Effect of human lactoferrin on Candida albicans infection and host response interactions in experimental oral candidiasis in mice.

OBJECTIVES: To determine the effect of human lactoferrin (hLF) in experimental oral candidiasis and examine the host-pathogen interactions in a mouse model. DESIGN: Experimental groups comprised of 4-6-week-old wild type (C57BL/6J) or lactoferrin knockout (ltf-/-) immunosuppressed mice. Six mice in each group were inoculated with C. albicans or sham infection by swabbing the oral cavity. To determine the effect of hLF on infection and host response, we added hLF (0.5 g/kg/day) to the drinking water. Candida and mice RNA were isolated from gingival tissue and analyzed by qRT-PCR for virulence genes and host expression of inflammatory mediators. RESULTS: Administration of hLF significantly reduced the C. albicans CFUs in both WT and ltf-/- mice (P < .001). Examination of the oral cavity of ltf-/-I mice revealed lesions characterized by white patches and inflammation when compared to WTI mice. Several Candida virulence genes (als, ece, efg, sap) were significantly downregulated on administration of hLF to WTI and ltf-/-I mice (P < .001). The WTI+hLF mice had significantly increased expression of toll-like receptors (TLRs) compared to other group. We observed that hLF increased expression of interleukins, IL-1ß, IL-6, IL-12, IL-17, tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-ß), inducible nitric oxide synthase (iNOS) and myeloperoxidase (MPO) compared to untreated gingival tissue. CONCLUSION: Our study highlights the protective effect of hLF against oral C. albicans infection by its actions on both microbial and host factors. HLF may be of therapeutic value to protect against oral candidiasis.

Age and Location in Severity of COVID-19 Pathology: Do Lactoferrin and Pneumococcal Vaccination Explain Low Infant Mortality and Regional Differences?

Two conundrums puzzle COVID-19 investigators: 1) morbidity and mortality is rare among infants and young children and 2) rates of morbidity and mortality exhibit large variances across nations, locales, and even within cities. It is found that the higher the rate of pneumococcal vaccination in a nation (or city) the lower the COVID-19 morbidity and mortality. Vaccination rates with Bacillus Calmette-Guerin, poliovirus, and other vaccines do not correlate with COVID-19 risks, nor do COVID-19 case or death rates correlate with number of people in the population with diabetes, obesity, or adults over 65. Infant protection may be due to maternal antibodies and antiviral proteins in milk such as lactoferrin that are known to protect against coronavirus infections. Subsequent protection might then be conferred (and correlate with) rates of Haemophilus influenzae type B (Hib) (universal in infants) and pneumococcal vaccination, the latter varying widely by geography among infants, at-risk adults, and the elderly. Also see the video abstract here https://youtu.be/GODBYRbPL00.

The Biology of Lactoferrin, an Iron-Binding Protein That Can Help Defend Against Viruses and Bacteria.

Lactoferrin is a nutrient classically found in mammalian milk. It binds iron and is transferred via a variety of receptors into and between cells, serum, bile, and cerebrospinal fluid. It has important immunological properties, and is both antibacterial and antiviral. In particular, there is evidence that it can bind to at least some of the receptors used by coronaviruses and thereby block their entry. Of importance are Heparan Sulfate Proteoglycans (HSPGs) and the host receptor angiotensin-converting enzyme 2 (ACE2), as based on other activities lactoferrin might prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from attaching to the host cells. Lactoferrin (and more specifically enteric-coated LF because of increased bioavailability) may consequently be of preventive and therapeutic value during the present COVID-19 pandemic.

Lactoferrin Reduces Necrotizing Enterocolitis Severity by Upregulating Intestinal Epithelial Proliferation.

