Citations

Abstract A human IgM Ab, serum-derived human IgM 12 (sHIgM12), is identified that binds mouse and human dendritic cells (DC), inducing dramatic immunopotentiation following treatment of the mouse DC in vitro. Competition, transfection, and knockout studies identified the ligand on mouse DC as the costimulatory molecule family member B7-DC. Potent T cell responses are stimulated by Ag-pulsed DC treated with the sHIgM12 Ab in vitro and upon adoptive transfer of Ab-treated Ag-pulsed DC into animals. The multivalent structure of pentameric IgM provides the potential for cross-linking cell surface targets, endowing the soluble Abs with biological potential not normally associated with immune function. The ability of the sHIgM12 Ab to potentiate the immune response is dependent on the multimeric structure of IgM, as bivalent monomers do not retain this property. Furthermore, pretreatment of DC with IgM monomers blocks subsequent potentiation by intact IgM pentamers, an indication that cross-linking of B7-DC on the cell surface is critical for potentiation of Ag presentation. These findings imply that, in addition to known costimulatory roles, B7-DC can function as a receptor for signals delivered by cells expressing B7-DC ligands.

Abstract Cross-linking cell surface molecules with IgM Abs is a specific approach for activating cells in vitro or in vivo. Dendritic cells (DC) activated with a human B7-DC (PD-L2)-specific IgM Ab can induce strong antitumor responses and block inflammatory airway disease in experimental models, yet the Ab-mediated molecular events promoting these responses remain unclear. Analysis of human or mouse DC treated with the B7-DC cross-linking Ab revealed PI3K-dependent phosphorylation of AKT accompanied by mobilization of NF-κB. Ab-activated DC up-regulated expression of cytokine and chemokine genes in an NF-κB-dependent manner. Importantly, PI3K→AKT→NF-κB activation was found to be indispensable for B7-DC cross-linking Ab-mediated protection of DC from cell death caused by cytokine withdrawal. Although other DC activators similarly protect DC from cell death, a synergy between cross-linking B7-DC and ligating RANK was observed. The parallel signaling events induced in human and mouse DC demonstrate that activation of cells using IgM Ab results in a response governed by a common mechanism and support the hypothesis that B7-DC cross-linking using this Ab may provide beneficial therapeutic immune modulation in human patients similar to those seen in animal models.

Abstract The activation of T cells and the initiation of an immune response is tightly controlled through the crosstalk of both positive and negative regulators. Two adaptors that function as negative regulators of T cell activation are adaptor in lymphocytes of unknown function X (ALX) and linker for activation of X cell (LAX). Previously, we showed that T cells from mice deficient in ALX and LAX display similar hyperresponsiveness, with increased IL-2 production and proliferation upon TCR/CD28 stimulation, and that these adaptors physically associate. In this study, we analyze the nature of the association between ALX and LAX. We demonstrate that this association occurs in the absence of TCR/CD28 signaling via a mechanism independent of both tyrosine phosphorylation of LAX and the SH2 domain of ALX. Cotransfection of ALX with LAX resulted in LAX tyrosine phosphorylation in the absence of TCR/CD28 stimulation. ALX-mediated LAX phosphorylation depends upon the ALX SH2 domain, which functions to recruit Lck to LAX. We also show that LAX, like ALX, can inhibit RE/AP reporter activation. However, in contrast to its inhibition of NFAT, the inhibition of RE/AP by LAX is independent of its tyrosine phosphorylation. Therefore, it can be concluded that inhibition of signaling events involved in T cell activation by LAX occurs through mechanisms both dependent on and independent of its tyrosine phosphorylation.

ABSTRACT Piperacillin-tazobactam (PTZ) is known to cause false-positive results in the Platelia Aspergillus enzyme-linked immunoassay (EIA), due to contamination with galactomannan (GM). We tested 32 lots of PTZ and 27 serum specimens from patients receiving PTZ. GM was not detected in the lots of PTZ; one serum specimen (3.7%) was positive. PTZ formulations commonly used in the United States today appear to be a rare cause for false-positive GM results.

Background: Nearly 90% of the children with heart disease in low- and middle-income countries (LMICs) cannot access cardiovascular (CV) services. Limitations include inadequate financial, human, and infrastructure resources. Nongovernmental organizations (NGOs) have played crucial roles in providing clinical services and infrastructure supports to LMICs CV programs; however, these outreach efforts are dispersed, inadequate, and lack coordination. Methods: A survey was sent to members of the World Society for Pediatric and Congenital Heart Society and PediHeart. Results: A clearinghouse was created to provide information on NGO structures, geographic reach, and scope of services. The survey identified 80 NGOs supporting CV programs in 92 LMICs. The largest outreach efforts were in South and Central America (42%), followed by Africa (18%), Europe (17%), Asia (17%), and Asia-Western Pacific (6%). Most NGOs (51%) supported two to five outreach missions per year. The majority (87%) of NGOs provided education, diagnostics, and surgical or catheter-based interventions. Working jointly with LMIC partners, 59% of the NGOs performed operations in children and infants; 41% performed nonbypass neonatal operations. Approximately a quarter (26%) reported that partner sites do not perform interventions in between missions. Conclusions: Disparity and inadequacy in pediatric CV services remain an important problem for LMICs. A global consensus and coordinated efforts are needed to guide strategies on the development of regional centers of excellence, a global outcome database, and a CV program registry. Future efforts should be held accountable for impacts such as growth in the number of independent LMIC programs as well as reduction in mortality and patient waiting lists.

