Immunostimulation of murine spleen cells by materials associated with bovine milk protein fractions

Dietary Whey Protein Supplementation Increases Immunoglobulin G Production by Affecting Helper T Cell Populations after Antigen Exposure

Whey protein is a by-product of cheese and casein manufacturing processes. It contains highly bioactive molecules, such as epidermal growth factor, colony-stimulating factor, transforming growth factor-α and -β, insulin-like growth factor, and fibroblast growth factor. Effects of whey protein on immune responses after antigen (hemagglutinin peptide) injection were evaluated in rats. Experimental diets were formulated based on NIH-31M and supplemented with 1% amino acids mixture (CON) or 1% whey protein concentrate (WPC) to generate isocaloric and isonitrogenous diets. Rats were fed the experimental diets for two weeks and then exposed to antigen two times (Days 0 and 14). Blood was collected on Days 0, 7, 14, and 21 for hematological analysis. The WPC group showed decreased IgA and cytotoxic T cells before the antigen injection (Day 0) but increased IgG, IL-2, and IL-4 after antigen injection due to increased B cells and T cells. Helper T cells were increased at Days 14 and 21, but cytotoxic T cells were not affected by WPC. WPC may activate adaptive immunity (IgG) against antigen by modulating helper T cells. Bioactive molecules might contribute to the immune-enhancing effects of whey protein concentrate.

Dietary Prevention of Atopic March in Pediatric Subjects With Cow's Milk Allergy

Cow's milk allergy (CMA) is one of the most prevalent food allergies and the most expensive allergic diseases in the pediatric age. There is no cure for CMA, and actual disease management is based on strict avoidance of cow milk protein-containing foods, access to rescue medication, and use of substitutive formulas. Early-life CMA could be one of the first steps of the "allergic march" (AM), leading to the occurrence of other atopic manifestations later in the life, including asthma and oculorhinitis, with subsequent further increase of costs for health care systems and families of affected children. In the last years, diet is emerged as a relevant strategy to prevent allergic diseases through, at least in part, epigenetic modulation of immune system. We provide an overview of studies that investigate the potential role of different dietary strategies in preventing the AM in pediatric patients with CMA.

The Effect of Dietary Replacement of Fish Meal with Whey Protein Concentrate on the Growth Performance, Fish Health, and Immune Status of Nile Tilapia Fingerlings, Oreochromis niloticus

Simple Summary

Although fish meal is considered the main animal protein source in fish diets, its high cost and unavailability limit its use in aquafeed. Recently, the search for other high-quality replacers of fish meal in aquatic feeds is being carried out with increased attentiveness. However, very few investigations have been performed to assess the possible use of whey protein concentrates (WPC) in Nile tilapia feeds. Five replacement percentages of fish meal with WPC (0%, 13.8%, 27.7%, 41.6%, and 55.5%) were assessed. WPC could replace the fish meal in Nile tilapia diets up to 27.7%, with improving the gut health, the total weight of survival fish, and immune status of fish challenged with Aeromonas hydrophila. High inclusion levels of WPC are not recommended in fish diets, since they negatively affected the intestinal and liver tissues and increased the level of cellular apoptosis, as indicated by the increased caspase 3 activity.

Abstract

The present study was conducted to assess the effect of replacing fish meal with whey protein concentrate (WPC) on the growth performance, histopathological condition of organs, economic efficiency, disease resistance to intraperitoneal inoculation of Aeromonas hydrophila, and the immune response of Oreochromis niloticus. The toxicity of WPC was tested by measuring the activity of caspase 3 as an indicator of cellular apoptosis. Oreochromis niloticus fingerlings with average initial weight 18.65 ± 0.05 gm/fish (n = 225) for a 10-week feeding trial. The fish were randomly allocated to five experimental groups, having five replacement percentages of fish meal with WPC: 0%, 13.8%, 27.7%, 41.6%, and 55.5% (WPC0, WPC13.8, WPC27.7, WPC41.6, and WPC55.5); zero percentage represented the control group. The results show that the fish fed WPC had the same growth performance as the WPC0. The total weight of bacterially challenged surviving fish increased linearly and quadratically (p ≤ 0.05) by increasing the replacement percentage of fish meal with WPC. The growth hormone, nitric oxide, IgM, complement 3, and lysozyme activity were seen to increase significantly in WPC27.7, especially after a bacterial challenge. The phagocytic percentage and phagocytic index increased significantly in WPC27.7, WPC41.6, and WPC55.5 groups. Histopathological examination of liver sections was badly affected by high replacement in WPC41.6–55.5. The activity of caspase 3 in the immunohistochemical stained sections of the intestine was increased significantly by increasing the inclusion level of WPC. Economically, the total return of the total surviving fish after the bacterial challenge was increased significantly by fish meal replacement with WPC. It could be concluded that WPC could replace the fish meal in Nile tilapia diets up to 27.7%, with improving the gut health, the total weight of survival fish, and immune status of fish challenged with A. hydrophila. High inclusion levels of WPC are not recommended in fish diets, since they negatively affected the intestinal and liver tissues and increased the level of cellular apoptosis, as indicated by the increased caspase 3 activity. Further researches are recommended to evaluate the effect of fish meal replacement with WPC on the histopathological examination of the kidney and to test the capacity of serum IgM to clot the bacteria used for the challenge.

