Lactoferrin a multiple bioactive protein: an overview

Lactoferrin: an overview of its main functions, immunomodulatory and antimicrobial role, and clinical significance

Lactoferrin (LF), a glycoprotein found in mucosal secretions, is characterized by a wide range of functions, including immunomodulatory and anti-inflammatory activities. Moreover, several investigations confirmed that LF displays high effectiveness against multiple bacteria and viruses and may be regarded as a potential inhibitor of enveloped viruses, such as presently prevailing SARS-CoV-2. In our review, we discuss available studies about LF functions and bioavailability of different LF forms in in vitro and in vivo models. Moreover, we characterize the potential benefits and side effects of LF use; we also briefly summarize the latest clinical trials examining LF application. Finally, we point potential role of LF in inflammatory bowel disease and indicate its use as a marker for disease severity.

In the Age of Viral Pandemic, Can Ingredients Inspired by Human Milk and Infant Nutrition Be Repurposed to Support the Immune System?

In 2020, with the advent of a pandemic touching all aspects of global life, there is a renewed interest in nutrition solutions to support the immune system. Infants are vulnerable to infection and breastfeeding has been demonstrated to provide protection. As such, human milk is a great model for sources of functional nutrition ingredients, which may play direct roles in protection against viral diseases. This review aims to summarize the literature around human milk (lactoferrin, milk fat globule membrane, osteopontin, glycerol monolaurate and human milk oligosaccharides) and infant nutrition (polyunsaturated fatty acids, probiotics and postbiotics) inspired ingredients for support against viral infections and the immune system more broadly. We believe that the application of these ingredients can span across all life stages and thus apply to both pediatric and adult nutrition. We highlight the opportunities for further research in this field to help provide tangible nutrition solutions to support one's immune system and fight against infections.

Protein Nanoparticles for Enhanced Oral Delivery of Coenzyme-Q10: in Vitro and in Silico Studies

Coenzyme-Q10 (CoQ10) is a hydrophobic benzoquinone with antioxidant and anti-inflammatory properties. It is known to reduce oxidative stress in various health conditions. However, due to the low solubility, permeability, stability, and poor oral bioavailability, the oral dose of CoQ10 required for the desired therapeutic effect is very high. In the present study, CoQ10 is encapsulated into two milk derived proteins β-lactoglobulin and lactoferrin (BLG and LF) to produce self-assembled nanostructures of around 100-300 nm with high encapsulation efficiency (5-10% w/w). Both CoQ10-BLG and CoQ10-LF nanoparticles (NPs) significantly improved the aqueous solubility of CoQ10 60-fold and 300-fold, compared to CoQ10 alone, which hardly dissolves in water. Insight into the difference in solubility enhancement between BLG and LF was obtained using in silico modeling, which predicted that LF possesses multiple prospective CoQ10 binding sites, potentially enabling greater loading of CoQ10 on LF compared to BLG, which was predicted to be less capable of binding CoQ10. At pH 7.4, CoQ10-LF NPs showed a burst release between 30 min and 2 h then plateaued at 12 h with 30% of the total drug released over 48 h. However, pure CoQ10-BLG and pure CoQ10 had a significantly lower release rate with less than 15% and 8% cumulative release in 48 h, respectively. Most importantly, both BLG and LF NPs significantly improved CoQ10 permeability compared to the pre-dissolved drug across the Caco-2 monolayer with up to 2.5-fold apparent permeability enhancement for CoQ10-LF-further confirming the utility of this nanoencapsulation approach. Finally, in murine macrophage cells (J774A.1), CoQ10-LF NPs displayed significantly higher anti-ROS properties compared to CoQ10 (predissolved in DMSO) without affecting the cell viability. This study paves the way in improving oral bioavailability of poorly soluble drugs and nutraceuticals using milk-based self-assembled nanoparticles.

Sensitive immunoassays based on specific monoclonal IgG for determination of bovine lactoferrin in cow milk samples

Lactoferrin (LF), a bioactive multifunctional protein of the transferrin family, is found mainly in the secretions of all mammals, especially in milk. In the present study, a hybridoma cell (LF8) secreting IgG against bovine LF was screened, and the purified LF8 mAb showed high specificity and affinity to bovine LF. The linear range of ic-ELISA to detect LF was 9.76 ~ 625 ng/mL, with a limit of detection (LOD) of 0.01 ng/mL. The average recovery of intra- and inter-assay were (104.45 ± 4.12)% and (107.13 ± 4.72)%, respectively. The LOD of colloidal gold- and AuNFs-based strip by naked eye were 9.7 and 2.4 ng/mL, respectively, and the detection time was less than 10 min without any samples pretreatment and expensive equipment. The developed ELISA and lateral flow immunosensors based on specific IgG could be used directly for rapid detection of the bovine LF content in cow milk samples.