INTRODUCTION: Necrotizing enterocolitis (NEC) is a devastating intestinal illness in premature infants characterized by severe intestinal inflammation. Despite medical interventions, NEC mortality remains alarmingly high, which necessitates improved therapies. Lactoferrin is among the most abundant proteins in human milk and has important immunomodulatory functions. While previous studies have indicated protective effects of lactoferrin against neonatal sepsis and NEC, the underlying mechanism remains unclear. We hypothesize that lactoferrin downregulates inflammation and upregulates proliferation in intestinal epithelium during NEC injury. MATERIALS AND METHODS: NEC was induced by hypoxia, gavage feeding of hyperosmolar formula and lipopolysaccharide between postnatal day P5 and P9 (n = 8). Breastfed mice were used as control (n = 7). Lactoferrin (0.3 g/kg/day) was administered once daily by gavage from P6 to P8 in both NEC (NEC + Lac; n = 9) and control mice (Cont + Lac; n = 5). Distal ileum was harvested on P9 and analyzed for disease severity, inflammation, and proliferation. Groups were compared using one-way ANOVA and t-test appropriately; p < 0.05 was considered significant. RESULTS: Compared to NEC group, lactoferrin-treated NEC mice had reduced disease severity, reduced inflammation markers IL-6 and TNF-α expression and increased intestinal stem cell marker Lgr5 + expression. Lactoferrin-treated NEC mice exhibited increased nuclear ß-catenin, indicating upregulated Wnt pathway, and increased Ki67 positivity, suggesting enhanced proliferation. Furthermore, lactoferrin administration to control mice did not affect intestinal inflammation as well as Lgr5 + stem cell expression and epithelial proliferation. This supports the safety of lactoferrin administration and indicates that the beneficial effects of lactoferrin are present when intestinal injury such as NEC is present. CONCLUSION: Lactoferrin administration reduces the intestinal injury in experimental NEC by downregulating inflammation and upregulating cell proliferation. This beneficial effect of lactoferrin in stimulating cell proliferation is mediated by the Wnt pathway. This experimental study provides insights on the mechanism of action of lactoferrin in NEC and the role of lactoferrin in enteral feeding.

The effects of human lactoferrin in experimentally induced systemic candidiasis.

Introduction. Candida albicans is responsible for several types of oral and systemic infections. In light of emerging resistance to antifungals, studies have demonstrated the antifungal effect of lactoferrin (LF), which is part of the innate immune system, has anticandidal activities.Methodology. C. albicans (2×106 c.f.u. ml-1) were incubated either with PBS or human LF (hLF) (100 µg ml-1) at 37 °C for 24 h and then RNA was isolated and virulence factors analysed. C. albicans (1×105 c.f.u.) was injected into the tail vein of immunocompromised wild-type and Ltf -/-. Then, 24 h later, the Ltf -/-I mice received hLF intravenously (100 µg g-1 body weight), while the control group received PBS. Then, 48 h later, the organs were collected, homogenized and C. albicans c.f.u.s were counted. In addition, the inflammatory mediators of kidneys and the virulence factors of C. albicans were analysed.Results. hLF-treated Ltf -/-I mice showed significant clearance of C. albicans in different organ tissues when compared to untreated Ltf -/-I mice. The inflammatory cytokines, such as IL-1ß, IL-6 , TNF-α and MPO and iNOS were downregulated in hLF-treated Ltf -/-I mice when compared to untreated Ltf -/-I mice. Whereas, IL-10 and IL-17A were upregulated at 72 h post infection when compared to Ltf -/-C mice. Histological analysis also revealed a significant decrease in the size and number of infectious foci in the hLF-treated groups. hLF treatment significantly downregulated several virulence factors of C. albicans both in vitro and in vivo.Conclusion. We concluded that hLF-treated Ltf -/- mice can reduce the severity of C. albicans-induced systemic infection.

Human Milk Proteins: Composition and Physiological Significance.

Human milk (HM) contains hundreds of proteins with very diverse functions that likely contribute to the short- and long-term beneficial effects of breastfeeding. These functions include serving as a source of amino acids, improving the bioavailability of micronutrients, including vitamins, minerals, and trace elements, providing immunologic defense, stimulating intestinal growth and maturation, shaping the microbiome, and enhancing learning and memory. Human milk proteins can be broadly classified into 3 categories: caseins, whey proteins, and mucins, which are present in the milk fat globule membrane. HM is whey predominant; however, the whey/casein ratio of HM changes from 90/10 in colostrum to 60/40 in mature HM. The whey proteins present in significant quantities in the whey fraction are α-lactalbumin, lactoferrin, IgA, osteopontin, and lysozyme. Additionally, bioactive peptides are formed during digestion of casein and whey, and glycans from glycoproteins are bifidogenic, adding further complexity to the functional properties of HM proteins. Recent advances in dairy technology have enabled isolation of bioactive milk proteins from bovine milk in sufficient quantities for clinical studies and, in some cases, addition to commercially available infant formula. Herein, the current evidence on HM protein composition and bioactivity of HM proteins is reviewed.

