Expression of the human HLA-DRA*01:01/HLA-DRB1*01:01 heterodimer in transgenic mice in the absence of the co-expression of the human, allergen-specific TCR elicited allergen-specific IgE production, however, in fewer animals and only with modest levels of lung eosinophilia and neutrophilia and without gross alterations of lung function. Here, HLA-DRB1 is linked to Increased total eosinophil count.