Binding of lactoferrin to the surface of low-density lipoproteins modified by myeloperoxidase prevents intracellular cholesterol accumulation by human blood monocytes

Myeloperoxidase (MPO) is a unique heme-containing peroxidase that can catalyze the formation of hypochlorous acid (HOCl). The strong interaction of MPO with low-density lipoproteins (LDL) promotes proatherogenic modification of LDL by HOCl. The MPO-modified LDL (Mox-LDL) accumulate in macrophages, resulting in the formation of foam cells, which is the pathognomonic symptom of atherosclerosis. A promising approach to prophylaxis and atherosclerosis therapy is searching for remedies that prevent the modification or accumulation of LDL in macrophages. Lactoferrin (LF) has several application points in obesity pathogenesis. We aimed to study LF binding to Mox-LDL and their accumulation in monocytes transformed into macrophages. Using surface plasmon resonance and ELISA techniques, we observed no LF interaction with intact LDL, whereas Mox-LDL strongly interacted with LF. The affinity of Mox-LDL to LF increased with the degree of oxidative modification of LDL. Moreover, an excess of MPO did not prevent interaction of Mox-LDL with LF. LF inhibits accumulation of cholesterol in macrophages exposed to Mox-LDL. The results obtained reinforce the notion of LF potency as a remedy against atherosclerosis.

Lactoferrin receptors in Gram-negative bacteria: an evolutionary perspective

In this short review, we outline the major events that led to the development of iron acquisition systems in Gram-negative bacteria and mammals since the beginning of life on earth. Naturally, the interaction between these organisms led to the development of a wonderfully complex set of protein systems used for competition over a once prevalent (but no longer) biocatalytic cofactor. These events led to the appearance of the lactoferrin gene, which has since been exploited into adopting countless new functions, including the provision of highly bactericidal degradation products. In parallel to lactoferrin's evolution, evolving bacterial receptors have countered the bactericidal properties of this innate immunity protein.

Lactoferrin: A Glycoprotein Involved in Immunomodulation, Anticancer, and Antimicrobial Processes

Lactoferrin is an iron binding glycoprotein with multiple roles in the body. Its participation in apoptotic processes in cancer cells, its ability to modulate various reactions of the immune system, and its activity against a broad spectrum of pathogenic microorganisms, including respiratory viruses, have made it a protein of broad interest in pharmaceutical and food research and industry. In this review, we have focused on describing the most important functions of lactoferrin and the possible mechanisms of action that lead to its function.

Pretreatment with Human Lactoferrin Had a Positive Effect on the Dynamics of Mouse Nigrostriatal System Recovery after Acute MPTP Exposure

We studied the effect of human lactoferrin (hLf) on degenerative changes in the nigrostriatal system and associated behavioral deficits in the animal model of Parkinson disease. Nigrostriatal dopaminergic injury was induced by single administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 40 mg/kg) to five-month-old C57Bl/6 mice. Behavioral disturbances were assessed in the open field and rotarod tests and by the stride length analysis. Structural deficits were assessed by the counts of tyrosine hydroxylase (TH)-immunoreactive neurons in the substantia nigra and optical density (OD) of TH-immunolabeled fibers in the striatum. Acute MPTP treatment induced long-term behavioral deficit and degenerative changes in the nigrostriatal system. Pretreatment with hLf prevented body weight loss and promoted recovery of motor functions and exploratory behavior. Importantly, OD of TH-positive fibers in the striatum of mice treated with hLf almost returned to normal, and the number of TH-positive cells in the substantia nigra significantly increased on day 28. These results indicate that hLf produces a neuroprotective effect and probably stimulates neuroregeneration under conditions of MPTP toxicity in our model. A relationship between behavioral deficits and nigrostriatal system disturbances at delayed terms after MPTP administration was found.

The role of transferrins and iron-related proteins in brain iron transport: applications to neurological diseases

Iron transport in the central nervous system (CNS) is a highly regulated process in which several important proteins participate to ensure this important metal reaches its sites of action. However, iron accumulation has been shown to be a common factor in different neurological disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Multiple Sclerosis, and Sanfilippo syndrome. This review is divided into four parts. The first part describes brain iron transport in homeostasis, mentioning the main proteins involved, whereas the second part contrasts the consequences of iron dysregulation, elaborating on its role in the aforementioned neurodegenerative diseases. The third part details the functions of the main proteins involved in brain iron homeostasis and their role in neurodegeneration. In the fourth part, in order to highlight the importance of transport proteins, the focus is set on human serum transferrin, the main iron transport protein. This final part describes perspectives about the mechanisms and chemical properties of human transferrin for the development of potential targeted drug delivery systems across the blood-brain barrier (BBB) or enhancers for the treatment of neurological diseases.

Lactoferrin Isolation and Hydrolysis from Red Deer (Cervus elaphus) Milk and the Antibacterial Activity of Deer Lactoferrin and Its Hydrolysates

Lactoferrin (Lf) and other whey proteins have been isolated from red deer milk for the first time using a three-step anion and cation exchange chromatography protocol. The separated deer Lf was subject to in vitro gastric and duodenal digestions to generate peptides. The purity of the deer Lf and its hydrolysis products were analyzed by SDS-PAGE. The antibacterial activity of the deer Lf and its hydrolysates were investigated and was compared to cow counterpart. Gastric and duodenal digested deer Lf had strong bactericidal activity against E. coli ATCC 25922 with minimum inhibition concentration (MIC) of 280 µM and 402 µM, respectively. These results suggest that deer milk contains bioactive whey proteins and can generate bioactive peptides, which can benefit human health by inhibiting food-borne pathogenic bacteria.

