Background
Healthcare disparity is the United States has been a long-standing issue. A disease of interest is diabetic retinopathy, one of the leading causes of blindness in the United States, as the minorities are disproportionately affected. Treatment regimens often consist of panretinal photocoagulation (PRP) and intravitreal injections (IVI) with anti-vascular endothelial growth factor (anti-VEGF). However, the efficacy of the treatment regimens as demonstrated in clinical trials have been limited in real-world settings as these necessitate frequent follow-ups, a challenge given that 25 to 51% of patients with diabetic retinopathy are lost to follow-ups. Furthermore, the effect of LTFU in itself on final outcomes have not been studied to date. Therefore, we examined factors associated with LTFU, the effect of LTFU on proliferative diabetic retinopathy, and its interaction with different treatments.

Methods
A retrospective cohort study at a large safety net hospital examined 271 eyes of 271 patients with PDR that received PRP or IVI over a 2-year period. LTFU was defined as failure to return to care for at least 6 months. Baseline patient characteristics were collected. Ocular data was gathered at the visit before being LTFU, the return visit after being LTFU, and the final clinic visit. Univariate analyses and multivariate regression with adjustment for multiple comparisons to control confounders were conducted. 

Results
A history of LTFU was associated with subsequent neovascularization elsewhere (NVE) and tractional retinal detachment (TRD) but not with final visual acuity (VA). Among those LTFU, those who received IVI were not at higher risk of TRD than those receiving PRP.

Conclusion
Undergoing PRP is associated with LTFU. LTFU is independently associated with subsequent development of NVE and TRD, but not with the final visual acuity. One rationale in opting for PRP over IVI for managing PDR was the risk of the patient being LTFU, but our study did not demonstrate a difference between those who received PRP prior to LTFU and those who received IVI prior to LTFU in terms of the rate of subsequent TRD formation. Further studies should expand upon those findings to design better interventions strategies. 


Out of Sight, Not Out of Mind: The Effect of Loss to Follow-Up on on Proliferative Diabetic Retinopathy

Background: Cholangiocarcinoma (CCA) is a malignancy of the bile ducts with five-year survival rates of less than 10%. For those with early-stage disease, resection or liver transplantation can be curative. Unfortunately, existing diagnostic tools fail to enable definitive diagnosis, as CCA is notoriously difficult to distinguish from fibrotic or inflammatory lesions. Therefore, novel tools are needed to enable early and accurate diagnosis of CCA, especially in those with indeterminate lesions. Proteases are enzymes that are frequently dysregulated in cancer, including CCA, playing diverse roles in angiogenesis, invasion, and metastasis. We have previously developed a class of peptide-based diagnostic agents, activatable zymography probes (AZPs), which bind to cell membranes after proteolytic cleavage and can be used for ex vivo and in vivo cancer imaging. In this work, we sought to develop AZPs to distinguish CCA from fibrosis.

Methods: We induced CCA in the Mdr2-/- mouse model of biliary fibrosis via hydrodynamic injection of plasmids encoding for AKT, YAP1, and the Sleeping Beauty (SB) transposase. We synthesized a panel of 26 AZPs, applied them to liver tissue sections from CCA and Mdr2-/- mice, and performed whole-slide fluorescence imaging. Select AZPs were co-stained with antibodies against vimentin and cytokeratin 7 and validated in a mouse model of FBXW7/AKT-mutant CCA. Finally, AZPs were PEGylated to increase solubility, intravenously injected into CCA and Mdr2-/- mice, and livers were imaged with in vivo imaging system (IVIS) to assess tumor uptake in vivo. 

Results: We found that 14 AZPs, most notably AZP6, exhibited significantly increased binding to CCA tumors (padj¬ < 0.05, fold change > 1.5) relative to fibrotic bile ducts. In CCA tumors, AZP6 bound significantly more strongly to cells with higher expression of vimentin (p < 0.01) and lower expression of cytokeratin 7 (p < 0.001), suggesting that AZP6 is cleaved by mesenchymal cells. AZP6 also specifically labeled tumors from an FBXW7/AKT-mutant CCA model in a pattern similar to that seen in the YAP1/AKT model, demonstrating its generalizability. Finally, after in vivo administration, AZP6 demonstrated significantly more fluorescence in explanted livers from mice with CCA than mice with fibrosis (p < 0.01), enabling perfect discrimination of malignant and benign disease (AUC = 1, p = 0.009).

