Host-based Th2 cell therapy for prolongation of cardiac allograft viability.

Donor T cell transfusion, which is a long-standing approach to prevent allograft rejection, operates indirectly by alteration of host T cell immunity. We therefore hypothesized that adoptive transfer of immune regulatory host Th2 cells would represent a novel intervention to enhance cardiac allograft survival. Using a well-described rat cardiac transplant model, we first developed a method for ex vivo manufacture of rat host-type Th2 cells in rapamycin, with subsequent injection of such Th2.R cells prior to class I and class II disparate cardiac allografting. Second, we determined whether Th2.R cell transfer polarized host immunity towards a Th2 phenotype. And third, we evaluated whether Th2.R cell therapy prolonged allograft viability when used alone or in combination with a short-course of cyclosporine (CSA) therapy. We found that host-type Th2.R cell therapy prior to cardiac allografting: (1) reduced the frequency of activated T cells in secondary lymphoid organs; (2) shifted post-transplant cytokines towards a Th2 phenotype; and (3) prolonged allograft viability when used in combination with short-course CSA therapy. These results provide further support for the rationale to use "direct" host T cell therapy for prolongation of allograft viability as an alternative to "indirect" therapy mediated by donor T cell infusion.

Impact of animal strain on gene expression in a rat model of acute cardiac rejection.

BACKGROUND: The expression levels of many genes show wide natural variation among strains or populations. This study investigated the potential for animal strain-related genotypic differences to confound gene expression profiles in acute cellular rejection (ACR). Using a rat heart transplant model and 2 different rat strains (Dark Agouti, and Brown Norway), microarrays were performed on native hearts, transplanted hearts, and peripheral blood mononuclear cells (PBMC). RESULTS: In heart tissue, strain alone affected the expression of only 33 probesets while rejection affected the expression of 1368 probesets (FDR 10% and FC > o= 3). Only 13 genes were affected by both strain and rejection, which was < 1% (13/1368) of all probesets differentially expressed in ACR. However, for PBMC, strain alone affected 265 probesets (FDR 10% and FC > or = 3) and the addition of ACR had little further effect. Pathway analysis of these differentially expressed strain effect genes connected them with immune response, cell motility and cell death, functional themes that overlap with those related to ACR. After accounting for animal strain, additional analysis identified 30 PBMC candidate genes potentially associated with ACR. CONCLUSION: In ACR, genetic background has a large impact on the transcriptome of immune cells, but not heart tissue. Gene expression studies of ACR should avoid study designs that require cross strain comparisons between leukocytes.

A portrait of tissue phosphoprotein stability in the clinical tissue procurement process.

Little is known about the preanalytical fluctuations of phosphoproteins during tissue procurement for molecular profiling. This information is crucial to establish guidelines for the reliable measurement of these analytes. To develop phosphoprotein profiles of tissue subjected to the trauma of excision, we measured the fidelity of 53 signal pathway phosphoproteins over time in tissue specimens procured in a community clinical practice. This information provides strategies for potential surrogate markers of stability and the design of phosphoprotein preservative/fixation solutions. Eleven different specimen collection time course experiments revealed augmentation (+/-20% from the time 0 sample) of signal pathway phosphoprotein levels as well as decreases over time independent of tissue type, post-translational modification, and protein subcellular location (tissues included breast, colon, lung, ovary, and uterus (endometrium/myometrium) and metastatic melanoma). Comparison across tissue specimens showed an >20% decrease of protein kinase B (AKT) Ser-473 (p < 0.002) and myristoylated alanine-rich C-kinase substrate protein Ser-152/156 (p < 0.0001) within the first 90-min postexcision. Proteins in apoptotic (cleaved caspase-3 Asp-175 (p < 0.001)), proliferation/survival/hypoxia (IRS-1 Ser-612 (p < 0.0003), AMP-activated protein kinase beta Ser-108 (p < 0.005), ERK Thr-202/Tyr-204 (p < 0.003), and GSK3alphabeta Ser-21/9 (p < 0.01)), and transcription factor pathways (STAT1 Tyr-701 (p < 0.005) and cAMP response element-binding protein Ser-133 (p < 0.01)) showed >20% increases within 90-min postprocurement. Endothelial nitric-oxide synthase Ser-1177 did not change over the time period evaluated with breast or leiomyoma tissue. Treatment with phosphatase or kinase inhibitors alone revealed that tissue kinase pathways are active ex vivo. Combinations of kinase and phosphatase inhibitors appeared to stabilize proteins that exhibited increases in the presence of phosphatase inhibitors alone (ATF-2 Thr-71, SAPK/JNK Thr-183/Tyr-185, STAT1 Tyr-701, JAK1 Tyr-1022/1023, and PAK1/PAK2 Ser-199/204/192/197). This time course study 1) establishes the dynamic nature of specific phosphoproteins in excised tissue, 2) demonstrates augmented phosphorylation in the presence of phosphatase inhibitors, 3) shows that kinase inhibitors block the upsurge in phosphorylation of phosphoproteins, 4) provides a rational strategy for room temperature preservation of proteins, and 5) constitutes a foundation for developing evidence-based tissue procurement guidelines.

Nested stromal epithelial tumor of the liver: six cases of a distinctive pediatric neoplasm with frequent calcifications and association with cushing syndrome.

Rare cases of nonhepatocytic mixed stromal and epithelial tumors of the liver with associated calcification and ossification have been described previously. We report 6 similar cases in children, including 2 cases associated with ectopic ACTH production. The patients were between 2 and 14 years of age at diagnosis. All tumors presented as a solitary liver mass with no extrahepatic involvement. Two adolescent females with palpable abdominal tumors presented with Cushing syndrome that abated after excision of the tumors. The other children had tumors identified incidentally on imaging studies or at laparotomy. All tumors were well circumscribed, ranging in size from 4.0 to 30.0 cm in greatest diameter. Histologically, they shared an organoid arrangement of cellular nests that were comprised of an admixture of both spindled and epithelioid cells. These cellular nests were surrounded by a band of delicate myofibroblasts and set in a dense fibrous stroma that contained slit-like to dilated blood vessels. A variable proliferation of bile ducts extended from the fibrous stroma and focally surrounded the cellular nests. One case showed a sheet-like overgrowth of the nested cells with associated necrosis. The cellular nest cells were immunoreactive for EMA, CD56, neuron specific enolase, pan-cytokeratin (4 of 6 cases), vimentin (5 of 6 cases), and WT-1 amino terminus (4 of 6 cases). Cytokeratin and EMA stained mostly epithelioid nest cells, with vimentin and WT-1 staining predominantly the spindled nest cells. The 3 cases from adolescent females showed immunoreactivity for ACTH in the nested cell population but not in the surrounding stromal cells. Immunohistochemical stains for synaptophysin and chromogranin were negative in all cases. Psammomatous calcifications were present focally in 2 cases and were extensive in 3 cases. Ossification or osteoid formation was present in 4 cases. The 1 patient whose tumor had sheet-like overgrowth of the nested cell population had a local recurrence with multiple hepatic nodules 1 year following the original resection. A 2-year-old patient has been subsequently diagnosed with nephroblastomatosis and Wilms tumor of the kidney. Follow-up information was available in an additional 3 patients with no tumor recurrence or metastatic disease at 2, 3, and 14 years.