Siglec-9 defines and restrains a natural killer subpopulation highly cytotoxic to HIV-infected cells.

Siglec-9 is an MHC-independent inhibitory receptor expressed on a subset of natural killer (NK) cells. Siglec-9 restrains NK cytotoxicity by binding to sialoglycans (sialic acid-containing glycans) on target cells. Despite the importance of Siglec-9 interactions in tumor immune evasion, their role as an immune evasion mechanism during HIV infection has not been investigated. Using in vivo phenotypic analyses, we found that Siglec-9+ CD56dim NK cells, during HIV infection, exhibit an activated phenotype with higher expression of activating receptors and markers (NKp30, CD38, CD16, DNAM-1, perforin) and lower expression of the inhibitory receptor NKG2A, compared to Siglec-9- CD56dim NK cells. We also found that levels of Siglec-9+ CD56dim NK cells inversely correlate with viral load during viremic infection and CD4+ T cell-associated HIV DNA during suppressed infection. Using in vitro cytotoxicity assays, we confirmed that Siglec-9+ NK cells exhibit higher cytotoxicity towards HIV-infected cells compared to Siglec-9- NK cells. These data are consistent with the notion that Siglec-9+ NK cells are highly cytotoxic against HIV-infected cells. However, blocking Siglec-9 enhanced NK cells' ability to lyse HIV-infected cells, consistent with the known inhibitory function of the Siglec-9 molecule. Together, these data support a model in which the Siglec-9+ CD56dim NK subpopulation is highly cytotoxic against HIV-infected cells even whilst being restrained by the inhibitory effects of Siglec-9. To harness the cytotoxic capacity of the Siglec-9+ NK subpopulation, which is dampened by Siglec-9, we developed a proof-of-concept approach to selectively disrupt Siglec/sialoglycan interactions between NK and HIV-infected cells. We achieved this goal by conjugating Sialidase to several HIV broadly neutralizing antibodies. These conjugates selectively desialylated HIV-infected cells and enhanced NK cells' capacity to kill them. In summary, we identified a novel, glycan-based interaction that may contribute to HIV-infected cells' ability to evade NK immunosurveillance and developed an approach to break this interaction.

Pregnancy and Childbirth After Spinal Fusion for Adolescent Idiopathic Scoliosis.

BACKGROUND: Little data exist on pregnancy and childbirth for adolescent idiopathic scoliosis (AIS) patients treated with a spinal fusion. The current literature relies on data from patients treated with spinal fusion techniques and instrumentation, such as Harrington rods, that are no longer in use. The objective of our study is to understand the effects of spinal fusion in adolescence on pregnancy and childbirth. METHODS: Prospectively collected data of AIS patients undergoing posterior spinal fusion that were enrolled in a multicenter study who have had a pregnancy and childbirth were reviewed. Results were summarized using descriptive statistics and compared with national averages using χ 2 test of independence. RESULTS: A total of 78 babies were born to 53 AIS patients. As part of their pre-natal care, 24% of patients surveyed reported meeting with an anesthesiologist before delivery. The most common types of delivery were spontaneous vaginal delivery (46%, n=36/78) and planned cesarean section (20%, n=16/78). Compared with the national average, study patients had a higher rate of cesarean delivery ( P =0.021). Of the women who had a spontaneous vaginal birth, 53% had no anesthesia (n=19/36), 19% received intravenous intermittent opioids (n=7/36), and 31% had regional spinal or epidural anesthesia (n=11/36). spontaneous vaginal delivery patients in our study cohort received epidural or spinal anesthesia less frequently than the national average ( P <0.001). Of those (n=26 pregnancies) who did not have regional anesthesia (patients who had no anesthesia or utilized IV intermittent opioids), 19% (n=5 pregnancies) were told by their perinatal providers that it was precluded by previous spine surgery. CONCLUSION: The majority of AIS patients reported not meeting with an anesthesiologist before giving birth and those who had a planned C-section did so under obstetrician recommendation. The presence of instrumentation after spinal fusion should be avoided with attempted access to the spinal canal but should not dictate a delivery plan. A multidisciplinary team consisting of obstetrician, anesthesiologist, and orthopaedic surgeon can provide the most comprehensive information to empower a patient to make her decisions regarding birth experience anesthesia based on maternal rather than provider preference. LEVEL OF EVIDENCE: IV.