Toll-like receptor mediated activation is possibly involved in immunoregulating properties of cow's milk hydrolysates

Immunomodulating proteins and peptides are formed during the hydrolysis of cow’s milk proteins. These proteins are potential ingredients in functional foods used for the management of a range of immune related problems, both in infants and adults. However, the mechanism behind these effects is unknown. We hypothesize that the interaction of peptides with Toll-like receptors (TLRs) can induce immune effects, since these receptors are known to sample many dietary molecules in the intestine in order to regulate immune effects. To investigate this, we compared the immune effects and TLR activation and inhibition by whey and casein hydrolysates with different hydrolysis levels. We first measured cytokine production in primary peripheral blood mononuclear cells stimulated with either whey, casein, or their hydrolysates. IL-10 and TNFα were induced by whey hydrolysates (decreasing with increasing hydrolysis level), but not by casein hydrolysates. Next, the activation of TLR 2, 3, 5 and 9 receptors were observed by intact and mildly hydrolysed whey proteins only and not by casein hydrolysates in TLR reporter cell lines. Many casein hydrolysates inhibited TLR signaling (mainly TLR 5 and 9). These results demonstrate that the effects of cow’s milk proteins on the immune system are protein type and hydrolysis dependent. TLR signaling is suggested as a possible mechanism for differences in effect. This knowledge contributes to a better understanding of the immune effects of hydrolysates and the design of infant formula, and nutrition in general, with specific immunoregulatory effects.

Immunomodulating properties of protein hydrolysates for application in cow's milk allergy

Cow's milk proteins cause allergic symptoms in 2-3% of all infants. In these individuals, the tolerogenic state of the intestinal immune system is broken, which can lead to sensitization against antigens and eventually to allergic responses. Although a true treatment for food allergy is not available, symptoms can be avoided by providing the infants with hydrolyzed proteins. Hydrolyzed proteins are proteins that are enzymatically degraded. They lack typical allergenic IgE-binding epitopes but are also thought to play a pertinent role in other mechanisms inducing hypoallergenic effects. This review discusses the mechanisms and evidence for immunomodulating properties of cow's milk hydrolysates. Hydrolysates are found to strengthen the epithelial barrier, modulate T-cell differentiation, and decrease inflammation. Some studies suggest a role for hydrolysates in manipulating pathogen recognition receptors signaling as underlying mechanism. Peptides from hydrolysates have been shown to bind to TLR2 and TLR4 and influence cytokine production in epithelial cells and macrophages. Current insight suggests that hydrolysates may actively participate in modulating the immune responses in subjects with cow's milk allergy and those at risk to develop cow's milk allergy. However, more research is required to design effective and reproducible means to develop targeting strategies to modulate the immune response.

Effect of thermal processing of cow and buffalo milk on the allergenic response to caseins and whey proteins in mice

BACKGROUND

Heat treatment is the most common method for reducing pathogen load, but it remains controversial in reducing the incidence of hyperimmune reactions. The aim of this study was to compare the allergenicity of caseins (CSN) and whey proteins (WP) of thermally processed cow and buffalo milk in a mouse model. Swiss albino mice were sensitised by intraperitoneal injections (administered in three doses at weekly intervals) of CSN or WP from cow or buffalo milk for the evaluation of humoral response and splenocyte stimulation index.

RESULTS

After 3 weeks of intraperitoneal stimulation of mice with milk proteins, the sterilised milk protein group displayed significantly lowered (P ≤ 0.05) serum IgG and IgE levels, while considerably increased cow milk protein-specific responses (IgE) were shown by proteins of pasteurised milk compared with those of raw milk. The stimulation index of splenocytes induced by CSN or WP of boiled and sterilised milk was also lower (P ≤ 0.05) than that of raw milk of both cow and buffalo.