Secondary Structural Transformation of Bovine Lactoferricin Affects Its Antibacterial Activity

Lactoferricin (Lfcin) is a potent antibacterial peptide derived from lactoferrin by pepsin hydrolysis. It was hypothesized that structural transformation of Lfcin could affect its antibacterial function through forming and breaking of intramolecular disulfide bond. To prove this hypothesis, bovine Lfcin (bLfcin) and its two derivatives, bLfcin with a disulfide bond (bLfcin DB) and bLfcin with a mutation C36G (bLfcin C36G), were synthesized, purified, and identified. The circular dichroism (CD) spectra of the peptides were detected in solutions with different ionic and hydrophobic strength. Then, the secondary structure contents of the peptides were calculated on the basis of the CD spectra. The antibacterial activity of the peptides against Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028, Shigella flexneri ATCC 12022, and Staphylococcus aureus ATCC 25923 was evaluated. The results showed that bLfcin and bLfcin C36G had similar percentages of secondary structure in water, while bLfcin and bLfcin DB had similar ratios of secondary structure under less hydrophobic conditions. The synthetic peptides exhibited antibacterial activity against all the tested bacteria, except for S. aureus ATCC 25923. bLfcin demonstrated higher antibacterial activity compared with its derivatives. The results suggested that bLfcin could transform its structure under alterative ionic strengths and hydrophobic conditions, and the transformation of structures was beneficial to enhancing the antibacterial function.

Brain-Targeted Delivery of Pre-miR-29b Using Lactoferrin-Stearic Acid-Modified-Chitosan/Polyethyleneimine Polyplexes

The efficacy of brain therapeutics is largely hampered by the presence of the blood–brain barrier (BBB), mainly due to the failure of most (bio) pharmaceuticals to cross it. Accordingly, this study aims to develop nanocarriers for targeted delivery of recombinant precursor microRNA (pre-miR-29b), foreseeing a decrease in the expression of the BACE1 protein, with potential implications in Alzheimer’s disease (AD) treatment. Stearic acid (SA) and lactoferrin (Lf) were successfully exploited as brain-targeting ligands to modify cationic polymers (chitosan (CS) or polyethyleneimine (PEI)), and its BBB penetration behavior was evaluated. The intracellular uptake of the dual-targeting drug delivery systems by neuronal cell models, as well as the gene silencing efficiency of recombinant pre-miR-29b, was analyzed in vitro. Labeled pre-miR-29b-CS/PEI-SA-Lf systems showed very strong fluorescence in the cytoplasm and nucleus of RBE4 cells, being verified the delivery of pre-miR-29b to neuronal cells after 1 h transfection. The experiment of transport across the BBB showed that CS-SA-Lf delivered 65% of recombinant pre-miR-29b in a period of 4 h, a significantly higher transport ratio than the 42% found for PEI-SA-Lf in the same time frame. Overall, a novel procedure for the dual targeting of DDS is disclosed, opening new perspectives in nanomedicines delivery, whereby a novel drug delivery system harvests the merits and properties of the different immobilized ligands.

Effect of a dietary supplement composed of hydrolyzed milk proteins and vanillin on the reduction of infection and oxidative stress induced by chemotherapy

This study evaluates the antioxidant and antibacterial activity of a mixture of lactoferrin hydrolysate (LfH), whey protein hydrolysate (WPH) and vanillin in vitro and in vivo to design a chemoprotective supplement for reducing the infection and oxidative stress induced by chemotherapy. The designed supplement showed significant antibacterial activity against E. coli. The supplement with the highest concentration exhibited considerable antioxidant activity in (2,2-diphenyl-1-picrylhydrazyl) DPPH free radicals, (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ABTS, and reducing power assays. In the biochemical analysis of liver homogenate, the supplement 3 increased the level of enzymes Catalase (CAT), Glutathione peroxidase (GPx), Superoxide dismutase (SOD), and also the Ferric Reducing Ability of Plasma (FRAP) while decreased thiobarbituric acid reactive substances (TBARS) in comparison to paclitaxel group, indicative of activity against oxidative stress. Antibacterial and antioxidant activity of the designed supplement makes it a good candidate for use as a functional food to reduce the side effects of chemotherapy. PRACTICAL APPLICATIONS: A dietary supplement composed of lactoferrin hydrolysate (LfH), whey protein hydrolysate (WPH) and vanillin showed antibacterial activity against E. coli and S. aureus in vitro. The studied supplement also exhibited significant antioxidant properties in the model system and anti-oxidative stress activity in mice exposed to paclitaxel. This supplement has a potential for use in the food matrix to reduce the chemotherapy side effects and to act as a chemoprotective agent.

