Modulation of the Tumor Microenvironment with Trastuzumab Enables Radiosensitization in HER2+ Breast Cancer.

DNA damage repair and tumor hypoxia contribute to intratumoral cellular and molecular heterogeneity and affect radiation response. The goal of this study is to investigate anti-HER2-induced radiosensitization of the tumor microenvironment to enhance fractionated radiotherapy in models of HER2+ breast cancer. This is monitored through in vitro and in vivo studies of phosphorylated γ-H2AX, [18F]-fluoromisonidazole (FMISO)-PET, and transcriptomic analysis. In vitro, HER2+ breast cancer cell lines were treated with trastuzumab prior to radiation and DNA double-strand breaks (DSB) were quantified. In vivo, HER2+ human cell line or patient-derived xenograft models were treated with trastuzumab, fractionated radiation, or a combination and monitored longitudinally with [18F]-FMISO-PET. In vitro DSB analysis revealed that trastuzumab administered prior to fractionated radiation increased DSB. In vivo, trastuzumab prior to fractionated radiation significantly reduced hypoxia, as detected through decreased [18F]-FMISO SUV, synergistically improving long-term tumor response. Significant changes in IL-2, IFN-gamma, and THBS-4 were observed in combination-treated tumors. Trastuzumab prior to fractionated radiation synergistically increases radiotherapy in vitro and in vivo in HER2+ breast cancer which is independent of anti-HER2 response alone. Modulation of the tumor microenvironment, through increased tumor oxygenation and decreased DNA damage response, can be translated to other cancers with first-line radiation therapy.

Phenotypes Conferred by Wheat Multiple Pathogen Resistance Locus, Sr2, Include Cell Death in Response to Biotic and Abiotic Stresses.

The wheat Sr2 locus confers partial resistance to four biotrophic pathogens: wheat stem rust (Puccinia graminis f. sp. tritici), leaf rust (P. triticina), stripe rust (P. striiformis f. sp. tritici), and powdery mildew (Blumeria graminis f. sp. tritici). In addition, Sr2 is linked with a brown coloration of ears and stems, termed pseudo-black chaff (PBC). PBC, initially believed to be elicited by stem rust infection, was subsequently recognized to occur in the absence of pathogen infection. The current study demonstrates that the resistance response to stem rust is associated with the death of photosynthetic cells around rust infection sites in the inoculated leaf sheath. Similarly, Sr2-dependent resistance to powdery mildew was associated with the death of leaf mesophyll cells around mildew infection sites. We demonstrate that PBC occurring in the absence of pathogen inoculation also corresponds with death and the collapse of photosynthetic cells in the affected parts of stems and ears. In addition, Sr2-dependent necrosis was inducible in leaves by application of petroleum jelly or by heat treatments. Thus, Sr2 was found to be associated with cell death, which could be triggered by either biotic or abiotic stresses. Our results suggest a role for the Sr2 locus in controlling cell death in response to stress.

Translational control of the undifferentiated phenotype in ER­positive breast tumor cells: Cytoplasmic localization of ERα and impact of IRES inhibition.

Using a series of potential biomarkers relevant to mechanisms of protein synthesis, we observed that estrogen receptor (ER)-positive breast tumor cells exist in two distinct yet interconvertible phenotypic states (of roughly equal proportion) which differ in the degree of differentiation and use of IRES-mediated translation. Nascently translated IGF1R in the cytoplasm positively correlated with IRES activity and the undifferentiated phenotype, while epitope accessibility of RACK1, an integral component of the 40S ribosomal subunit, aligned with the more differentiated IRES-off state. When deprived of soluble growth factors, the entire tumor cell population shifted to the undifferentiated phenotype in which IRES-mediated translation was active, facilitating survival under these adverse microenvironmental conditions. However, if IRES-mediated translation was inhibited, the cells instead were forced to transition uniformly to the more differentiated state. Notably, cytoplasmic localization of estrogen receptor α (ERα/ESR1) precisely mirrored the pattern observed with nascent IGF1R, correlating with the undifferentiated IRES-active phenotype. Inhibition of IRES-mediated translation resulted in both a shift in ERα to the nucleus (consistent with differentiation) and a marked decrease in ERα abundance (consistent with the inhibition of ERα synthesis via its IRES). Although breast tumor cells tolerated forced differentiation without extensive loss of their viability, their reproductive capacity was severely compromised. In addition, CDK1 was decreased, connexin 43 eliminated and Myc translation altered as a consequence of IRES inhibition. Isolated or low-density ER-positive breast tumor cells were particularly vulnerable to IRES inhibition, losing the ability to generate viable cohesive colonies, or undergoing massive cell death. Collectively, these results provide further evidence for the integral relationship between IRES-mediated translation and the undifferentiated phenotype and demonstrate how therapeutic manipulation of this specialized mode of protein synthesis may be used to limit the phenotypic plasticity and incapacitate or eliminate these otherwise highly resilient breast tumor cells.

