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Item Airway exposure initiates peanut allergy by involving the IL-1 pathway and T follicular helper cells in mice(Elsevier, 2018-10) Dolence, Joseph J.; Kobayashi, Takao; Iijima, Koji; Krempski, James; Drake, Li Y.; Dent, Alexander L.; Kita, Hirohito; Microbiology and Immunology, School of MedicineBACKGROUND: Little is currently known regarding the immunologic mechanism(s) that initiate peanut allergy. Notably, peanut proteins have been detected in house dust, and their levels correlate with peanut allergy prevalence. OBJECTIVE: This study aimed to develop a new mouse model for peanut allergy and to investigate the immunologic mechanisms involved in peanut allergen sensitization. METHODS: To mimic environmental exposure, naive mice were exposed to peanut flour by inhalation for up to 4 weeks. We then analyzed serum levels of IgE antibody and challenged mice with peanut proteins. Immunological mechanisms involved in sensitization were analyzed using cytokine reporter mice, an adoptive cell transfer model, and gene knockout mice. RESULTS: When exposed to peanut flour by inhalation, both BALB/c and C57BL/6 mice developed peanut allergy, as demonstrated by the presence of peanut-specific IgE antibodies and manifestation of acute anaphylaxis on challenge. A large number of follicular helper T (Tfh) cells were also detected in draining lymph nodes of allergic mice. These cells produced IL-4 and IL-21, and they more robustly promoted peanut-specific IgE production than Th2 cells did. Genetic depletion of Tfh cells decreased IgE antibody levels and protected mice from anaphylaxis, without affecting Th2 cells. Furthermore, peanut flour exposure increased lung levels of IL-1α and IL-1β, and mice deficient in the receptor for these cytokines showed a significant decrease in Tfh cells compared with in wild-type mice. CONCLUSIONS: Tfh cells play a key role in peanut allergy, and the IL-1 pathway is involved in the Tfh response to peanut allergen exposure.Item Amoxicillin-Clavulanate-Induced Liver Injury(Springer, 2016-08) deLomos, Andrew S.; Ghabril, Marwan; Rockey, Don C.; Gu, Jiezhun; Barnhart, Huiman X.; Fontana, Robert J.; Kleiner, David E.; Bonkovsky, Herbert L.; Department of Medicine, IU School of MedicineBackground and Aims Amoxicillin–clavulanate (AC) is the most frequent cause of idiosyncratic drug-induced injury (DILI) in the US DILI Network (DILIN) registry. Here, we examined a large cohort of AC-DILI cases and compared features of AC-DILI to those of other drugs. Methods Subjects with suspected DILI were enrolled prospectively, and cases were adjudicated as previously described. Clinical variables and outcomes of patients with AC-DILI were compared to the overall DILIN cohort and to DILI caused by other antimicrobials. Results One hundred and seventeen subjects with AC-DILI were identified from the cohort (n = 1038) representing 11 % of all cases and 24 % of those due to antimicrobial agents (n = 479). Those with AC-DILI were older (60 vs. 48 years, P < 0.001). AC-DILI was more frequent in men than women (62 vs. 39 %) compared to the overall cohort (40 vs. 60 %, P < 0.001). The mean time to symptom onset was 31 days. The Tb, ALT, and ALP were 7 mg/dL, 478, and 325 U/L at onset. Nearly all liver biopsies showed prominent cholestatic features. Resolution of AC-DILI, defined by return of Tb to <2.5 mg/dL, occurred on average 55 days after the peak value. Three female subjects required liver transplantation, and none died due to DILI. Conclusion AC-DILI causes a moderately severe, mixed hepatocellular–cholestatic injury, particularly in older men, unlike DILI in general, which predominates in women. Although often protracted, eventual apparent recovery is typical, particularly for men and usually in women, but three women required liver transplantation.Item Asthma, Allergy and Vitamin E: Current and Future Perspectives(Elsevier, 2022) Cook-Mills, Joan M.; Averill, Samantha H.; Lajiness, Jacquelyn D.; Pediatrics, School of MedicineAsthma and allergic disease result from interactions of environmental exposures and genetics. Vitamin E is one environmental factor that can modify development of allergy early in life and modify responses to allergen