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Food allergy is becoming a medical, economical and social problem. Soybean, together with milk, peanuts and eggs, are the major allergenic foods. This pathology affects the infant population, when the gut barrier is immature and the immune system is still refining its ability to tolerate food proteins. In our country, cow's milk allergy (CMA) constitutes the main food allergy in infancy, but soy allergy has become exacerbated because of the increased utilization of soy-based formulas as cow's milk (CM) substitutes and the inclusion of soy-proteins in many processed foods. Once a food allergy is diagnosed, the only proven therapy is the strict elimination of the offending allergens from the diet. Available substitutes for CM include milks from different mammalian animals, soy-based formulas, hydrolysed cow's milk proteins (CMP) and amino acid-based formulas. Furthermore, there is evidence that soy proteins may trigger allergic reactions in CMA patients, as assessed by a double-blind placebo controlled food challenge (DBPCFC) [1].Milk contains more than 50 proteins and the major ones are implicated in a number of immunologically mediated reactions [2]. Caseins and b-lactoglobulin (b-Lg) have been described as the main antigenic and allergenic components for human beings [3,4], although immunoglobulins, a-lactalbumin (a-La), and bovine serum albumin (BSA) were also found to be reactive with different isotypes of human antibodies [5,6]. Several immunoreactive epitopes have been identified in caseins [7,. Most of the epitopes present in the casein molecules are sequential since the high number of proline and hydrophobic residues (45%) in these proteins determine an undefined secondary and tertiary structure [10]. Besides, caseins tend to aggregate as a result of hydrophobic interactions to give quaternary structures [11], and this may create conformational epitopes buried in the hydrophobic interior of the micelle [7]. These epitopes are only exposed and accessible to the immune system after denaturation of the complex by digestion.A number of soy proteins that bind antibodies, especially IgE, have been identified [12,13]. The main fractions of storage globulins from seed proteins are the complexes 7S or b-conglycinin, and 11S or glycinin. The 7S complex is generally a trimer with MW 150-200 kD, whereas 11S is a hexamer with MW 300-400 kD [14]. In the 7S fraction, or b-conglycinin, several IgE-binding proteins have been identified and some of them have been purified and characterized: Gly m Bd 28K, Gly m Bd 30K, Gly m Bd 60K [15,16]. Sequence homology has been reported between these allergens and the thiol proteinase family SUMMARYSoy-based formulas are the most employed cow's milk substitutes in the treatment of cow's milk allergy in our country. Since adverse reactions have been reported in allergic patients as a consequence of exposure to soy proteins, we have investigated the possible cross-reactivity between components from soybean and cow's milk. A cow's milk specific polyclonal antiserum and casein specific m...

The objective of this study was to analyze both the allergenicity and immunogenicity of cow's milk proteins. To this end, 80 milk-atopic patients were selected on the basis of the presence of cow's milk-specific IgE antibodies in serum and compatible clinical history. Fifteen patients allergic to other allergens and 10 nonatopic subjects were studied as controls. The specificity of serum IgG and IgE antibodies was determined by immunoblotting, employing both cow's milk and milk components, i.e., a-and P-casein, P-lactoglobulin, and a-lactalbumin separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The experiments showed that casein-specific IgE antibodies were present in all (80/80) sera examined; 10/80 showed reactivity to P-lactoglobulin, and 5/80 showed reactivity to a-lactalbumin. None of the 25 negative control sera analyzed showed the presence of specific IgE antibodies against milk proteins. These results were similar to those corresponding to the detection, by the radioallergosorbent test, of IgE antibodies against the milk components coupled to paper disks. All sera from milk-atopic patients also showed IgE reactivity against a high-molecular-mass fraction that hardly enters the gel. This fraction, after separation by gel filtration and treatment with 0-mercaptoethanol and urea, was shown by SDS-PAGE analysis to be formed by casein monomers. All sera analyzed by immunoblotting reacted against the components corresponding to casein monomers. Inhibition of immunoblotting by adsorption with different milk components confirmed that those high-molecular-mass aggregates are formed by casein components. The results presented here strongly suggest that casein is the major allergenic component of cow's

