Targeting NKG2D ligands in glioblastoma with a bispecific T-cell engager is augmented with conventional therapy and enhances oncolytic virotherapy of glioma stem-like cells.

BACKGROUND: Glioblastoma (GBM) almost invariably becomes resistant towards conventional treatment of radiotherapy and temozolomide (TMZ) chemotherapy, partly due to subpopulations of intrinsically resistant glioma stem-like cells (GSC). The oncolytic herpes simplex virus-1 G207 is a promising approach for GBM virotherapy although its efficacy in patients with GBM is often limited. Natural killer group 2 member D ligands (NKG2DLs) are minimally expressed by healthy cells but are upregulated by the DNA damage response (DDR) and in malignant cells with chronic DDR signaling, resulting in innate immune activation. METHODS: We have designed a bispecific T-cell engager (BiTE) capable of cross-linking CD3 on T cells with NKG2DL-expressing GBM cells. We then engineered the G207 virus to express the NKG2D BiTE and secrete it from infected cells. The efficacy of the free BiTE and BiTE delivered by G207 was evaluated in combination with conventional therapies in GBM cells and against patient-derived GSCs in the context of T-cell activation and target cell viability. RESULTS: NKG2D BiTE-mediated cross-linking of GBM cells and T cells causes antigen-independent T-cell activation, pro-inflammatory cytokine release, and tumor cell death, thereby combining direct viral oncolysis with BiTE-mediated cytotoxicity. Surface NKG2DL expression was further elevated on GBM cells following pretreatment with sublethal doses of TMZ and radiation to induce the DDR, increasing sensitivity towards G207-NKG2D BiTE and achieving synergistic cytotoxicity. We also demonstrate a novel strategy for targeting GSCs that are non-permissive to G207 infection but remain sensitive to NKG2D BiTE. CONCLUSIONS: We propose a potential model for targeting GSCs in heterogeneous tumors, whereby differentiated GBM cells infected with G207-NKG2D BiTE produce NKG2D BiTE locally, directing T-cell cytotoxicity towards the GSC subpopulations in the tumor microenvironment.

Improving the outcomes for people with diabetes undergoing surgery: An observational study of the Improving the Peri-operative Pathway of People with Diabetes (IP3D) intervention.

AIMS: We evaluated the effectiveness of an intervention to improve the care of people with diabetes undergoing surgery when implemented across multiple organisations. METHODS: This was an observational study using routinely collected data. Eight hospitals in England implemented the Improving the Peri-operative Pathway of People with Diabetes (IP3D) intervention, with pre-implementation data collected from 1st February to 31st July 2019 and post-implementation data collection within the period 1st February to 31st October 2021. Key elements were the use of a patient empowering peri-operative passport and the employment of a peri-operative diabetes specialist nurse. The primary outcome was the change in length of stay. RESULTS: In total 1837 patients at pre-implementation and 1164 patients at post-implementation undergoing elective surgery were included. Pre- and post-implementation 23.8 % and 33.4 % of patients had day-case surgery respectively. For in-patients median length of stay decreased from 3.2 days (inter-quartile range 1.5-6.1) pre-implementation to 2.5 days (inter-quartile range 1.4-5.4) post-implementation. There were also significant improvements in patient experience, hypo- and hyper-glycaemic events, wound complications and diabetes related complications. CONCLUSIONS: The IP3D intervention has the potential to increase efficiency and reduce waiting lists for elective surgery on a nationwide basis.

Implied consent for HIV testing in the UK: time for a new approach?

Despite HIV infection being a treatable chronic illness and the many advances in testing for HIV, late diagnosis is still common, with associated avoidable morbidity and mortality. Requirements for explicit consent for HIV testing in the UK differ from those for other blood tests and are major barriers to testing. We argue that the disparity is illogical and outdated. We propose a model for normalising HIV testing that allows for routine testing in various health-care settings via implied consent, where other blood tests are performed. Inclusion of testing for hepatitis B and hepatitis C might also be incorporated into this model. The ethical argument for this approach is principally beneficence towards people with undiagnosed infection and the people they might infect. Patient autonomy would be maintained using systems allowing for individuals to opt out of implied consent.

Positional dependence of activity determination in single photon emission computed tomography.

Accurate image quantification requires accurate calibration of the detector and is vital if dosimetry is to be performed in molecular radiotherapy. A dependence on the position of calibration has been observed in single photon emission computed tomography images when attenuation correction (AC) and scatter correction are applied. This work investigates the origin of this dependence in single photon emission computed tomography scans of phantom inserts filled with Lu solution. A 113 ml sphere and inserts representing a mathematical model of a spleen and an anatomical model of a patient spleen were imaged at the centre and edge of elliptical phantoms. For these inserts, the difference in calibration factor between the positions was around 10% for images reconstructed with AC and triple energy window scatter correction. A combination of experimental imaging and Monte Carlo simulation was used to isolate possible causes due to imaging or reconstruction in turn. Inconsistent application of AC between different reconstruction systems was identified as the origin of the positional dependence.