CONCLUSION

The experiment showed that boiling and sterilisation of cow and buffalo milk clearly affect the allergenicity by decreasing the humoral and cell-mediated responses in mice. All results indicated that CSN and WP of sterilised milk are less allergenic than those of raw milk in mice.

Invited review: physiological properties of bioactive peptides obtained from whey proteins

Processing of whey proteins yields several bioactive peptides that can trigger physiological effects in the human body: on the nervous system via their opiate and ileum-contracting activities; on the cardiovascular system via their antithrombotic and antihypertensive activities; on the immune system via their antimicrobial and antiviral activities; and on the nutrition system via their digestibility and hypocholesterolemic effects. The specific physiological effects, as well the mechanisms by which they are achieved and the stabilities of the peptides obtained from various whey fractions during their gastrointestinal route, are specifically discussed in this review.

A bovine whey protein extract can enhance innate immunity by priming normal human blood neutrophils

Bovine milk-derived products, in particular whey proteins, exhibit beneficial properties for human health, including the acquired immune response. However, their effects on innate immunity have received little attention. Neutrophils are key cells of innate defenses through their primary functions of chemotaxis, phagocytosis, oxidative burst, and degranulation. A whey protein extract (WPE) purified from bovine lactoserum was evaluated for its direct and indirect effects on these primary functions of normal human blood neutrophils in vitro. Although WPE had no direct effects on primary functions, a 24-h pretreatment of neutrophils with WPE was associated with a significant and dose-dependent increase of their chemotaxis, superoxide production, and degranulation in response to N-formyl-methionine-leucine-phenylalanine, as well as of their phagocytosis of bioparticles. The pretreatment increased the surface expression of CD11b, CD16B, and CD32A receptors. The major WPE protein components beta-lactoglobulin (beta-LG) and alpha-lactalbumin (alpha-LA) were the main active fractions having an additive effect on human neutrophils that became more responsive to a subsequent stimulation. This effect on NADPH oxidase activity was associated with translocation of p47(phox) to plasma membrane. Glycomacropeptide, a peptide present in measurable amounts in WPE products, was able to enhance the individual effect of beta-LG or alpha-LA on neutrophils. The present data suggest that WPE, through beta-LG and alpha-LA, has the capacity to enhance or "prime" human neutrophil responses to a subsequent stimulation, an effect that could be associated with increased innate defenses in vivo.

Immunomodulation by a Malleable Matrix Composed of Fermented Whey Proteins and Lactic Acid Bacteria

Functional foods and nutraceuticals have gained in popularity over the last 10 years. Among natural health products, whey proteins and fermented milk products are paramount. A malleable protein matrix (MPM), composed of whey fermented by a lactic acid bacterium, capsular exopolysaccharides, vitamins, minerals, and peptides generated during the fermentation process, has the potential to be unique by combining multiple health-promoting components. Forced feeding experiments on healthy animals were performed to evaluate the immunomodulatory effect of MPM. Glutathione production, antibody response, and the modulation of leukocyte populations were monitored. The stimulation of the immune system by MPM consumption was evident as seen by the increased polymorphonuclear cell counts and intracellular glutathione levels. The absence of MPM-specific antibody production indicated a lack of undesirable immune recognition of MPM. The MPM, with its immunomodulatory properties, has the potential to be a food substitute or a functional food for maintenance of general immune health.

Immunostimulatory principles from Chlorella pyrenoidosa--part 1: isolation and biological assessment in vitro

Our proprietary preparation obtained by extraction of Chlorella pyrenoidosa cells, ONC-107 (Respondin), was recently found to selectively boost antibody response to the influenza vaccine in a human clinical trial. Respondin is a potent stimulator of mouse B cell proliferation and an activator of macrophages. Bioactivity-guided resolution concluded that Respondin is composed of a mixture of immunostimulatory principles of different chemical nature. A combination of size exclusion, anion exchange and hydrophobic interaction chromatography revealed that the bulk of the immunostimulatory activity resides in polysaccharide/protein complexes with molecular masses larger than 100 kDa that are composed primarily of galactose, rhamnose and arabinose.