A ferret model of COPD-related chronic bronchitis.

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death in the US. The majority of COPD patients have symptoms of chronic bronchitis, which lacks specific therapies. A major impediment to therapeutic development has been the absence of animal models that recapitulate key clinical and pathologic features of human disease. Ferrets are well suited for the investigation of the significance of respiratory diseases, given prior data indicating similarities to human airway physiology and submucosal gland distribution. Here, we exposed ferrets to chronic cigarette smoke and found them to approximate complex clinical features of human COPD. Unlike mice, which develop solely emphysema, smoke-exposed ferrets exhibited markedly higher numbers of early-morning spontaneous coughs and sporadic infectious exacerbations as well as a higher level of airway obstruction accompanied by goblet cell metaplasia/hyperplasia and increased mucus expression in small airways, indicative of chronic bronchitis and bronchiolitis. Overall, we demonstrate the first COPD animal model exhibiting clinical and pathologic features of chronic bronchitis to our knowledge, providing a key advance that will greatly facilitate the preclinical development of novel treatments for this disease.

SPARC-Independent Delivery of Nab-Paclitaxel without Depleting Tumor Stroma in Patient-Derived Pancreatic Cancer Xenografts.

The study goal was to examine the relationship between nab-paclitaxel delivery and SPARC (secreted protein acidic and rich in cysteine) expression in pancreatic tumor xenografts and to determine the antistromal effect of nab-paclitaxel, which may affect tumor vascular perfusion. SPARC-positive and -negative mice bearing Panc02 tumor xenografts (n = 5-6/group) were injected with IRDye 800CW (IR800)-labeled nab-paclitaxel. After 24 hours, tumors were collected and stained with DL650-labeled anti-SPARC antibody, and the correlation between nab-paclitaxel and SPARC distributions was examined. Eight groups of mice bearing either Panc039 or Panc198 patient-derived xenografts (PDX; 4 groups/model, 5 animals/group) were untreated (served as control) or treated with gemcitabine (100 mg/kg body weight, i.p., twice per week), nab-paclitaxel (30 mg/kg body weight, i.v., for 5 consecutive days), and these agents in combination, respectively, for 3 weeks, and tumor volume and perfusion changes were assessed using T2-weighted MRI and dynamic contrast-enhanced (DCE) MRI, respectively. All tumors were collected and stained with Masson's Trichrome Stain, followed by a blinded comparative analysis of tumor stroma density. IR800-nab-paclitaxel was mainly distributed in tumor stromal tissue, but nab-paclitaxel and SPARC distributions were minimally correlated in either SPARC-positive or -negative animals. Nab-paclitaxel treatment neither decreased tumor stroma nor increased tumor vascular perfusion in either PDX model when compared with control groups. These data suggest that the specific tumor delivery of nab-paclitaxel is not directly related to SPARC expression, and nab-paclitaxel does not deplete tumor stroma in general. Mol Cancer Ther; 15(4); 680-8. ©2016 AACR.

Dynamic contrast enhanced magnetic resonance imaging of an orthotopic pancreatic cancer mouse model.

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) has been limitedly used for orthotopic pancreatic tumor xenografts due to severe respiratory motion artifact in the abdominal area. Orthotopic tumor models offer advantages over subcutaneous ones, because those can reflect the primary tumor microenvironment affecting blood supply, neovascularization, and tumor cell invasion. We have recently established a protocol of DCE-MRI of orthotopic pancreatic tumor xenografts in mouse models by securing tumors with an orthogonally bent plastic board to prevent motion transfer from the chest region during imaging. The pressure by this board was localized on the abdominal area, and has not resulted in respiratory difficulty of the animals. This article demonstrates the detailed procedure of orthotopic pancreatic tumor modeling using small animals and DCE-MRI of the tumor xenografts. Quantification method of pharmacokinetic parameters in DCE-MRI is also introduced. The procedure described in this article will assist investigators to apply DCE-MRI for orthotopic gastrointestinal cancer mouse models.