Conclusion: AZPs detect and localize dysregulated protease activity ex vivo and in vivo in mouse models of CCA, without false positives from benign biliary fibrosis. With further refinement, AZPs may aid in the diagnosis of CCA.

Detection of cholangiocarcinoma with protease activity probes

Background
Pack-year history is an invaluable clinical tool for measuring tobacco-associated disease risk and determining eligibility for lung cancer screening with low-dose computed tomography. Patient-reported measures of smoking history have demonstrated strong test-retest reliability across various survey methods, but the variation between research and clinical settings suggests that non-standardized smoking history interview questions in community practice may not always reveal the true extent of a patient’s tobacco exposure. To date, no study has compared patient responses to differently phrased questions assessing the same measure of smoking history. We hypothesize there is a significant discordance between patient-reported number of years smoked and calculated elapsed time between age at initiation and age at cessation (or present age if current smoker).

Methods
This was a two-month prospective survey-based study conducted at the Western Michigan University Homer Stryker M.D. School of Medicine's Internal Medicine resident clinic in Kalamazoo, Michigan, including patients with a documented smoking history in their electronic medical records. Through verbal interviews, we collected data on number of years smoked, packs per day, and age of smoking initiation/cessation. Primary outcome variables were total years smoked and calculated pack-years. Secondary outcome variables were gender, age, and age of smoking initiation.

Results
There were 124 respondents (36% male, 63% female, 1% non-binary) with an average age of 55 and average smoking history of 1.2 packs per day. Of them, 46% were current and 54% were former smokers. Using a paired sample one-tail t-test, we compared patient-reported years smoked (M=22.06, SD=12.44) to calculated years based on age of initiation/cessation (M=24.03, SD=13.53), which showed a significant mean difference of 1.97 years (95% CI 1.16- 2.78, t=4.05, p<0.001). This discordance translated to a 21.29% increase in pack-years (from 24.32 to 29.50 pack-years) and a mean difference of 5.21 pack-years (95% CI 1.04-9.38, t=2.07, p=0.02).

Conclusion
Our study underscores the importance of critically evaluating the ways in which we gather a patient’s smoking history. When compared to pack-years calculated using age of smoking initiation/cessation, our sample population tended to underestimate their exposure by over 5 pack-years—a clinically significant difference for someone at high risk who might not otherwise receive screening imaging. Often a pivotal moment in adolescence, participants recalled their age of smoking initiation with greater precision compared to their estimations of total exposure. These results call for urgent reevaluation of the tobacco history interview, its notation in electronic medical records, and the methodology of taking a substance abuse history in general.

Rethinking the Smoking History Interview: A Prospective Survey-based Study

Spalt-Like Transcription Factor 4 (SALL4), a member of the SALL family, is a regulator of embryonic stem cell development that plays a crucial role in cell renewal and proliferation. SALL4 expression is normally repressed in most adult organs but is reactivated in a multitude of solid and blood cancers and upon treatment with hypomethylating agents (HMA). There is outstanding clinical need for the development and validation of a less invasive SALL4 expression assay via peripheral blood, which can be used for monitoring patients on HMA treatment and SALL4-targeting therapy such as molecular glue degraders.

Using the Simoa (Single Molecule Array) platform, a bead-based digital enzyme-linked immunosorbent assay, we cross-tested 5 commercial SALL4 antibodies and 13 antibody pair combinations, using the best antibody pair to test the matrix effects of human plasma, buffy coats, and bone marrow aspirates. Quantitative assay development further included creating recombinant protein standards, antibody pair screening and validation, and pre-analytical optimization. Upon completion of these steps, a retrospective cohort analysis via patient peripheral blood samples is currently being conducted to validate assay accuracy and precision. Additionally, we are aiming to conduct prospective studies to explore the role of the SALL4 protein biomarker in risk stratification and treatment monitoring.

