TY - JOUR
T1 - Molecular pathway-specific 99mTc-N-(3-bromo-2,4, 6-trimethyacetanilide) iminodiacetic acid liver imaging to assess innate immune responses induced by cell transplantation
AU - Joseph, Brigid
AU - Bhargava, Kuldeep K.
AU - Tronco, Gene G.
AU - Palestro, Christopher J.
AU - Gupta, Sanjeev
PY - 2009/2
Y1 - 2009/2
N2 - Objectives Inflammatory responses after cell transplantation impair engraftment of transplanted cells. We studied whether perturbations in specific molecular pathways after inflammation in a syngeneic cell transplantation model could be identified by noninvasive imaging. Methods After transplanting hepatocytes into the liver of dipeptidyl peptidase IV-deficient Fischer 344 rats, we imaged hepatobiliary excretion of 99mTc-N-(3-bromo-2,4,6- trimethyacetanilide)iminodiacetic acid ( 99mTc-mebrofenin). Fractional retention of peak hepatic mebrofenin activity over 60-min periods was correlated with parameters of hepatic inflammation. Results In healthy animals, 28 ± 6% 99mTc-mebrofenin activity was in the liver after 60 min, whereas cell transplantation dose-dependently inhibited excretion of 99mTc-mebrofenin, P value of less than 0.001. Resolution of this abnormality in 99mTc-mebrofenin transport required 2 weeks in the setting of prolonged activation of Kupffer cells with increased TNF-α and IL-6 expression. Hepatic transport of 99mTc-mebrofenin was promptly restored by anti-inflammatory treatments, including inhibition of cyclooxygenase activity, depletion of neutrophils, or blocking of inflammatory cytokines before cell transplantation. Moreover, these treatments improved transplanted cell engraftment Conclusion Molecular pathway-based imaging offers appropriate noninvasive means to address activation of innate immune responses. This will help in developing suitable strategies for characterizing and overcoming immune responses for cell and gene therapy.
AB - Objectives Inflammatory responses after cell transplantation impair engraftment of transplanted cells. We studied whether perturbations in specific molecular pathways after inflammation in a syngeneic cell transplantation model could be identified by noninvasive imaging. Methods After transplanting hepatocytes into the liver of dipeptidyl peptidase IV-deficient Fischer 344 rats, we imaged hepatobiliary excretion of 99mTc-N-(3-bromo-2,4,6- trimethyacetanilide)iminodiacetic acid ( 99mTc-mebrofenin). Fractional retention of peak hepatic mebrofenin activity over 60-min periods was correlated with parameters of hepatic inflammation. Results In healthy animals, 28 ± 6% 99mTc-mebrofenin activity was in the liver after 60 min, whereas cell transplantation dose-dependently inhibited excretion of 99mTc-mebrofenin, P value of less than 0.001. Resolution of this abnormality in 99mTc-mebrofenin transport required 2 weeks in the setting of prolonged activation of Kupffer cells with increased TNF-α and IL-6 expression. Hepatic transport of 99mTc-mebrofenin was promptly restored by anti-inflammatory treatments, including inhibition of cyclooxygenase activity, depletion of neutrophils, or blocking of inflammatory cytokines before cell transplantation. Moreover, these treatments improved transplanted cell engraftment Conclusion Molecular pathway-based imaging offers appropriate noninvasive means to address activation of innate immune responses. This will help in developing suitable strategies for characterizing and overcoming immune responses for cell and gene therapy.
KW - Cell transplantation
KW - Cytokine
KW - Inflammation
KW - Liver
KW - Mebrofenin
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U2 - 10.1097/MNM.0b013e32831e89cd
DO - 10.1097/MNM.0b013e32831e89cd
M3 - Article
C2 - 19077914
AN - SCOPUS:58549084858
SN - 0143-3636
VL - 30
SP - 126
EP - 133
JO - Nuclear Medicine Communications
JF - Nuclear Medicine Communications
IS - 2
ER -