Development and evaluation of a community of practice to improve stem cell donor recruitment in Canada.

Background and Objectives Communities of practice (CoPs) represent effective models to achieve quality outcomes in health care. We report the development and evaluation of a CoP to improve stem cell donor recruitment in Canada. Materials and Methods In September 2017, we invited national stakeholders in stem cell donor recruitment to participate in a Facebook group and regular e-meetings. E-meetings involved speakers and roundtable discussion on topics related to donor recruitment. The Facebook group facilitated sharing of resources. We evaluated stakeholder perspective of the CoP and the impact on recruitment outcomes. Results As of December 2020, the CoP included 382 members who published 243 posts to the Facebook group about patient/donor stories (40%), resources (27%), updates/questions (21%) and recruitment outcomes (12%). In January 2020, we surveyed 44 CoP participants; the majority felt that the Facebook group (86%) and e-meetings (59%) supported the community, and that the CoP fostered collaboration (82%), improved their donor recruitment knowledge (75%) and practice (77%) and improved their ability to recruit needed donors (64%). The launch of the CoP correlated with improved donor recruitment outcomes. In 2016-2017, CoP participants recruited 2918 registrants (46% male; 55.9% non-Caucasian) compared to 4531 registrants in 2018-2019 (52.9% male; 62.7% non-Caucasian). Members of the CoP developed innovative resources to support recruitment efforts and led national campaigns securing coverage in major media outlets. Conclusion We describe the first CoP in stem cell donor recruitment to be formally evaluated. The CoP model may be adopted by donor recruitment organisations, registries and blood banks worldwide to improve recruitment outcomes. HIGHLIGHTS: • A community of practice (CoP) in stem cell donor recruitment was valued by participants and supported efforts to improve recruitment outcomes. • The CoP model may be adopted by donor recruitment organizations, donor registries, and blood banks worldwide to improve recruitment outcomes.

Standardizing evaluation of patient-specific 3D printed models in surgical planning: development of a cross-disciplinary survey tool for physician and trainee feedback.

BACKGROUND: 3D printed models are becoming increasingly popular in healthcare as visual and tactile tools to enhance understanding of anatomy and pathology in medical trainee education, provide procedural simulation training, and guide surgical procedures. Patient-specific 3D models are currently being used preoperatively for trainee medical education in planning surgical approaches and intraoperatively to guide decision-making in several specialties. Our study group utilized a modified Delphi process to create a standardized assessment for trainees using patient-specific 3D models as a tool in medical education during pre-surgical planning. METHODS: A literature review was conducted to identify survey questions administered to clinicians in published surgical planning studies regarding the use of patient-specific 3D models. A core study team reviewed these questions, removed duplicates, categorized them, mapped them to overarching themes, and, where applicable, modified individual questions into a form generalizable across surgical specialties. The core study panel included a physician, physician-scientist, social scientist, engineer/medical student, and 3D printing lab manager. A modified Delphi process was then used to solicit feedback on the clarity and relevance of the individual questions from an expert panel consisting of 12 physicians from specialties including anesthesiology, emergency medicine, radiology, urology, otolaryngology, and obstetrics/gynecology. When the Radiological Society of North America (RSNA)/American College of Radiology (ACR) 3D Printing Registry Data Dictionary was released, additional survey questions were reviewed. A final cross-disciplinary survey of the utility of 3D printed models in surgical planning medical education was developed. RESULTS: The literature review identified 100 questions previously published in surveys assessing patient-specific 3D models for surgical planning. Following the review, generalization, and mapping of survey questions from these studies, a list of 24 questions was generated for review by the expert study team. Five additional questions were identified in the RSNA/ACR 3D Printing Registry Data Dictionary and included for review. A final questionnaire consisting of 20 questions was developed. CONCLUSIONS: As 3D printed models become more common in medical education, the need for standardized assessment is increasingly essential. The standardized questionnaire developed in this study reflects the interests of a variety of stakeholders in patient-specific 3D models across disciplines.

