The Th17/Treg imbalance in bovine β-lactoglobulin-sensitised mice

Analysis of altered miRNA profiling in the colon of a mouse model with β-lactoglobulin allergy

OBJECTIVES

The differences in the expression profiles of colonic miRNAs between β-lactoglobulin (β-Lg) allergic mice and normal mice were analyzed to investigate the important role of the miRNA regulation mechanism in the pathogenesis of cow's milk allergy.

METHODS

The present study performed Illumina sequencing to characterize the miRNA profile changes in mouse colon responding to β-Lg challenge. Target genes were predicted by TargetScan 50 and miRanda 3.3a algorithms and assessed by GO and KEGG analysis. The expression levels of selected miRNAs and cytokine production were verified by cell transfection and quantitative RT-PCR.

RESULTS

A total of 15 miRNAs were diversely expressed between the colon of the normal and β-Lg-sensitized mice (P < 0.05, fold change of >1.50 or <0.67), including six up-regulated miRNAs and nine down-regulated miRNAs, among which seven miRNAs were validated using qRT-PCR. GO enrichment and KEGG pathway analyses further revealed that biological process, protein binding, cytoplasm and the pathways of cancer were significantly enriched, which were closely connected to the allergic inflammation development. Additionally, six key functional interaction pairs in β-Lg allergy were identified in miRNA prediction algorithms and verified using qRT-PCR.

CONCLUSIONS

We can conclude that our results suggested that the miRNAs regulation network participated in the pathogenesis of cow's milk allergy.

[Effect of maternal immune level at different pregnancy stages on cow's milk protein allergy in infants]

OBJECTIVE

To study the association between maternal Th1/Th2 immune level at different pregnancy stages and cow's milk protein allergy (CMPA) in infants.

METHODS

The healthy women with a singleton pregnancy, as well as their offspring, who attended Yidu Central Hospital of Weifang and Qingzhou Traditional Chinese Medicine Hospital from July 2016 to December 2018 were enrolled. The maternal levels of interleukin-2 (IL-2), interferon gamma (IFN-γ), interleukin-4 (IL-4), and interleukin-10 (IL-10) at the second and third trimesters of pregnancy were measured. A CMPA questionnaire survey was conducted within one year after birth. Food avoidance and cow's milk oral challenge tests were performed in infants suspected of CMPA. The 48 infants who met the diagnostic criteria for CMPA were included in the observation group, and the remaining 977 normal infants were included in the control group. A univariate analysis was performed on the infants with CMPA. A Poisson regression analysis was used to determine the association between maternal Th1/Th2 immune factors at different pregnancy stages and CMPA.

RESULTS

The detection rate of CMPA was 4.68%. The clinical manifestations included the symptoms of the digestive system, skin, and respiratory system and other symptoms. The univariate analysis showed that compared with the control group, the observation group had significantly higher incidence rates of maternal food allergy and maternal history of allergic diseases (P<0.05) and a significantly lower breastfeeding rate (P<0.05). The observation group had significantly lower maternal levels of IL-2 (second and third trimesters) and IFN-γ (third trimester) than the control group (P<0.05). Maternal low IFN-γ at the third trimester and maternal low IL-2 at the second and third trimesters were significantly associated with CMPA in infants (P<0.05). After correction of the factors of breastfeeding, maternal food allergy, and maternal history of allergic diseases, it was found that maternal low IL-2 and IFN-γ at the third trimester were still significantly associated with CMPA in infants (P<0.05).

CONCLUSIONS

The maternal decrease in Th1 level at the third trimester of pregnancy may lead to the change in fetal immunity and thus increase the risk of CMPA in offspring.