Protein-polyphenol functional ingredients: The foaming properties of lactoferrin are enhanced by forming complexes with procyanidin

The solution turbidity and intrinsic fluorescence quenching increased after procyanidin was mixed with lactoferrin. The addition of procyanidin also caused a reduction in the surface hydrophobicity of the lactoferrin, suggesting procyanidin bound to non-polar patches on lactoferrin's surfaces. Moreover, the binding interaction caused an appreciable alteration in the structure of both the polyphenol and protein. Thermodynamic analysis indicated the interaction was spontaneous and mainly driven by entropy changes, suggesting that hydrophobic interactions dominated. A computational docking simulation provided insights into the location of the most-likely binding sites on the protein, as well as the nature of the interaction forces involved. In particular, both hydrophobic and hydrogen bonding were found to be important. The binding of the procyanidin to the lactoferrin enhanced its foaming properties. These results may lead to the development of a new class of natural functional ingredients that can be used in food products to improve their quality attributes.

Lactoferrin Functionalized Biomaterials: Tools for Prevention of Implant-Associated Infections

Tissue engineering is one of the most important biotechnologies in the biomedical field. It requires the application of the principles of scientific engineering in order to design and build natural or synthetic biomaterials feasible for the maintenance of tissues and organs. Depending on the specific applications, the selection of the proper material remains a significant clinical concern. Implant-associated infection is one of the most severe complications in orthopedic implant surgeries. The treatment of these infections is difficult because the surface of the implant serves not only as a substrate for the formation of the biofilm, but also for the selection of multidrug-resistant bacterial strains. Therefore, a promising new approach for prevention of implant-related infection involves development of new implantable, non-antibiotic-based biomaterials. This review provides a brief overview of antimicrobial peptide-based biomaterials-especially those coated with lactoferrin.

Comparative study of antimicrobial activity between some medicine plants and recombinant Lactoferrin peptide against some pathogens of cultivated button mushroom

The adverse effects of chemical pesticides on human health and environment cannot be ignored, hence it seems that novel alternative compounds should be applied to control plant pathogens. Among various alternative sources, natural compounds such as plant essential oils, plant extracts and recombinant antimicrobial peptides are of significance. The aim of the present study was to investigate antimicrobial activity of plants essential oils and plant extracts of six medicinal plants (Lippia citriodora, Ferula gummosa, Bunium persicum, Mentha piperita, Plantago major and Salvadora persica) along with a chimera peptide of camel lactoferrin, which is the most important antimicrobial component of camel milk, against Pseudomonas tolaasii and Trichoderma harzianum as pathogens of white button mushroom. The antibacterial activity test was conducted under in vitro conditions through disc diffusion method. The results showed that chimera camel lactoferrin peptide, with the highest amount of inhibitory zone (14.63 mm in 20 μg/mL concentration), has a significant difference in antibacterial activity compared to other treatments. Ferula gummosa conferred no antibacterial activity. Also, the results of antifungal effects indicated that plant essential oils and extracts have more antifungal activity than recombinant peptide. Generally, L. citriodora, B. persicum, M. piperita treatments could completely prevent growth of fungal in in vitro conditions. Therefore, using the mentioned plants can be a good replacement for reducing the chemical pesticides against pathogenic agents of button mushroom, without any adverse effects on environment and human health.

Lactoferrin: A Critical Mediator of Both Host Immune Response and Antimicrobial Activity in Response to Streptococcal Infections

Streptococcal species are Gram-positive bacteria responsible for a variety of disease outcomes including pneumonia, meningitis, endocarditis, erysipelas, necrotizing fasciitis, periodontitis, skin and soft tissue infections, chorioamnionitis, premature rupture of membranes, preterm birth, and neonatal sepsis. In response to streptococcal infections, the host innate immune system deploys a repertoire of antimicrobial and immune modulating molecules. One important molecule that is produced in response to streptococcal infections is lactoferrin. Lactoferrin has antimicrobial properties including the ability to bind iron with high affinity and sequester this important nutrient from an invading pathogen. Additionally, lactoferrin has the capacity to alter the host inflammatory response and contribute to disease outcome. This Review presents the most recent published work that studies the interaction between the host innate immune protein lactoferrin and the invading pathogen, Streptococcus.

Recombinant human lactoferrin induces apoptosis, disruption of F-actin structure and cell cycle arrest with selective cytotoxicity on human triple negative breast cancer cells

Breast cancer is the most frequently diagnosed cancer among women worldwide. Here, recombinant human lactoferrin (rhLf) expressed in Pichia pastoris was tested for its potential cytotoxic activity on a panel of six human breast cancer cell lines. The rhLf cytotoxic effect was determined via a live-cell HTS imaging assay. Also, confocal microscopy and flow cytometry protocols were employed to investigate the rhLf mode of action. The rhLf revealed an effective CC₅₀ of 91.4 and 109.46 µg/ml on non-metastatic and metastatic MDA-MB-231 cells, with favorable selective cytotoxicity index values, 11.68 and 13.99, respectively. Moreover, rhLf displayed satisfactory SCI values on four additional cell lines, MDA-MB-468, HCC70, MCF-7 and T-47D (1.55-3.34). Also, rhLf provoked plasma membrane blebbing, chromatin condensation and cell shrinkage in MDA-MB-231 cells, being all three apoptosis-related morphological changes. Also, rhLf was able to shrink the microfilaments, forming a punctuated cytoplasmic pattern in both the MDA-MB-231 and Hs-27 cells, as visualized in confocal photomicrographs. Moreover, performing flow cytometric analysis, rhLf provoked significant phosphatidylserine externalization, cell cycle arrest in the S phase and apoptosis-induced DNA fragmentation in MDA-MB-231 cells. Hence, rhLf possesses selective cytotoxicity on breast cancer cells. Also, rhLf caused apoptosis-associated morphologic changes, disruption of F-actin cytoskeleton organization, phosphatidylserine externalization, DNA fragmentation, and arrest of the cell cycle progression on triple-negative breast cancer MDA-MB-231 cells. Overall results suggest that rhLf is using the apoptosis pathway as its mechanism to inflict cell death. Findings warranty further evaluation of rhLf as a potential anti-breast cancer drug option.

