Interest in combining radiotherapy and immune checkpoint therapy is growing rapidly. In this study, we explored a novel combination of this type to augment anti-tumor immune responses in preclinical murine models of melanoma, neuroblastoma, and head and neck squamous cell carcinoma. Cooperative effects were observed with local radiotherapy and intratumoral injection of tumor-specific antibodies, arising in part from enhanced antibody-dependent cell-mediated cytotoxicity (ADCC). We could improve this response by combining radiation with intratumoral injection of an IL-2-linked tumor-specific antibody (termed here an immunocytokine), resulting in complete regression of established tumors in most animals associated with a tumor-specific memory T cell response. Given the T cell response elicited by combined local radiation and intratumoral immunocytokine, we tested the potential benefit of adding this treatment to immune checkpoint blockade. In mice bearing large primary tumors or disseminated metastases, the triple-combination of intratumoral immunocytokine, radiation, and systemic anti-CTLA-4 improved primary tumor response and animal survival compared to combinations of any two of these three interventions. Taken together, our results show how combining radiation and intratumoral immunocytokine in murine tumor models can eradicate large tumors and metastases, eliciting an in situ vaccination effect that can be leveraged further by T cell checkpoint blockade, with immediate implications for clinical evaluation.

The abundance of six tetracycline resistance genes tet(O), tet(Q), tet(W), tet(M), tet(B) and tet(L), were quantified over time in wastewater lagoons at concentrated animal feeding operations (CAFO) to assess how feedlot operation affects resistance genes in downstream surface waters. Eight lagoons at five cattle feedlots in the Midwestern United States were monitored for 6 months. Resistance and 16S-rRNA gene abundances were quantified using real-time PCR, and physicochemical lagoon conditions, tetracycline levels, and other factors (e.g. feedlot size and weather conditions) were monitored over time. Lagoons were sorted according to antibiotic use practice at each site, and designated as 'no-use', 'mixed-use' or 'high-use' for comparison. High-use lagoons had significantly higher detected resistance gene levels (tet(R); 2.8 x 10(6) copies ml(-1)) relative to no-use lagoons (5.1 x 10(3) copies ml(-1); P < 0.01) and mixed-use lagoons (7.3 x 10(5) copies ml(-1); P = 0.076). Bivariate correlation analysis on pooled data (n = 54) confirmed that tet(R) level strongly correlated with feedlot area (r = 0.67, P < 0.01) and 'total' bacterial 16S-rRNA gene level in each lagoon (r = 0.51, P < 0.01), which are both characteristic of large CAFOs. tet(M) was the most commonly detected gene, both in absolute number and normalized to 16S-rRNA gene level, although tet(O), tet(Q) and tet(W) levels were also high in the mixed and high-use lagoons. Finally, resistance gene levels were highly seasonal with abundances being 10-100 times greater in the autumn versus the summer. Results show that antibiotic use strategy strongly affects both the abundance and seasonal distribution of resistance genes in associated lagoons, which has implications on water quality and feedlot management practices.

Response to immunocytokine (IC) therapy is dependent on natural killer cells in murine neuroblastoma (NBL) models. Furthermore, killer immunoglobulin-like receptor (KIR)/KIR-ligand mismatch is associated with improved outcome to autologous stem cell transplant for NBL. Additionally, clinical antitumor response to monoclonal antibodies has been associated with specific polymorphic-FcgR alleles. Relapsed/refractory NBL patients received the hu14.18-IL2 IC (humanized anti-GD2 monoclonal antibody linked to human IL2) in a Children's Oncology Group phase II trial. In this report, these patients were genotyped for KIR, HLA, and FcR alleles to determine whether KIR receptor-ligand mismatch or specific FcgR alleles were associated with antitumor response. DNA samples were available for 38 of 39 patients enrolled: 24 were found to have autologous KIR/KIR-ligand mismatch; 14 were matched. Of the 24 mismatched patients, 7 experienced either complete response or improvement of their disease after IC therapy. There was no response or comparable improvement of disease in patients who were matched. Thus KIR/KIR-ligand mismatch was associated with response/improvement to IC (P ¼ 0.03). There was a trend toward patients with the FcgR2A 131-H/H genotype showing a higher response rate than other FcgR2A genotypes (P ¼ 0.06). These analyses indicate that response or improvement of relapsed/refractory NBL patients after IC treatment is associated with autologous KIR/KIR-ligand mismatch, consistent with a role for natural killer cells in this clinical response. Cancer Res; 70(23); 9554-61. Ó2010 AACR.