Improving molecular radiotherapy dosimetry using anthropomorphic calibration.

The optimised delivery of Molecular Radiotherapy requires individualised calculation of absorbed dose to both targeted lesions and neighbouring healthy tissue. To achieve this, accurate quantification of the activity distribution in the patient by external detection is vital. METHODS: This work extends specific anatomy-related calibration to true organ shapes. A set of patient-specific 3D printed organ inserts based on a diagnostic CT scan was produced, comprising the liver, spleen and both kidneys. The inserts were used to calculate patient-specific calibration factors for 177Lu. These calibration factors were compared with previously reported calibration factors for corresponding organ models based on the Cristy and Eckerman phantom series and for a comparably sized sphere. Monte Carlo calculations of the patient-specific radiation dose were performed for comparison with current clinical dosimetry methods for these data. RESULTS: Patient-specific calibration factors are shown to be dependent on the volume, shape and position of the organ containing activity with a corresponding impact on the calculation of the dose to the patient. The impact of organ morphology on calculated dose is reduced when the dominant contributor to dose is beta particles. This is due to the small range of beta particles in tissue. Overestimations of recovered activity and hence dose of up to 135% are observed. CONCLUSION: For accurate quantification to be performed calibration factors accounting for organ size, shape and position must be used. Such quantification is vital if accurate, patient-specific dosimetry is to be achieved.

Organ-specific SPECT activity calibration using 3D printed phantoms for molecular radiotherapy dosimetry.

BACKGROUND: Patient-specific absorbed dose calculations for molecular radiotherapy require accurate activity quantification. This is commonly derived from Single-Photon Emission Computed Tomography (SPECT) imaging using a calibration factor relating detected counts to known activity in a phantom insert. METHODS: A series of phantom inserts, based on the mathematical models underlying many clinical dosimetry calculations, have been produced using 3D printing techniques. SPECT/CT data for the phantom inserts has been used to calculate new organ-specific calibration factors for (99m) Tc and (177)Lu. The measured calibration factors are compared to predicted values from calculations using a Gaussian kernel. RESULTS: Measured SPECT calibration factors for 3D printed organs display a clear dependence on organ shape for (99m) Tc and (177)Lu. The observed variation in calibration factor is reproduced using Gaussian kernel-based calculation over two orders of magnitude change in insert volume for (99m) Tc and (177)Lu. These new organ-specific calibration factors show a 24, 11 and 8 % reduction in absorbed dose for the liver, spleen and kidneys, respectively. CONCLUSIONS: Non-spherical calibration factors from 3D printed phantom inserts can significantly improve the accuracy of whole organ activity quantification for molecular radiotherapy, providing a crucial step towards individualised activity quantification and patient-specific dosimetry. 3D printed inserts are found to provide a cost effective and efficient way for clinical centres to access more realistic phantom data.

Loss of Th22 cells is associated with increased immune activation and IDO-1 activity in HIV-1 infection.

BACKGROUND: Immune activation plays a key role in the immunopathogenesis of HIV-1 infection. Microbial translocation, secondary to loss of epithelial integrity and mucosal immune deficiency, is believed to contribute to systemic immune activation. Interleukin 22 maintains intestinal epithelial barrier integrity and stimulates the secretion of antimicrobial peptides that limit bacterial dissemination and intestinal inflammation. Interleukin 22 is secreted by CD4 T-helper (Th)22 cells independently of interleukin 17A and interferon γ. Th22 cells are characterized by the expression of chemokine receptors (CCR)4, CCR6, and CCR10. METHODS: We analyzed the frequency of Th22, Th17, Th1, and CD4 T regulatory (Treg) cells, markers of immune activation (expression of CD38 on CD8 T cells, neopterin, soluble CD14), microbial translocation (lipopolysaccharide-binding protein and 16s ribosomal DNA), and indoleamine 2,3-dioxygenase 1 activity in peripheral blood of antiretroviral therapy (ART)-experienced and ART-naive HIV-1-infected patients and healthy controls. RESULTS: We showed a significant reduction in the frequency of Th22 cells in HIV ART-naive patients compared with the healthy controls and HIV ART-experienced patients. We observed a shift away from Th22 and Th17 to Treg cells, which was partially reversed by effective ART. Markers of immune activation negatively correlated with Th22 and Th17 proportions, and with Th22:Treg and Th17:Treg ratios in ART-naive patients. Increased indoleamine 2,3-dioxygenase 1 activity negatively correlated with Th22:Treg and Th17:Treg ratios in the ART-naive group. CONCLUSIONS: Loss of Th22 cells and disruption in the balance of Th22 and Treg cells may contribute toward systemic immune activation and mucosal immune deficiency during HIV-1 infection.