Protease-Activatable Adeno-Associated Virus Vector for Gene Delivery to Damaged Heart Tissue.

Adeno-associated virus (AAV) has emerged as a promising gene delivery vector because of its non-pathogenicity, simple structure and genome, and low immunogenicity compared to other viruses. However, its adoption as a safe and effective delivery vector for certain diseases relies on altering its tropism to deliver transgenes to desired cell populations. To this end, we have developed a protease-activatable AAV vector, named provector, that responds to elevated extracellular protease activity commonly found in diseased tissue microenvironments. The AAV9-based provector is initially inactive, but then it can be switched on by matrix metalloproteinases (MMP)-2 and -9. Cryo-electron microscopy and image reconstruction reveal that the provector capsid is structurally similar to that of AAV9, with a flexible peptide insertion at the top of the 3-fold protrusions. In an in vivo model of myocardial infarction (MI), the provector is able to deliver transgenes site specifically to high-MMP-activity regions of the damaged heart, with concomitant decreased delivery to many off-target organs, including the liver. The AAV provector may be useful in the future for enhanced delivery of transgenes to sites of cardiac damage.

Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow.

The first example of photocatalytic trifluoromethoxylation of arenes and heteroarenes under continuous-flow conditions is described. Application of continuous-flow microreactor technology allowed to reduce the residence time up to 16 times in comparison to the batch procedure, while achieving similar or higher yields. In addition, the use of inorganic bases was demonstrated to increase the reaction yield under batch conditions.

A pipeline for rapidly generating genetically engineered mouse models of pancreatic cancer using in vivo CRISPR-Cas9-mediated somatic recombination.

Genetically engineered mouse models (GEMMs) that recapitulate the major genetic drivers in pancreatic ductal adenocarcinoma (PDAC) have provided unprecedented insights into the pathogenesis of this lethal neoplasm. Nonetheless, generating an autochthonous model is an expensive, time consuming and labor intensive process, particularly when tissue specific expression or deletion of compound alleles are involved. In addition, many of the current PDAC GEMMs cause embryonic, pancreas-wide activation or loss of driver alleles, neither of which reflects the cognate human disease scenario. The advent of CRISPR/Cas9 based gene editing can potentially circumvent many of the aforementioned shortcomings of conventional breeding schema, but ensuring the efficiency of gene editing in vivo remains a challenge. Here we have developed a pipeline for generating PDAC GEMMs of complex genotypes with high efficiency using a single "workhorse" mouse strain expressing Cas9 in the adult pancreas under a p48 promoter. Using adeno-associated virus (AAV) mediated delivery of multiplexed guide RNAs (sgRNAs) to the adult murine pancreas of p48-Cre; LSL-Cas9 mice, we confirm our ability to express an oncogenic Kras G12D allele through homology-directed repair (HDR), in conjunction with CRISPR-induced disruption of cooperating alleles (Trp53, Lkb1 and Arid1A). The resulting GEMMs demonstrate a spectrum of precursor lesions (pancreatic intraepithelial neoplasia [PanIN] or Intraductal papillary mucinous neoplasm [IPMN] with eventual progression to PDAC. Next generation sequencing of the resulting murine PDAC confirms HDR of oncogenic KrasG12D allele at the endogenous locus, and insertion deletion ("indel") and frameshift mutations of targeted tumor suppressor alleles. By using a single "workhorse" mouse strain and optimal AAV serotype for in vivo gene editing with combination of driver alleles, we present a facile autochthonous platform for interrogation of the PDAC genome.

Correction of the sickle cell disease mutation in human hematopoietic stem/progenitor cells.