Thus far, for quantitative assay development, we have successfully expressed and purified full-length SALL4 which will be used to calibrate the standard curve and determine the assay’s limit of quantification. We also optimized multiple pre-analytic steps, including our cell lysis protocol, isolation of buffy coats using density gradient separation, and sample collection method comparison. The best antibody pair can detect both SALL4A and SALL4B isoforms, with stronger signal detected with the SALL4A isoform. For the retrospective cohort validation, we have obtained samples for analysis for liver cancer, myelodysplastic syndrome (MDS), and acute myeloid leukemia (AML) with plans to expand to breast cancer and lung cancer.

In conclusion, we have developed an ultrasensitive SALL4 protein expression diagnostic assay for use in monitoring patient treatment response and for guiding targeted therapy by analyzing peripheral blood for both solid and liquid tumors. Future steps include validating the diagnostic assay for specificity and sensitivity in a retrospective cohort analysis and conducting prospective studies to explore the role of the SALL4 protein biomarker for risk stratification, monitoring on HMA treatment, and guiding targeted therapy.

Ultrasensitive detection of SALL4 oncoproteins for the use in therapeutic monitoring

Background: SARS-CoV-2 or (CoV2) utilizes the receptor binding domain (RBD) of its surface SPIKE protein to infect human cells that express ACE2 receptor. Infected persons can be asymptomatic or progress to a potentially fatal pneumonia-associated illness. Antibodies that prevent SPIKE/RBD/ACE2 interaction can result from infection or vaccination. However, their quantity, function, and cross-reactive protection requires serological testing. We obtained 50 deidentified serum samples, and were blinded to CoV2 vaccination (Vax+; Vax-) or CoV2 positive test (CoV2+; CoV2-). Serum IgG antibodies to SPIKE and RBD were quantified and efficacy in preventing CoV2 infection in vitro determined. We hypothesized that high titer RBD IgG would be efficient at preventing viral infection and be effective against a later CoV2 variant.

Methods: ELISA was used to quantify SPIKE and RBD antibodies in sera. Neutralizing capability of antibodies was determined by mixing sera with a firefly luciferase lentivirus psuedotyped with Wuhan CoV2 SPIKE. The mixture was applied to ACE2 expressing cells and luciferase activity used to calculate infection rates. Samples were unblinded to determine correlation between in vitro results and CoV2 exposure or vaccination. Cross-protection was determined by repeating neutralization assays with the Omicron BA.2 variant.

Results Thirteen participants reported no CoV2 vaccine or CoV2 positive test (Vax-/CoV2-) yet 7 had anti-SPIKE and -RBD titers and neutralizing function suggesting prior asymptomatic CoV2 infection. The remaining 37 participants reported Vax-/CoV2+ (n=8), Vax+/CoV2- (n=27), or Vax+/CoV2+ (n=2). Titers to RBD were comparatively lower than titers to SPIKE in most patient samples. Average RBD antibody titers were higher for the Vax+/CoV2- group (1:2600) versus Vax-/CoV2+ cohort (1:900). Highest RBD antibody titers were found in Vax+/CoV2+ patients (1:5400). Finally, sera with RBD titer ≥1:2700 and neutralization capacity had equal neutralizing function on Omicron BA.2, a variant with 28 amino acid changes in SPIKE and 16 in the critical RBD region.

Conclusion High-titer RBD sera correlated with greater viral neutralization activity highlighting the functional importance of this domain in infection. High-titer anti-RBD IgG to the initial Wuhan CoV2 virus also provided potent neutralization activity against the BA.2 variant despite 16 amino acid changes in its RBD region. This information could be used in future vaccination efforts and passive immunization, as well as provide a greater level of confidence to healthcare workers, first responders, and other high-risk populations regardless of the CoV2 strain. Serial immune studies in high risk populations could provide indications for booster vaccines.