The value of biodiversity in legume symbiotic nitrogen fixation and nodulation for biofuel and food production.

Much of modern agriculture is based on immense populations of genetically identical or near-identical varieties, called cultivars. However, advancement of knowledge, and thus experimental utility, is found through biodiversity, whether naturally-found or induced by the experimenter. Globally we are confronted by ever-growing food and energy challenges. Here we demonstrate how such biodiversity from the food legume crop soybean (Glycine max L. Merr) and the bioenergy legume tree Pongamia (Millettia) pinnata is a great value. Legume plants are diverse and are represented by over 18,000 species on this planet. Some, such as soybean, pea and medics are used as food and animal feed crops. Others serve as ornamental (e.g., wisteria), timber (e.g., acacia/wattle) or biofuel (e.g., Pongamia pinnata) resources. Most legumes develop root organs (nodules) after microsymbiont induction that serve as their habitat for biological nitrogen fixation. Through this, nitrogen fertiliser demand is reduced by the efficient symbiosis between soil Rhizobium-type bacteria and the appropriate legume partner. Mechanistic research into the genetics, biochemistry and physiology of legumes is thus strategically essential for future global agriculture. Here we demonstrate how molecular plant science analysis of the genetics of an established food crop (soybean) and an emerging biofuel P. pinnata feedstock contributes to their utility by sustainable production aided by symbiotic nitrogen fixation.

IND-directed safety and biodistribution study of intravenously injected cetuximab-IRDye800 in cynomolgus macaques.

PURPOSE: The use of receptor-targeted antibodies conjugated to fluorophores is actively being explored for real-time imaging of disease states; however, the toxicity of the bioconjugate has not been assessed in non-human primates. PROCEDURES: To this end, the in vivo toxicity and pharmacokinetics of IRDye800 conjugated to cetuximab (cetuximab-IRDye800; 21 mg/kg; equivalent to 250 mg/m(2) human dose) were assessed in male cynomolgus monkeys over 15 days following intravenous injection and compared with an unlabeled cetuximab-dosed control group. RESULTS: Cetuximab-IRDye800 was well tolerated. There were no infusion reactions, adverse clinical signs, mortality, weight loss, or clinical histopathology findings. The plasma half-life for the cetuximab-IRDye800 and cetuximab groups was equivalent (2.5 days). The total recovered cetuximab-IRDye800 in all tissues at study termination was estimated to be 12 % of the total dose. Both cetuximab-IRDye800 and cetuximab groups showed increased QTc after dosing. The QTc for the cetuximab-dosed group returned to baseline by day 15, while the QTc of the cetuximab-IRDye800 remained elevated compared to baseline. CONCLUSION: IRDye800 in low molar ratios does not significantly impact cetuximab half-life or result in organ toxicity. These studies support careful cardiac monitoring (ECG) for human studies using fluorescent dyes.

Combination therapy with anti-DR5 antibody and tamoxifen for triple negative breast cancer.

TRA-8, a monoclonal antibody targeting death receptor, has demonstrated high therapeutic effect for triple negative breast cancer (TNBC) in preclinical models. Tamoxifen, the standard of care for ERα-positive breast cancer, induces apoptosis via ERß, which commonly presents in TNBC cells. The current study investigates the combination effects of TRA-8 and tamoxifen for TNBC. In vitro assays were implemented with two ERß-positive TNBC cell lines, SUM159 and 2LMP, and in vivo therapy studies were followed using orthotopic breast tumor mouse models. IC50 of tamoxifen for SUM159 and 2LMP were 29 µM and 38 µM, respectively. Synergy between TRA-8 (0-1000 ng/mL) and tamoxifen (20 µM) was observed for both the cell lines. Tamoxifen (400 mg/kg diet) markedly suppressed the growth of SUM159 tumors for 6 weeks after therapy initiation, but it did not induce antitumor effect for 2LMP tumors. TRA-8 (0.1 mg, weekly, i.p.) successfully arrested the growth of both SUM159 and 2LMP tumors during therapy, but an antagonistic effect was observed when tamoxifen was combined. TRA-8 uptake into tumors was not changed by tamoxifen treatment. Histological analysis confirmed that caspase-3 activation induced by TRA-8 was significantly decreased when tamoxifen was used in combination. In conclusion, our findings suggest that the combined use of TRA-8 and tamoxifen may cause antagonistic effects for TNBC patients.