Sickle cell disease (SCD) is characterized by a single point mutation in the seventh codon of the ß-globin gene. Site-specific correction of the sickle mutation in hematopoietic stem cells would allow for permanent production of normal red blood cells. Using zinc-finger nucleases (ZFNs) designed to flank the sickle mutation, we demonstrate efficient targeted cleavage at the ß-globin locus with minimal off-target modification. By co-delivering a homologous donor template (either an integrase-defective lentiviral vector or a DNA oligonucleotide), high levels of gene modification were achieved in CD34(+) hematopoietic stem and progenitor cells. Modified cells maintained their ability to engraft NOD/SCID/IL2rγ(null) mice and to produce cells from multiple lineages, although with a reduction in the modification levels relative to the in vitro samples. Importantly, ZFN-driven gene correction in CD34(+) cells from the bone marrow of patients with SCD resulted in the production of wild-type hemoglobin tetramers.

CRISPR/Cas9-Mediated Correction of the Sickle Mutation in Human CD34+ cells.

Targeted genome editing technology can correct the sickle cell disease mutation of the ß-globin gene in hematopoietic stem cells. This correction supports production of red blood cells that synthesize normal hemoglobin proteins. Here, we demonstrate that Transcription Activator-Like Effector Nucleases (TALENs) and the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 nuclease system can target DNA sequences around the sickle-cell mutation in the ß-globin gene for site-specific cleavage and facilitate precise correction when a homologous donor template is codelivered. Several pairs of TALENs and multiple CRISPR guide RNAs were evaluated for both on-target and off-target cleavage rates. Delivery of the CRISPR/Cas9 components to CD34+ cells led to over 18% gene modification in vitro. Additionally, we demonstrate the correction of the sickle cell disease mutation in bone marrow derived CD34+ hematopoietic stem and progenitor cells from sickle cell disease patients, leading to the production of wild-type hemoglobin. These results demonstrate correction of the sickle mutation in patient-derived CD34+ cells using CRISPR/Cas9 technology.

Endovascular repair of an asymptomatic aortic pseudoaneurysm after penetrating injury.

Penetrating injuries to the aorta usually result in immediate life-threatening hemorrhage. Because these lesions are typically either fatal or identified and controlled surgically, chronic pseudoaneurysms after penetrating aortic trauma are rare. Most of these patients present with rupture or local complications, and management before the endovascular era has historically been open repair. As such, there are limited data to guide the modern management of an asymptomatic, posttraumatic aortic pseudoaneurysm. Here, we describe a 54-year-old man who was diagnosed with an incidental, supraceliac aortic pseudoaneurysm 14 years after an abdominal stab wound. He underwent successful and uncomplicated endovascular repair.

Flipping the script: A multiyear assessment and comparison of flipped classroom versus traditional didactic teaching at two academic institutions.

RATIONALE AND OBJECTIVES: Historically radiology resident education has taken the form of workstation and didactic teaching. Due to increasing clinical demand and administrative burden for academic radiologists, the need for more efficient and effective teaching has increased. Flipped classroom teaching, where trainees independently learn material prior to interactive teaching sessions with faculty, is a possible alternative. While the use of flipped teaching in radiology has been studied in the medical student setting, its use in the radiology residency setting has been less published. MATERIALS AND METHODS: At two academic institutions (University of Washington and Northwestern), exam scores from five PGY-2 Core rotations were collected. Flipped teaching was used for one rotation at the University of Washington (FR). The influence of teaching method, rotation, and institution on exam score was examined. Resident surveys were also collected to understand perceptions of flipped classroom teaching. RESULTS: At the University of Washington, the mean exam score for the flipped rotation was significantly higher than the majority of other rotations utilizing traditional teaching (p<0.05). Between the University of Washington and Northwestern, there was no difference in exam scores when comparing comparable rotations. Among residents at the University of Washington, the flipped teaching rotation was perceived as more educationally valuable than traditional teaching rotations. CONCLUSION: Flipped classroom teaching is at least as effective as the traditional teaching model and associated with better performance on standardized exams at one institution. Among residents, flipped learning is also associated with higher perceived educational value.

