Effect of a protein-free diet in the development of food allergy and oral tolerance in BALB/c mice

Abstract

The aim of the present study was to investigate the effect of a protein-free diet in the induction of food allergy and oral tolerance in BALB/c mice. The experimental model used was mice that were fed, since weaning up to adulthood, a balanced diet in which all dietary proteins were replaced by amino acid diet (Aa). The absence of dietary proteins did not prevent the development of food allergy to ovalbumin (OVA) in these mice. However, Aa-fed mice produced lower levels of IgE, secretory IgA and cytokines. In addition, when compared with mice from control group, Aa-fed mice had a milder aversive reaction to the allergen measured by consumption of OVA-containing solution and weight loss during food allergy development. In addition, mice that did not have dietary proteins in their diets were less susceptible to induction of oral tolerance. One single oral administration was not enough to suppress specific serum Ig and IgG1 levels in the Aa-fed group, although it was efficient to induce suppression in the control group. The present results indicate that the stimulation by dietary proteins alters both inflammatory reactivity and regulatory immune reactivity in mice probably due to their effect in the maturation of the immune system.

Consumption of Diet Containing Free Amino Acids Exacerbates Colitis in Mice

“…Consumption of AA diet was nutritionally equivalent to CAS diet concerning parameters such as weight maintenance and levels of total serum proteins, albumin, transferrin, glycemia, and triglycerides. Previous studies in humans and animals also showed nutritional equivalence between diets containing intact proteins and free amino acids ( 8 , 11 , 28 , 29 ).…”

“…The immunological role of dietary proteins has been already addressed by studies using either a standard rodent diet in which intact proteins were replaced by equivalent amounts of amino acids ( 7 , 11 ) or by elemental diets ( 8 , 28 ). Menezes et al ( 7 ) showed that exposure to food proteins after weaning plays a physiological role in inducing the maturation of the immune system both locally and systemically ( 7 ).…”

“…Menezes et al ( 7 ) showed that exposure to food proteins after weaning plays a physiological role in inducing the maturation of the immune system both locally and systemically ( 7 ). Furthermore, it was demonstrated that mice fed a diet containing free amino acids from weaning to adulthood are more susceptible to Leishmania infection ( 9 ) and more resistant to induction of nasal and oral tolerance ( 10 , 11 ) as well as food allergy ( 11 ). In concert with these results, it has been shown recently that dietary proteins from solid food are responsible for the generation of the great majority of the small intestinal CD4+ Foxp3+ regulatory T cells involved in the induction of oral tolerance to food antigens ( 8 ).…”

“…In both cases, intact dietary proteins were replaced by equivalent amounts of free amino acids as nitrogen source and they were shown to influence the maturation of the immune system, particularly the gut-associated lymphoid tissue when consumed from weaning to adulthood ( 7 ). Moreover, the presence of intact dietary proteins after weaning is important for the generation of regulatory T cells in the small intestine ( 8 ) and for the full development of immune activities during adulthood such as a protective response to infection ( 9 ), induction of nasal ( 10 ) and oral tolerance as well as allergic reactions ( 11 ). Thus, the role of intact dietary proteins in the maturation of immunological activity at the early stages of life is clear.…”

Human umbilical cord‑derived mesenchymal stem cells ameliorate the enteropathy of food allergies in mice

“…To induce food allergy, Mice (n=5 per group, a total of 15 mice in three OVA challenged groups) were intraperitoneally (i.p.) injected with 50 µg OVA (Grade V; A-5503; Sigma-Aldrich; Merck KGaA) in 1 mg alum adjuvant on days 0 and 14 as previously described ( 38 ). From day 28, the mice were challenged intragastrically with 50 mg of OVA in 250 µl PBS every other day for 12 days (6 administrations).…”