after allergen sensitization. Seemingly varied outcomes from vitamin E are consistent with the differential functions of the isoforms of vitamin E. Mechanistic studies demonstrate that the vitamin E isoforms α-tocopherol and γ-tocopherol have opposite functions in regulation of allergic inflammation and development of allergic disease, with α-tocopherol having anti-inflammatory functions and γ-tocopherol having pro-inflammatory functions in allergy and asthma. Moreover, global differences in prevalence of asthma by country may be a result, at least in part, of differences in consumption of these two isoforms of tocopherols. It is critical in clinical and animal studies that measurements of the isoforms of tocopherols be determined in vehicles for the treatments, and in the plasma and/or tissues before and after intervention. As allergic inflammation is modifiable by tocopherol isoforms, differential regulation by tocopherol isoforms provide a foundation for development of interventions to improve lung function in disease and raise the possibility of early life dietary interventions to limit the development of lung disease.Item Cord blood sphingolipids are associated with atopic dermatitis and wheeze in the first year of life(Elsevier, 2022) Hoji, Aki; Kumar, Rajesh; Gern, James E.; Bendixsen, Casper G.; Seroogy, Christine M.; Cook-Mills, Joan M.; Pediatrics, School of MedicineBackground: Allergen-sensitized pregnant mice have increased plasma levels of the lipids β-glucosylceramides (βGlcCers) that are transplacentally transferred to the fetus, increased subsets of proinflammatory dendritic cells in the fetal liver and pup lung, and increased allergen-induced offspring lung inflammation. Objective: Our aim was to determine whether these preclinical observations extend to a human association of βGlcCers with wheeze and allergic disease in the prospective Wisconsin Infant Study Cohort. Methods: We measured 74 lipids in cord blood plasma by using mass spectrometry detection of sphingolipids, eicosanoids, and docosinoids, as well as an ELISA for 13-hydroxyoctadecadienoic acid. Lipid profiles were determined by unbiased Uniform Manifold Approximation and Projection dimensional reduction machine learning. Lipid profiles and a proinflammatory lipid index were analyzed for association with maternal allergy and childhood outcomes of wheeze, atopic dermatitis, cord blood leukocytes, and total IgE level at age 1 year. Results: Uniform Manifold Approximation and Projection analysis of lipids defined 8 cluster-specific plasma lipid profiles. Cluster 6 had significantly lower levels of plasma βGlcCers and a higher frequency of cord blood plasmacytoid dendritic cells that mediate anti-inflammatory responses, which is consistent with an anti-inflammatory profile. For clusters and for each infant, a proinflammatory lipid index was calculated to reflect the sum of the proinflammatory lipids minus the anti-inflammatory lipids that were significantly different than in cluster 6. The cluster proinflammatory lipid index was associated with cord blood basophil frequency and with wheeze and atopic dermatitis in the first year of life. The infant inflammatory lipid index was associated with increased risk of wheeze in the first year of life. Conclusion: The cord blood proinflammatory lipid index is associated with early-life atopic dermatitis and wheezing.Item Designer covalent heterobivalent inhibitors prevent IgE-dependent responses to peanut allergen(National Academy of Sciences, 2019-04-30) Deak, Peter E.; Kim, Baksun; Qayum, Amina Abdul; Shin, Jaeho; Vitalpur, Girish; Kloepfer, Kirsten M.; Turner, Matthew J.; Smith, Neal; Shreffler, Wayne G.; Kiziltepe, Tanyel; Kaplan, Mark H.; Bilgicer, Basar; Pediatrics, School of MedicineAllergies are a result of allergen proteins cross-linking allergen-specific IgE (sIgE) on the surface of mast cells and basophils. The diversity and complexity of allergen epitopes, and high-affinity of the sIgE-allergen interaction have impaired the development of allergen-specific inhibitors of allergic responses. This study presents a design of food allergen-specific sIgE inhibitors named covalent heterobivalent inhibitors (cHBIs) that selectively form covalent bonds to only sIgEs, thereby