No abstract

Background: Cow’s milk allergy (CMA) is an important problem worldwide and the development of an in vivo system to study new immunotherapeutic strategies is of interest. Intolerance to soybean formula has been described in CMA patients, but it is not fully understood. In this work, we used a food allergy model in BALB/c mice to study the cross-reactivity between cow’s milk protein (CMP) and soy proteins (SP). Methods: Mice were orally sensitized with cholera toxin and CMP, and then challenged with CMP or SP to induce allergy. Elicited symptoms, plasma histamine, humoral and cellular immune response were analyzed. Th1- and Th2-associated cytokines and transcription factors were assessed at mucosal sites and in splenocytes. Cutaneous tests were also performed. Results: We found that the immediate symptoms elicited in CMP-sensitized mice orally challenged with SP were consistent with a plasma histamine increase. The serum levels of CMP-specific IgE and IgG1 antibodies were increased. These antibodies also recognized soy proteins. Splenocytes and mesenteric lymph node cells incubated with CMP or SP secreted IL-5 and IL-13. mRNA expression of Th2-associated genes (IL-5, IL-13, and GATA-3) was upregulated in mucosal samples. In addition, sensitized animals exhibited positive cutaneous tests after the injection of CMP or SP. Conclusions: We demonstrate that CMP-sensitized mice, without previous exposure to soy proteins, elicited hypersensitivity signs immediately after the oral administration of SP, suggesting that the immunochemical cross-reactivity might be clinically relevant. This model may provide an approach to further characterize cross-allergenicity phenomena and develop new immunotherapeutic treatments for allergic patients.

Inflammatory bowel disease (IBD) is a major source of morbidity in children and adults. Its incidence is rising, particularly in young people. IBD carries a lifelong risk of cancer, which is proportional to disease duration. Drug and surgical treatments rarely offer cure and often carry a high side effect burden. Dietary therapy is highly effective in Crohn's disease. For these reasons, there is much interest in developing novel dietary treatments in IBD. Curcumin, a component of the spice turmeric, and an anti-inflammatory and anti-cancer agent, shows preclinical and clinical potential in IBD. Its mechanisms of action are unknown. Our aim was to assess the effect of curcumin on key disease mediators p38 mitogen-activated protein kinase (MAPK), IL-1b, IL-10 and matrix metalloproteinase-3 (MMP-3) in the gut of children and adults with IBD. Colonic mucosal biopsies and colonic myofibroblasts (CMF) from children and adults with active IBD were cultured ex vivo with curcumin. p38 MAPK, NF-kB and MMP-3 were measured by immunoblotting. IL-1b and IL-10 were measured by ELISA. We show reduced p38 MAPK activation in curcumintreated mucosal biopsies, enhanced IL-10 and reduced IL-1b. We demonstrate dose-dependent suppression of MMP-3 in CMF with curcumin. We conclude that curcumin, a naturally occurring food substance with no known human toxicity, holds promise as a novel therapy in IBD.

This work shows that although Raiden has fewer cross-reactive components than conventional soybean, it still has a residual cross-reactive component: the alpha-subunit beta-conglycinin. This reactivity might make this genotype unsuitable to treat CMA and also explains adverse reactions to soybean in CMA infants.

Massive vaccination offers great promise for halting the global COVID-19 pandemic. However, limited supply and uneven vaccine distribution create an urgent need to optimize vaccination strategies. We evaluate SARS-CoV-2-specific antibody responses after Sputnik V vaccination of healthcare workers in Argentina, measuring IgG anti-spike titers and neutralizing capacity after one and two doses in a cohort of naïve or previously infected volunteers. By 21 days after receiving the first dose of vaccine, 94% of naïve participants develop spike-specific IgG antibodies. A single Sputnik V dose elicits higher antibody levels and virus neutralizing capacity in previously infected individuals than in naïve ones receiving the full two-dose schedule. The high seroconversion rate after a single dose in naïve participants suggests a benefit of delaying second dose administration to increase the number of people vaccinated. The data presented provide information for guiding public health decisions in light of the current global health emergency.