Differences in Gene Expression in Older Compared With Younger Kidney Transplant Recipients
TRANSPLANTATION DIRECT
Authors: Schaenman, Joanna M.; Rossetti, Maura; Lum, Erik; Abdalla, Basmah; Bunnapradist, Suphamai; Thu-Phuong Pham; Danovitch, Gabriel; Reed, Elaine F.; Cole, Steve
Abstract
Background. For the growing numbers of older transplant patients, increased incidence of infection and death compared with younger patients may limit the many benefits provided by transplantation. However, little is known about age-associated immune dysfunction in the older transplant recipient. Methods. A cohort of 60 kidney transplant recipients, 23 older (>= 60y) and 37 younger (30-59y), matched on antithymocyte induction and donor type (living vs deceased) was evaluated. Gene expression in peripheral blood mononuclear cells 3 months after kidney transplantation was analyzed to compare differences between older and younger patients. Results. Proinflammatory genes were upregulated in older kidney transplant patients, including cytokines IL1-beta and IL-6. Downregulated genes were associated with B-cell and T-cell function, including CCR7 and CD27. Analysis of predicted transcription factor binding suggested an increase in proinflammatory transcription factor CCAAT/enhancer binding protein beta-binding sites in older patients, whereas interferon regulatory factor 2 transcription factor binding sites were less prevalent. Conclusions. Older kidney transplant recipients exhibited multiple differences in gene expression compared with younger patients, with upregulation of proinflammatory genes and downregulation of adaptive immune response genes. These findings may explain the mechanism of increased vulnerability to infection and malignancy observed in older transplant patients.
Noninvasive Photoacoustic Imaging of Dendritic Cell Stimulated with Tumor Cell-Derived Exosome
MOLECULAR IMAGING AND BIOLOGY
Authors: Piao, Yin Ji; Kim, Hoe Suk; Moon, Woo Kyung
Abstract
Purpose The tools to trigger dendritic cell (DC) activation and to verify DC migration in vivo are important for directing DC immunotherapy toward successful treatment. We evaluated whether tumor cell-derived exosome (TEX)-stimulated DC migration into lymph node (LN) in mouse could be tracked using gold nanoparticle (GN)-labeling and ultrasound (US)-guided photoacoustic imaging (PAI). Procedures GFP-transduced DC2.4 cells were used. RFP-tagged TEXs were purified from a stable 4T1 cell line overexpressing the exosomal CD63-RFP fusion protein. The TEX uptake by DCs was visualized using confocal laser scanning microscopy. GNs with surface plasmon resonance at 808 nm were used for DC-labeling. DCs that migrated into axillary LN were longitudinally monitored by US-guided PAI and analyzed by silver staining and immunohistochemistry. Results TEXs were easily internalized in DCs, increased proliferation and migration capacities, and upregulated co-stimulatory molecules, CCR7 and TNF-alpha without cytotoxicity. The GN-labeling exerted no adverse effects on the biological functions of DCs. US-guided PAI and DC-labeling allowed for sensitive and longitudinal monitoring of TEX-stimulated DC migration toaxillary LN. Conclusions TEXs efficiently activated DCs and GN-labeled DC migration into LN was successfully monitored using US-guided PAI, suggesting that TEXs are a good source for DC activation and US-guided PAI is a cost-effective and easy-to-use imaging modality for noninvasive tracking of DCs.