and eosinophil cationic protein in alcoholics after alcohol withdrawal.

12 male alcoholics were followed for 16 d after alcohol withdrawal with respect to the number of the different circulating blood cells and to serum levels of leucocyte markers such as beta 2-microglobulin, eosinophil cationic protein (ECP), lactoferrin and lysozyme. The results suggest a direct toxic effect of ethanol on the neutrophil granulocytes as indicated by high S-lactoferrin levels. Relatively low levels of S-lysozyme as compared to S-lactoferrin could suggest a reduced activity of the monocytes/macrophages. The eosinophils and lymphocytes seemed quite unaffected by ethanol. Increased haematopoietic activity after withdrawal was indicated by increasing cell numbers in the peripheral blood and by increasing serum levels of lactoferrin and lysozyme. The increasing monocyte/macrophage activity after withdrawal as suggested by S-lysozyme levels was closely related (P less than 0.001) to the increased thrombopoietic activity as evaluated by peripheral thrombocyte counts. This latter finding could point to a direct relationship between monocyte/macrophage activity and thrombocyte production.

Adult↗
PubMed1986

Relationship of plasma lactoferrin content to neutrophil regeneration and bone marrow infusion.

Plasma concentrations of lactoferrin were measured in immediately separated EDTA samples from 5 subjects who had received HLA identical bone marrow transplants for leukaemia or aplastic anaemia and from 7 subjects who were leukopenic as a consequence of chemotherapy for a variety of malignant conditions. Plasma lactoferrin concentrations were found to closely parallel the leucocyte count and were not found to either predict or to antedate leucocyte regeneration. Serial measurements of plasma lactoferrin in a subject with no circulating neutrophils who received a bone marrow graft revealed that the clearance of lactoferrin followed an exponential pattern and had an initial half time of 2.2 h.

Agranulocytosis↗
PubMed1987

Serum and plasma measurements of neutrophil granule proteins during cardiopulmonary bypass: a model to estimate human turnover of lactoferrin and myeloperoxidase.

During extracorporeal circulation (ECC), granule proteins such as lactoferrin and myeloperoxidase escape to the plasma in large amounts. ECC was used to study the turnover of these proteins and compare their variations in plasma and serum. During ECC both proteins rose to very high levels and the variations were similar in both serum and plasma (r = 0.93 for lactoferrin and 0.80 for myeloperoxidase). The initial elimination after termination of operation (t 1/2) was, for lactoferrin 0.75 and for myeloperoxidase 0.5 h. Both proteins followed a second order kinetics of elimination with a t 1/2 for lactoferrin of about 9 and for myeloperoxidase of about 25 h. 48 and 72 h postoperatively serum levels, but not plasma levels, of myeloperoxidase rose again 10-fold. We conclude that serum and plasma measurements of neutrophil granule proteins are complementary. The period after disconnection of the patient from the extracorporeal device may be used to estimate the turnover kinetics of neutrophil granule proteins.

Aged↗
PubMed1987

Salivary lactoferrin in a selected group of subjects with exceptional extrinsic dental staining.

Some people exhibit an exceptional tendency to develop brownish extrinsic staining on their teeth and previous studies indicate that iron may be involved in certain types. The object of this investigation was to find out whether the level of salivary lactoferrin, which is an ironbinding glycoprotein, is elevated in persons exhibiting extreme staining tendency. Subjects who developed dark brownish discoloration on the facial surfaces of their anterior teeth during a 3-week period following professional cleaning of the teeth were selected for study. Salivary lactoferrin was measured by the enzyme-linked immunosorbent assay (ELISA). The results showed that this group of persons exhibited a markedly higher concentration of salivary lactoferrin compared with non-stainers. It was also demonstrated in an in vitro study that combinations of lactoferrin, iron, and tannic acid produced stain on slabs of enamel and dentin.

Dental Enamel↗
PubMed1998

Lactoferrin impedes epithelial cell adhesion in vitro.

