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New sensitive method for the measurement of lysozyme and lactoferrin to explore mucosal innate immunity. Part II: time-resolved immunofluorometric assay used in HIV patients with oral candidiasis.

The aim of this study was to explore lysozyme and lactoferrin concentrations in human immunodeficiency virus (HIV)-infected patients with oropharyngeal candidiasis (OPC). These proteins were measured by time-resolved immunofluorometric assay, validated in Part I of this study, in paired serum and salivary secretions of 30 patients. Eleven HIV-positive patients without OPC, eight HIV-positive patients with OPC and eleven HIV-negative healthy subjects were included in the study. The relative coefficient of excretion of salivary albumin was used to establish protein origin. In serum, the low lactoferrin concentrations in HIV-infected patients with and without OPC (0.610 mg/l (p < 0.05) and 0.896 mg/l (p < 0.01) vs. 1.439 mg/l in healthy subjects) were probably due to a decrease in nonspecific immunity, particularly the polymorphonuclear cells. In HIV-infected patients with OPC, the high salivary lysozyme and lactoferrin concentrations (170.94 mg/l and 66.48 mg/l vs. 23.35 mg/l and 10.20 mg/l in healthy subjects, respectively) and their mean relative coefficient of excretion of above 1 indicated a high local production of lysozyme and lactoferrin in saliva. The development of OPC in HIV-infected patients could be a consequence of inefficient lysozyme and lactoferrin concentrations and of decreased cooperation between innate and adaptative immune systems.

Candidiasis, Oral↗

Fluorometric study on the interaction between lomefloxacin and bovine lactoferrin.

The binding of lomefloxacin to bovine lactoferrin (BLf) in a dilute aqueous solution was studied using fluorescence spectra. The binding constant (K) and the number of binding sites (n) were obtained by a fluorescence quenching method. The binding distance (r) and energy-transfer efficiency (E) between lomefloxacin and bovine lactoferrin were also obtained according to the mechanism of Foörster-type dipole-dipole nonradiative energy-transfer. The effect of lomefloxacin on the conformation of bovine lactoferrin was also analyzed by synchronous fluorescence spectroscopy. The interaction between lomefloxacin and bovine lactoferrin is strong. Lomefloxacin can affect the conformation of bovine lactoferrin to some degree.

Animals↗

Immunoradiometric assay of plasma lactoferrin.

The concentration of lactoferrin, a non-heme iron binding glycoprotein, was determined in more than 1500 EDTA plasma samples by a 2-site solid phase immunoradiometric assay to assess the significance of lactoferrin in plasma and to investigate applications for this assay. The use of commercially available antibody and antigen and a relatively short assay time make this assay more suitable for use in routine clinical laboratories than previous methods. A normal range of 250-750 micrograms/l was established. There was a correlation between plasma lactoferrin concentration and the circulating blood neutrophil count in most patients except those with splenomegaly, post-splenectomy and undergoing intensive chemotherapy. Patients with gross splenomegaly usually had an increased and post-splenectomy patients a decreased lactoferrin/neutrophil ratio indicating a respective increase and decrease in the marginated pool. In patients with acute leukemia after chemotherapy or transplantation plasma lactoferrin levels increased 1 to 5 d before blood neutrophil counts rose. As plasma lactoferrin seems to be derived from neutrophils, its concentration is probably related to the size of the total blood granulocyte pool. Calculation of the lactoferrin/neutrophil ratio demonstrated variations in the size of the bone marrow reserve and the marginated neutrophil pool.

Humans↗

The non-immune inflammatory response: serial changes in plasma iron, iron-binding capacity, lactoferrin, ferritin and C-reactive protein.