Ultrasound-mediated therapies for the treatment of biofilms in chronic wounds: a review of present knowledge

Bacterial biofilms are an ever-growing concern for public health, featuring both inherited genetic resistance and a conferred innate tolerance to traditional antibiotic therapies. Consequently, there is a growing interest in novel methods of drug delivery, in order to increase the efficacy of antimicrobial agents. One such method is the use of acoustically activated microbubbles, which undergo volumetric oscillations and collapse upon exposure to an ultrasound field. This facilitates physical perturbation of the biofilm and provides the means to control drug delivery both temporally and spatially. In line with current literature in this area, this review offers a rounded argument for why ultrasound-responsive agents could be an integral part of advancing wound care. To achieve this, we will outline the development and clinical significance of biofilms in the context of chronic infections. We will then discuss current practices used in combating biofilms in chronic wounds and then critically evaluate the use of acoustically activated gas microbubbles as an emerging treatment modality. Moreover, we will introduce the novel concept of microbubbles carrying biologically active gases that may facilitate biofilm dispersal.

Hepcidin and Erythroferrone Correlate with Hepatic Iron Transporters in Rats Supplemented with Multispecies Probiotics

The influence of probiotic supplementation on iron metabolism remains poorly investigated. However, a range of studies, especially on Lactobacillus plantarum 299v (Lp229v), have indicated a possible positive impact of probiotics on iron absorption. The aim of the study was to determine the effect of multistrain probiotic supply on iron balance. Thirty Wistar rats were randomized into three groups: placebo (KK group), and multistrain probiotic per os in a daily dose of 2.5 × 10⁹ colony forming units (CFU) (PA group) or 1 × 10¹⁰ CFU (PB group). Multistrain probiotic consisted of nine bacterial strains: Bifidobacterium bifidum W23, B. lactis W51, B. lactis W52, Lactobacillus acidophilus W37, L. brevis W63, L. casei W56, L. salivarius W24, Lactococcus lactis W19, and Lc. lactis W58, in equal proportions. After six weeks, blood and organ samples were collected. No differences were found between the three groups in terms of serum concentrations of hepcidin (HEPC), lactoferrin (LTF), homocysteine (HCY), ferritin (Ft), or erythroferrone (ErFe), or in liver content of divalent metal transporter 1 (DMT1), transferrin receptors 1 and 2 (TfR), or ZRT/IRT-like protein 14 (ZIP14) proteins. In the overall sample, positive correlations were noted between the serum concentrations of hepcidin and lactoferrin, and hepcidin and ferritin; serum concentration of hepcidin and DMT1 and TfR1 in the liver; and serum concentration of erythroferrone and TfR2 in the liver. The correlations of serum hepcidin and erythroferrone with liver DMT1 and TfR represent significant mechanisms of Fe homeostasis. Our study has shown that multistrain probiotic supplementation used in the experiment did not disrupt the biochemical and hepatic regulatory processes of Fe balance and did not demonstrate significant influence on selected parameters of Fe metabolism.

Interactions of Whey Proteins with Metal Ions

Whey proteins tend to interact with metal ions, which have implications in different fields related to human life quality. There are two impacts of such interactions: they can provide opportunities for applications in food and nutraceuticals, but may lead to analytical challenges related to their study and outcomes for food processing, storage, and food interactions. Moreover, interactions of whey proteins with metal ions are complicated, requiring deep understanding, leading to consequences, such as metalloproteins, metallocomplexes, nanoparticles, or aggregates, creating a biologically active system. To understand the phenomena of metal-protein interactions, it is important to develop analytical approaches combined with studies of changes in the biological activity and to analyze the impact of such interactions on different fields. The aim of this review was to discuss chemistry of β-lactoglobulin, α-lactalbumin, and lactotransferrin, their interactions with different metal ions, analytical techniques used to study them and the implications for food and nutraceuticals.

Influence of Maternal Milk on the Neonatal Intestinal Microbiome

The intestinal microbiome plays an important role in maintaining health throughout life. The microbiota develops progressively after birth and is influenced by many factors, including the mode of delivery, antibiotics, and diet. Maternal milk is critically important to the development of the neonatal intestinal microbiota. Different bioactive components of milk, such as human milk oligosaccharides, lactoferrin, and secretory immunoglobulins, modify the composition of the neonatal microbiota. In this article, we review the role of each of these maternal milk-derived bioactive factors on the microbiota and how this modulation of intestinal bacteria shapes health, and disease.