Genetic Polymorphisms in LTF/EcoRI and TLR4/AluI loci as candidates for milk and reproductive performance assessment in Holstein cattle.

The aim of this study was to explore the genetic polymorphisms in LTF/EcoRI and TLR4/AluI loci and their association with milk and reproductive performance in Holstein cattle. A randomly selected 800 Holstein dairy cows from two dairy farms (400 animals each) in Egypt were used. Based on the two farm records, association between LTF/EcoRI genotypes and milk performance traits (order of lactation, daily milk yield, days in milk, corrected milk at 305 day and dry period) was carried out. Meanwhile, exploring of TLR4/AluI genotypes effect was done on data for reproductive performance (age at first freshening, calving interval, number of services per conception, ovarian rebound and days open). DNA was extracted from blood samples collected from Holstein dairy cows of the both farms and restriction analysis of 301-bp PCR products of LTF gene revealed two genotypes: AA genotype (301 bp) and AB genotype (301, 201 and 100 bp). Meanwhile, restriction analysis of 382-bp PCR products of TLR4 gene digested with AluI yielded two alleles (A and B) and three genotypes (AA, AB and BB). The A allele was indicated by two bands at 300 and 82 bp, and the B allele resulted in three fragments of 160, 140 and 82 bp. There was a significant association (p ≤ 0.05) between LTF genotypes and milk performance traits except for days in milk. The TLR4 genotypes had significant effects (p ≤ 0.05) on age at first freshening, calving interval, number of services per conception, ovarian rebound and days open. Ordinal logistic regression statistical model also revealed that it is possible to calculate high reproductive performance traits and to predict favourable dairy cows based on LTF and TLR4 genotypes. This research reveals the effectiveness of LTF/EcoRI and TLR4/AluI loci as candidates for reproductive performance assessment in Holstein cattle.

Lactoferrin: Structure, function, denaturation and digestion.

Lactoferrin (LF) is a multifunctional protein occurring in many biological secretions including milk. It possesses iron binding/transferring, antibacterial, antiviral, antifungal, anti-inflammatory and anti-carcinogenic properties. These functional properties intimately depend on the structural integrity of LF especially its higher order conformation. LF is primarily extracted from bovine milk and it is subsequently added into many commercial products such as nutritional supplements, infant formula, cosmetics and toothpaste. LF is sensitive to denaturation induced by temperature and other physicochemical stresses. Hence, the extraction, powder formation processes of LF and processing parameters of LF-containing products have to be optimized to minimise its undesired denaturation. This review documents the advances made on structure-function relationships and discusses the effectiveness of methods used to preserve the structure of LF during thermal processing. Oral delivery, as the most convenient way for administering LF, is also discussed focusing on digestion of LF in oral, gastric and intestinal stages. The effectiveness of methods used to deliver LF to intestinal digestion stage in structurally intact form is also compared. Altogether, this work comprehensively reviews the fate of LF during thermal processing and digestion, and suggests suitable means to preserve its structural integrity and functional properties. Scope of review The manuscript aims at providing a comprehensive review of the latest publications on four aspects of LF: structural features, functional properties, nature and extent of denaturation and gastrointestinal digestion. It also analyses how these publications benefit food and pharmaceutical industries.

Lactoferrin: Major Physiological Functions and Applications.

Lactoferrin (lactotransferrin; Lf) is an iron-binding glycoprotein and one of the most important bioactivators in milk and other external secretions. It has numerous biological roles, including the regulation of iron absorption and modulation of immune responses, and has anti-microbial, anti-viral, antioxidant, anti-cancer, and anti-inflammatory activities. Lf regulates the quantity of iron absorbed in the intestine via its role in iron transport and can also chelate iron, directly or indirectly. Notably, it has been used as an adjuvant therapy for some intestinal diseases. It is now used in nutraceuticalsupplemented infant formula and other food products. This article reviews the content, distribution, physiologic functions and current applications of Lf, and aims to shed light on future prospects for additional applications of Lf.

Age-Related Dry Eye Lactoferrin and Lactobionic Acid.

