title: A microdevice for multiplexed detection of T-cell-secreted cytokines.
abstract: Cytokines are produced by immune cells in response to viral or bacterial pathogens and therefore have significant diagnostic value. The goal of the present study was to develop a miniature device for detection of interleukin (IL)-2 and interferon (IFN)-gamma cytokines secreted by a small population of CD4 and CD8 T-cells. Microarrays of T-cell- and cytokine-specific Ab spots were printed onto poly(ethylene glycol) (PEG) hydrogel-coated glass slides and enclosed inside a microfluidic device, creating a miniature ( approximately 3 microL) immunoreaction chamber. Introduction of the red blood cell (RBC) depleted whole human blood into the microfluidic device followed by washing at a pre-defined shear stress resulted in isolation of pure CD4 and CD8 T-cells on their respective Ab spots. Importantly, the cells became localized next to anti-IL-2 and -IFN-gamma Ab spots. Mitogenic activation of the captured T-cells was followed by immunofluorescent staining (all steps carried out inside a microfluidic device), revealing concentration gradients of surface-bound cytokine molecules. A microarray scanner was then used to quantify the concentration of IFN-gamma and IL-2 near CD4 and CD8 T-cells. This study represents one of the first demonstrations of a microdevice for capturing desired T-cell subsets from a small blood volume and determining, on-chip, cytokine profiles of the isolated cells. Such a microdevice is envisioned as an immunology tool for multi-parametric analysis of T-cell function with direct applications in diagnosis/monitoring of HIV and other infectious diseases.
authors.affiliation: Department of Biomedical Engineering, University of California, Davis, 451 East Health Sciences St. #2619, Davis, CA 95616, USA.
authors.forename: He
authors.initials: H
authors.lastname: Zhu
authors.forename: Gulnaz
authors.initials: G
authors.lastname: Stybayeva
authors.forename: Monica
authors.initials: M
authors.lastname: Macal
authors.forename: Erlan
authors.initials: E
authors.lastname: Ramanculov
authors.forename: Michael D
authors.initials: MD
authors.lastname: George
authors.forename: Satya
authors.initials: S
authors.lastname: Dandekar
authors.forename: Alexander
authors.initials: A
authors.lastname: Revzin
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis* / Q000737:chemistry; D007376:Interleukin-2 / Q000032:analysis* / Q000737:chemistry; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods*; D008904:Miniaturization
chemical_list: D007376:Interleukin-2; D007371:Interferon-gamma