In the process of host defence against microbial challenge, neutrophils release granule contents with the potential side effect of damaging structural tissues. In the junctional epithelium such damage may contribute to the degeneration and renewal of the epithelial cells attached directly to the tooth (DAT cells), and subsequently to periodontal pocket formation. This study reports on lactoferrin, one of the substances released by neutrophils, and its effects on epithelial cell adhesion, growth, DNA synthesis and spreading of cell colonies at concentrations recorded in the crevicular fluid. We show that, in opposition to what has been reported on bacterial cells, lactoferrin has no effect on the DNA synthesis of attached epithelial cells in model systems attempting to simulate the DAT cells in vivo. However, both iron-saturated and unsaturated lactoferrin hampered cell adhesion, growth and spreading of cell colonies in a dose-dependent manner. These findings suggest that lactoferrin does not affect epithelial cell proliferation but it may have a role in delaying the repair of the DAT cell population during inflammation by interfering with cell adhesion.

Adolescent↗
PubMed2004

The investigation of glutathione peroxidase, lactoferrin, myeloperoxidase and interleukin-1beta in gingival crevicular fluid: implications for oxidative stress in human periodontal diseases.

BACKGROUND: Human periodontal diseases are inflammatory disorders that are the result of complex interactions between periodontopathogens and the host's immune response. Two important and interrelated factors are involved in the pathophysiological progression of periodontal diseases, i.e. the activation of immune system and the production of oxygen radicals and their related metabolites. Increased production of oxygen radicals may contribute to oxidative stress, which is reported to be involved in many diseases, including periodontal diseases. OBJECTIVES: The objective of this study was to investigate glutathione peroxidase, lactoferrin and myeloperoxidase, which play an essential role in free radical production and defenses, and the proinflammatory cytokine interleukin-1beta (IL-1beta), which is important in the regulation of immunological and inflammatory reactions in human periodontal diseases. METHODS: Gingival crevicular fluid (GCF) samples were collected from 27 subjects, 19 periodontitis patients and eight healthy controls, ranging in ages from 24 to 62 years. Clinical parameters were recorded. GCF glutathione peroxidase, lactoferrin, myeloperoxidase and IL-1beta were analyzed by enzyme-linked immunosorbent assays (ELISA). RESULTS: The periodontitis sites exhibited significantly greater total amount of glutathione peroxidase, lactoferrin, myeloperoxidase and IL-1beta than healthy sites. Total amount of glutathione peroxidase, lactoferrin, myeloperoxidase and IL-1beta was positively correlated with plaque index, gingival index, probing depth and probing attachment level (p < 0.05). CONCLUSION: The imbalance between the levels of myeloperoxidase/IL-1beta and glutathione peroxidase/lactoferrin could result in tissue damage of reactive oxygen species (ROS) in periodontitis which is initiated and perpetuated by the chronic insults of periodontopathogens.

Adult↗
PubMed1996

Peroxidases, lactoferrin and lysozyme in peripheral blood neutrophils, gingival crevicular fluid and whole saliva of patients with localized juvenile periodontitis.

OBJECTIVE: The aim of this study was to examine the longitudinal association of selected non-immune anti-microbial host factors (peroxidases, lysozyme and lactoferrin) to the localized juvenile periodontitis (LJP) disease status. MATERIALS AND METHODS: Peroxidases, lysozyme and lactoferrin were quantitated from seven patients with LJP before and after periodontal therapy. Analyses were performed from simultaneously collected samples of peripheral blood polymorphonuclear leukocytes (PMNs), gingival crevicular fluid (GCF from diseased sites) and paraffin-stimulated whole saliva. Similar assays were done also from seven periodontally healthy controls. RESULTS: During untreated phase of LJP myeloperoxidase, lysozyme and lactoferrin concentrations were remarkably elevated in peripheral blood PMNs, also reflected in their high concentrations in GCF. All these values normalised with respect to healthy controls during the periodontal therapy. No similar longitudinal changes were seen in whole saliva but during therapy salivary peroxidase concentrations declined below the control values, in accordance with our previous observations in parotid saliva samples of LJP patients. CONCLUSIONS: In LJP the concentrations of lysozyme, lactoferrin and myeloperoxidase are significantly elevated in peripheral blood PMNs, also reflected in GCF. During periodontal therapy these values decline and approach those observed in healthy controls. No similar changes are seen in stimulated whole saliva.

Adolescent↗
PubMed1981

Distribution of lactoferrin in human fetal tissues.