Dry eye is the most prominent pathology among those involving the ocular surface: a decrease of the aqueous (less frequent) or the lipid (more frequent) component of the tear film is the cause of the diminished stability of tears that is observed in this pathology. Dry eye shows a clear distribution linked to both sex (being more frequent among women) and age (increasing with aging). Therefore, specific treatments taking into account the etiology of the disease would be desired. The role of lactoferrin and its functional mimetic lactobionic acid are reported here as a possible remedy for age-related dry eye.

Effect of technological treatments on bovine lactoferrin: An overview.

Lactoferrin (LF) is a multifunctional protein that exerts important activities in the neonate through its presence in milk, and also in other external mucosas, acting as a defense protein of innate immunity. The addition of bovine LF to infant formula and also to other functional products and cosmetics has increased during the last decades. Consequently, it is essential to know the effect that the technological processes, necessary to elaborate those products, have on LF activity. In this study, we have revised the effect of classical treatments on lactoferrin structure and activity, such as heat treatment or drying, and also of emerging technologies, like high pressure or pulsed electric field. The results of the studies included in this review indicate that LF stability is dependent on its level of iron-saturation and on the characteristics of the treatment media. Furthermore, the studies revised here reveal that the non-thermal treatments are interesting alternatives to the traditional ones, as they protect better the structure and activity of lactoferrin. It is also clear the need for research on LF encapsulation by different ways, to protect its properties before it reaches the intestine. All this knowledge would allow designing processes less harmful for LF, thus maintaining all its functionality.

Multifunctional capacity and therapeutic potential of lactoferrin.

Lactoferrin (LF) is a glycoprotein with high functional versatility that is found in most body fluids. The objective of this study was to gather and update information on the properties attributed to LF. According to this review, LF is a good immunomodulatory agent that acts on both innate and adaptive immune responses. It possesses antimicrobial activity against parasites, fungi, and viruses and also has regenerative properties at tissue level and anti-carcinogenic activity. All of these properties endow LF with major therapeutic potential of which little advantage has been taken to date.

Control mechanisms for producing antimicrobial factors in ruminant mammary gland.

Mastitis, a symptom of inflammation in mammary tissue by infection with various kinds of bacteria, causes huge economic losses in the milk industry. One of the popular methods for treatment of mastitis is antibiotics, although this prohibits milk shipping and sometimes causes resistant microbes. Therefore, a new strategy to treat mastitis without antibiotics is eagerly required around the world. Antimicrobial factors belong to innate immunity and can start their function extremely early after bacterial stimulation. These factors have antimicrobial activity for a broad spectrum of bacteria. Elucidation of causal mechanisms and functions of antimicrobial factors in the mammary gland is thought to result in suitable methods for prevention and treatment of mastitis. Therefore, this review introduces traits of some antimicrobial factors and the mechanisms for expressing, producing and secreting them in the mammary gland. For antimicrobial factors, lingual antimicrobial peptide (LAP), S100A7, cathelicidin and lactoferrin are controlled in different sites and different time courses, suggesting that antimicrobial factors play different roles for local defense against bacterial infection in the mammary gland. These findings will contribute to the development of prevention and treatment methods for mastitis.

Variability of lysozyme and lactoferrin bioactive protein concentrations in equine milk in relation to LYZ and LTF gene polymorphisms and expression.

BACKGROUND: Equine milk is considered to be an interesting product for human nutrition, mainly owing to its low allergenicity and significant amounts of bioactive proteins, including lysozyme (LYZ) and lactoferrin (LTF). The present study assessed the effect of genetic factors on LYZ and LTF concentration variability in mare's milk. RESULTS: Significant effects of horse breed and lactation stage on milk LYZ and LTF contents were observed. The highest level of LTF and the lowest concentration of LYZ were recorded for the Polish Warmblood Horse breed. The highest amounts of both proteins were found for the earliest investigated time point of lactation (5th week). Altogether 13 (nine novel) polymorphisms were found in the 5'-flanking regions of both genes, but they showed no significant relationship with milk LYZ and LTF contents. Several associations were found between selected SNPs and the LYZ gene relative transcript level. CONCLUSION: While the present study indicated the existence of intra- and interbreed variability of LYZ and LTF contents in mare's milk, this variation is rather unrelated to the 5'-flanking variants of genes encoding both proteins. This study is a good introduction for broader investigations focused on the genetic background for variability of bioactive protein contents in mare's milk. © 2016 Society of Chemical Industry.