Development of a Survey Tool: Understanding the Patient Experience With Personalized 3D Models in Surgical Patient Education.

BACKGROUND: Three-dimensional (3D) printing has been increasingly utilized in the healthcare sector for many applications including guiding surgical procedures, creating medical devices, and producing custom prosthetics. As personalized medicine becomes more accessible and desired, 3D printed models emerge as a potential tool in providing patient-specific education. These personalized 3D models are at the intersection of technological innovation and medical education. Our study group utilized a modified Delphi process to create a comprehensive survey tool assessing patient experience with personalized 3D models in preoperative education. METHODS: A rigorous literature review was conducted of prior patient education survey tools in surgical cases across specialties involving personalized 3D printed models. Through categorization and mapping, a core study team reviewed individual questions, removed duplicates, and edited them into generalizable form. A modified Delphi process was then used to solicit feedback on question clarity and relevance from both 3D printing healthcare experts and patients to create a final survey.  Results: 173 survey questions from the literature were evaluated by the core study team, yielding 31 unique questions for further review. After multiple rounds of feedback, a final survey containing 18 questions was developed.  Conclusion: 3D printed models have the potential to be helpful tools in surgical patient education, and there exists a need to standardize the assessment of patient experience with these models. This survey provides a standardized, generalizable way to investigate the patient experience with personalized 3D-printed models.

The use of individualized 3D-printed models on trainee and patient education, and surgical planning for robotic partial nephrectomies.

3D printing is a growing tool in surgical education to visualize and teach complex procedures. Previous studies demonstrating the usefulness of 3D models as teaching tools for partial nephrectomy used highly detailed models costing between $250 and 1000. We aimed to create thorough, inexpensive 3D models to accelerate learning for trainees and increase health literacy in patients. Patient-specific, cost-effective ($30-50) 3D models of the affected urologic structures were created using pre-operative imaging of 40 patients undergoing partial nephrectomy at Thomas Jefferson University Hospital (TJUH) between July 2020 and May 2021. Patients undergoing surgery filled out a survey before and after seeing the model to assess patient understanding of their kidney, pathophysiology, surgical procedure, and risks of surgery. Three urological residents, one fellow, and six attendings filled out separate surveys to assess their surgical plan and confidence before and after seeing the model. In a third survey, they ranked how much the model helped their comprehension and confidence during surgery. Patient understanding of all four subjects significantly improved after seeing the 3D model (P < 0.001). The urology residents (P < 0.001) and fellow (P < 0.001) reported significantly increased self-confidence after interacting with the model. Attending surgeon confidence increased significantly after seeing the 3D model (P < 0.01) as well. Cost-effective 3D models are effective learning tools and assist with the evaluation of patients presenting with renal masses, and increase patient, resident, and fellow understanding in partial nephrectomies. Further research should continue to explore the utility of inexpensive models in other urologic procedures.

The prognostic impact of t(11;14) in multiple myeloma: A real-world analysis from the Australian Lymphoma Leukaemia Group (ALLG) and the Australian Myeloma and Related Diseases Registry (MRDR).

The prognostic impact of t(11;14) in multiple myeloma (MM) needs to be better understood to inform future treatment decisions. The Australian Lymphoma Leukaemia Group embarked on a retrospective, observational cohort study using real-world data to interrogate treatment patterns and outcomes in 74 MM patients with t(11;14) [t(11;14)-MM] diagnosed over 10 years. This was compared to 159 and 111 MM patients with high-risk IgH translocations (IgH HR-MM) and hyperdiploidy (Hyperdiploid-MM), respectively, from the Australian Myeloma and Related Diseases Registry. No appreciable differences in age, gender, ISS, LDH levels, 1q21 or del(17p) status, or treatment patterns were observed between groups. Median PFS-1 was not different between groups but both t(11;14)-MM and IgH HR-MM had an inferior PFS-2 vs. Hyperdiploid-MM: median PFS-2 8.2 months, 10.0 months, and 19.8 months (p = 0.002), respectively. The 3-year OS were 69%, 71%, and 82% (p = 0.026), respectively. In the t(11;14)-MM group, gain or amplification of 1q21 at diagnosis predicted for poorer OS (HR 3.46, p = 0.002). Eleven patients had received venetoclax with 45% achieving better than a very good partial response. Results suggest that t(11;14) MM may confer an unfavorable risk profile and that the use of targeted therapies such as venetoclax earlier in the treatment algorithm should be explored.