Functional Serologic Testing and Cross Reactivity of Serum Antibodies to SARS-CoV-2 SPIKE Protein

Background:
First-line treatment for major depressive disorder (MDD) include cognitive behavioral therapy (CBT) and/or antidepressant medications (ADM). However, these treatments can be highly effective in one patient but ineffective in another. Previous treatment selection biomarker studies using resting state fMRI implicate differential subcallosal connectivity to the left anterior insula, left ventromedial prefrontal, and left periaqueductal gray in CBT and medication remitters (Dunlop AJP 2017). Structural connectivity changes that might mediate these functional connectivity patterns are unknown. Therefore, we evaluated pretreatment White matter (WM) integrity in treatment naïve MDD patients as a function of differential 3-month clinical outcome to monotherapy with CBT or ADM. 
Methods
A retrospective analysis of diffusion-weighted imaging scans (DWI) was performed in 167 treatment naive MDD patients randomized to 12 weeks of CBT or ADM. Subjects were grouped into CBT or ADM remitters (HDRS17 score <7 at 10 and 12 weeks) and CBT or ADM failure (HDRS score change <30%). A Whole brain fractional anisotropy (FA) map was calculated for each subject using Fdt toolbox in FMRIB and Tract-Based Spatial Statistics (TBSS) generated for statistical comparison across outcome groups. A voxel-wise 2 x 2 ANOVA: treatment (CBT/ADM) by outcome (remitter/nonresponder) was performed using the AFNI 3dMVM toolbox. Lastly, regional WM changes were correlated with HDRS score changes with treatment. 
Results
A significant treatment by outcome interaction was identified affecting WM tracts adjacent to the left anterior insula, left supplementary motor area, and left hippocampus (p < 0.001). Post hoc analysis revealed ADM remitters and CBT nonresponders show higher FA values in the left insula and SMA compared to both ADM nonresponders and CBT remitters, similar to the location and differential pattern of functional connectivity. In contrast, ADM remitters and CBT nonresponders show lower FA in the left hippocampus compared to ADM nonresponders and CBT remitters. The left SMA and hippocampus showed significant correlation (R2=0.05 p<0.005) with HDRS score improvement in all groups. The VMPFC and SMA showed similar results within the ADM group. The CBT group showed significant correlation with the DLPFC (R2=0.17 p<0.005).
Conclusion
These findings identify differential WM integrity in WM tracts adjacent to the insula, SMA, and hippocampus in remitters and failures to CBT and ADM. These structural and functional connectivity patterns may define imaging biotypes that guide optimal first line MDD treatment selection. Finally, these findings implicate WM connectivity in differential predictive outcomes in MDD treatment success by treatment.

White matter markers for treatment outcomes in major depressive disorder

Background: 
Monkeypox, caused by the Monkeypox virus (MPV), is a double-stranded DNA virus belonging to the genus Orthopoxvirus. While confirmed cases of Mpox disease have been reported in since the 1970s, the recent global outbreak has escalated Monkeypox to a public health emergency. Although Monkeypox is typically considered a self-limiting disease, the recent outbreak has demonstrated an increase in disease morbidity and mortality, particularly in those with immunocompromised status. For those with HIV infection, co-infection with Monkeypox can lead to atypical disease presentation. This poster highlights an example of a highly atypical dermatological presentation in a patient with HIV and Monkeypox co-infection. 

Discussion: A 28-year-old male with a history of untreated HIV/AIDS presented with diffuse bilateral eschars with well-extended surrounding erythema for two days. The lesions were expansive and located diffusely across the bilateral upper extremities. The patient reported the lesions were slowly enlarging and mildly pruritic. Additionally, bilateral tender inguinal lymphadenopathy and a single painful shallow ulcer on the right-side penile shaft was present. While Monkeypox typically presents with small well-localized eschars surrounded by slight erythema, this patient demonstrated well-extended erythema and diffuse eschars on the bilateral upper extremities. This case illustrates that HIV and Monkeypox co-infection may lead to exacerbation of the typical symptoms of each disease– resulting in atypical dermatologic presentations, unique disease manifestations, and more difficult management. 