Volumetric contrast-enhanced ultrasound imaging of renal perfusion.

OBJECTIVES: To determine whether volumetric contrast-enhanced ultrasound (US) imaging has the potential to monitor changes in renal perfusion after vascular injury. METHODS: Volumetric contrast-enhanced US uses a series of planar image acquisitions, capturing the nonlinear second harmonic signal from microbubble contrast agents flowing in the vasculature. Tissue perfusion parameters (peak intensity [IPK], time to peak intensity [TPK], wash-in rate [WIR], and area under the curve [AUC]) were derived from time-intensity curve data collected during in vitro flow phantom studies and in vivo animal studies of healthy and injured kidneys. For the flow phantom studies, either the contrast agent concentration was held constant (10 µL/L) with varying volumetric flow rates (10, 20, and 30 mL/min), or the flow rate was held constant (30 mL/min) with varying contrast agent concentrations (5, 10, and 20 µL/L). Animal studies used healthy rats or those that underwent renal ischemia-reperfusion injury. Renal studies were performed with healthy rats while the transducer angle was varied for each volumetric contrast-enhanced US image acquisition (reference or 0°, 45°, and 90°) to determine whether repeated renal perfusion measures were isotropic and independent of transducer position. Blood serum biomarkers and immunohistology were used to confirm acute kidney injury. RESULTS: Flow phantom results revealed a linear relationship between microbubble concentrations injected into the flow system and the IPK, WIR, and AUC (R(2) > 0.56; P < .005). Furthermore, there was a linear relationship between volume flow rate changes and the TPK, WIR, and AUC (R(2) > 0.77; P < .005). No significant difference was found between the transducer angle during data acquisition and any of the perfusion measures (P > .60). After induction of renal ischemia-reperfusion injury in the rat animal model (n = 4), volumetric contrast-enhanced US imaging of the injured kidney revealed an initial reduction in renal perfusion compared to control animals, followed by progressive recovery of vascular function. CONCLUSIONS: Volumetric contrast-enhanced US-based renal perfusion imaging may prove clinically feasible for detecting and monitoring acute kidney injury.

Biodistribution of P-selectin targeted microbubbles.

PURPOSE: To evaluate binding of P-selectin targeted microbubbles (MB) in tumor vasculature; a whole-body imaging and biodistribution study was performed in a tumor bearing mouse model. METHODS: Antibodies were radiolabeled with Tc-99 m using the HYNIC method. Tc-99 m labeled anti-P-selectin antibodies were avidin-bound to lipid-shelled, perfluorocarbon gas-filled MB and intravenously injected into mice bearing MDA-MB-231 breast tumors. Whole-body biodistribution was performed at 5 min (n = 12) and 60 min (n = 4) using a gamma counter. Tc-99 m-labeled IgG bound IgG-control-MB group (n = 12 at 5 min; n = 4 at 60 min), Tc-99 m-labeled IgG-control-Ab group (n = 5 at 5 min; n = 3 at 60 min) and Tc-99 m-labeled anti P-selectin-Ab group (n = 5 at 5 min; n = 3 at 60 min) were also evaluated. Planar gamma camera imaging was also performed at each time point. RESULTS: Targeted-MB retention in tumor (60 min: 1.8 ± 0.3% ID/g) was significantly greater (p = 0.01) than targeted-MB levels in adjacent skeletal muscle at both time points (5 min: 0.7 ± 0.2% ID/g; 60 min: 0.2 ± 0.1% ID/g) while there was no significant difference (p = 0.17) between muscle and tumor retention for the IgG-control-MB group at 5 min. CONCLUSIONS: P-selectin targeted MBs were significantly higher in tumor tissue, as compared with adjacent skeletal tissue or tumor retention of IgG-control-MB.

Early therapy assessment of combined anti-DR5 antibody and carboplatin in triple-negative breast cancer xenografts in mice using diffusion-weighted imaging and (1)H MR spectroscopy.