The Role of Lactoferrin in Gastrointestinal and Immune Development and Function: A Preclinical Perspective.

The early postnatal period is a critical time for gastrointestinal (GI) and immune development. Neonates fed mother's milk have more rapid GI and immune development than fed-formula infants. In addition, clinical and epidemiologic data provide strong evidence that breastfeeding reduces the incidence and/or severity of infectious diseases. Lactoferrin is a 77 kDa, iron-binding glycoprotein that is present at high concentration in human milk compared with bovine milk and infant formula. It is a multifunctional protein that mediates many of the physiological processes in which breastfed infants have advantages over their formula-fed peers, including promoting GI and immune development, protection from infections, and improved cognitive development. Feeding bovine lactoferrin or recombinant human lactoferrin was well tolerated and stimulated intestinal cell proliferation and increased villus length and crypt depth in piglets. Lactoferrin also influenced both systemic and GI immune development by stimulating a balanced T-helper-1/T-helper-2 cytokine immune response. Further, there was a tendency for immune cells to secrete more anti-inflammatory cytokines in an unstimulated state, while being primed for a robust pro-inflammatory response when presented with a bacterial trigger in piglets fed lactoferrin. These findings support clinical studies demonstrating benefits of dietary lactoferrin in the prevention of infections, late onset sepsis, and necrotizing enterocolitis.

Molecular Determinants of Milk Lactoferrin as a Bioactive Compound in Early Neurodevelopment and Cognition.

Lactoferrin is a sialic acid-rich, iron-binding milk glycoprotein, known to have multifunctional health benefits, including its ability to modulate immune function and facilitate iron absorption, as well as its antibacterial and antiinflammatory actions. Human milk contains significantly higher lactoferrin levels than bovine milk at the same stages of lactation. The purpose of this review is to discuss the current state of knowledge of lactoferrin as a conditional nutrient for neurodevelopment, neuroprotection, and cognitive function during the period of rapid brain growth.

Lactoferrin, a Pleiotropic Protein in Health and Disease.

SIGNIFICANCE: Lactoferrin (Lf) is a nonheme iron-binding glycoprotein strongly expressed in human and bovine milk and it plays many functions during infancy such as iron homeostasis and defense against microorganisms. In humans, Lf is mainly expressed in mucosal epithelial and immune cells. Growing evidence suggests multiple physiological roles for Lf after weaning. RECENT ADVANCES: The aim of this review is to highlight the recent advances concerning multifunctional Lf activities. CRITICAL ISSUES: First, we will provide an overview of the mechanisms related to Lf intrinsic synthesis or intestinal absorption as well as its interaction with a wide spectrum of mammalian receptors and distribution in organs and cell types. Second, we will discuss the large variety of its physiological functions such as iron homeostasis, transportation, immune regulation, oxidative stress, inflammation, and apoptosis while specifying the mechanisms of action. Third, we will focus on its recent physiopathology implication in metabolic disorders, including obesity, type 2 diabetes, and cardiovascular diseases. Additional efforts are necessary before suggesting the potential use of Lf as a diagnostic marker or as a therapeutic tool. FUTURE DIRECTIONS: The main sources of Lf in human cardiometabolic disorders should be clarified to identify new perspectives for future research and develop new strategies using Lf in therapeutics. Antioxid. Redox Signal. 24, 813-836.

Lactoferrin and neonatology - role in neonatal sepsis and necrotizing enterocolitis: present, past and future.

Neonatal sepsis and necrotizing enterocolitis (NEC) are two most important neonatal problems in nursery which constitute the bulk of neonatal mortality and morbidity. Inflammatory mediators secondary to sepsis and NEC increases morbidity, by affecting various system of body like lung, brain and eye, thus causing long term implications. Lactoferrin (LF) is a component of breast milk and multiple actions that includes antimicrobial, antiviral, anti-fungal and anti-cancer and various other actions. Few studies have been completed and a number of them are in progress for evaluation of efficacy and safety of LF in the prevention of neonatal sepsis and NEC in field of neonatology. In future, LF prophylaxis and therapy may have a significant impact in improving clinical outcomes of vulnerable preterm neonates. This review analyse the role of lactoferrin in prevention of neonatal sepsis and NEC, with emphasis on mechanism of action, recent studies and current studies going on around the globe.