From the ground up: understanding the developing infrastructure and resources of 3D printing facilities in hospital-based settings.

BACKGROUND: 3D printing is a popular technology in many industries secondary to its ability to rapidly produce inexpensive, high fidelity models/products, mainly through layer-by-layer fusion of various substrate materials. In healthcare, 3D printing has garnered interest for its applications in surgery, simulation, education, and medical device development, and 3D printing facilities are now being integrated into hospital-based settings. Yet, little is known regarding the leadership, resources, outputs, and role of these new onsite entities. METHODS: The purpose of this research was to survey features of North American hospital-based 3D printing facilities to understand their design and utility in anticipation of future expansion. Hospital-based 3D printing labs were recruited through online special interest groups to participate via survey response. Anonymous, voluntary data were collected from 21 facilities over 9 weeks and reported/analyzed in aggregate. RESULTS: Of the respondents, > 50% were founded in the past 5 years and 80% in the past decade, indicating recent and rapid growth of such facilities. Labs were most commonly found within large, university-affiliated hospitals/health systems with administration frequently, but not exclusively, through radiology departments, which was shown to enhance collaboration. All groups reported collaborating with other medical specialties/departments and image segmentation as part of the workflow, showing widespread interest in high fidelity, personalized medicine applications. Lab leadership was most often multidisciplinary, with physicians present on nearly all leadership teams. Budgets, personnel, and outputs varied among groups, however, all groups reported engagement in multiple 3D printing applications. CONCLUSION: This preliminary study provides a foundation for understanding the unique nature of hospital-based 3D printing labs. While there is much to learn about such in-house facilities, the data obtained reveal important baseline characteristics. Further research is indicated to validate these early findings and create a detailed picture of the developing infrastructure of 3D printing in healthcare settings.

Techniques for Developing and Assessing Immune Responses Induced by Synthetic DNA Vaccines for Emerging Infectious Diseases.

Vaccines are one of mankind's greatest medical advances, and their use has drastically reduced and in some cases eliminated (e.g., smallpox) disease and death caused by infectious agents. Traditional vaccine modalities including live-attenuated pathogen vaccines, wholly inactivated pathogen vaccines, and protein-based pathogen subunit vaccines have successfully been used to create efficacious vaccines against measles, mumps, rubella, polio, and yellow fever. These traditional vaccine modalities, however, take many months to years to develop and have thus proven less effective for use in creating vaccines to emerging or reemerging infectious diseases (EIDs) including influenza, Human immunodeficiency virus (HIV), dengue virus (DENV), chikungunya virus (CHIKV), West Nile virus (WNV), Middle East respiratory syndrome (MERS), and the severe acute respiratory syndrome coronaviruses 1 and 2 (SARS-CoV and SARS-CoV-2). As factors such as climate change and increased globalization continue to increase the pace of EID development, newer vaccine modalities are required to develop vaccines that can prevent or attenuate EID outbreaks throughout the world. One such modality, DNA vaccines, has been studied for over 30 years and has numerous qualities that make them ideal for meeting the challenge of EIDs including; (1) DNA vaccine candidates can be designed within hours of publishing of a pathogens genetic sequence; (2) they can be manufactured cheaply and rapidly in large quantities; (3) they are thermostable and have reduced requirement for a cold-chain during distribution, and (4) they have a remarkable safety record in the clinic. Optimizations made in plasmid design as well as in DNA vaccine delivery have greatly improved the immunogenicity of these vaccines. Here we describe the process of making a DNA vaccine to an EID pathogen and describe methods used for assessing the immunogenicity and protective efficacy of DNA vaccines in small animal models.

