The primary goal of this project is to develop MRI techniques for non-invasive detection of acute organ rejection following transplantation. Our current research focuses on two approaches to detecting rejection by MRI. The first involves tagging an NMR detectable agent to a rejection marker cell and the second involves the measurement of tissue perfusion in the transplanted organ as a marker of rejection. It is well known that the T-cell is the primary effector cell in acute graft rejection, and the homing of T-cells is a major field of transplantation immunology. T-cells isolated from rats are labeled with superparamagnetic iron oxide (SPIO) particles and injected to rats that have undergone organ transplantation. The transplanted organ is imaged by MRI at different time points post-transplantation to track the homing of the SPIO labeled T-cells to the site of rejection. It is also believed that other mediators of rejection, e.g. macrophages are also attracted to the site of rejection. We have just begun work to track the migration of SPIO labeled macrophages as well in the rat transplant model. To determine if changes in tissue perfusion can be used as a marker of organ rejection, perfusion images of rat kidneys are obtained in a rat renal transplant model. Quantitative perfusion images are obtained in rats with one transplanted and one native kidney, using the arterial spin labeling technique developed in this Center. Preliminary results indicate a significant decrease in perfusion in the transplanted kidney, as compared to the native kidney. Control experiments are under way to isolate the immunological response from any possible surgical complications due to the transplantation.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR003631-09
Application #
5224623
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
9
Fiscal Year
1996
Total Cost
Indirect Cost
Ramachandran, Suchitra; Meyer, Travis; Olson, Carl R (2016) Prediction suppression in monkey inferotemporal cortex depends on the conditional probability between images. J Neurophysiol 115:355-62
Meyer, Travis; Walker, Christopher; Cho, Raymond Y et al. (2014) Image familiarization sharpens response dynamics of neurons in inferotemporal cortex. Nat Neurosci 17:1388-94
Hall, Nathan; Colby, Carol (2014) S-cone visual stimuli activate superior colliculus neurons in old world monkeys: implications for understanding blindsight. J Cogn Neurosci 26:1234-56
Subramanian, Janani; Colby, Carol L (2014) Shape selectivity and remapping in dorsal stream visual area LIP. J Neurophysiol 111:613-27
Berdyyeva, Tamara K; Olson, Carl R (2014) Intracortical microstimulation of supplementary eye field impairs ability of monkeys to make serially ordered saccades. J Neurophysiol 111:1529-40
Meyer, Travis; Ramachandran, Suchitra; Olson, Carl R (2014) Statistical learning of serial visual transitions by neurons in monkey inferotemporal cortex. J Neurosci 34:9332-7
Hall, Nathan; Colby, Carol (2013) Psychophysical definition of S-cone stimuli in the macaque. J Vis 13:
Leathers, Marvin L; Olson, Carl R (2012) In monkeys making value-based decisions, LIP neurons encode cue salience and not action value. Science 338:132-5
Meyer, Travis; Olson, Carl R (2011) Statistical learning of visual transitions in monkey inferotemporal cortex. Proc Natl Acad Sci U S A 108:19401-6
Berdyyeva, Tamara K; Olson, Carl R (2011) Relation of ordinal position signals to the expectation of reward and passage of time in four areas of the macaque frontal cortex. J Neurophysiol 105:2547-59

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