Rare presentation of Monkeypox in a Patient with Coexisting HIV

Glioblastoma Multiforme (GBM) is one of the most common and aggressive high-grade primary brain tumors that arises from the glial cells of the central nervous system and occurs most often in the frontal and temporal lobes. Despite current treatment options, long-term prognosis of GBM remains low with no significant improvement rates. Chimeric antigen receptor (CAR)-expressing T cells target the B cell marker CD19 and have shown increased efficacy in B cell lymphomas, and lymphoblastic leukemias suggesting benefits in GBM. This study aims to quantify the persistence of CAR-T cells in the context of GBM tumor volume following neurosurgical debulking procedure. A radiology software known as the mint Lesion was utilized to provide Tumor Response Assessment by Criteria (TRAC) reports that consist of volumetric measurements of the tumor lesions (target enhancing lesions, non-target enhancing lesions, and non-target non-enhancing lesions). Fluorescence-activated cell sorting (FACS) analysis takes a sample mixture of cells and sorts them into different populations based on specific biomarkers and characteristics. B7-H3 CAR-T cell persistence was increased in patients with a larger post-surgical tumor volume (3.04% Subject 001 with 2438 mm² volume and 2.38% Subject 003 with 224 mm² tumor volume). However, the number of CAR-T cells per 1 mm² was significantly reduced in patients with a larger post-surgical tumor volume (0.0012 cells/mm² Subject 001 and 0.010 cells/mm² Subject 003). This study shows that although there is an overall increased CAR-T cell persistence for a larger tumor volume, the number of CAR-T cells per 1 mm² is significantly smaller for larger tumor volumes, while illustrating that a larger post-surgical tumor bulk volume is correlated with an increased CAR-T cell persistence within 1-week post-infusion. These findings provide novel information and complement other correlative studies as part of the Phase 1 interventional clinical trial for glioblastoma patients.

Glioblastoma Multiforme Tumor Volume and Persistence of Chimeric Antigen Receptor T Cells Following Neurosurgical Debulking

Background: Life adversities, such as neighborhood disadvantage and lower household incomes, are associated with well-established impairments on language development, which predict academic difficulties throughout school. These language delays are observable by age 2, but it remains unclear if adversities experienced in utero affect neurological underpinnings of language development before delays emerge. Of interest are 3 white matter tracts implicated in early language skills: the corpus callosum (CC), inferior fronto-occipital fasciculus (IFOF), and uncinate (Unc).

Methods: A longitudinal cohort of 160 term-born (>36 weeks gestation) neonates were recruited from the eLABE study at Washington University, which oversampled St. Louis families exposed to poverty. Structural equation modeling was used to create 2 latent constructs of prenatal adversity. The first, “social disadvantage”, aggregates neighborhood disadvantage, family income, insurance status, maternal education, and diet. The second, “maternal psychosocial stress”, models maternal depression, stress, life adversities, and perceived discrimination. At birth, diffusion MRI data were collected, and parameters for white matter tract development were created using probabilistic tractography in FSL. In-person follow-up at age 2 evaluated child language skills. To assess the independent and interactive effects of prenatal adversities and neonatal white matter microstructure on language skills, stepwise linear regression models were conducted after adjustment for child sex, gestational age, and postmenstrual age at scan. 


Results: Prenatal social disadvantage (p=.00) and maternal psychosocial stress (p=.00) predicted significantly lower language scores by age 2. However, in a joint model, only the effects due to social disadvantage remained significant. Lower CC fractional anisotropy predicted significantly lower language scores (p=.02) independently of social disadvantage (p=.00). IFOF and Unc were not predictive of language ( p > .05). To examine the relationship between CC maturation and social disadvantage, a moderation analysis was conducted after dichotomizing families’ income into above and below 200% the federal poverty line (FPL), as most federal assistance programs use this value as a threshold for benefit eligibility. The interaction term was not significant (p= .11), but upon plotting results by income group, the slope for infants above 200% FPL was somewhat stronger. 