Engineering Chirally Blind Protein Pseudocapsids into Antibacterial Persisters

Antimicrobial resistance stimulates the search for antimicrobial forms that may be less subject to acquired resistance. Here we report a conceptual design of protein pseudocapsids exhibiting a broad spectrum of antimicrobial activities. Unlike conventional antibiotics, these agents are effective against phenotypic bacterial variants, while clearing "superbugs" in vivo without toxicity. The design adopts an icosahedral architecture that is polymorphic in size, but not in shape, and that is available in both l and d epimeric forms. Using a combination of nanoscale and single-cell imaging we demonstrate that such pseudocapsids inflict rapid and irreparable damage to bacterial cells. In phospholipid membranes they rapidly convert into nanopores, which remain confined to the binding positions of individual pseudocapsids. This mechanism ensures precisely delivered influxes of high antimicrobial doses, rendering the design a versatile platform for engineering structurally diverse and functionally persistent antimicrobial agents.

Types of acute phase reactants and their importance in vaccination

Vaccines are considered to be one of the most cost-effective life-saving interventions in human history. The body's inflammatory response to vaccines has both desired effects (immune response), undesired effects [(acute phase reactions (APRs)] and trade-offs. Trade-offs are more potent immune responses which may be potentially difficult to separate from potent acute phase reactions. Thus, studying acute phase proteins (APPs) during vaccination may aid our understanding of APRs and homeostatic changes which can result from inflammatory responses. Depending on the severity of the response in humans, these reactions can be classified as major, moderate or minor. In this review, types of APPs and their importance in vaccination will be discussed.

Quantitative Proteomics and Weighted Correlation Network Analysis of Tear Samples in Type 2 Diabetes Patients Complicated with Dry Eye

PURPOSE

Diabetic patients are more likely to experience dry eye (DE). TMT-based proteomics and WGCNA are used to identify the differentially expressed proteins in tear proteome of type 2 diabetes with DE. The aim is to provide a molecular basis for exploring possible mechanisms underlying the pathogenesis of diabetic DE.

EXPERIMENTAL DESIGN

Subjects are divided into four groups (ten in each): type 2 diabetes with DE; type 2 diabetes without DE; non-diabetes with DE and normal controls. All subjects undergo DE tests. Total proteins are extracted and quantitatively labeled with TMT, then analyzed using liquid chromatography-mass spectrometry. WGCNA is used to identify the hub genes. Finally, differentially expressed proteins are validated by ELISA.

RESULTS

A total of 1922 proteins are identified, of which 1814 contain quantitative information. Ultimately, 650 of these proteins yield quantitative values. WGCNA performed on these 650 proteins reveal four distinct hub genes of diabetic DE.

CONCLUSIONS AND CLINICAL RELEVANCE

DE is associated with the differential expression of tear proteins in type 2 diabetes. Inflammation, immune factors, and lipid metabolism may play a role in the development of diabetic DE. LTF, LYZ, ZAG, and DNAJC3 have the potential to be the biomarkers of DE in diabetes.

Short communication: Characterization of the milk protein expression profiles in dairy buffaloes with and without subclinical mastitis

The aim of this study was to characterize the proteins present in milk whey from buffaloes with and without subclinical mastitis using a proteomic approach to identify differentially expressed proteins as potential biomarkers for this disease. Whey from Murrah buffaloes with subclinical mastitis was compared with whey from healthy animals using liquid chromatography-tandem mass spectrometry. The annotated protein databases for Bubalus bubalis and Bos taurus were used in the analysis, and the gene annotations from the buffalo and bovine reference assemblies were also used. After integrating gene annotations from both buffaloes and bovines, a total of 1,033 proteins were identified, of which 156 were differentially expressed. Eighteen biological processes were annotated with Gene Ontology. Cathelicidin-3 was identified as a potential biomarker for subclinical mastitis. These results are important to the characterization of mastitis in the buffalo mammary gland and may aid in the development of tools for early diagnosis.

Short peptides conjugated to non-peptidic motifs exhibit antibacterial activity

Short peptides derived from buforin and lactoferricin B were conjugated with other antimicrobial molecules of different chemical natures.

Effects of Lactoferrin on Subjective Skin Conditions in Winter: A Preliminary, Randomized, Double-Blinded, Placebo-Controlled Trial

Objective

To investigate the effects of lactoferrin (LF) on subjective skin conditions in winter.

Design

A preliminary, randomized, double-blinded, placebo-controlled trial.

Setting and subjects

Healthy adults in Japan.

Interventions

Intake of placebo, 200 mg, or 600 mg of LF for 12 weeks in winter.

Endpoints

Changes in the scores of subjective skin conditions.

Results

Three hundred and forty-six subjects were randomized. Nine subjects (placebo, n=0; 200 mg, n=5; 600 mg, n=4) withdrew consent, and 7 subjects (placebo, n=4; 200 mg, n=2; 600 mg, n=1) were lost to follow-up, resulting in 330 for a full analysis set.