Mode of inactivation of probiotic bacteria affects interleukin 6 and interleukin 8 production in human intestinal epithelial-like Caco-2 cells

Five lactic acid bacteria and two bifidobacteria strains were heat or irradiation inactivated. Inactivated cultures were evaluated for their effects on cytokines interleukin (IL) 6 and IL-8 production in human intestinal-like Caco-2 cells. For both heat- and irradiation-inactivated cultures, production of IL-6 and IL-8 was dependent on the specific microorganism. However, with all of the cultures, both IL-6 and IL-8 production was significantly higher (P < 0.05) in Caco-2 cells that were treated with heat-inactivated probiotic bacteria compare to the irradiation-inactivated bacteria. In the majority of the cases, heat-inactivated bacteria induced IL-6 and IL-8 production, whereas irradiation-inactivated bacteria attenuated both cytokine production. Our results indicate that the same probiotic bacteria used in the same cell culture could provide opposite cytokine production and immune modulation results based on its mode of inactivation; therefore, it is important to describe inactivation methods and conditions in detail when characterizing probiotic effects.

Whey proteins and peptides: beneficial effects on immune health

A 65-year-old male with liver metastases after lung cancer resection was treated with five courses of chemotherapy consisting of gemcitabine (GEM) 1,000 mg/m2 (day 1, 8, every 4 weeks) plus carboplatin (CBDCA) AUC 6 (day 1, every 4 weeks). A partial response (PR) was achieved, his symptoms abated and his quality of life(QOL) improved. Although bone marrow suppression was observed as a side effect, it was within the tolerable range and did not interfere with therapy. This approach may be worth considering as a first-line anti-cancer chemotherapy for recurrence lung cancer.

Immunostimulation effects of proteose-peptone component 3 fragment on human hybridomas and peripheral blood lymphocytes

Fat-free bovine milk fermented by 12 kinds of lactic acid bacteria and yeast enhanced monoclonal antibody production of human hybridoma HB4C5 cells 2.8-fold in serum-free medium. Immunoglobulin production of human peripheral blood lymphocytes (PBL) was also stimulated in vitro. IgM and IgG production of human PBL was accelerated up to 2.8-fold and 5.4-fold, respectively. Interferon-gamma production of human PBL was also accelerated 6.0-fold by 50 microg/ml of the fermented milk. However, interleukin-4 production of PBL was not affected, and tumor necrosis factor-alpha production was suppressed. The activity was enhanced 2.5-fold by the thermal treatment for 30 min at 65 degrees C and was completely lost by trypsin digestion. The findings suggested that the active substance in the fermented milk was heat stable protein. Gel-filtration and the SDS-PAGE analysis revealed that the molecular weight of the active substance was estimated as 19.0 kDa, which was not detected in fat-free bovine milk before fermentation. N-terminal amino acid sequence of the 19.0 kDa protein was highly homologous to proteose-peptone component 3 (PP3). Since molecular weight of PP3 is 28 kDa, it is suggested that the 19.0 kDa protein is derived from degradation of PP3 during fermentation of fat-free milk. Moreover, PP3 purified from fat-free milk also enhanced IgM production of HB4C5 cells.

An aqueous Chlorella extract inhibits IL-5 production by mast cells in vitro and reduces ovalbumin-induced eosinophil infiltration in the airway in mice in vivo

An aqueous extract of the edible microalga (CP) (1), has recently been tested for its immunomodulatory effects in a human clinical trial. Here, the CP extract was dialyzed and fractionated using Sephadex G 100 chromatography. The effects of a dialyzed aqueous CP extract, fraction 2 , on mast cell mediator release in vitro and ovalbumin-induced allergic airway inflammation in vivo were examined. In vitro, treatment of mouse bone marrow-derived mast cells with 2 for 18 h significantly inhibited antigen (trinitrophenyl-BSA)-induced IL-5 production. In vivo, treatment of mice with 2 during ovalbumin sensitization and stimulation process significantly reduced eosinophil and neutrophil infiltration in the airways. Moreover, fractions obtained by size exclusion chromatography of 2 inhibited IgE-dependent cytokine GM-CSF production from human cord blood-derived mast cells. Taken together, these results suggest that 2 is composed of biopolymers with anti-allergic potential.

