Application of the pMHC Array to Characterise Tumour Antigen Specific T Cell Populations in Leukaemia Patients at Disease Diagnosis.

Immunotherapy treatments for cancer are becoming increasingly successful, however to further improve our understanding of the T-cell recognition involved in effective responses and to encourage moves towards the development of personalised treatments for leukaemia immunotherapy, precise antigenic targets in individual patients have been identified. Cellular arrays using peptide-MHC (pMHC) tetramers allow the simultaneous detection of different antigen specific T-cell populations naturally circulating in patients and normal donors. We have developed the pMHC array to detect CD8+ T-cell populations in leukaemia patients that recognise epitopes within viral antigens (cytomegalovirus (CMV) and influenza (Flu)) and leukaemia antigens (including Per Arnt Sim domain 1 (PASD1), MelanA, Wilms' Tumour (WT1) and tyrosinase). We show that the pMHC array is at least as sensitive as flow cytometry and has the potential to rapidly identify more than 40 specific T-cell populations in a small sample of T-cells (0.8-1.4 x 10(6)). Fourteen of the twenty-six acute myeloid leukaemia (AML) patients analysed had T cells that recognised tumour antigen epitopes, and eight of these recognised PASD1 epitopes. Other tumour epitopes recognised were MelanA (n = 3), tyrosinase (n = 3) and WT1(126-134) (n = 1). One of the seven acute lymphocytic leukaemia (ALL) patients analysed had T cells that recognised the MUC1(950-958) epitope. In the future the pMHC array may be used provide point of care T-cell analyses, predict patient response to conventional therapy and direct personalised immunotherapy for patients.

Infrequent Expression of the Cancer-Testis Antigen, PASD1, in Ovarian Cancer.

Ovarian cancer is very treatable in the early stages of disease; however, it is usually detected in the later stages, at which time, treatment is no longer as effective. If discovered early (Stage I), there is a 90% chance of five-year survival. Therefore, it is imperative that early-stage biomarkers are identified to enhance the early detection of ovarian cancer. Cancer-testis antigens (CTAs), such as Per ARNT SIM (PAS) domain containing 1 (PASD1), are unique in that their expression is restricted to immunologically restricted sites, such as the testis and placenta, which do not express MHC class I, and cancer, making them ideally positioned to act as targets for immunotherapy as well as potential biomarkers for cancer detection where expressed. We examined the expression of PASD1a and b in a number of cell lines, as well as eight healthy ovary samples, eight normal adjacent ovarian tissues, and 191 ovarian cancer tissues, which were predominantly stage I (n = 164) and stage II (n = 14) disease. We found that despite the positive staining of skin cancer, only one stage Ic ovarian cancer patient tissue expressed PASD1a and b at detectable levels. This may reflect the predominantly stage I ovarian cancer samples examined. To examine the restriction of PASD1 expression, we examined endometrial tissue arrays and found no expression in 30 malignant tumor tissues, 23 cases of hyperplasia, or 16 normal endometrial tissues. Our study suggests that the search for a single cancer-testes antigen/biomarker that can detect early ovarian cancer must continue.

Glutamate cycling may drive organic anion transport on the basal membrane of human placental syncytiotrophoblast.

The organic anion transporter OAT4 (SLC22A11) and organic anion transporting polypeptide OATP2B1 (SLCO2B1) are expressed in the basal membrane of the placental syncytiotrophoblast. These transporters mediate exchange whereby uptake of one organic anion is coupled to efflux of a counter-ion. In placenta, these exchangers mediate placental uptake of substrates for oestrogen synthesis as well as clearing waste products and xenobiotics from the fetal circulation. However, the identity of the counter-ion driving this transport in the placenta, and in other tissues, is unclear. While glutamate is not a known OAT4 or OATP2B1 substrate, we propose that its high intracellular concentration has the potential to drive accumulation of substrates from the fetal circulation. In the isolated perfused placenta, glutamate exchange was observed between the placenta and the fetal circulation. This exchange could not be explained by known glutamate exchangers. However, glutamate efflux was trans-stimulated by an OAT4 and OATP2B1 substrate (bromosulphothalein). Exchange of glutamate for bromosulphothalein was only observed when glutamate reuptake was inhibited (by addition of aspartate). To determine if OAT4 and/or OATP2B1 mediate glutamate exchange, uptake and efflux of glutamate were investigated in Xenopus laevis oocytes. Our data demonstrate that in Xenopus oocytes expressing either OAT4 or OATP2B1 efflux of intracellular [(14)C]glutamate could be stimulated by conditions including extracellular glutamate (OAT4), estrone-sulphate and bromosulphothalein (both OAT4 and OATP2B1) or pravastatin (OATP2B1). Cycling of glutamate across the placenta involving efflux via OAT4 and OATP2B1 and subsequent reuptake will drive placental uptake of organic anions from the fetal circulation.

Risk factors for complications of radiation therapy on tissue expander breast reconstructions.

Radiation therapy has been shown to increase complication rates of tissue expander/implant breast reconstructions. The purpose of this study was to evaluate patient characteristics to assess their impact on complications. A retrospective review of patients who underwent mastectomy plus tissue expander/implant reconstruction from January 2000 to December 2006 was performed. The main outcome of interest was the development of postoperative complications. Analyses were performed to detect risk factors for complications. A total of 560 patients were included in the study. A total of 385 patients underwent unilateral and 174 underwent bilateral tissue expander/implant reconstructions, for a total of 733 reconstructions. A total complication rate of 31.8% and a major complication rate of 24.4% were calculated. The risk factors associated with a significantly increased incidence of complications were age greater than 50 years, body mass index (BMI) greater than 30, and radiation. Women younger than 50 years had a complication rate of 28.4%, whereas women older than 50 years had a complication rate of 37.0%. Women with a BMI less than 30 had a complication rate of 27.5%, whereas women with a BMI greater than 30 had a complication rate of 49%. The major complication rate in nonradiated and radiated patients was 21.2% and 45.4%, respectively. Despite higher complication rates, tissue expander/implant reconstructions were successful in 70.1% of radiated patients. Based on this study, the ideal radiated patient would have a BMI less than 30 and be younger than 50 years of age to maximize the likelihood of a successful tissue expander/implant reconstruction.

