Food Protein-Induced Non-Immunoglobulin E-Mediated Allergic Colitis in Infants and Older Children: What Cytokines Are Involved?

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is mostly a non-immunoglobulin E-mediated disease where a T-cell-mediated reaction to cow's milk protein has been suggested. We determined the expression of transforming growth factor (TGF)-β, TGF-β receptor-1, tumor necrosis factor (TNF)-α, CD86, and CD23 on the colon mucosa to investigate their roles in the pathogenesis of the two subtypes of FPIAP, i.e. infantile FPIAP and FPIAP in older children.

METHODS

Group 1 comprised children with infantile FPIAP (age <6 months, n = 21), group 2 referred to FPIAP in older children (age >1.5 years, n = 7), and group 3 included children with juvenile hyperplastic polyps (n = 22). Immunohistochemical staining of colonic biopsy specimens was performed.

RESULTS

The expression of TNF-α was significantly higher in groups 1 and 2 compared to group 3. Group 2 patients had a significantly lower TGF-β expression compared to the other groups. The expression of CD86 was higher in group 1 than in group 3 (p = 0.012). Eosinophil counts per high-power field in the lamina propria were significantly correlated with CD86 expression (p = 0.026, r = 0.388).

CONCLUSION

Our results suggest that TNF-α is implicated in the pathogenesis of both types of FPIAP. The decreased activity of TGF-β receptor-1 accompanied by the increased expression of CD86 in infants and the decreased activity of TGF-β in older children appear to play a role in the development of FPIAP.

Identification and characterization of the antigenic site (epitope) on bovine β-lactoglobulin: common residues in linear and conformational epitopes

BACKGROUND

β-Lactoglobulin is recognised as one of major allergens in milk and its epitopes include linear and conformational epitopes contributed to milk allergy.

RESULTS

In our work, two types of epitopes have been identified. Linear epitopes identified by using SPOT™ peptide arrays approach and three common peptide sequences AA77-82 (KIPAVF), AA126-131 (PEVDNE) and AA142-147 (ALPMHI) were obtained by reacting with specific sera from two rabbits. At the same time, mimotopes were screened by the panning of a phage display peptide library and the corresponding conformational epitopes were calculated by the web tool of Peptiope server with Mapitope algorithm. Three conformational epitopes against two specific sera were identified, in which there were 15 common residues as well and located in the different position and appeared mainly as an α-helix.

CONCLUSION

Common residues on the linear and conformational epitopes were identified in the first time, respectively, which could be regarded as informative epitopes for detection of allergen in dairy products.