PURPOSE: To assess the early response of triple-negative breast-cancer (TNBC) following TRA-8 and carboplatin therapy using DWI and MRS in 2LMP and SUM159 mouse models. MATERIALS AND METHODS: Four groups (n = 5/group) of each model were untreated or treated with carboplatin, TRA-8, and combination, respectively. DWI and MRS were applied on 0, 3, and 7 days after therapy initiation, and all tumors were collected thereafter for terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining. The changes in intratumoral apparent diffusion coefficient (ADC) and fat-water ratios (FWRs) were compared with tumor volume changes and apoptotic cell densities. RESULTS: Mean ADC values of 2LMP and SUM159 tumors significantly increased 4 ± 4% and 37 ± 11% during 7 days of combination therapy, respectively, as compared to control groups (P < 0.05). Similarly, mean FWRs of 2LMP and SUM159 tumors significantly increased 102 ± 30% and 126 ± 52%, respectively, for 7 days of combined treatment (P < 0.05). The changes of the mean ADC values for 3 days (or FWRs for 7 days) were linearly proportional to either the mean volume changes or apoptotic cell densities in both models. CONCLUSION: DWI and MRS assessed the early tumor response to TRA-8 and carboplatin in TNBC mouse models.

Antagonistic effects of anti-EMMPRIN antibody when combined with chemotherapy against hypovascular pancreatic cancers.

PURPOSE: To examine the antagonistic effects of anti-extracellular matrix metalloprotease inducer (anti-EMMPRIN) antibody when combined with chemotherapy using a hypovascular pancreatic tumor model. PROCEDURES: Severely compromised immunodeficient mice bearing orthotopic MIA PaCa-2 tumors were used (five to six animals per group). Dynamic contrast-enhanced magnetic resonance imaging was used to examine the relationship between tumor vascularity and size. Therapy was initiated when tumors were hypovascular. Treatments included: (1) gemcitabine alone, (2) anti-EMMPRIN antibody alone, and (3) combination, each for 2 weeks. Additionally, another treatment arm included ß-lapachone, an NAD(P)H/quinone 1 (NQO1) bioactivated agent. (18)F-fluoro-D-glucose-positron emission tomography/computed tomography imaging was used weekly to monitor therapeutic effects. RESULTS: Gemcitabine or anti-EMMPRIN monotherapy significantly delayed tumor growth, but the combination therapy showed an antagonistic effect. Similarly, tumor growth was significantly suppressed by ß-lapachone alone, and additive effects were noted when combined with gemcitabine, but the therapeutic efficacy was reduced when anti-EMMPRIN antibody was added. CONCLUSIONS: Anti-EMMPRIN antibody with chemotherapy in hypovascular tumors results in antagonistic effects.

Dual combination therapy targeting DR5 and EMMPRIN in pancreatic adenocarcinoma.

The goal of the study was to assess the efficacy of combined extracellular matrix metalloprotease inducer (EMMPRIN)- and death receptor 5 (DR5)-targeted therapy for pancreatic adenocarcinoma in orthotopic mouse models with multimodal imaging. Cytotoxicity of anti-EMMPRIN antibody and anti-DR5 antibody (TRA-8) in MIA PaCa-2 and PANC-1 cell lines was measured by ATPlite assay in vitro. The distributions of Cy5.5-labeled TRA-8 and Cy3-labeled anti-EMMPRIN antibody in the 2 cell lines were analyzed by fluorescence imaging in vitro. Groups 1 to 12 of severe combined immunodeficient mice bearing orthotopic MIA PaCa-2 (groups 1-8) or PANC-1 (groups 9-12) tumors were used for in vivo studies. Dynamic contrast-enhanced-MRI was applied in group 1 (untreated) or group 2 (anti-EMMPRIN antibody). The tumor uptake of Tc-99m-labeled TRA-8 was measured in group 3 (untreated) and group 4 (anti-EMMPRIN antibody). Positron emission tomography/computed tomography imaging with (18)F-FDG was applied in groups 5 to 12. Groups 5 to 8 (or groups 9 to 12) were untreated or treated with anti-EMMPRIN antibody, TRA-8, and combination, respectively. TRA-8 showed high killing efficacy for both MIA PaCa-2 and PANC-1 cells in vitro, but additional anti-EMMPRIN treatment did not improve the cytotoxicity. Cy5.5-TRA-8 formed cellular caps in both the cell lines, whereas the maximum signal intensity was correlated with TRA-8 cytotoxicity. Anti-EMMPRIN therapy significantly enhanced the tumor delivery of the MR contrast agent, but not Tc-99m-TRA-8. Tumor growth was significantly suppressed by the combination therapy, and the additive effect of the combination was shown in both MIA PaCa-2 and PANC-1 tumor models.

