Using BALB/c mice as a model of food allergy to study gene expression profiles in response to common food allergens
Food allergy is a serious health concern among infants and young children, and its prevalence is growing in westernized countries. Although the immunological mechanism(s) of food allergy are well documented, our understanding of its molecular mechanism(s) is very limited and a suitable animal model for such studies has not been established. The aim of this study therefore, was to use BALB/c mice as a model to characterize genes involved in the sensitization and elicitation phases of the immune response to common food allergens. Female BALB/c mice received intraperitoneal (i.p.) injections for two days with common food allergens cow's milk [beta]-lactoglobulin (BLG), egg ovalbumin (OVA) and peanut agglutinin (PNA), or were intragastrically (i.g.) exposed to egg ovomucoid (OVM) at weekly intervals for 5 weeks. Mice were euthanized to collect for immunological analysis, and mesenteric lymph node (MLN) and spleen tissues that were used for analysis of gene expression during the sensitization and elicitation phases respectively. The MLNs from BLG, OVA and PNA injected mice were used for cDNA microarray analysis, and spleen from OVM mice used for Affymetrix microarray analysis. Mice responded to BLG, OVA and PNA injection and developed type-1 hypersensitivity responses that were indicated by increased concentrations of histamine, and immunoglobulins IgG1 and 19E. The ear swelling response to topical exposure to these antigens provided a suitable tool to quantify the magnitude of allergic response, and a passive cutaneous anaphylaxis (PCA) test confirmed the presence of allergen specific IgEs. Gene expression profiling of the MLN from BLG, OVA or PNA injected mice and spleen from OVM-treated mice revealed a complex network of genes that are involved in the immune response to common food allergens. Some of these genes may be potential candidate biomarker genes for food allergy.