Christopher Allen, PhD

My laboratory is interested in the cellular communication and differentiation programs in allergic immune responses, particularly in asthma. My laboratory is applying sophisticated imaging, flow cytometry, mouse genetics, and other techniques to uncover novel paradigms underlying allergic inflammation. As a major area of emphasis, we are studying the generation and function of IgE antibodies that initiate allergic inflammation. We generated fluorescent IgE reporter mice and allowing us to identify and track rare IgE-producing B cells in vivo. We also optimized a flow cytometry procedure to identify rare IgE-producing B cells in both mouse and human samples, facilitating mechanistic studies. Our work has revealed that the IgE B cell receptor exhibits antigen (ligand)-independent signaling that promotes plasma cell differentiation and limits IgE germinal center B cell responses. We are also imaging the lungs and associated lymphoid tissues by two-photon laser scanning microscopy to directly visualize cellular interactions in situ. Using this approach, we achieved the first in vivo analysis of the interactions of CD4 T cells with basophils, which are rare IgE effector cells. We are now analyzing the interactions of basophils with other cell types during secondary immune responses to further elucidate the functions of these cells. More broadly, we are considering the combined cellular interactions among various types of inflammatory cells in the lungs in mouse models of asthma.