Isolation and Functional Immunophenotyping of Subpopulations of Immune Cells

© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim DOI: 10.1002/adhm.201200378 W. Chen[+], N.-T. Huang,[+] B. Oh, Prof. K. Kurabayashi, Prof. J. Fu Department of Mechanical Engineering University of Michigan Ann Arbor, MI 48109 USA E-mail: [email protected] ; [email protected] Prof. J. Fu Department of Biomedical Engineering University of Michigan Ann Arbor, MI 48109 USA Prof. K. Kurabayashi Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor, MI 48109 USA Prof. R. H. W. Lam Department of Mechanical and Biomedical Engineering City University of Hong Kong, Hong Kong, China An accurate measurement of the immune status in patients with immune system disorders is critical in evaluating the stage of diseases and tailoring drug treatments. The functional cellular immunity test is a promising method to establish the diagnosis of immune dysfunctions. The conventional functional cellular immunity test involves measurements of the capacity of peripheral blood mononuclear cells to produce pro-infl ammatory cytokines when stimulated ex vivo. However, this “bulk” assay measures the overall reactivity of a population of lymphocytes and monocytes, making it diffi cult to pinpoint the phenotype or real identity of the reactive immune cells involved. In this research, we develop a large surface micromachined polydimethylsiloxane (PDMS) microfi ltration membrane (PMM) with high porosity, which is integrated in a microfl uidic microfi ltration platform. Using the PMM with functionalized microbeads conjugated with antibodies against specifi c cell surface proteins, we demonstrated rapid, effi cient and high-throughput on-chip isolation, enrichment, and stimulation of subpopulations of immune cells from blood specimens. Furthermore, the PMM-integrated microfi ltration platform, coupled with a no-wash homogeneous chemiluminescence assay (“AlphaLISA”), enables us to demonstrate rapid and sensitive on-chip immunophenotyping assays for subpopulations of immune cells isolated directly from minute quantities of blood samples.