Conclusion: This study suggests that prenatal adversity, particularly social disadvantage, and immature CC myelination are strong predictors of language delays by age 2. These data can be used as empirical evidence to advocate for increased funding of federal assistance programs that benefit pregnant people (ex., WIC) and downstream fetal brain development. By continuing to explore the relationship between prenatal adversities on fetal brain development and emerging language skills, future studies will continue to identify specific neurological markers of early language development to allow clinicians to intervene before delays emerge.

The Effects of Prenatal Adversity and Neonatal White Matter Microstructure on Child Language Skills at Age 2

Introduction: Hand-foot-mouth disease (HFMD) is a common childhood infectious disease. Atypical skin findings of HFMD, often associated with coxsackievirus A6 (CVA6), were first reported in 2008, with increasing reports worldwide since. Atypical lesions of HFMD often involve sites beyond the palms and soles and tend to have unusual, polymorphic morphology. 
Methods: A systematic review was conducted on clinical features and outcomes of pediatric HFMD with atypical cutaneous manifestations.
Results: Eighty-five studies were included, representing 1,359 cases with mean age 2.4 years and a male predominance of 61%. The most reported morphologies were vesicles (53%), papules (49%), and bullae (36%). Other morphologies included eczema herpeticum-like (19%), purpuric/petechial (7%), and Gianotti Crosti-like (4%). Common atypical sites included the arms and/or legs (47%), face (45%), and trunk (27%). CVA6 was identified in 63% of cases. Symptoms resolved in a mean of 10 days. Overall, 16% of cases received treatment, most commonly with acyclovir, intravenous antibiotics, or topical steroids. The most common complications were nail changes (21%) and desquamation (4%) which occurred a mean of three and two weeks after symptoms, respectively. 
Conclusion: Due to unusual morphologies resembling other conditions, HFMD with atypical cutaneous findings may be misdiagnosed, leading to inappropriate and unnecessary investigations, hospitalization, and treatment. Greater awareness of atypical presentations of HFMD is warranted to improve patient care and counseling on infection control precautions.

Atypical Cutaneous Findings of Hand-Foot-Mouth Disease in Children: A Systematic Review

Background: Recurrent urinary tract infections (rUTI) are common in postmenopausal women with type 2 diabetes mellitus (T2DM). However, little is known about the composition of the urinary microbiome in this population and how it contributes to rUTI susceptibility. We aimed to identify key differences in urinary microbiome composition and function between women with and without T2DM through shotgun metagenomic sequencing of their urine.

Methods: Following IRB approval, urine samples were collected from consenting postmenopausal women with T2DM across 3 groups: rUTI remission (rUTI history, no active infection), rUTI relapse (active infection), and no history of UTI. Groups were age and estrogen-matched and DNA was purified from 20 mL of urine per patient. Sample concentrations were standardized and 20 pg of spike-in DNA of a rare bacterial genome was added. Shotgun metagenomic sequencing was performed using the Illumina NextSeq2000 platform. Reads were quality controlled and purified of human-mapping sequences using CLC Genomics Workbench. All microbial reads were taxonomically analyzed using MetaPhlan3. For further controls, data for non-diabetic women in the same groups were obtained.

Results: Fifteen TD2M and 15 non-T2DM samples were compared for this study. The mean genomic DNA yield across diabetic samples was 18.5 ng/uL. We observed an average of 75.8% human mapping reads, which were censored from further analysis. The remaining dataset contained an average of 5.1 million microbial reads. In the No UTI group, common urogenital flora microbes dominated across all samples in both T2DM and non-T2DM groups. In the rUTI Remission group, urogenital flora microbes were the most common again in non-diabetics, while common UTI pathogens such as Escherichia coli, Staphylococcus spp. and Pseudomonas aeruginosa were present in diabetic samples. For the rUTI Relapse group, both T2DM and non-T2DM were infected with common UTI pathogens (Escherichia coli, Klebsiella pneumoniae, Anaerococcus vaginalis, Enterococcus faecalis), however, 5/5 diabetic samples showed multi-strain infections while only 2/5 non-diabetic samples did.