We used an immunoperoxidase method to study the distribution of lactoferrin in seven human fetuses from 11 to 21 weeks of age. Lactoferrin was found in mononuclear cells, presumably granulocytes, in various organs from thirteen weeks of gestation onwards. In addition to the liver, spleen, lung and thymus, lactoferrin-positive mononuclear cells were also found close to vessel walls in human pancreas in fetuses more than 20 weeks old. This finding might suggest that there is significant granulopoiesis in the pancreas at this stage of maturation. In addition to the mononuclear cells, lactoferrin could be found in Hassal's corpuscles of the thymus from 13 weeks and in glandular cells of the tongue from 20 weeks onwards. The present results are in good agreement with the maturation of humoral and cellular acquired immunity and the onset of synthesis of lysozyme and interferon.

Female↗
PubMed1991

Iron availability from an infant formula supplemented with bovine lactoferrin.

Iron balance studies were performed in 16 term infants from their 3rd until their 17th week of life. The balance studies were performed at home and comprised five periods with an interval of 3 to 4 weeks, each consisting of three 24-hour collections of milk and stool samples. Seven infants were fed an adapted infant formula supplemented with bovine lactoferrin (100 mg/100 ml) and nine received the same formula without lactoferrin. The lactoferrin supplemented group received 169 micrograms iron/kg b.w. x day and retained 63 micrograms/kg b.w. x day. The mean iron intake of infants fed with the adapted formula without supplementation of lactoferrin was 118 micrograms/kg b.w. x day. The retention of iron was 43 micrograms/kg b.w. x day. Mean percentage retention of iron in the supplemented group was 36%, in the non-supplemented group 28%.

Biological Availability↗
PubMed1994

Ocular surface damage and tear lactoferrin in dry eye syndrome.

We studied the relationship between the severity of ocular surface damage and the level of tear lactoferrin in primary and secondary Sjögren's syndrome and keratoconjunctivitis sicca not associated with Sjögren's syndrome. A significant negative correlation was found between Rose Bengal staining score and level of tear lactoferrin in all three groups. Analysis of covariance disclosed no significant differences in regression lines for Rose Bengal staining score vs tear lactoferrin level among the three groups. The three regression lines appeared to be identical to each other. These findings indicate that the severity of ocular surface damage due to dry eye largely depends on the tear secretory function of the lacrimal gland, and that the function of the lacrimal gland can be evaluated by determination of level of tear lactoferrin using the same standards regardless of differences in pathogenesis of underlying diseases.

Adolescent↗
PubMed1985

Levels of salivary lysozyme, lactoperoxidase, and lactoferrin in diabetic hamsters.

In an attempt to clarify the mechanism(s) of increased susceptibility to oral infection in diabetics, we examined the levels of salivary antibacterial factors, including lysozyme, lactoperoxidase, and lactoferrin, in diabetic hamsters whose condition was induced with streptozotocin. Saliva was collected from these hamsters periodically for 19 weeks after the administration of streptozotocin. Diabetes persisted with significant hyperglycemia throughout the experiment after a single injection of streptozotocin. There was no significant difference between groups in the amount of saliva secreted. In diabetic hamsters, lysozyme activity decreased by 56% and lactoperoxidase activity decreased by 53% compared with the control hamsters 19 weeks after the administration of streptozotocin. There was no significant difference between groups in the amount of salivary lactoferrin. However, the ratio of lactoferrin to total protein increased to approximately double the amount of that of the control hamsters. Insulin treatment had a significant effect on lysozyme and lactoperoxidase activity, recovering 73 and 74% those of the controls, respectively, and the ratio of lactoferrin to total salivary protein reverted to normal values. Growth inhibition of Lactobacillus plantarum ATCC 8014 with whole saliva and amylase activity significantly decreased in diabetic hamsters. The position of each protein band of whole saliva on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was almost the same for control and diabetic hamsters; however, there was some variability in band intensity.

Amylases↗
PubMed1988

Killing of Actinobacillus actinomycetemcomitans by human lactoferrin.