The interrelationships between various components of the non-immune inflammatory response (white cell count, plasma lactoferrin, C-reactive protein, ferritin, iron and iron-binding capacity), were studied serially in a variety of inflammatory conditions including acute lobar pneumonia, active pulmonary tuberculosis, rheumatoid arthritis on gold therapy and sepsis in the face of marrow hypoplasia induced by chemotherapy. Lactoferrin concentrations paralleled the white count in all groups. They were highest in pneumonia and tuberculosis, mildly elevated in rheumatoid arthritis and markedly decreased in neutropenic sepsis. Very high initial lactoferrin concentrations were associated with a poor prognosis in acute pneumonia. C-reactive protein and ferritin concentrations remained elevated through the period of study in acute pneumonia and neutropenic sepsis, while they gradually normalised over weeks in subjects with tuberculosis or rheumatoid arthritis on therapy. In pneumonia and tuberculosis moderate hypoferraemia and a reduced iron-binding capacity were evident. In contrast, a raised percentage saturation was present in neutropenic sepsis, probably related to erythroid marrow suppression. Comparisons between ferritin, lactoferrin and C-reactive protein in the various groups supported the concept that ferritin behaves in part as an acute phase reactant and that hypoferraemia in inflammation is due to deviation of iron into ferritin stores. The suggestion that lactoferrin is responsible for the hypoferraemia and hyperferritinaemia was not supported by the present data. Iron deficiency appeared to limit the hyperferritinaemic response in rheumatoid arthritis, while erythropoietic inhibition by chemotherapy dampened the hypoferraemic response in neutropenic sepsis.

Arthritis, Rheumatoid↗

Duodenal output of lactoferrin in normal subjects and correlation to output of amylase, bicarbonate, and total bile acids.

Nineteen normal subjects were studied before and after pancreatic stimulation. Duodenal flow was quantitated by means of a dilution indicator technique, and the secretion pattern of lactoferrin, amylase, total bile acids, and bicarbonate was studied. Output of lactoferrin in the duodenum was increased both after stimulation with a test meal and after hormonal stimulation by cholecystokinin alone or cholecystokinin in combination with secretin. Output of lactoferrin was not affected by stimulation by secretin alone. Lactoferrin was secreted in parallel with amylase and bile acids. The results indicate that the origin of lactoferrin in duodenum can be bile or pancreatic juice, or a combination of these.

Adult↗

Occurrence of anti-lactoferrin antibodies in patients with systemic lupus erythematosus, hydralazine-induced lupus, and rheumatoid arthritis.

Antibodies directed against neutrophil granulocyte components have gained an increasing importance in diagnosing systemic vasculitis diseases. The present study was aimed to investigate distribution of anti-lactoferrin antibodies in systemic lupus erythematosus, the hydralazine-induced SLE-like syndrome, and in rheumatoid arthritis compared to RA complicated with vasculitis. Antibodies were detected by ELISA and verified by Western blotting and inhibition assay. Sera positive for IgM were absorbed to remove the rheumatoid factor. IgG and IgM anti-lactoferrin antibodies were found in SLE in 5% and 10% respectively. All patients with hydralazine-induced SLE had antibodies of both isotypes and the antibody level declined rapidly after withdrawal of the drug. In rheumatoid arthritis no IgG anti-lactoferrin antibodies were found, but 20% of the patients with vasculitis had IgM antibodies. Anti-lactoferrin antibodies seem partly to discriminate between genuine and hydralazine-induced SLE, which might indicate a pathogenic relevance in drug-induced autoimmunity. In uncomplicated rheumatoid arthritis it can be concluded that anti-lactoferrin antibodies lack clinical, as well as pathogenic relevance.

Adult↗

Effects of an enhanced vitamin A intake during the dry period on retinoids, lactoferrin, IGF system, mammary gland epithelial cell apoptosis, and subsequent lactation in dairy cows.

