Colostrum's Proteins and Peptides: A Brief Overview

Colostrum is Mother Nature's very first food for all mammals. Colostrum is, gram for gram, the most zoonutrient dense of all foods. Zoonutrients in animals, much like phytonutrients in plants, are "quasi-nutrients" that have salubrious effects on the health beyond the provision of energy and structural "raw" materials garnered from fats, proteins, carbohydrates, vitamins and minerals.

The zoonutrients in colostrum generally are in the form of proteins, glycoproteins and peptides. The major functions of colostrum are to provide passive immunity factors from the mother; to provide signals to initiate active immunity in the neonate; and to provide growth factors to stimulate growth.

Generally, the protein subfractions of colostrum are most potent in relation to their passive immunity effects. These have great import in that the neonate has had neither the time nor the exposure to produce antibodies and related defenses against potential microbial pathogens and opportunists in its environment.

The peptides tend rather to be signals and/or bits of information for the production of proteins and glycoproteins related to active immunity and growth/repair, and can act as modulators to keep the inflammatory cascade and growth/repair activities in balance. To the left is a chart1 of some of the more important subfraction proteins and peptides in colostrum and some of their functions.

Colostrum Factors: Active and Passive Immunity

Colostrum generally has been known for its immune globulins (Ig) and their ability to support intestinal health and resistance through the predominantly passive immunity they provide. However, when colostrum is processed to achieve higher Ig levels, some other proteins and peptides that promote active immunity are diminished, including the peptide that is quickly becoming the focus of interest: proline-rich polypeptide (aka PRP).

Proline-Rich Polypeptides (PRPs)

PRPs may well be the premier immune factors in colostrum, continually modulating our immune system activity throughout life.² Lawrence discovered PRPs in 1949, when he demonstrated that an immune fraction of a person's white blood cells was able to transfer immunity in a nonsensitized individual - PRP as transfer factor.^3,4

PRPs are very small peptide chains (3,500-6,000 daltons) of less than a dozen amino acids, with proline predominating. In the past, they were derived from dialyzed white blood cells (WBCs), but now can be purified from bovine colostrum. PRPs are produced by T-lymphocytes and:

• can transfer the ability to recognize a pathogen to cells that have never been in contact with the pathogen (memory function);
• are involved in triggering T-cell recognition of antigen and can heighten the immune system's ability to react to pathogens (Th-1 inducer function); and
• can block the response of the T-cells, and signals a down regulation of the immune response (Th-2 suppressor function).^5,6

Th-1 and Th-2  Helper Paradigm

The main function of PRP is to modulate the cytokine and antibody production to keep our immune system responses in balance. To best appreciate this function, it is helpful to have a basic understanding of the Th-1 helper/Th-2 helper paradigm.

Th-1 cells, which modulate cell-mediated immunity, produce the immune cell signaling peptides called cytokines, including for example interleukin-2, interferon-gamma and tissue necrosis factor-alpha (TNF-a). Cell-mediated Th-1 helper responses are important in the body's ability to defend itself against viruses, fungi, parasites, cancer and intracellular organisms.⁷

Th-2 cells, which modulate humoral immunity or antibody production, produce IL-4, IL-5, IL-6, IL-10, and IL-13. If one has a Th-2-dominated condition, with decreased cellular immunity and heightened humoral immunity, the conditions that tend to prevail are:

• allergies, chronic sinusitis, atopic eczema, asthma and ulcerative colitis;
• systemic autoimmune conditions such as lupus erythema-tosus, mercury-induced auto-immunity and vaccination- induced states;
• hyper-insulinism and hyper-cortisolism;
• malaria, helminth infection, chronic giardiasis, chronic candidiasis, viral infections (herpes, HIV, hepatitis C); and
• cancer.⁸

Pregnancy is a Th-2-dominant state. This is an advantage during pregnancy, since a Th-1 dominant cell-mediated immune response might induce rejection of the fetus and placenta. Indeed, certain autoimmune diseases such as multiple sclerosis and rheumatoid arthritis, which are Th-1-dominant states, are ameliorated during pregnancy.^9,10 Because it stimulates a Th-1 response in most cases, as a precaution, PRP should not be used in pregnancy, though there are no adverse events reported in the literature of which I am aware.¹¹

Bioavailability

Peptides are by definition simple chains of amino acids and, as such, are very susceptible to denaturization (deactivation) by digestive acids and PH. Therefore, PRP as a separate nutraceutical product often is delivered sublingually. Alternately, the use of lecithin and/or milk-based phospholipids liposomes are used to enhance alimentary bioavailability.¹²

Immune-system functioning is at the heart of the many disorders seen in clinical practice. Whole colostrum¹³ provides unique immune and tissue repair supporting zoonutrients, especially when fortified with PRP and nano-encapsulated in a liposomal delivery system to maximize the bioavailability of the more delicate peptides. Its use as a nutritional adjunctive therapy to support a return to and the maintenance of immune-system balance often might be well indicated, especially when it is challenged by tumor growth, chronic fatigue, viral infections, allergies, chronic infections and autoimmune diseases.

References

1. Other proteins and peptides in whole colostrum include beta 2-microglobulin, enzymes, haemopexin, haploglobulin, orotic acid, peroxidase, xanthine oxidase enzyme, gonadotropin-releasing hormone (GnRH), prolactin, insulin, sulfur, glycoproteins (including protease- and trypsin-inhibitors), lactalbumin, multimeric a-lactalbumic, gamma-globulin, B lactoglobulin complement 3 & 4 (C3 & C4), kappa-casein, alpha-2-AP glycoprotein, alpha 1-antitrypsin, alpha 2- macroglobulin, orosomucoids, prealbumin, albumin, oligosaecharides, nonspecific inhibitors (NSIs), secretory lgA (SlgA), lgA-specific helper.
2. Janusz M, Lisowski J. Proline-rich polypeptide (PRP) - an immunomodulatory peptide from ovine colostrum. Archivum Immunologiae et Therapiae Experimentalis, 1993;41:275-9.
3. Lawrence HS, Borkowsky W. TRANSFER FACTOR: current status and future prospects. Biotherapy, 1996;9:1-5.
4. Ibid.
5. Wieczorek Z, Zimecki M, Spiegel K, et al. Differentiation of T cells into helper cells from immature precursors: identification of a target cell for a proline-rich polypeptide (PRP). Archivum Immunologiae et Ttherapiae Experimentalis (Warszava), 1989;37(3-4):313-22.
6. Zimecki M, Janusz M, Staroscik K, et al. Immunological activity of a proline rich polypeptide from ovine colostrum. Archivum Immunologiae et Therapiae Experimentalis (Warszava), 1978;26(1-6):23-9.
7. Bock S. Transfer factor and its clinical applications. The International Journal of Integrative Medicine. Available at: www.rhinebeckhealth.com/rhc/t-factor.php.
8. Ibid.
9. Kim S, Lira SM, Dalal MA, et al. Estriol ameliorates autoimmune demyelinating disease. Neurology, 1999;4:1230-7.
10. Formby. Immunologic response in pregnancy. Endocrine and Metabolic Clinics of North America, 1995;24: 187-205.
11. PDRhealth.com: www.pdrhealth.com/drug_info/nmdrugprofiles/ nutsupdrugs/bov_0082.shtml.
12. Wong A, Toth I. Lipid. Sugar and liposaccharide based delivery systems. Current Medical Chemistry, 2001;8(9):1123-36.
13. By whole colostrum, I mean colostrum that has not been processed to heighten passive immune factors at the expense of other proteins and/or peptides. Generally, colostrum is defatted to prevent rancidification.