Extracelluar matrix metalloproteinase as a novel target for pancreatic cancer therapy.

The objective of this study was to evaluate extracellular matrix metalloproteinase (EMMPRIN) as a novel target in orthotopic pancreatic cancer murine models. MIA PaCa-2 human pancreatic tumor cells were implanted in groups 1 and 3-7, whereas MIA PaCa-2 EMMPRIN knockdown cells were implanted in group 2. Dosing with anti-EMMPRIN antibody started immediately after implantation for groups 1-3 (residual tumor model) and at 21 days after cell implantation for groups 4-7 (established tumor model). Groups 3, 5, and 7 were treated with anti-EMMRPIN antibody (0.2-1.0 mg) twice weekly for 2-3 weeks, whereas the other groups served as the control. In the residual tumor model, tumor growth of anti-EMMPRIN-treated group was successfully arrested for 21 days (15 ± 4 mm(3)), which was significantly lower than that of the EMMPRIN knockdown group (80 ± 15 mm(3); P=0.001) or the control group (240 ± 41 mm(3); P<0.001). In the established tumor model, anti-EMMPRIN therapy lowered tumor volume increase by approximately 40% compared with the control, regardless of the dose amount. Ki67-expressed cell density of group 5 was 939 ± 150 mm(-2), which was significantly lower than that of group 4 (1709 ± 145 mm(-2); P=0.006). Microvessel density of group 5 (30 ± 6 mm(-2)) was also significantly lower than that of group 4 (53 ± 5 mm(-2); P=0.014), whereas the microvessel size of group 5 (191 ± 22 µm(2)) was significantly larger than that of group 4 (113 ± 26 µm(2); P=0.049). These data show the high potential of anti-EMMPRIN therapy for pancreatic cancer and support its clinical translation.

Adoptively transferred ex vivo expanded gammadelta-T cells mediate in vivo antitumor activity in preclinical mouse models of breast cancer.

In contrast to antigen-specific alphabeta-T cells (adaptive immune system), gammadelta-T cells can recognize and lyse malignantly transformed cells almost immediately upon encounter in a manner that does not require the recognition of tumor-specific antigens (innate immune system). Given the well-documented capacity of gammadelta-T cells to innately kill a variety of malignant cells, efforts are now actively underway to exploit the antitumor properties of gammadelta-T cells for clinical purposes. Here, we present for the first time preclinical in vivo mouse models of gammadelta-T cell-based immunotherapy directed against breast cancer. These studies were explicitly designed to approximate clinical situations in which adoptively transferred gammadelta-T cells would be employed therapeutically against breast cancer. Using radioisotope-labeled gammadelta-T cells, we first show that adoptively transferred gammadelta-T cells localize to breast tumors in a mouse model (4T1 mammary adenocarcinoma) of human breast cancer. Moreover, by using an antibody directed against the gammadelta-T cell receptor (TCR), we determined that localization of adoptively transferred gammadelta-T cells to tumor is a TCR-dependant process. Additionally, biodistribution studies revealed that adoptively transferred gammadelta-T cells traffic differently in tumor-bearing mice compared to healthy mice with fewer gammadelta-T cells localizing into the spleens of tumor-bearing mice. Finally, in both syngeneic (4T1) and xenogeneic (2Lmp) models of breast cancer, we demonstrate that adoptively transferred gammadelta-T cells are both effective against breast cancer and are otherwise well-tolerated by treated animals. These findings provide a strong preclinical rationale for using ex vivo expanded adoptively transferred gammadelta-T cells as a form of cell-based immunotherapy for the treatment of breast cancer. Additionally, these studies establish that clinically applicable methods for radiolabeling gammadelta-T cells allows for the tracking of adoptively transferred gammadelta-T cells in tumor-bearing hosts.

Deficiency of P-selectin or P-selectin glycoprotein ligand-1 leads to accelerated development of glomerulonephritis and increased expression of CC chemokine ligand 2 in lupus-prone mice.

