School of Medicine

Pathobionts have evolved many strategies to coexist with the host, but how immune evasion mechanisms contribute to the difficulty of developing vaccines against pathobionts is unclear. Meanwhile, Staphylococcus aureus (SA) has resisted human vaccine development to date. Here we show that prior SA exposure induces non-protective CD4+ T cell imprints, leading to the blunting of protective IsdB vaccine responses. Mechanistically, these SA-experienced CD4+ T cells express IL-10, which is further amplified by vaccination and impedes vaccine protection by binding with IL-10Rα on CD4+ T cell and inhibit IL-17A production. IL-10 also mediates cross-suppression of IsdB and sdrE multi-antigen vaccine. By contrast, the inefficiency of SA IsdB, IsdA and MntC vaccines can be overcome by co-treatment with adjuvants that promote IL-17A and IFN-γ responses. We thus propose that IL-10 secreting, SA-experienced CD4+ T cell imprints represent a staphylococcal immune escaping mechanism that needs to be taken into consideration for future vaccine development.

We hypothesized that the inferior disease-free survival (DFS) seen in older patients who underwent αβ-T-cell/CD19-depleted (AB-TCD) haploidentical hematopoietic cell transplantation (HCT) for hematologic malignancies is caused by excessive exposure to rabbit antithymocyte globulin (rATG; Thymoglobulin). Between 2015 and 2023, 163 patients with a median age of 13 years (range, 0.4-27.4) underwent AB-TCD haploidentical HCT for the treatment of acute lymphoblastic leukemia (n = 98), acute myeloid leukemia/myelodysplastic syndrome (n = 49), or other malignancies (n = 16) at 9 centers in 2 prospective trials. Exposures to rATG before and after HCT were predicted using a validated pharmacokinetic model. Receiver operating characteristic curves were used to identify the optimal target windows for rATG exposure in terms of outcomes. We identified 4 quadrants of rATG exposure, namely quadrant 1 (n = 52) with a high pre-HCT area under curve (AUC; ≥50 arbitrary units [AU] per day per milliliter) and a low post-HCT AUC (<12 AU per day per liter); quadrant 2 (n = 47) with a low pre- and post-HCT AUC; quadrant 3 (n = 13) with a low pre-HCT and a high post-HCT AUC; and quadrant 4 (n = 51) with a high pre- and post-HCT AUC. Quadrant 1 had a 3-year DFS of 86.5%, quadrant 2 had a DFS of 64.6%, quadrant 3 had a DFS of 32.9%, and for quadrant 4 it was 48.2%. An adjusted regression analysis demonstrated additional factors that were associated with an increased hazard for worse DFS, namely minimal residual disease (MRD) positivity and cytomegalovirus (CMV) R+/D- serostatus. Nonoptimal rATG exposure exhibited the strongest effect in unadjusted and adjusted (MRD status or CMV serostatus) analyses. High exposure to rATG after HCT was associated with inferior DFS following AB-TCD haploidentical HCT for pediatric patients with hematologic malignancies. Model-based dosing of rATG to achieve optimal exposure may improve DFS. These trials were registered at www.ClinicalTrials.gov as #NCT02646839 and #NCT04337515.

Multisystem inflammatory syndrome in children (MIS-C) is a rare condition following SARS-CoV-2 infection associated with intestinal manifestations. Genetic predisposition, including inborn errors of the OAS-RNAseL pathway, has been reported. We sequenced 154 MIS-C patients and utilized a novel statistical framework of gene burden analysis, burdenMC, which identified an enrichment for rare predicted-deleterious variants in BTNL8 (OR = 4.2, 95% CI: 3.5-5.3, P < 10-6). BTNL8 encodes an intestinal epithelial regulator of Vγ4+γδ T cells implicated in regulating gut homeostasis. Enrichment was exclusive to MIS-C, being absent in patients with COVID-19 or bacterial disease. Using an available functional test for BTNL8, rare variants from a larger cohort of MIS-C patients (n = 835) were tested which identified eight variants in 18 patients (2.2%) with impaired engagement of Vγ4+γδ T cells. Most of these variants were in the B30.2 domain of BTNL8 implicated in sensing epithelial cell status. These findings were associated with altered intestinal permeability, suggesting a possible link between disrupted gut homeostasis and MIS-C-associated enteropathy triggered by SARS-CoV-2.