Conclusion: We aim to identify differences in urinary microbiomes between women with T2DM with rUTI relapse, rUTI remission, and no history of UTI. By comparing our results with a published study on women without T2DM, we found that our cohort had ~10% more human mapping reads. Our pilot study suggest that T2DM patients may have higher rates of multi-strain infections compared to their non-T2DM counterparts. An expanded study (n = 60) is currently in progress to further understand the differences in urinary microbiomes in women with and without T2DM. 


Metagenomic Sequencing of the Urinary Microbiome of Postmenopausal Women with Recurrent Urinary Tract Infection and Type 2 Diabetes

Background
Leukemia, lymphoma and myeloma accounted for nearly 10% of new cancer cases and more than 50,000 deaths in 2022. Although multiple treatment modalities exist, Chimeric Antigen Receptor (CAR) T cells have been particularly useful, using genetic modification of a patient’s harvested T cells to better target cancer cells. Current methods of altering antigen specificity and targeting, however, have proven to be inadequate over time, requiring additional genes to boost the immune response. One such gene is OX40, a co-stimulatory cassette member of the Tumor Necrosis Factor Receptor (TNFR) superfamily that is thought to boost T cell migration, proliferation and survival. Given these inherent qualities of OX40, we hypothesized that incorporating OX40 variants into CAR T cells could enhance their duration of response and tumor-targeting capabilities.

Methods
We combined variants of the OX40 gene with our 2nd generation CAR T cells, adding a costimulatory cassette to CD19 CARs. We started with transformations of plasmid cloning vectors containing OX40 genes, using these CD19 CAR/OX40 constructs to transiently transfect retroviral cell lines. The transient virus produced was used to transduce donor human T cells, inducing uptake of the CD19 CAR/OX40 vectors. Once transduced, T cell reactivity and longevity were assessed using ELISA assays, flow cytometry and cell counts.

Results
We successfully used our CD19 CAR/OX40 T cells to transduce various human donor T cells, demonstrating a 1:1 linear relationship between OX40 and CAR T cell expression via flow cytometry. We also found that the constructs produced markedly higher levels of OX40+ expression compared to endogenous levels, particularly in regulatory T cells. When tested against a Burkitt’s lymphoma line, our
constructs showed reactivity above the standard deviation. With regards to longevity, our highest proliferating construct was a truncated version that survived over 60 days in culture.

Conclusion
We were able to produce CD19 CAR/OX40 donor T cells that had increased longevity and enhanced hematologic tumor targeting capabilities over time, likely due to an increased regulatory T cell response. Surprisingly, our truncated construct survived and proliferated the most, suggesting that the missing signaling domain could be key to balancing OX40’s enhanced growth effects versus over-proliferation.
With the endogenous signaling domain in place, OX40 is a promising addition to our CAR repertoire, boosting the in vitro antitumor response while balancing sustained proliferation and longevity. Our next steps will include translation into in vivo mouse models before bringing it to patients’ bedsides as a novel immunotherapy treatment.

Underline digital video library

Out of Sight, Not Out of Mind: The Effect of Loss to Follow-Up on on Proliferative Diabetic Retinopathy

Detection of cholangiocarcinoma with protease activity probes

Rethinking the Smoking History Interview: A Prospective Survey-based Study

Ultrasensitive detection of SALL4 oncoproteins for the use in therapeutic monitoring

Functional Serologic Testing and Cross Reactivity of Serum Antibodies to SARS-CoV-2 SPIKE Protein

White matter markers for treatment outcomes in major depressive disorder

Rare presentation of Monkeypox in a Patient with Coexisting HIV

Glioblastoma Multiforme Tumor Volume and Persistence of Chimeric Antigen Receptor T Cells Following Neurosurgical Debulking

The Effects of Prenatal Adversity and Neonatal White Matter Microstructure on Child Language Skills at Age 2

Atypical Cutaneous Findings of Hand-Foot-Mouth Disease in Children: A Systematic Review

Metagenomic Sequencing of the Urinary Microbiome of Postmenopausal Women with Recurrent Urinary Tract Infection and Type 2 Diabetes

Driving CARs Forward: An OX40 Tale of Immunotherapy

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