4 research outputs found
Neutrophil Migration in Opposing Chemoattractant Gradients Using Microfluidic Chemotaxis Devices
Neutrophils migrating in tissue respond to complex overlapping signals generated by a variety of chemotactic factors (CFs). Previous studies suggested a hierarchy between bacteriaderived CFs and host-derived CFs but could not differentiate neutrophil
response to potentially equal host-derived CFs (IL-8 and LTB4). This paper reports neutrophil migration in conflicting gradients
of IL-8 and LTB4 using a microfluidic chemotaxis device that can generate stable and well-defined gradients. We quantitatively
characterized the movement of cells from time-lapse images. Neutrophils migrate more efficiently toward single IL-8 gradients than single LTB4 gradients as measured by the effective chemotactic index (ECI). In opposing gradients of IL-8 and LTB4,
neutrophils show obvious chemotaxis toward a distant gradient, consistent with previous reports. When an opposing gradient of
LTB4 is present, neutrophils show less effective chemotaxis toward IL-8 than when they are in a gradient of IL-8 alone. In
contrast, the chemotactic response of neutrophils to LTB4 is not reduced in opposing gradients as compared to that in a single LTB4 gradient. These results indicate that the presence of one host-derived CF modifies the response of neutrophils to a second CF suggesting a subtle hierarchy between them.F. Lin thanks the National Institutes of Health General
Medical Science Grant (GM-66051) for a fellowship.
We thank the excellent service provided by the General
Clinical Research Center (GCRC) at UC Irvine. This research
was supported by NSF (DBI-0138055) and NIH
(R03AIO055033)