Studies in vitro show important interactions among vitamin A, lactoferrin, and insulin-like growth factor (IGF) binding proteins (IGFBP) and, thus, the IGF system. As a consequence, mammary gland epithelial cell proliferation and apoptosis during the bovine dry period and potential milk yield may be affected. We have studied effects of feeding vitamin A (550,000 IU/ d) that exceed daily requirements about 8-fold for up to 2 mo to dairy cows during the dry period on concentrations of retinol and its metabolites in plasma and milk, milk lactoferrin, plasma and milk IGF-I and IGFBP-3, lactoferrin and IGF-I mRNA levels in mammary gland tissue, mammary gland apoptosis, and 100-d milk yield in the ensuing lactation. In the group supplemented with vitamin A, the peripartal decrease of plasma retinol was delayed and attenuated, and colostral retinol plus retinylester concentration was enhanced, but colostral beta-carotene concentration decreased. The retinoic acid isomer 9,13-dicis retinoic acid that coeluted with 13-cis retinoic acid, was the predominant circulating retinoic acid and was higher in GrA than the control group. Plasma IGFBP-3 concentrations were positively correlated with plasma retinol concentrations (r = 0.51), but there were no group differences. Numbers of apoptotic epithelial cells in mammary epithelium were higher at drying off and parturition than in the middle of the dry period, coinciding with high concentrations of IGF-I and lactoferrin in mammary secretions. At parturition, numbers of apoptotic cells in mammary gland biopsies in cows supplemented with vitamin A were higher than in control cows. In conclusion, supplementation of dairy cows during the dry period with high amounts of vitamin A did not significantly modify concentrations of lactoferrin, IGFBP-3, and IGF-I in plasma and in mammary secretions, but slightly decreased energy-corrected 100-d milk yield and milk fat yield, possibly because of enhanced apoptic rates of mammary cells.

Animals↗

Growth characteristics of calves fed an intensified milk replacer regimen with additional lactoferrin.

The objective of this study was to evaluate the effect of lactoferrin addition to milk replacer varying in crude protein (CP) on dry matter intake, growth, and days medicated. Thirty-four Holstein heifer calves were assigned to 4 treatments in a 2 x 2 factorial arrangement of treatments in a randomized complete block design. Treatments were as follows: 562 g daily of a nonmedicated conventional milk replacer (20% CP:20% fat) feeding regimen with or without 1 g of supplemental bovine lactoferrin (n = 9 for both treatments) or a nonmedicated intensified milk replacer feeding regimen (28% CP:20% fat) fed on a metabolizable energy basis (0.2 Mcal/kg BW(0.75)) from d 2 to 9, and at 0.27 Mcal/kg BW(0.75) from d 10 to 42 with or without 1g supplemental bovine lactoferrin (n = 8 for both treatments). Calves were fed pelleted starter (25% CP) in 227.5-g increments beginning on d 2 and had free access to water. Calves remained on the study for 14 d postweaning. Dry matter intake was determined daily. Growth measurements were taken weekly. Blood samples were taken twice weekly for determination of blood urea N. On d 10 of life, calves were subjected to a xylose challenge. Calves on conventional treatments ate more starter preweaning, during weaning, and postweaning. Preweaning, intensively fed calves had higher dry matter intakes. Weights of intensified-fed calves were greater at weaning. Intensified milk replacer-fed calves had greater average daily gain preweaning and overall and higher gain:feed ratios preweaning, but conventionally fed calves had higher gain:feed ratios during weaning. Intensified milk replacer-fed calves had greater hip heights during weaning and postweaning and greater heart girths preweaning, weaning, and postweaning. Days medicated were greater preweaning and overall for intensified-fed calves. There were no differences among treatments for xylose absorption. Calves on conventional treatments had increased blood urea nitrogen concentrations preweaning. There were no effects of lactoferrin on any experimental variable. Intensified milk replacer-fed calves consumed less starter but had higher average daily gains overall and larger frames and greater BW than conventionally fed calves. An intensified milk replacer feeding regimen promotes faster growth during the preweaning period when compared with calves fed conventional treatments, but supplemental bovine lactoferrin was not beneficial under these experimental conditions.

Animal Feed↗

Interacting properties of bovine lactoferrin with immobilized cibacron blue F3GA in column chromatography.

Bovine lactoferrin, isolated from colostral milk, interacted strongly with immobilized Cibacron blue F3GA column. Lactoferrin, adsorbed on the dye column, could not be eluted by 8 M urea, 1% Triton X-100, and 75% ethylene glycol, but was eluted by .1 M sodium hydroxide, 1 M potassium thiocyanate, 3 M potassium chloride, and free Cibacron blue F3GA. Electrostatic forces between the sulfonic groups of Cibacron blue F3GA and the basic side-chain groups in lactoferrin molecule probably are responsible for the observed interaction. The elution profile for lactoferrin differed from those of lactoperoxidase and serum albumin, which might allow efficient isolation of lactoferrin from whey via affinity chromatography.

