Microfluidic Squeezing Enables MHC Class I Antigen Presentation by Diverse Immune Cells to Elicit CD8+ T Cell Responses with Antitumor Activity.

CD8+ T cell responses are the foundation of the recent clinical success of immunotherapy in oncologic indications. Although checkpoint inhibitors have enhanced the activity of existing CD8+ T cell responses, therapeutic approaches to generate Ag-specific CD8+ T cell responses have had limited success. Here, we demonstrate that cytosolic delivery of Ag through microfluidic squeezing enables MHC class I presentation to CD8+ T cells by diverse cell types. In murine dendritic cells (DCs), squeezed DCs were ∼1000-fold more potent at eliciting CD8+ T cell responses than DCs cross-presenting the same amount of protein Ag. The approach also enabled engineering of less conventional APCs, such as T cells, for effective priming of CD8+ T cells in vitro and in vivo. Mixtures of immune cells, such as murine splenocytes, also elicited CD8+ T cell responses in vivo when squeezed with Ag. We demonstrate that squeezing enables effective MHC class I presentation by human DCs, T cells, B cells, and PBMCs and that, in clinical scale formats, the system can squeeze up to 2 billion cells per minute. Using the human papillomavirus 16 (HPV16) murine model, TC-1, we demonstrate that squeezed B cells, T cells, and unfractionated splenocytes elicit antitumor immunity and correlate with an influx of HPV-specific CD8+ T cells such that >80% of CD8s in the tumor were HPV specific. Together, these findings demonstrate the potential of cytosolic Ag delivery to drive robust CD8+ T cell responses and illustrate the potential for an autologous cell-based vaccine with minimal turnaround time for patients.

Investigating the Radiological Outcomes of Syndesmosis Injuries in Ankle Fracture Patients After Suture Button Fixation.

Concomitant syndesmotic injury occurs in 10% of ankle fractures. Anatomic reduction and maintenance of this reduction is critical in ensuring ankle stability and preventing long-term complications. This is a retrospective cohort study aimed at evaluating the mid-term radiological outcomes of syndesmotic injuries in ankle fracture patients after surgical fixation with suture button device. The study group included 33 patients. Plain radiographs including anteroposterior, lateral and mortise views of the affected ankle were performed preoperatively, postoperatively and at 3-month follow-up. Anteroposterior views were used to measure the amount of tibiofibular overlap and tibiofibular clear space. Paired Student's t test and linear model regression were performed. Between the immediate postoperative and 3-month follow-up period, there was a mean decrease in tibiofibular overlap of 0.841 (±2.07) mm (p = .0259). There was a mean increase in tibiofibular clear space of 0.621 (±1.46) mm (p = .0201). In addition, we found significant correlation between fracture type and change in tibiofibular clear space (p = .047). Our study showed that there is statistically significant widening of the syndesmosis after suture button fixation at 3-month follow-up as evidenced by reduced tibiofibular overlap and increase in tibiofibular clear space. However, they remain within the maximum threshold for acceptable syndesmotic widening of 1.5 mm. Further correlation between radiological outcomes and patient function is needed to determine clinical significance of these changes.

Radiographic grading of the patellofemoral joint is more accurate in skyline compared to lateral views.

BACKGROUND: The patellofemoral joint is perhaps the most commonly involved compartment in knee osteoarthritis (OA). Radiographic studies are routinely ordered and are seen as the first-line investigations for patellofemoral osteoarthritis (PFOA). The Kellgren-Lawrence (K&L) grading scale is often used to quantify the severity of radiographic OA. In this study, we aim to determine the correlation of the K&L grading scale on both the skyline and lateral views with arthroscopic visualization of articular cartilage damage. METHODS: All patients with clinical and radiographic features of PFOA who underwent knee arthroscopy by a single surgeon from 2006 to 2010 in our institution were reviewed. The study group consisted of 66 patients with PFOA. All patients had skyline and lateral radiographs of the knee taken before surgery. All patients had arthroscopic evidence of PFOA. Blinded investigators graded the radiographs according to the K&L grading scale. At arthroscopy, the patellofemoral joint was graded according to the Outerbridge classification. Correlation and statistical analysis of the radiographic and arthroscopic grade was carried out. RESULTS: The general trend shows that the higher the radiographic K&L grading, the greater the severity of articular cartilage degeneration on arthroscopy. However, an increasing K&L grade accounts for only 39.7% and 28.4% of the variation of severity of arthroscopically-determined articular cartilage degeneration on skyline and lateral views respectively. Interestingly, on both views, better correlation with arthroscopic findings was seen in early (K&L grades 1 and 2) PFOA. Skyline views were superior to lateral views in terms of specificity, PPV, NPV and accuracy in predicting early OA. CONCLUSIONS: Skyline radiographs are more accurate than lateral radiographs in prediction of severity of PFOA.