Outcomes

Changes in the scores of moisture were greater in the 600 mg group than in the placebo group. Changes in the scores of moisture were greater in the 200 mg and 600 mg groups, and of texture were greater in the 600 mg group than in the placebo group in female subjects.

Conclusion

Intake of LF may improve moisture or texture of skin in winter.

Effect of the Zn Supplementation on Immuno-Modulatory Activities of Bovine Lactoferrin in the Murine Splenocytes and RAW264.7 Macrophages

Lactoferrin (LF) has important bio-functions including immuno-modulation, while essential trace metals may interact with LF and thereby induce property especially bio-activity changes. Bovine LF was thus supplemented with Zn²⁺ at 0.16, 0.32, and 0.64 mg/g LF to yield 10%, 20%, and 40% Zn-saturation, respectively. Afterwards, bovine LF and the Zn-supplemented LF products at 10-40-μg/mL doses were compared for their immuno-modulatory activities in two immune cells (murine splenocytes and RAW264.7 macrophages), using the stimulation index of the splenocytes, T lymphocyte subpopulations, macrophage phagocytosis, and cytokine production as evaluation reflectors. The results showed that bovine LF and the Zn-supplemented LF products had suppressive effect on the splenocytes and concanavalin A (ConA)- and lipopolysaccharide-stimulated splenocytes, but lower Zn-saturation and lower dose could alleviate and even counteract this suppressive effect (P < 0.05). More importantly, the Zn-supplemented LF product with lower Zn-saturation at lower dose exerted slightly higher macrophage stimulation, increased CD4⁺/CD8⁺ ratio of T lymphocyte subpopulations, and were capable of enhancing the interleukin-2 (IL-2), IL-4, and interferon-γ production in the splenocytes or the IL-1β, IL-6, and tumor necrosis factor-α production in the macrophages significantly (P < 0.05). Contrary to its counterpart at lower dose, the Zn-supplemented LF product with higher Zn-saturation at higher dose mostly showed opposite effects in the two cell models. It is concluded that Zn supplementation has an impact on the immuno-modulation of bovine LF, while Zn-saturation is a key factor to modulate these assessed immune activities.

Polymorphism of lactoferrin gene in Egyptian goats and its association with milk composition traits in Zaraibi breed

The objectives of this study were to identify polymorphisms in the lactoferrin gene among three Egyptian goat breeds (Barki, Zaraibi, and Damascus) and to investigate the effect of LF genotype, parity, and lactation stage on milk composition traits of Zaraibi goats. One hundred and thirty-two blood samples were collected for DNA extraction, with 53 from Zaraibi, 40 from Damascus, and 39 from Barki breeds. Fat, protein, total solids, solids-not-fat, and lactose percentages were determined in Zaraibi goat milk using an automatic milk analyzer. Two genotypes, GG and GA, in the lactoferrin gene were identified using single-strand conformation polymorphism and were confirmed by direct sequencing technique. The Zaraibi breed recorded the highest heterozygosity (0.272) and effective number of alleles (1.369), while the Damascus breed recorded the lowest values. The G/A SNP showed a significant association with protein, solids-not-fat, and total solid content of Zaraibi goat milk. Protein, solids-not-fat, and total solid content in our study were significantly higher at early and late parities. Lactose percentage decreased significantly from early to late parity. Fat, protein, solids-not-fat, and total solid content were significantly higher at early and late stages of lactation, and our results encourage the utilization of Zaraibi goat milk in cheese and butter processing at these stages. Moreover, the G/A SNP of the LF gene may be a useful marker for assisted selection programs to improve goat milk composition.

The goat β‑casein/CMV chimeric promoter drives the expression of hLF in transgenic goats produced by cell transgene microinjection

There is growing interest in the application of lactoferrin (LF) as a drug or food additive for animals and humans. The objective of this study was to produce transgenic cloned goats that would serve as living bioreactors, expressing high levels of recombinant human LF (rhLF) in their milk. We designed a pCL25 expression vector containing goat β-casein/CMV chimeric promoter in order to facilitate rhLF expression. This pCL25-rhLF-Neo vector was microinjected into goat fetal fibroblasts. G418 selection and PCR analysis were used to identify transgenic donor cells suitable for somatic cell nuclear transfer (SCNT). After SCNT and embryo transplantation, goats harboring the hLF gene were produced, as confirmed via PCR and southern blotting. The average rhLF concentration in milk from this transgenic goat was 3.89 mg/ml as determined via ELISA. We also used an optimized buffer in order to effectively elute high-purity (95.8%) rhLF from a cation-exchange column, with the recovered rhLF exhibiting high biological activity. Findings from this study demonstrated that it is possible to generate a transgenic goat harboring the hLF transgene driven by the goat β-casein/CMV chimeric promoter. It represents an initial step towards the production of rhLF, potentially allowing for industrialized purification in the future.