Hypotonic stimulation induces airway constriction in normal and asthmatic airways. However, the osmolarity sensor in the airway has not been characterized. TRPV4 (also known as VR-OAC, VRL-2, TRP12, OTRPC4), an osmotic-sensitive cation channel in the transient receptor potential (TRP) channel family, was recently cloned. In the present study, we show that TRPV4 mRNA was expressed in cultured human airway smooth muscle cells as analyzed by RT-PCR. Hypotonic stimulation induced Ca2+influx in human airway smooth muscle cells in an osmolarity-dependent manner, consistent with the reported biological activity of TRPV4 in transfected cells. In cultured muscle cells, 4α-phorbol 12,13-didecanoate (4-αPDD), a TRPV4 ligand, increased intracellular Ca2+level only when Ca2+was present in the extracellular solution. The 4-αPDD-induced Ca2+response was inhibited by ruthenium red (1 μM), a known TRPV4 inhibitor, but not by capsazepine (1 μM), a TRPV1 antagonist, indicating that 4-αPDD-induced Ca2+response is mediated by TRPV4. Verapamil (10 μM), an L-type voltage-gated Ca2+channel inhibitor, had no effect on the 4-αPDD-induced Ca2+response, excluding the involvement of L-type Ca2+channels. Furthermore, hypotonic stimulation elicited smooth muscle contraction through a mechanism dependent on membrane Ca2+channels in both isolated human and guinea pig airways. Hypotonicity-induced airway contraction was not inhibited by the L-type Ca2+channel inhibitor nifedipine (1 μM) or by the TRPV1 inhibitor capsazepine (1 μM). We conclude that functional TRPV4 is expressed in human airway smooth muscle cells and may act as an osmolarity sensor in the airway.

A new real-time PCR method is presented that detects and quantifies three tetracycline resistance (Tc r ) genes [tet(O), tet(W), and tet(Q)] in mixed microbial communities resident in feedlot lagoon wastewater. Tc r gene real-time TaqMan primer-probe sets were developed and optimized to quantify the Tc r genes present in seven different cattle feedlot lagoons, to validate the method, and to assess whether resistance gene concentrations correlate with free-tetracycline levels in lagoon waters. The method proved to be sensitive across a wide range of gene concentrations and provided consistent and reproducible results from complex lagoon water samples. The log 10 of the sum of the three resistance gene concentrations was correlated with free-tetracycline levels (r 2 ‫؍‬ 0.50, P < 0.001; n ‫؍‬ 18), with the geometric means of individual resistance concentrations ranging from 4-to 8.3-fold greater in lagoon samples with above-median tetracycline levels (>1.95 g/liter by enzymelinked immunosorbent assay techniques) than in below-median lagoon samples. Of the three Tc r genes tested, tet(W) and tet(Q) were more commonly found in lagoon water samples. Successful development of this real-time PCR assay will permit other studies quantifying Tc r gene numbers in environmental and other samples.The tetracycline class of antibiotics is used frequently for the treatment and/or prevention of bacterial disease and for growth promotion in the cattle and swine industries (24, 25). For example, since the mid-1990s, more than 10 6 kg of tetracycline has been used per year in the U.S. livestock industry alone (9). There is growing evidence that such use of antibiotics for therapy, prophylaxis, and animal growth promotion may be resulting in the selection of resistant animal pathogens and commensals in the environment (reviewed by Chopra and Roberts [9] and Wegener [26]) because of the selection of tetracycline-resistant (Tc r ) strains in the rumina and intestines of exposed animals. A recent study on integrated livestock-fish farming indicated a significant increase in bacterial resistance to six antimicrobials in water-sediment samples from fish ponds exposed to manure from antibiotic-fed chickens (18). However, little quantitative information is available on the numbers of resistance genes in the environment.Phenotypic resistance testing of tetracycline and other antibiotics has been performed for years, although these methods tend to detect only resistance in culturable bacterial species and do not directly detect specific genes that confer the resistance. Previous studies have used nonquantitative PCR with Tc r gene-specific primers for the detection of tetracycline efflux genes (2, 5); however, such systems are not optimal for sensitive detection or for precise quantification. Therefore, a quantitative method for tracking resistance genes in environmental samples is needed to help determine whether antibacterial resistance in the environment is truly increasing because of anthropogenic practices.In this study, a new quantitat...