Anti-tumor immunotherapy via antigen delivery from a live attenuated genetically engineered Pseudomonas aeruginosa type III secretion system-based vector.

Immunotherapy requiring an efficient T lymphocyte response is initiated by antigen delivery to antigen-presenting cells. Several studies have assessed the efficiency of various antigen loading procedures, including microbial vectors. Here a live strain of Pseudomonas aeruginosa was engineered to translocate a recombinant antigenic protein into mammalian cells via the type III secretion system, a bacterial device translocating effector proteins into host cells. Optimization of the vector included virulence attenuation and determination of the N-terminal sequence allowing translocation of fused antigens into cells. In vitro delivery of an ovalbumin fragment by the bacterial vector into dendritic cells induced the activation of ovalbumin-specific CD8(+) T lymphocytes. Mice injected with the ovalbumin-delivering vector developed ovalbumin-specific CD8(+) T lymphocytes and were resistant to a subsequent challenge with an ovalbumin-expressing melanoma. Moreover, in a curative assay, injection of the vaccine vector 5 and 12 days after tumor implantation led to a complete cure in five of six animals. These results highlight the utility of type III secretion system-based vectors for anti-tumor immunotherapy.     

Osteoarthritic human chondrocytes proliferate in 3D co‐culture with mesenchymal stem cells in suspension bioreactors

Osteoarthritis (OA) is a painful disease, characterized by progressive surface erosion of articular cartilage. The use of human articular chondrocytes (hACs) sourced from OA patients has been proposed as a potential therapy for cartilage repair, but this approach is limited by the lack of scalable methods to produce clinically relevant quantities of cartilage‐generating cells. Previous studies in static culture have shown that hACs co‐cultured with human mesenchymal stem cells (hMSCs) as 3D pellets can upregulate proliferation and generate neocartilage with enhanced functional matrix formation relative to that produced from either cell type alone. However, because static culture flasks are not readily amenable to scale up, scalable suspension bioreactors were investigated to determine if they could support the co‐culture of hMSCs and OA hACs under serum‐free conditions to facilitate clinical translation of this approach. When hACs and hMSCs (1:3 ratio) were inoculated at 20,000 cells/ml into 125‐ml suspension bioreactors and fed weekly, they spontaneously formed 3D aggregates and proliferated, resulting in a 4.75‐fold increase over 16 days. Whereas the apparent growth rate was lower than that achieved during co‐culture as a 2D monolayer in static culture flasks, bioreactor co‐culture as 3D aggregates resulted in a significantly lower collagen I to II mRNA expression ratio and more than double the glycosaminoglycan/DNA content (5.8 vs. 2.5 μg/μg). The proliferation of hMSCs and hACs as 3D aggregates in serum‐free suspension culture demonstrates that scalable bioreactors represent an accessible platform capable of supporting the generation of clinical quantities of cells for use in cell‐based cartilage repair.     

Application of the ISTH bleeding score in hemophilia

Background

Hemophilia is an inherited bleeding disorder. With proper treatment and self-care, persons with hemophilia can maintain an active, productive lifestyle. Hemophilia can be mild, moderate, or severe, depending on the degree of plasma clotting factor deficiency. The aim of the study was to assess the utility of ISTH-BAT in diagnosis, determining severity of the bleeding condition in newly diagnosed and known hemophilia patients, compare the bleeding score (BS) in adult and pediatric groups and investigate its association with plasma factor levels.

Outcomes of COVID-19 Complications and their Possibilities as Potential Triggers of Stroke

IntroductionThere is limited literature on coronavirus disease 2019 (COVID -19) complications such as thromboembolism, cardiac complications etc. as possible trigger for stroke. Hence, we aim to evaluate the prevalence and outcomes of COVID-19 related cardiovascular complications and secondary infection and their possibility as potential triggers for the stroke.MethodsData from observational studies describing the complications [acute cardiac injury (ACI), cardiac arrhythmias (CA), disseminated intravascular coagulation (DIC), septic shock, secondary infection] and outcomes of COVID‐19 hospitalized patients from December 1, 2019 to June 30, 2020, were extracted following PRISMA guidelines. Adverse outcomes defined as intensive care units, oxygen saturation less than 90%, invasive mechanical ventilation, severe disease, and in‐hospital mortality. The odds ratio and 95% confidence interval were obtained, and forest plots were created using random‐effects models. A short review of these complications as triggers of stroke was conducted.Results16 studies with 3480 confirmed COVID-19 patients, prevalence of ACI [38%vs5.9%], CA [26%vs5.3%], DIC [4%vs0.74%], septic shock [18%vs0.36%], and infection [30%vs12.5%] was higher among patients with poor outcomes. In meta-analysis, ACI [aOR:9.93(95%CI:3.95–25.00], CA [7.52(3.29–17.18)], DIC [7.36(1.24–43.73)], septic shock [30.12(7.56–120.10)], and infection [10.41(4.47–24.27)] had higher odds of adverse outcomes. Patients hospitalized with acute ischemic stroke and intracerebral hemorrhage, had complications like pulmonary embolism, venous thromboembolism, DIC, etc. and had poor outcomesConclusionThe complications like acute cardiac injury, cardiac arrhythmias, DIC, septic shock, and secondary infection had poor outcomes. Patients with stroke were having history of these complications. Long term monitoring is required in such patients to prevent stroke and mitigate adverse outcomes.