Human Mesenchymal Stem Cell Response to Lactoferrin-based Composite Coatings

The potential of mesenchymal stem cells (MSCs) for implantology and cell-based therapy represents one of the major ongoing research subjects within the last decades. In bone regeneration applications, the various environmental factors including bioactive compounds such as growth factors, chemicals and physical characteristics of biointerfaces are the key factors in controlling and regulating osteogenic differentiation from MSCs. In our study, we have investigated the influence of Lactoferrin (Lf) and Hydroxyapatite (HA) embedded within a biodegradable PEG-PCL copolymer on the osteogenic fate of MSCs, previous studies revealing an anti-inflammatory potential of the coating and osteogenic differentiation of murine pre-osteoblast cells. The copolymer matrix was obtained by the Matrix Assisted Pulsed Laser Evaporation technique (MAPLE) and the composite layers containing the bioactive compounds (Lf, HA, and Lf-HA) were characterised by Scanning Electron Microscopy and Atomic Force Microscopy. Energy-dispersive X-ray spectroscopy contact angle and surface energy of the analysed coatings were also measured. The characteristics of the composite surfaces were correlated with the viability, proliferation, and morphology of human MSCs (hMSCs) cultured on the developed coatings. All surfaces were found not to exhibit toxicity, as confirmed by the LIVE/DEAD assay. The Lf-HA composite exhibited an increase in osteogenic differentiation of hMSCs, results supported by alkaline phosphatase and mineralisation assays. This is the first report of the capacity of biodegradable composite layers containing Lf to induce osteogenic differentiation from hMSCs, a property revealing its potential for application in bone regeneration.

Functional analysis of recombinant buffalo lactoferrin and monoferric lobes and their cytotoxic effect on buffalo mammary epithelial cells

Lactoferrin (Lf) has been involved in diverse type of cellular activities and its biochemical properties are species specific. Lf is a bilobal molecule in which each lobe binds with one Fe²⁺/Fe³⁺ ion. A lot of physiological effects of Lf are regulated by its iron binding and release properties; however these properties are species-specific. To understand the iron-binding, thermal stability and cytotoxic effect of buffalo Lf (buLf) and contribution of individual N- and C-terminal lobes therein, buLf and the truncated monoferric lobes were expressed in Kluyveromyces lactis or Pichia pastoris yeast expression systems. The iron-uptake/release behavior and thermal stability of recombinant buLf was observed similar to the Lf purified from buffalo milk. Supplementation of recombinant buLf to the buffalo mammary epithelial cells (BuMEC) culture decreased their proliferation and the cell viability in a dose dependent manner. The cell growth decreased by 37% at 1.0 mg/ml Lf. C-lobe decreased the viability of BuMEC by 15% at 1 mg/ml. The C-lobe showed greater cytotoxic effect against BuMEC in comparison to N-lobe. buLf caused a reduced expression of the casein in BuMEC. At 1.0 mg/ml of buLf, CSN2 transcript level was reduced by 74% and 78% in the normal and hormone free media, respectively. The expression of IL-1β gene in BuMEC increased by 4-5 fold in the presence of 1.0 mg/ml of Lf. The effect was similar to that observed in the involutory mammary gland, suggesting the role of elevated level of Lf in remodeling of buffalo mammary tissue during involution.

Transport of Human Lactoferrin into Mouse Brain: Administration Routes and Distribution

We studied different ways of transport of human lactoferrin to the brain of C57Bl/6 mice after its administration via different routes, analyzed its distribution in the brain, and determined the phenotype of lactoferrin-containing cells. Colocalization of lactoferrin and markers of various cell types was estimated by fluorescent immunohistochemical analysis. Lactoferrin was detected in mouse brain sections after its intranasal, sublingual, and intraperitoneal administration, but not after conjunctival administration. After intranasal administration, lactoferrin rapidly penetrated into the brain and accumulated in the cytoplasm of vascular endothelial cells in the neocortex, striatum, hippocampus, and thalamus. After application of protein solution onto fixed floating sections, highly specific binding of lactoferrin was found in the nuclei of neurons, astrocytes, and microglia cells, but not in the nuclei of endothelial cells of mouse brain.

Development of dairy herd of transgenic goats as biofactory for large-scale production of biologically active recombinant human lactoferrin

The primary male-goats Lac-1 (human lactoferrin gene construct hLF5) and Lac-2 (human lactoferrin gene construct hLF3) with genome containing human lactoferrin gene were bred and the sperm bank of primary male-goats and their male descendents (F₁-F₇) was created. The herd of goats (200 transgenic females) that produced recombinant human lactoferrin (rhLF) in their milk at levels up to 16 g/L was obtained. The rhLF from milk of transgenic goats, natural human lactoferrin (hLF) from woman milk and natural goat lactoferrin (gLF) from milk of non-transgenic goats were purified using cation-exchange chromatography. It has been shown that rhLF is a glycoprotein and its physicochemical characteristics of rhLF are similar to hLf as revealed by different analytical methods including electron paramagnetic resonance, spectrophotometry, differential scanning calorimetry, mass spectrometry and peptide mapping. The high expression level of rhLF achieved in milk of transgenic goats provides a solid basis for developing an efficient and cost-effective downstream processing. The rhLF exhibited a prominent biological activity suggesting it as a promising biopharmaceutical and food supplements.