Genetic regulation of OAS1 nonsense-mediated decay underlies association with COVID-19 hospitalization in patients of European and African ancestries.

The chr12q24.13 locus encoding OAS1-OAS3 antiviral proteins has been associated with coronavirus disease 2019 (COVID-19) susceptibility. Here, we report genetic, functional and clinical insights into this locus in relation to COVID-19 severity. In our analysis of patients of European (n = 2,249) and African (n = 835) ancestries with hospitalized versus nonhospitalized COVID-19, the risk of hospitalized disease was associated with a common OAS1 haplotype, which was also associated with reduced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clearance in a clinical trial with pegIFN-λ1. Bioinformatic analyses and in vitro studies reveal the functional contribution of two associated OAS1 exonic variants comprising the risk haplotype. Derived human-specific alleles rs10774671-A and rs1131454 -A decrease OAS1 protein abundance through allele-specific regulation of splicing and nonsense-mediated decay (NMD). We conclude that decreased OAS1 expression due to a common haplotype contributes to COVID-19 severity. Our results provide insight into molecular mechanisms through which early treatment with interferons could accelerate SARS-CoV-2 clearance and mitigate against severe COVID-19.

N-terminal serine/threonine motif has diverse and important effects on behavior of multiple AAV serotypes.

Adeno-associated virus (AAV) is a promising gene therapy vector, but questions remain regarding mechanisms of basic viral functions. We previously showed that a serine/threonine (S/T) triplet motif and its flanking residues, located in the overlapping N-terminus of VP1/VP2 and highly conserved across most AAV serotypes, are critical for viral transcript production in vitro. Here we generate a panel of S/T triplet mutants in AAV serotypes 2, 4, and 9 and characterize their behaviors in vitro and in vivo using next generation sequencing. We show that S/T triplet mutations can significantly hinder some stages of transduction in a serotype-dependent manner in vitro. Interestingly, these defects are largely overcome in C57BL/6 mice, with only one mutant displaying altered behavior in vivo. Taken together, our results identify a short N-terminal capsid motif with diverse roles across several AAV serotypes which better informs engineering efforts to improve AAV as a vector for gene therapy.

Development of Siglec-9 Blocking Antibody to Enhance Anti-Tumor Immunity.

Sialic acid-binding Immunoglobulin-like lectin-9 (Siglec-9) is a glyco-immune negative checkpoint expressed on several immune cells. Siglec-9 exerts its inhibitory effects by binding to sialoglycan ligands expressed on cancer cells, enabling them to evade immunosurveillance. We developed a panel of human anti-Siglec-9 hybridoma clones by immunizing mice with Siglec-9-encoding DNA and Siglec-9 protein. The lead antibodies, with high specificity and functionality against Siglec-9, were identified through screening of clones. The in vitro cytotoxicity assays showed that our lead antibody enhances anti-tumor immune activity. Further, in vivo testing utilizing ovarian cancer humanized mouse model showed a drastic reduction in tumor volume. Together, we developed novel antibodies that augment anti-tumor immunity through interference with Siglec-9-mediated immunosuppression.

Landscape of humoral immune responses against SARS-CoV-2 in patients with COVID-19 disease and the value of antibody testing.

A new pandemic is ongoing in several parts of the world. The agent responsible is the newly emerged severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The symptoms associated with this virus are known as the coronavirus disease-2019 (COVID-19). In this review, we summarize the published data on virus specific antibodies in hospitalized patients with COVID-19 disease, patients recovered from the disease and the individuals who are asymptomatic with SARS-CoV-2 infections. The review highlights the following: i) an adjunct role of antibody tests in the diagnosis of COVID-19 in combination with RT-PCR; ii) status of antibodies from COVID-19 convalescent patients to select donors for plasma therapy; iii) the potential confounding effects of other coronaviruses, measles, mumps and rubella in antibody testing due to homology of certain viral genes; and iv) the role of antibody testing for conducting surveillance in populations, incidence estimation, contact tracing and epidemiologic studies.