Actinobacillus actinomycetemcomitans is a fastidious, facultative gram-negative rod associated with endocarditis, certain forms of periodontal disease, and other focal infections. Human neutrophils have demonstrated bactericidal activity against A. actinomycetemcomitans, and much of the oxygen-dependent killing has been attributed to the myeloperoxidase-H2O2-halide system. However, the contribution of other neutrophil components to killing activity is obscure. Lactoferrin, an iron-binding glycoprotein, is a major constituent of neutrophil-specific granules and is also found in mucosal secretions. In this report, we show that human lactoferrin is bactericidal for A. actinomycetemcomitans. Killing activity required an unsaturated (iron- and anion-free) molecule that produced a 2-log decrease in viability within 120 min at 37 degrees C at a concentration of 1.9 microM. Besides exhibiting concentration dependence, killing kinetics were affected by minor variations in temperature and pH. Magnesium, a divalent cation thought to stabilize lipopolysaccharide interactions on the surface of gram-negative organisms, enhanced lactoferrin killing of A. actinomycetemcomitans, while other cations, such as potassium and calcium, had no effect. Our data suggest that lactoferrin contributes to killing of A. actinomycetemcomitans by human neutrophils and that it may also play a significant role in innate secretory defense against this potential periodontopathogen.

Actinobacillus↗
PubMed1990

Cross-reactivity and sequence homology between the 65-kilodalton mycobacterial heat shock protein and human lactoferrin, transferrin, and DR beta subsets of major histocompatibility complex class II molecules.

Immunogold ultracytochemistry and Western immunoblotting showed that polyclonal antibodies against human lactoferrin bind to the highly immunogenic 65-kilodalton (kDa) heat shock protein of mycobacteria. The fast-growing mycobacterial species Mycobacterium smegmatis showed a higher density of these receptors for antilactoferrin sera than the slow-growing M. avium. Polyclonal antibodies against mycobacteria (M. bovis BCG) recognized human lactoferrin. Comparison of the amino acid sequence of lactoferrin with that of the 65-kDa protein of M. tuberculosis revealed seven instances of four amino acid sequence homology between the microbial and the human iron-binding protein. Four of these tetrapeptide sequences were also shared with the human transferrin molecule. The shared amino acid sequence KDLL was also present in the DR1, DR3, and DR4 subsets of the DR beta subregion of major histocompatibility complex (MHC) class II molecules. The molecular mimicry between the 65-kDa mycobacterial protein and the human proteins (lactoferrin, transferrin, and MHC class II molecules) offers a molecular setting for mycobacteria-associated, T-cell-dependent autoimmune disease, namely, for rheumatoid arthritis.

Amino Acid Sequence↗
PubMed1992

Lactoferrin release and interleukin-1, interleukin-6, and tumor necrosis factor production by human polymorphonuclear cells stimulated by various lipopolysaccharides: relationship to growth inhibition of Candida albicans.

Lipopolysaccharides (LPSs) from Escherichia coli, Serratia marcescens, and Salmonella typhimurium, at doses from 1 to 100 ng/ml, strongly enhanced growth inhibition of Candida albicans by human polymorphonuclear leukocytes (PMN) in vitro. Flow cytometry analysis demonstrated that LPS markedly augmented phagocytosis of Candida cells by increasing the number of yeasts ingested per neutrophil as well as the number of neutrophils capable of ingesting fungal cells. LPS activation caused augmented release of lactoferrin, an iron-binding protein which itself could inhibit the growth of C. albicans in vitro. Antibodies against lactoferrin effectively and specifically reduced the anti-C. albicans activity of both LPS-stimulated and unstimulated PMN. Northern (RNA blot) analysis showed enhanced production of mRNAs for interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 and in neutrophils within 1 h of stimulation with LPS. The cytokines were also detected in the supernatant of the activated PMN, and their synthesis was prevented by pretreatment of LPS-stimulated PMN with protein synthesis inhibitors, such as emetine and cycloheximide. These inhibitors, however, did not block either lactoferrin release or the anti-Candida activity of LPS-stimulated PMN. These results demonstrate the ability of various bacterial LPSs to augment neutrophil function against C. albicans and suggest that the release of a candidastatic, iron-binding protein, lactoferrin, may contribute to the antifungal effect of PMN. Moreover, the ability to produce cytokines upon stimulation by ubiquitous microbial products such as the endotoxins points to an extraphagocytic, immunomodulatory role of PMN during infection.

Candida albicans↗