The selectins and their ligands mediate leukocyte rolling on endothelial cells, the initial step in the emigration cascade leading to leukocyte infiltration of tissue. These adhesion molecules have been shown to be key promoters of acute leukocyte emigration events; however, their roles in the development of long-term inflammatory responses, including those that occur during chronic inflammatory diseases such as systemic lupus erythematosus, are unclear. To assess participation of P-selectin in such disorders, we studied the progression of systemic lupus erythematosus-like disease in P-selectin-deficient and control MRL/MpJ-Fas(lpr) (Fas(lpr)) mice. Surprisingly, we found that P-selectin deficiency resulted in significantly earlier mortality, characterized by a more rapid development of glomerulonephritis and dermatitis. Expression of CCL2 (MCP-1) was increased in the kidneys of P-selectin mutant mice and in supernatants of LPS-stimulated primary renal endothelial cell cultures from these mice. A closely similar phenotype, including elevated renal expression of CCL2, was also observed in Fas(lpr) mice deficient in the major P-selectin ligand, P-selectin glycoprotein ligand-1. These results indicate that P-selectin and P-selectin glycoprotein ligand-1 are not required for leukocyte infiltration and the development of autoimmune disease in Fas(lpr) mice, but rather expression of these adhesion molecules is important for modulating the progression of glomerulonephritis, possibly through down-regulation of endothelial CCL2 expression.

Serial passage through human glioma xenografts selects for a Deltagamma134.5 herpes simplex virus type 1 mutant that exhibits decreased neurotoxicity and prolongs survival of mice with experimental brain tumors.

Previous studies have described in vitro serial passage of a Deltagamma(1)34.5 herpes simplex virus type 1 (HSV-1) strain in SK-N-SH neuroblastoma cells and selection of mutants that have acquired the ability to infect and replicate in this previously nonpermissive cell line. Here we describe the selection of a mutant HSV-1 strain by in vivo serial passage, which prolongs survival in two separate experimental murine brain tumor models. Two conditionally replication-competent Deltagamma(1)34.5 viruses, M002, which expresses murine interleukin-12, and its parent virus, R3659, were serially passaged within human malignant glioma D54-MG cell lines in vitro or flank tumor xenografts in vivo. The major findings are (i) viruses passaged in vivo demonstrate decreased neurovirulence, whereas those passaged in vitro demonstrate a partial recovery of the neurovirulence associated with HSV-1; and (ii) vvD54-M002, the virus selected after in vivo serial passage of M002 in D54-MG tumors, improves survival in two independent murine brain tumor models compared to the parent (unpassaged) M002. Additionally, in vitro-passaged, but not in vivo-passaged, M002 displayed changes in the protein synthesis profile in previously nonpermissive cell lines, as well as early U(S)11 transcription. Thus, a mutant HSV-1 strain expressing a foreign gene can be selected for enhanced antitumor efficacy via in vivo serial passage within flank D54-MG tumor xenografts. The enhanced antitumor efficacy of vvD54-M002 is not due to restoration of protein synthesis or early U(S)11 expression. This finding emphasizes the contribution of the in vivo tumor environment for selecting novel oncolytic HSV specifically adapted for tumor cell destruction in vivo.

Accelerated development of arthritis in mice lacking endothelial selectins.

The selectins, along with very late antigen-4 and CD44, have been implicated in mediating leukocyte rolling interactions that lead to joint recruitment and inflammation during the pathogenesis of rheumatoid arthritis. Previously, we showed that P-selectin deficiency in mice resulted in accelerated onset of joint inflammation in the murine collagen-immunized arthritis model. Here, we report that mice deficient either in E-selectin or in E-selectin and P-selectin (E/P-selectin mutant) also exhibit accelerated development of arthritis compared with wild type mice in the CIA model, suggesting that these adhesion molecules perform overlapping functions in regulating joint disease. Analyses of cytokine and chemokine expression in joint tissue from E/P-selectin mutant mice before the onset of joint swelling revealed significantly higher joint levels of macrophage inflammatory protein-1alpha and IL-1beta compared to wild-type mice. IL-1beta remained significantly increased in E/P-selectin mutant joint tissue during the early and chronic phases of arthritis. Overall, these data illustrate the novel finding that E-selectin and P-selectin expression can significantly influence cytokine and chemokine production in joint tissue, and suggest that these adhesion molecules play important regulatory roles in the development of arthritis in E/P-selectin mutant mice.