Stimulation of interleukin-10 production by acidic beta-lactoglobulin-derived peptides hydrolyzed with Lactobacillus paracasei NCC2461 peptidases

We have previously demonstrated that Lactobacillus paracasei NCC2461 may help to prevent cow's milk allergy in mice by inducing oral tolerance to beta-lactoglobulin (BLG). To investigate the mechanisms involved in this beneficial effect, we examined the possibility that L. paracasei induces tolerance by hydrolyzing BLG-derived peptides and liberating peptides that stimulate interleukin-10 (IL-10) production. L. paracasei peptidases have been shown to hydrolyze tryptic-chymotryptic peptides from BLG, releasing numerous small peptides with immunomodulating properties. We have now shown that acidic tryptic-chymotryptic peptides stimulate splenocyte proliferation and gamma interferon (IFN-gamma) production in vitro. Hydrolysis of these peptides with L. paracasei peptidases repressed the lymphocyte stimulation, up-regulated IL-10 production, and down-regulated IFN-gamma and IL-4 secretion. L. paracasei NCC2461 may therefore induce oral tolerance to BLG in vivo by degrading acidic peptides and releasing immunomodulatory peptides stimulating regulatory T cells, which function as major immunosuppressive agents by secreting IL-10.

Immunostimulatory potential of beta-lactoglobulin preparations: effects caused by endotoxin contamination

BACKGROUND

The immunomodulating potential residing in cow's milk proteins is currently receiving increasing attention because of growing interest in functional foods and the complex problem of cow's milk allergy. One of the major cow's milk allergens, whey protein beta-lactoglobulin, has previously been shown to mediate cellular activation in both human and murine immune cells.

OBJECTIVE

We examined the response to different beta-lactoglobulin preparations in naive immune cells.

METHODS

Splenocytes and cells from mesenteric lymph nodes derived from BALB/c mice bred and maintained on a milk-free diet were cultured in vitro with different beta-lactoglobulin preparations. Cell proliferation, cytokine production, and increases in intracellular glutathione were used as cellular activation markers. Moreover, the effect of beta-lactoglobulin on cytokine production in murine bone-marrow-derived dendritic cells was examined.

RESULTS

We observed that some commercial beta-lactoglobulin preparations induced pronounced proliferation of both spleen cells and cells from mesenteric lymph nodes; production of TNF-alpha, IL-6, IL-1beta, and IL-10; and an increased level of intracellular glutathione in spleen cell cultures. Furthermore, TNF-alpha, IL-6, IL-1beta, and IL-10 production was induced in murine bone-marrow-derived dendritic cells. Purification of beta-lactoglobulin from raw milk using nondenaturating conditions, however, revealed that the beta-lactoglobulin per se did not possess the immunomodulatory activity. Eventually, the immunostimulatory effect was found to be caused by endotoxin contamination.

CONCLUSION

These results identify endotoxin as the main immunostimulatory component present in some commercial beta-lactoglobulin preparations. Moreover, the present study makes it evident that immunomodulatory effects attributed to beta-lactoglobulin need to be reassessed.

Immunomodulating principles from shark cartilage. Part 1. Isolation and biological assessment in vitro

Extracts from shark cartilage exhibiting powerful immunostimulating activity in vitro are described. The study shows that a simple extraction with water is very effective in producing the immunostimulating principles and implies that it is ideal for scale-up and manufacturing on a large scale. The extracts are potent stimulators of B cells and macrophages isolated from BALB/c mice spleen while stimulation of T cells was insignificant in our in vitro models. The study demonstrates that the active principles are thermally stable proteoglycans with molecular masses exceeding 100 kDa. This in vitro study represents an important step needed for further assessment of the products in vivo and their value for nutraceutical use.

Effect of dietary whey protein concentrate on primary and secondary antibody responses in immunized BALB/c mice

Proteins derived from the whey fraction of bovine milk are known to modulate immune responses. We have previously described a rennet whey protein concentrate (WPC) that can boost intestinal tract antibody responses to orally administered T-dependent antigens. In the present study, we investigated the effects of feeding WPC to mice on specific antibody responses to several orally or parenterally administered antigens, including influenza vaccine, diphtheria and tetanus toxoids, poliomyelitis vaccine, ovalbumin and cholera toxin sub-unit. WPC-fed mice produced elevated levels of antigen-specific intestinal tract and serum antibodies against all tested antigens, compared to mice that were fed a standard chow diet. Both primary and secondary intestinal tract antibody responses were elevated by WPC feeding, while only secondary serum responses were increased in WPC-fed mice. Significant up-regulation of intestinal tract antibody was observed within 2 weeks of primary oral immunizations. A period of pre-feeding with WPC, prior to commencement of immunization, did not alter the kinetics or magnitude of immune enhancement. These results identify bovine WPC as a potentially important dietary protein supplement, capable of enhancing humoral immune responses to a range of heterologous antigens.