Adsorption↗

Immunomodulatory effect of bovine lactoferrin pepsin hydrolysate on murine splenocytes and Peyer's patch cells.

The effects were examined of a pepsin hydrolysate of bovine lactoferrin on the proliferation of murine splenocytes. The hydrolysate enhanced [3H]thymidine uptake by splenocytes, but undigested bovine lactoferrin exerted an inhibitory effect. The hydrolysate had the ability to inhibit the blastogenesis that was induced by mitogens such as concanavalin A, phytohemagglutinin, and lipopolysaccharide; inhibition was similar to that with undigested lactoferrin. These results suggested that the hydrolysate contained both immunostimulatory and immunoinhibitory peptides. The stimulatory effect of the hydrolysate in the absence of mitogens was then explored in more detail using nonadherent splenocytes. The proliferative response of splenocytes to the hydrolysate was much greater in the fraction that was enriched with B cells than in the fraction that was enriched with T cells. The hydrolysate did not affect thymocyte proliferation. These data indicated that the adherent cells resembling macrophages and found among the splenocytes were not the target cells of the hydrolysate. The stimulatory effect of the hydrolysate was due to the activation of B cells by the hydrolysate and enhanced immunoglobulin production by splenocytes. Because the hydrolysate also enhanced the proliferation and immunoglobulin A production of Peyer's Patch cells, the immunostimulatory effect of the hydrolysate in vivo was examined using mice that had been orally immunized with cholera toxin. The concentrations of immunoglobulin A conjugated against cholera toxin in bile and in the intestinal contents of mice fed liquid diets containing 1% (wt/vol) lactoferrin hydrolysate were greater than those of mice fed control diets. This result suggested that the use of the lactoferrin hydrolysate is beneficial to enhance mucosal immunity.

Adjuvants, Immunologic↗

[Development of a two-site immunoassay using polyclonal antibodies for determination of lactoferrin in human blood].

The two-site enzyme-linked immunosorbent assay (ELISA) for lactoferrin using polyclonal antibodies to spatially distant epitopes has been developed. The assay sensitivity defined as minimal detectable lactoferrin concentration for p = 0.05 is 0.5 ng/ml. Accuracy of the assay (variance coefficient) is 7% within the clinical range of antigen concentrations. Human albumin, hemoglobin, and transferrin in concentrations up to 5 mg/ml practically do not interfere with the measurement. Sera of healthy donors and viral hepatitis patients were investigated using the two-site ELISA. The lactoferrin content in 44 donors' sera was 130 +/- 40 ng/ml (medium +/- standard deviation). A study of the serum specimens of 95 patients with hepatitis A, B, and C showed significant increase in serum lactoferrin concentration: 850 +/- 420, 780 +/- 580, and 680 +/- 500 ng/ml respectively. The assay showed good characteristics and may be recommended for lactoferrin measurement in patients' sera.

Animals↗

Immunohistochemical detection of lactoferrin in human astrocytomas and multiforme glioblastomas.

The presence of lactoferrin in astrocytomas, anaplastic astrocytomas and multiforme glioblastomas was determined by immunohistochemistry; the staining intensity and the percentage of neoplastic stained cells were graded and statistical analysis was performed by non-parametric methods. A moderate to strong diffuse immunoreactivity for lactoferrin was shown in glial elements of astrocytomas, while the positivity was progressively reduced in anaplastic astrocytomas and in multiforme glioblastomas, some of which were unstained; a highly significant difference was found between scores relative to astrocytomas and glioblastomas. We suggest that the lactoferrin may be produced by neoplastic astrocytes which permits a greater availability of iron for metabolic cellular processes. Alternatively, the cytoplasmic localization of lactoferrin in neoplastic astrocytes may be the consequence of defective or functionally impaired lactoferrin receptors at the cellular surface.