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The HEALthy Brain and Child Development (HBCD) Study, a multi-site prospective longitudinal cohort study, will examine human brain, cognitive, behavioral, social, and emotional development beginning prenatally and planned through early childhood. Central to its mission of reducing health disparities is the establishment of the Spanish Language and Culture Committee (SLCC) within the HBCD framework, a significant step towards demographic representation and inclusivity in research. By addressing linguistic and sociocultural barriers and embracing the diverse identities of Hispanic/Latine individuals nationwide, the SLCC aims to promote inclusion, equity, and representation of all Hispanic/Latine subgroups, a population that has been historically misrepresented in health research. In this paper we describe the role of the SLCC in advocating for Hispanic/Latine families within the study, ensuring their inclusion from inception. This report also provides an overview of the SLCC organization, workflow, challenges and lessons learned thus far to reduce stigma and improve study outcomes, highlighting recruitment and retention strategies for the Hispanic/Latine population, and expanding outreach to promote inclusion across diverse Hispanic/Latine subgroups in the United States.

Breast cancer, the second most prevalent cancer among women worldwide, necessitates the exploration of novel therapeutic approaches. To target the four subgroups of breast cancer "hormone receptor-positive and HER2-negative, hormone receptor-positive and HER2-positive, hormone receptor-negative and HER2-positive, and hormone receptor-negative and HER2-negative" it is crucial to inhibit specific targets such as EGFR, HER2, ER, NF-κB, and PR. In this study, we evaluated various methods for binary and multiclass classification. Among them, the GA-SVM-SVM:GA-SVM-SVM model was selected with an accuracy of 0.74, an F1-score of 0.73, and an AUC of 0.92 for virtual screening of ligands from the BindingDB database. This model successfully identified 4454, 803, 438, and 378 ligands with over 90% precision in both active/inactive and target prediction for the classes of EGFR+HER2, ER, NF-κB, and PR, respectively, from the BindingDB database. Based on to the selected ligands, we created a dendrogram that categorizes different ligands based on their targets. This dendrogram aims to facilitate the exploration of chemical space for various therapeutic targets. Ligands that surpassed a 90% threshold in the product of activity probability and correct target selection probability were chosen for further investigation using molecular docking. The binding energy range for these ligands against their respective targets was calculated to be between -15 and -5 kcal/mol. Finally, based on general and common rules in medicinal chemistry, we selected 2, 3, 3, and 8 new ligands with high priority for further studies in the EGFR+HER2, ER, NF-κB, and PR classes, respectively.

