The Role of Lactoferrin in Human Immunity
Lactoferrin is a glycoprotein that is present in human milk and cow milk. Lactoferrin is found in abundance in mammalian milk. The lactoferrin found in cow milk is known as Bovine Lactoferrin. [1]
Lactoferrin is present in many other parts of the human body like the intestine, respiratory tract, eyes, and nose. Lactoferrin is also available as a medicine in the form of lactoferrin capsules.
Lactoferrin has a lot of health benefits. It acts as a cell-secreted mediator that plays an important role in our innate and adaptive immune responses. Lactoferrin can bind with iron and can interact with various molecular and cellular responses. [2]
The health benefits of human and bovine lactoferrin and five key ways by which human and bovine lactoferrin supports a healthy immune system in the human body are described below:
LACTOFERRIN AS A MEDIATOR BRIDGING THE INNATE AND ADAPTIVE IMMUNE RESPONSES
Lactoferrin plays a very important role in innate immune responses as these act as the first line of defense against foreign pathogens. Lactoferrin also plays an important role in acute and chronic inflammation. Lactoferrin has a high affinity to iron, so it is a vital component of our first-line host defense mechanisms against various invading pathogens.
Lactoferrin can cause significant changes in the leukocyte immune system by increasing the activity of natural killer cells. Lactoferrin promotes the function of neutrophils by enhancing phagocytic activity and modifying the production of ROS. Lactoferrin activates macrophages through increasing cytokine and NO production and it limits intracellular pathogen proliferation. So daily use of bovine lactoferrin or lactoferrin capsules can enhance our innate and adaptive immunity. [3]
LACTOFERRIN IS A POWERFUL ANTIOXIDANT
Bovine Lactoferrin acts as an anti-oxidant by reducing intracellular levels of reactive oxygen species (ROS) that are induced by glucose oxidize. Bovine Lactoferrin also helps to reduce oxidative stress-induced apoptosis. During apoptosis, which is a natural process of cell death in our body triggered by caspases, Bovine Lactoferrin can inhibit caspase-3 activation. So Bovine Lactoferrin can limit caspases-induced apoptosis. Also, Bovine lactoferrin can limit glucose oxidase-induced apoptosis. So, daily oral use of bovine lactoferrin capsules can support our healthy immune system because of its antioxidant properties. [3]
LACTOFERRIN’S ROLE IN SYSTEMIC INFLAMMATORY RESPONSE SYNDROME (SIRS)
When a person has septicemia or endotoxemia, there is an early rise in lactoferrin concentration in the serum. Systemic inflammatory response syndrome, induced by bacteria or viruses, or endotoxins causes an increase in the levels of reactive oxygen species (ROS) in our body. These ROS cause inflammation. Lactoferrin reduces lipopolysaccharide-induced mitochondrial degeneration of reactive oxygen species (ROS) and it reduces inflammation. So daily use of lactoferrin capsules can be very helpful to boost our healthy immunity and it can play an important role during Systemic Inflammatory Response Syndrome, septicemia, and endotoxemia. [4]
LACTOFERRIN'S ROLE IN OXIDATIVE STRESS-INDUCED RESPONSES
Lactoferrin is the primary constituent of our natural immune system that helps to reduce oxidative stress at the molecular level, and it controls various inflammatory responses. When the production of reactive oxygen species (ROS) exceeds our body's natural antioxidant defenses, then oxidative stress will occur and it can lead to cell death. Cells can maintain their physical and metabolic activities under small levels of oxidative stress. But when the oxidative stress is very severe, cells will eventually lose their physical and metabolic functions leading to cell death. A lot of diseases occur due to high levels of oxidative stress in the human body such as Parkinson's disease which causes cell death in our brain's specific parts. [5]
Iron is a very important component that regulates the production of these reactive oxygen species in our bodies. So Iron also plays an important role in controlling oxidative stress. As we know, Lactoferrin has a high affinity to iron, so it plays a very important role in regulating oxidative stress in the human body. So daily oral use of bovine lactoferrin or lactoferrin capsules can prevent severe oxidative stress and it will increase our natural healthy immunity. [6]
LACTOFERRIN'S ROLE IN ANTIGEN-SPECIFIC ADAPTIVE IMMUNE RESPONSES
Lactoferrin plays a very important role in our innate and adaptive immune responses, both T-cell and B-cell mediated responses. All T cell subsets have the expression of lactoferrin receptors. Both human and bovine lactoferrin can bind with these lactoferrin receptors on the T cells. Bovine or human lactoferrin can affect T cells in many ways and it depends on the stage of T cells like maturation, activation, or differentiation. The lactoferrin present in the human body binds with CD4- and CD8- murine T cells and modulates T cell activity and its reactivity to local antigens. [6]
Lactoferrin has strong anti-inflammatory and stimulatory effects on T cells. Both bovine and human lactoferrin reduce overall cytokines production. They also reduce the production of specific interferons and interleukins. Lactoferrin can enhance the humoral immune responses in immunocompromised patients. Lactoferrin administered either orally or intraperitoneally can restore the host DTH response by increasing circulating T-cell populations. So Lactoferrin has the ability to modulate antigen-specific T cell responses that can last for several weeks after the initial sensitization. So lactoferrin greatly affects processes during priming of naïve T-cells to specific antigens. [6]
In addition to Lactoferrin's role in enhancing T cell-mediated immunity, Human and Bovine lactoferrin can also enhance B cell-mediated immunity. Human and Bovine Lactoferrin can enhance B cell-mediated depleted immunoreactivity. Human and Bovine Lactoferrin promotes maturation of murine immature B-cells by increasing C3R expression and it promotes the acquisition of surface IgD. So, by promoting the maturation of immature B cells, human and bovine lactoferrin enhance antigen-specific T cell proliferation. Orally administered Lactoferrin (Bovine lactoferrin) increases the secretion of IgA and IgG. So in short, Bovine lactoferrin acts on B cells and increases the antibodies responses in the human body. So orally administered lactoferrin (Bovine lactoferrin or lactoferrin capsules) can increase our natural immunity by affecting both B cells and T cells. [6]
References:
1.Dominique Legrand, P. "Overview of Lactoferrin as a Natural Immune Modulator" Retrieved from The Journal of Pediatrics: https://www.jpeds.com/article/S0022-3476(16)00294-8/fulltext
2.Douglas B. Kell, E. P. “The Biology of Lactoferrin, an Iron-Binding Protein That Can Help Defend Against Viruses and Bacteria”. Retrieved from Frontiers in Immunology: https://www.frontiersin.org/articles/10.3389/fimmu.2020.01221/full
3.Jeffrey K Actor, S.-A. H. “Lactoferrin as a natural immune modulator”. Retrieved from PubMed.gov: https://pubmed.ncbi.nlm.nih.gov/19519436/
4.Marian L Kruzel, J. K. “Lactoferrin in a Context of Inflammation-Induced Pathology”. Retrieved from Frontiers in Immunology: https://www.frontiersin.org/articles/10.3389/fimmu.2017.01438/full
5.Plaut, A. G. “Lactoferrin”. Retrieved from Science Direct: https://www.sciencedirect.com/topics/neuroscience/lactoferrin
6.Shen-An Hwang, J. K. “Lactoferrin as a Natural Immune Modulator”. Retrieved from NCBI: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2915836/