Astrocytoma↗

Effect of lactoferrin on lipopolysaccharide (LPS) induced preterm delivery in mice.

BACKGROUND: The present study attempted to confirm the preventive effect of lactoferrin on lipopolysaccharide (LPS) induced preterm delivery in mice. METHODS: Female C3H/HeNCrj mice were pair-mated with male Crj: B6D2F1 mice. On day 15 of gestation, a 50 micron/kg intraperitoneal injection of LPS (LPS group) was administered twice with a 3-hour interval between injections (at 2:00 and 5:00 PM). The mice were also given an intraperitoneal injection of lactoferrin (0.2 or 1 mg/200 microl/body) 1 hour prior to each LPS injection) (at 1:00 and 4:00 PM). To determine the effect of LF on plasma IL-6 level, mother mice were sacrificed and blood samples were obtained at 6 hours after the second treatment of LPS. RESULTS: Preterm delivery was induced by LPS in all mice on day 16 of gestation. Lactoferrin administration to LPS-treated mice significantly prolonged (p<0.001) gestation when compared with the LPS group. Plasma levels of IL-6 in the LPS group (1.628+/-115 pg/ml) were significantly higher (p<0.001) than in the untreated group (497+/-39 pg/ml). On the other hand, administration of lactoferrin (1 mg/body) to LPS-treated mice significantly suppressed (p<0.001) IL-6 levels (1.060+/-154 pg/ml). CONCLUSIONS: Lactoferrin exerts a preventive effect on the incidence of preterm delivery in mice via a suppression of plasma IL-6 augmentation by LPS.

Animals↗

Inhibition of Escherichia coli by bovine colostrum and post-colostral milk. II. The bacteriostatic effect of lactoferrin on a serum susceptible and serum resistant strain of E. coli.

Two strains of Escherichia coli were inhibited by complement-inactivated cow serum and to a lesser extent by precolostral calf serum devoid of specific antibodies. They were not inhibited by undiluted colostral whey or milk but colostral whey became bacteriostatic after dialysis or dilution in Kolmer saline and addition of precolostral calf serum or lactoferrin. The inhibition in all these fluids was due to iron-binding proteins (transferrin or lactoferrin). Undiluted dialysed milk was not inhibitory because of its low content of lactoferrin but became inhibitory after addition of 1 mg/ml of lactoferrin. The lack of inhibition in undiluted whey is due to the high concentration of citrate in colostral whey (and milk) and it is suggested that citrate competes with the iron-binding proteins for iron and makes it availabe to the bacteria. Addition of bicarbonate, which is required for the binding of iron by transferrin and lactoferrin, can overcome the effect of citrate; hence, the bacteriostatic effect of cow serum and precolostral calf serum is due to the presence of both transferrin and bicarbonate as well as the low lefel of citrate.

Animals↗

[Detection of lactoferrin in feces for differential diagnosis in diarrhea].

INTRODUCTION: Routine stool culture is used to evaluate patients with diarrheal illness. However, the results are often delayed, and the tests are very expensive. Therefore a rapid, simple method for screening would be a helpful adjunct in a diagnostic algorithm. Fecal leukocytes are found in diarrhea patients with diffuse colonic inflammation but missing in non-inflammatory cases, and are most commonly identified in infectious diarrheas of bacterial origin. It supports the use of immediate empiric therapy in very young, elderly and immunocompromised individuals. When negative, it may eliminate the need for stool culture in some cases of diarrhea. Recently, a new latex bead assay has been developed for the detection of lactoferrin, an iron binding glycoprotein found in polymorphonuclear leukocytes. AIMS: Evaluate the value of fecal leukocytes and lactoferrin in the workup of patients with diarrhea. METHODS: Fecal samples of 50 consecutive adult patients with acute or chronic diarrhea were tested for fecal leukocytes and lactoferrin. The results were compared with findings from fecal cultures, tests for parasite, Clostridium difficile A toxin latex test, data of the gastrointestinal examination and clinical evaluation. The authors defined two groups of the cases: the inflammatory and non-inflammatory diarrheas. RESULTS: The sensitivity, specificity, positive and negative predictive value of microscopic leukocyte count and the lactoferrin test were 42 and 63%, 87 and 87%, 67 and 75%, 71 and 79% respectively. CONCLUSIONS: In agreement with the literature the results of the present study indicate that fecal lactoferrin appears more sensitive than fecal leukocyte smear, and accurately rules out inflammatory diarrhea.