IMPORTANCE: Pediatric patients with complex medical problems benefit from pediatric sub-specialty care; however, a significant proportion of children live greater than 80 mi. away from pediatric sub-specialty care. OBJECTIVE: To identify current knowledge gaps and outline concrete next steps to make progress on issues that have persistently challenged the pediatric nephrology workforce. EVIDENCE REVIEW: Workforce Summit 2.0 employed the round table format and methodology for consensus building using adapted Delphi principles. Content domains were identified via input from the ASPN Workforce Committee, the ASPNs 2023 Strategic Plan survey, the ASPNs Pediatric Nephrology Division Directors survey, and ongoing feedback from ASPN members. Working groups met prior to the Summit to conduct an organized literature review and establish key questions to be addressed. The Summit was held in-person in November 2023. During the Summit, work groups presented their preliminary findings, and the at-large group developed the key action statements and future directions. FINDINGS: A holistic appraisal of the effort required to cover inpatient and outpatient sub-specialty care will help define faculty effort and time distribution. Most pediatric nephrologists practice in academic settings, so work beyond clinical care including education, research, advocacy, and administrative/service tasks may form a substantial amount of a faculty members time and effort. An academic relative value unit (RVU) may assist in creating a more inclusive assessment of their contributions to their academic practice. Pediatric sub-specialties, such as nephrology, contribute to the clinical mission and care of their institutions beyond their direct billable RVUs. Advocacy throughout the field of pediatrics is necessary in order for reimbursement of pediatric sub-specialist care to accurately reflect the time and effort required to address complex care needs. Flexible, individualized training pathways may improve recruitment into sub-specialty fields such as nephrology. CONCLUSIONS AND RELEVANCE: The workforce crisis facing the pediatric nephrology field is echoed throughout many pediatric sub-specialties. Efforts to improve recruitment, retention, and reimbursement are necessary to improve the care delivered to pediatric patients.

Rab11 family interacting protein 4 (Rab11-FIP4) regulates endocytic trafficking. A possible role for Rab11-FIP4 in the regulation of lysosomal function has been proposed, but its precise function in the regulation of cellular homeostasis is unknown. By mRNA array and protein analysis, we found that Rab11-FIP4 is downregulated in the lysosomal storage disease cystinosis, which is caused by genetic defects in the lysosomal cystine transporter, cystinosin. Rescue of Rab11-FIP4 expression in Ctns^-/- fibroblasts re-established normal autophagosome levels and decreased LC3B-II expression in cystinotic cells. Furthermore, Rab11-FIP4 reconstitution increased the localization of the chaperone-mediated autophagy receptor LAMP2A at the lysosomal membrane. Treatment with genistein, a phytoestrogen that upregulates macroautophagy, or the CMA activator QX77 (CA77) restored Rab11-FIP4 expression levels in cystinotic cells supporting a cross-regulation between two independent autophagic mechanisms, lysosomal function and Rab11-FIP4. Improved cellular homeostasis in cystinotic cells rescued by Rab11-FIP4 expression correlated with decreased endoplasmic reticulum stress, an effect that was potentiated by Rab11 and partially blocked by expression of a dominant negative Rab11. Restoring Rab11-FIP4 expression in cystinotic proximal tubule cells increased the localization of the endocytic receptor megalin at the plasma membrane, suggesting that Rab11-FIP4 reconstitution has the potential to improve cellular homeostasis and function in cystinosis.

Substance use disorders (SUD) and drug addiction are major threats to public health, impacting not only the millions of individuals struggling with SUD, but also surrounding families and communities. One of the seminal challenges in treating and studying addiction in human populations is the high prevalence of co-morbid conditions, including an increased risk of contracting a human immunodeficiency virus (HIV) infection. Of the ~15 million people who inject drugs globally, 17% are persons with HIV. Conversely, HIV is a risk factor for SUD because chronic pain syndromes, often encountered in persons with HIV, can lead to an increased use of opioid pain medications that in turn can increase the risk for opioid addiction. We hypothesize that SUD and HIV exert shared effects on brain cell types, including adaptations related to neuroplasticity, neurodegeneration, and neuroinflammation. Basic research is needed to refine our understanding of these affected cell types and adaptations. Studying the effects of SUD in the context of HIV at the single-cell level represents a compelling strategy to understand the reciprocal interactions among both conditions, made feasible by the availability of large, extensively-phenotyped human brain tissue collections that have been amassed by the Neuro-HIV research community. In addition, sophisticated animal models that have been developed for both conditions provide a means to precisely evaluate specific exposures and stages of disease. We propose that single-cell genomics is a uniquely powerful technology to characterize the effects of SUD and HIV in the brain, integrating data from human cohorts and animal models. We have formed the Single-Cell Opioid Responses in the Context of HIV (SCORCH) consortium to carry out this strategy.