Variations in T-Cell Response Among Cow’s Milk Allergy Children With Or Without Sensitization to Casein Protein

Objective: To explore the potential differences in allergen-specific T immunological responses among cow’s milk allergic(CMA) patients with or without casein sensitization.Methods: A total of 25 children with IgE-dependent CMA were recruited from outpatient clinic in Beijing Children’s Hospital from January to August of 2017, including 14 CMA patient with a positive sensitization to casein component, 11 CMA patient being sensitized to cow’s milk, but a negative sIgE for casein component, and another 10 atopic control subjects without CMA were also included as negative control group in this study. The expression level of T cell related transcription factor in PBMCs or total CD4+ cells were detected by quantitative PCR, and the release of T cell related cytokines in donor’s serum was determined by Luminex xMAP 200 System. Upon in-vitro stimulation with casein protein, the proliferation rates of PBMCs-derived T cells were assessed by flow cytometry, and T related cytokines production in culture supernatant was evaluated as well.Results: A significantly higher level of GATA3 expression transcripts in PBMCs or total CD4+ cells were detected in casein-sensitized CMA patients than those without casein sensitization. An increase in IL-4 (74.1±16.5pg/ml vs 64.9±12.8 pg/ml, P<0.05) and a decrease in IL-10 (3.1±2.4 pg/ml vs 4.9±2.8 pg/ml, P<0.05) production were found in casein-sensitized CMA patient’s plasma than patients without casein sensitization. Upon in-vitro stimulation with cow’s milk protein mixture, a significantly higher proliferation rate of casein-specific CD4+T cells (30.0±5.8% vs 20.7±5.5%, P<0.05) as well as increased productions of IL-4(4.1±13.6 vs 64.7±12.3pg/ml, P<0.05) and IL- 13(48.7±10.3 vs 38.7±9.4pg/ml, P<0.05) were found in casein-sensitized CMA patients compared those without casein sensitization.Conclusions: Our findings preliminarily revealed that a distinctive T cell mediated immune response among CMA patient with the different sensitized component.