Adult↗

The adjuvant activity of lactoferrin in the generation of DTH to ovalbumin can be inhibited by bovine serum albumin bearing alpha-D-mannopyranosyl residues.

Lactoferrin (LF) is an iron-binding glycoprotein present in the cytoplasmic granules of neutrophils and in external secretions of mammals. Although the biological role of human and bovine lactoferrin has been extensively studied, there is still uncertainty as to the nature and function of lactoferrin receptors. We recently determined that methyl-alpha-D-mannopyranoside given intraperitoneally (i.p.) could suppress the adjuvant activity of LF in the generation of delayed-type hypersensitivity (DTH) to ovalbumin (OVA). We concluded that the lactoferrin effects in DTH are mediated by carbohydrate-recognizing receptors like the mannose receptor (MR). This study indicates that subcutaneous (s.c.) administration of very small doses of the Man-bovine serum albumin (Man-BSA) complex, together with a sensitizing dose of the antigen, gives the same effects as i.p. administration of methyl-alpha-D-mannopyranoside. The latter is also a blocker of MR, although of a much lower affinity to the receptor than Man-BSA. The blocking of the adjuvant effect of LF by the Man-BSA complex (when given together with the sensitising dose of antigen) suggests that the function of antigen-presenting cells in the skin (presumably immature dendritic cells expressing MR) is inhibited. The results of our study indicate that a receptor with an affinity for mannose is essential for the mediation of adjuvant lactoferrin function in the generation of DTH.

Adjuvants, Immunologic↗

[Content of protein lactoferrin in precancer laryngeal disease].

Lactoferrin was studied in 50 patients with laryngeal precancer: chronic hyperplastic laryngitis (n=28), leukoplakia (n=22). Lactoferrin was measured before the treatment, 10-12 days and 12 months after the treatment. Blood serum concentration of lactoferrin was significantly increased before the treatment. By the authors, it was due to inflammation in laryngeal tissues. Conservative treatment of patients with chronic hyperplastic laryngitis resulted in a considerable reduction in this protein concentration. Surgical removal of leukoplakias stimulated laryngeal inflammation and raised lactoferrin concentration in blood serum. One year after the examination, those patients who had neither exacerbation of chronic hyperplastic laryngitis no recurrent leukoplakia exhibited serum lactoferrin in concentrations close to the baseline but still higher than in healthy individuals. This is explained by chronicity of inflammation in laryngeal tissues. These findings can be used in diagnosis and prognosis of the disease course in patients with laryngeal precancer.

Adult↗

The utility of lactoferrin in differentiating parasitic from bacterial infections.

Lactoferrin is an iron binding glycoprotein found in the 2ry granules of PMN. In order to determine the usefulness of such marker for neutrophilic activity in differentiating cases suffering from amoebic and bacillary dysentery, Schistosoma and bacterial UTI infections, we examined stool and urine specimens using anti-lactoferrin antibodies (lactoferrin latex agglutination test: LFLA), compared with different standard gold techniques. Our results demonstrated that cases with either shigllosis or UTI revealed a high lactoferrin titer which was positively correllated with the number of PMN. In addition cases with Entamoeba histolytica or S. haematobium were characterized by relatively lower inflammatory process as expressed by mild lactoferrin titer which was also correlated with the PMN count. In addition, the findings of the present work indicated that LFLA was sensitive and specific when used alone and its sensitivity was augmented after coupling with other simple indirect methods of diagnosis. In conclusion, results described the reliability of using LFLA as a simple, rapid, sensitive method in differentiating, certain parasitic from bacterial diseases.

Animals↗