Peptides accompanying chicken egg yolk IgY – alternative methods of isolation and immunoregulatory activity

Abstract

In the hen immune system the egg content plays as significant a role in the development of the chick as colostrum does in newborn mammals. One of the most important proteins in this system seems to be the main yolk immunoglobulin IgY. It has been shown that IgY is accompanied by an immunostimulatory polypeptide complex named yolkin. In this report the biological activities of yolkin separated by means of four different procedures are presented. It was shown that yolkin acts as an inducer rather than a modulator of cytokine and nitric oxide release, and does not participate in the protection of cells against destructive effects of reactive oxygen species. However, using the perchloric acid procedure it is possible to obtain a peptide fraction with higher inducing activity, stronger antioxidant properties and ability to decrease the NO level induced by lipopolysaccharide. The results obtained show that it is feasible to select one of the presented methods of yolkin isolation that yields a product of particular activity. The properties of yolk peptides not only indicate their roles in the development of chicks, but can also be useful for the regulation of some immunological disturbances.

Yolkin Isolated from Hen Egg Yolk as a Natural Immunoregulator, Activating Innate Immune Response in BMDM Macrophages

“…It was shown by Polanowski et al [6,7] that hen egg yolk immunoglobulin Y occurs as a complex with polypeptides, named yolkin, which are homologous with the C-terminal domain of vitellogenin II. In our previous studies, we reported that yolkin is a good immunoregulator and stimulates human whole blood cells to produce significant amounts of cytokines [6][7][8]. In the present study, we explained the mechanism of action of the yolkin polypeptide complex in murine bone marrow-derived macrophages (BMDM cell line).…”

“…Whereas fractions of MW higher than 16 kDa are glycoproteins corresponding also to the amino acid sequence of vitellogenin II starting at position 1572aa [6]. Our studies obtained up to now have demonstrated that yolkin possesses immunoregulatory, antioxidant, and neuroprotective activities, stimulating human whole blood (ex-vivo) to produce a wide spectrum of cytokines [6][7][8], downregulating the level of intracellular free oxygen radicals, and stimulating neuron-like cells to produce brain-derived neurotrophic factor (BDNF) [9].…”

Pro-Cognitive Properties of the Immunomodulatory Polypeptide Complex, Yolkin, from Chicken Egg Yolk and Colostrum-Derived Substances: Analyses Based on Animal Model of Age-Related Cognitive Deficits

“…The mechanism of action of Yolkin is still under investigation. The recently obtained results indicate that Yolkin stimulates human whole blood cells to release cytokines: IL-6 and IL-10, shows the ability to modulate the nitric oxide (NO) production by mouse macrophages and protects against lipid peroxidation (Zabłocka et al 2014 ). Also, Yolkin stimulates neuronal cells to produce and release the mature form of BDNF (the latest unpublished data).…”

C-Terminal Fragment of Vitellogenin II, a Potential Yolkin Polypeptide Complex Precursor Protein—Heterologous Expression, Purification, and Immunoregulatory Activity

“…The natural source of yolkin is the yolk of a laying hen's egg. The methods applied for its isolation [8,10,18] allow one to obtain a heterogeneous group of yolk-derived peptides, alongside IgY purification; nevertheless, the purification yield of both methods is not high [8]. Nowadays, another approach to produce different biopeptides involves recombinant DNA technology.…”