BACKGROUNDTo ensure that National Institutes of Health‐funded research is relevant to the population's needs, specific emphasis on proportional representation of minority/sex groups into National Cancer Institute (NCI) cancer centers' clinical research programs is reported to the NCI.METHODSEMPaCT investigators at 5 regionally diverse comprehensive cancer centers compared data reported to the NCI for their most recent Cancer Center Support Grant competitive renewal to assess and compare the centers' catchment area designations, data definitions, data elements, collection processes, reporting, and performance regarding proportional representation of race/ethnicity and sex subsets.RESULTSCancer centers' catchment area definitions differed widely in terms of their cancer patient versus general population specificity, levels of specificity, and geographic coverage. Racial/ethnic categories were similar, yet were defined differently, across institutions. Patients' socioeconomic status and insurance status were inconsistently captured across the 5 centers.CONCLUSIONSCatchment area definitions and the collection of patient‐level demographic factors varied widely across the 5 comprehensive cancer centers. This challenged the assessment of success by cancer centers in accruing representative populations into the cancer research enterprise. Accrual of minorities was less than desired for at least 1 racial/ethnic subcategory at 4 of the 5 centers. Institutions should clearly and consistently declare their primary catchment area and the rationale and should report how race/ethnicity and sex are defined, determined, collected, and reported. More standardized, frequent, consistent collection, reporting, and review of these data are recommended, as is a commitment to collecting socioeconomic data, given that socioeconomic status is a primary driver of cancer disparities in the United States. Cancer 2014;120(7 suppl):1113–21. © 2014 American Cancer Society.

BackgroundFewer than 5 % of cancer patients participate in clinical research. Although this paltry rate has led to extensive research on this topic, previous studies have not sought verbatim comments in a real‐time, comprehensive manner to understand why patients decline.MethodsThis study used a low‐risk, non‐interventional parent study that focused on cancer‐associated weight loss to understand patients' reasons for declining research participation. A research assistant wrote down the name and verbatim reason of all patients who declined to participate. These comments with accompanying patient demographic data are the subject of this report.ResultsOf the 334 patients, 51 (15 %) declined parent study enrollment; three comment‐related themes emerged: (1) a repelling sense of too much institutional research, (2) overwhelming personal health issues, and (3) a low likelihood of returning to the institution. In univariate and multivariate analyses, only age (older) and gender (female) were associated with non‐enrollment. Interestingly, 41 patients with fatigue scores of 7 or worse and 26 with pain scores of 7 or worse were enrolled.ConclusionsAlthough many factors were associated with declining to participate in research, symptom severity was not. Upfront education might help cancer patients better prioritize their participation in research, particularly as some patients felt overwhelmed by too much research in the institution; and for now, investigators should continue to keep asking patients for their participation.

BACKGROUNDSince 2002, priority Model for End‐stage Liver Disease (MELD) exception status has been given to patients with hepatocellular carcinoma (HCC) who meet the Milan criteria. Since then, the number of liver transplantations performed in patients with HCC has increased, but to the authors' knowledge, few studies to date have examined the effect of MELD exception recommendations on therapy use and survival rates in a nationwide sample. The current study examines therapy use and long‐term survival rates among patients with HCC tumors meeting the Milan criteria in the post‐MELD exception era.METHODSThe current study is a retrospective cohort study of 2179 patients with localized HCC meeting the Milan criteria who were registered between 2004 and 2007 in the Surveillance, Epidemiology, and End Results database.RESULTSA total of 43% of patients did not receive any specific therapy. Overall, the 5‐year relative survival rate for patients receiving only supportive care was dismal at 24% (95% confidence interval [95% CI], 21%‐27%), whereas that for patients undergoing liver transplantation was 77% (95% CI, 71%‐82%). Long‐term survival was found to be dependent on age, race/ethnicity, and type of therapy received. A multivariate Cox proportional hazards model adjusted for age, race/ethnicity, and type of therapy received demonstrated that, compared with white patients, black patients had significantly poorer survival outcomes (hazards ratio, 1.23; 95% CI, 1.03‐1.47 [P = .02]), whereas Asian/Pacific Islander patients had significantly better survival rates when compared with white patients (HR, 0.66; 95% CI, 0.57‐0.77 [P < .001]).CONCLUSIONSDespite having localized disease that met transplantation criteria, nearly 50% of the large nationwide cohort of patients with HCC in the current study received only supportive care and had dismal 5‐year relative survival rates, especially among black patients. Cancer 2014;120:1725–1732. © 2014 American Cancer Society.