Project description:Food allergy affects an estimated 8% of children in the US, with increasing severity and global prevalence. Using single-cell RNA sequencing and paired TCR sequencing, we assessed the transcriptomes of CD154+ and CD137+ peanut-reactive T helper cells from 12 peanut-allergic patients longitudinally throughout peanut oral immunotherapy. These results demonstrate a differential response to OIT among subsets of peanut-reactive T helper cells, and indicate that non-Th2 activation signatures may be associated with clinical outcomes.
Project description:MS/MS analysis of the peanut protein extract (PPE) confirmed the presence of the four major peanut allergens and identified the presence of Ara h 1 isotypes, Ara h 2 isotypes, Ara h 3 isotypes, Ara h 6 isotypes and Ara h 7 isotypes. Allergen-specific immunotherapy (IT) is emerging as a viable option for treatment of peanut allergy. Yet, prophylactic IT remains unexplored despite early introduction of peanut in infancy was shown to prevent allergy. There is a need to understand how allergens interact with the immune system depending on the route of administration, and how different dosages of allergen may protect from sensitisation and a clinical active allergy. Here we compared peanut allergen delivery via the oral, sublingual (SL), intragastric (IG) and subcutaneous (SC) routes for the prevention of peanut allergy in Brown Norway (BN) rats. BN rats were administered PBS or three different doses of PPE via either oral IT (OIT), SLIT, IGIT and SCIT followed by intraperitoneal (IP) injections of PPE to assess the protection from peanut sensitisation. The development of IgE and IgG1 responses to PPE and the major peanut allergens were evaluated by ELISAs. The clinical response to PPE was assessed by an ear swelling test (EST) and proliferation was assessed by stimulating splenocytes with PPE. Low and medium dose OIT (1 and 10 mg) and all doses of SCIT (1, 10, 100 µg) induced sensitisation to PPE, whereas high dose OIT (100 mg), SLIT (10, 100 or 1000 µg) or IGIT (1, 10 and 100 mg) did not. High dose OIT and SLIT as well as high and medium dose IGIT prevented sensitisation from the following IP injections of PPE and suppressed PPE-specific IgE levels in a dose-dependent manner. Hence, administration of peanut protein via different routes confers different risks for sensitisation and protection from peanut allergy development. Overall, the IgE levels toward the individual major peanut allergens followed the PPE-specific IgE levels. Collectively, this study showed that the preventive effect of allergen-specific IT is determined by the interplay between the specific site of PPE delivery for presentation to the immune system, and the allergen quantity, and that targeting and modulating tolerance mechanisms at specific mucosal sites may be a prophylactic strategy for prevention of peanut allergy.
Project description:Oral immunotherapy (OIT) is the only FDA-approved treatment for peanut allergy (PA). Peanut-reactive (pr) CD4+ T cells are pivotal in PA pathogenesis as well as OIT-induced desensitization (DS). However, the underlying pr CD4+ T cell immune mechanisms leading to sustained unresponsiveness (SU) after OIT discontinuation remain largely unknown. We analyzed single-cell RNA and protein immunophenotypes and TCR repertoires of pr CD4+ T cells from a phase 2 peanut OIT trial cohort. We identify increased cytotoxicity-related phenotypes and Th1 CTL (cytotoxic T lymphocytes)-like cell clonal expansion during OIT in pr T effector memory cells, while Th2-related phenotypes and Th2a-like cell clonal expansion decreased. OIT participants who achieved SU had lower baseline Th2-related phenotypes, elevated cytotoxicity-related gene signatures in pr Teff cells post-OIT and higher CD39 expression in pr Tregs (T regulatory cells) after OIT withdrawal. These findings clarify OIT-induced CD4+ T cell tolerance mechanisms and can guide effective allergen-specific OIT strategies.
Project description:Peanut allergy reaction severity correlates with increased intestinal epithelial cell (IEC) barrier permeability. CC027/GeniUnc mice develop peanut allergy by intragastric administration of peanut proteins without adjuvant. We report that peanut-allergic CC027/GeniUnc mice showed increased IEC barrier permeability and systemic peanut allergen Ara h 2 after challenge. Jejunal epithelial cell transcriptomics showed effects of peanut allergy on IEC proliferation, survival, and metabolism, and revealed IEC-predominant angiopoietin like-4 (Angptl4) as a unique feature of CC027/GeniUnc peanut allergy. Peanut-allergic pediatric patients demonstrated significantly higher serum ANGPTL4 compared to non-peanut-allergic but atopic patients, highlighting its potential as a biomarker of peanut allergy.
Project description:WD repeat domain 5 (WDR5) is a core scaffolding component of many multi-protein complexes that perform a variety of critical chromatin-centric processes in the nucleus. WDR5 is component of the mixed lineage leukemia MLL/SET complex and localizes MYC to chromatin tumor-critical target genes. Overexpression of WDR5 promotes oncogenesis in a variety of human cancers that are often associated with poor prognoses. Thus, WDR5 has been recognized as an attractive therapeutic target for treating both solid and hematological tumors. Previously, small-molecule WDR5 WIN-site inhibitors and WDR5 degraders have demonstrated robust in vitro cellular efficacy in cancer cell lines and established the therapeutic potential of WDR5. However, these agents have not demonstrated significant in vivo efficacy at pharmacologically relevant doses by oral administration in animal disease models. We have discovered WDR5 WIN-site inhibitors that feature bicyclic heteroaryl P7 units through structure-based design and address the limitations of our previous series of small-molecule inhibitors. Importantly, our new lead compounds exhibit enhanced on-target potency, excellent oral pharmacokinetic (PK) profiles, and potent dose-dependent in vivo efficacy in a mouse MV4:11 subcutaneous xenograft model by oral dosing. Furthermore, these in vivo probes show excellent tolerability under a repeated high dose regimen in rodents to demonstrate the safety of the WDR5 WIN site inhibition mechanism. Collectively, our results provide strong support for WDR5 WIN-site inhibitors to be utilized as potential anticancer therapeutics.
Project description:Peanut-responsive T cells from peanut allergic subjects were identified and selected based on CD154 expression after stimulation of peripheral blood mononuclear cells with crude peanut extract for 18h. As controls, polyclonally activated CD4+ T cells from peanut allergic subjects were selected. Additional controls included CD4+CD25+CD127- Tregs from peanut allergic or healthy controls. Single cells were obtained using the C1 system from Fluidigm, and a barcoded library constructed. Sequencing (Illumina) was performed using 100 nt paired end reads. Data on a total of 431 cells was available. The goal of the study was to understand the heterogeneity of the peanut-specific T cell response.