Metabolic induction and early responses of mouse blastocyst developmental programming following maternal low protein diet affecting life-long health.

Previously, we have shown that a maternal low protein diet, fed exclusively during the preimplantation period of mouse development (Emb-LPD), is sufficient to induce by the blastocyst stage a compensatory growth phenotype in late gestation and postnatally, correlating with increased risk of adult onset cardiovascular disease and behavioural dysfunction. Here, we examine mechanisms of induction of maternal Emb-LPD programming and early compensatory responses by the embryo. Emb-LPD induced changes in maternal serum metabolites at the time of blastocyst formation (E3.5), notably reduced insulin and increased glucose, together with reduced levels of free amino acids (AAs) including branched chain AAs leucine, isoleucine and valine. Emb-LPD also caused reduction in the branched chain AAs within uterine fluid at the blastocyst stage. These maternal changes coincided with an altered content of blastocyst AAs and reduced mTORC1 signalling within blastocysts evident in reduced phosphorylation of effector S6 ribosomal protein and its ratio to total S6 protein but no change in effector 4E-BP1 phosphorylated and total pools. These changes were accompanied by increased proliferation of blastocyst trophectoderm and total cells and subsequent increased spreading of trophoblast cells in blastocyst outgrowths. We propose that induction of metabolic programming following Emb-LPD is achieved through mTORC1signalling which acts as a sensor for preimplantation embryos to detect maternal nutrient levels via branched chain AAs and/or insulin availability. Moreover, this induction step associates with changes in extra-embryonic trophectoderm behaviour occurring as early compensatory responses leading to later nutrient recovery.

Clinical evaluation of cellular immunotherapy in acute myeloid leukaemia.

Immunotherapy is currently under active investigation as an adjuvant therapy to improve the overall survival of patients with acute myeloid leukaemia (AML) by eliminating residual leukaemic cells following standard therapy. The graft-versus-leukaemia effect observed following allogeneic haematopoietic stem cell transplantation has already demonstrated the significant role of immune cells in controlling AML, paving the way to further exploitation of this effect in optimized immunotherapy protocols. In this review, we discuss the current state of cellular immunotherapy as adjuvant therapy for AML, with a particular focus on new strategies and recently published results of preclinical and clinical studies. Therapeutic vaccines that are being tested in AML include whole tumour cells as an autologous source of multiple leukaemia-associated antigens (LAA) and autologous dendritic cells loaded with LAA as effective antigen-presenting cells. Furthermore, adoptive transfer of cytotoxic T cells or natural killer cells is under active investigation. Results from phase I and II trials are promising and support further investigation into the potential of cellular immunotherapeutic strategies to prevent or fight relapse in AML patients.

Complication rates of radiation on tissue expander and autologous tissue breast reconstruction.

BACKGROUND: To evaluate risk factors for complications of tissue expander/implant and autologous tissue breast reconstructions and determine if radiation increases complication rates. MATERIALS AND METHODS: We performed a retrospective review of patients who underwent mastectomy plus autologous tissue or expander/implant reconstruction at the Cleveland Clinic. Univariate and multivariate analysis were performed in each group to evaluate for risk factors for complications. A complication was considered major if it required reoperation. A predictive model was used to compare the 2 groups to one another. RESULTS: A total of 1037 patients were included in the study. In the tissue expander/implant population, there was a total complication rate of 31.8% and overall major complication rate of 24.4%. Radiation increased the major complication rate from 21.2 to 45.4%. However, 70.1% of the radiated patients ultimately had a successful implant-based reconstruction while an additional 10.3% went on to have autologous reconstruction. Age and body mass index (BMI) > 30 also led to higher major complication rates in tissue expander/implant reconstruction while smoking, hypertension, and chemotherapy had no impact. In the autologous reconstruction group, there was a total complication rate of 31.5% and a major complication rate of 19.7%. There was no statistically significant difference between the radiated and nonradiated autologous tissue reconstructions with major complication rates of 17.9 and 20.5%, respectively. BMI > 30 was the only significant factor leading to higher major complications in the autologous reconstructions. CONCLUSION: Total complication rates were similar between tissue expander and autologous reconstructions. Increased major complication rates in patients with tissue expander reconstructions occurred in those with radiation, but was still successful in the majority of patients. Radiation had no influence on autologous tissue reconstruction major complication rates.

Markedly elevated lipase as a clue to diagnosis of small bowel obstruction after gastric bypass.

We describe an afferent loop obstruction in a patient who had a subtotal gastrectomy with Roux-en Y gastrojejunostomy for postvagotomy syndrome. The clinical presentation and initial studies suggested acute pancreatitis. A computed tomography scan showed a small bowel obstruction distal to the jejunojejunal anastomosis. The patient was taken to the operating room for an exploratory laparotomy, lysis of adhesions, and closure of her jejunostomy. Surgery was successful at resolving her obstruction. In any Roux-en-Y gastric reconstruction or gastric bypass patient presenting to the emergency department with abdominal pain and elevated transamines or pancreatic enzymes, a small bowel obstruction must be considered. Additional imaging with a computed tomography scan is advocated, as well as surgical consultation.