permanently inhibiting them. Using screening reagents termed nanoallergens, we identified two immunodominant epitopes in peanuts that were common in a population of 16 allergic patients. Two cHBIs designed to inhibit only these two epitopes completely abrogated the allergic response in 14 of the 16 patients in an in vitro assay and inhibited basophil activation in an allergic patient ex vivo analysis. The efficacy of the cHBI design has valuable clinical implications for many allergen-specific responses and more broadly for any antibody-based disease.Item The Development and Function of IL-9-Secreting T Helper Cells During Chronic and Allergen Recall-Induced Allergic Airway Disease(2021-04) Ulrich, Benjamin Joseph; Kaplan, Mark H.; Dent, Alexander L.; Srour, Edward F.; Tepper, Robert S.Asthma is a chronic inflammatory lung disease with intermittent flares predominately mediated through memory T cells. The majority of the T cells in tissues such as the lung are tissue-resident memory (Trm) cells, defined as cells that maintain long-lasting presence in the tissue and have rapid functional recall following challenge. Allergen-specific CD4 T helper cells that secrete the cytokine IL-9 have been shown to be a necessary component of asthma pathogenesis. However, the precise characterization and function of IL-9-secreting CD4+ cells (Th9 cells) are unknown. Here we demonstrate that IL-9 production is progressively lost in Th9 cells over several rounds of culture and that environmental cues dictate the instability or effector function of the Th9 phenotype. We show Th9 cells are long-lived tissue-resident cells with the capacity to rapidly respond to secondary allergen challenge causing allergic airway disease (AAD). We found in a memory model of Aspergillus fumigatus challenge, Th9 cells maintain tissue residency throughout a 12-week period of antigen-free rest. Additionally, we demonstrated increased frequency of IL-9-producing cells and quantity of IL-9 upon rechallenge, characteristic of a secondary response. Antibody blockade of IL-9 immediately prior to the recall challenge significantly reduced overall allergic lung inflammation, suggesting that IL-9 plays an obligate role in the allergic memory response following pulmonary allergen challenge. The protection afforded by IL-9 antibody blockade was not seen in a chronic model asthma-like disease demonstrating IL-9 has a specific role in allergic memory responses. Interestingly, IL-9-secreting cells have a polyfunctional multi-cytokine phenotype demonstrating a highly pathogenic state that we reproduced in culture. These observations suggest that IL-9 from Trm cell populations and Th9 cells play a novel role in allergen recall responses and are potential therapeutic targets for patients suffering from chronic intermittent asthma.Item Dysbiotic lung microbial communities of neonates from allergic mothers confer neonate responsiveness to suboptimal allergen(Frontiers Media, 2023-03-10) Bloodworth, Jeffery C.; Hoji, Aki; Wolff, Garen; Mandal, Rabindra K.; Schmidt, Nathan W.; Deshane, Jessy S.; Morrow, Casey D.; Kloepfer, Kirsten M.; Cook-Mills, Joan M.; Pediatrics, School of MedicineIn humans and animals, offspring of allergic mothers have increased responsiveness to allergens. This is blocked in mice by maternal supplementation with α-tocopherol (αT). Also, adults and children with allergic asthma have airway microbiome dysbiosis with increased Proteobacteria and may have decreased Bacteroidota. It is not known whether αT alters neonate development of lung microbiome dysbiosis or whether neonate lung dysbiosis modifies development of allergy. To address this, the bronchoalveolar lavage was analyzed by 16S rRNA gene analysis (bacterial microbiome) from pups of allergic and non-allergic mothers with a basal diet or αT-supplemented diet. Before and after allergen challenge, pups of allergic mothers had dysbiosis in lung microbial composition with increased Proteobacteria and decreased Bacteroidota and this was blocked by αT supplementation. We determined whether intratracheal transfer of pup lung dysbiotic microbial communities modifies the development of allergy in recipient pups early in life. Interestingly, transfer of dysbiotic lung microbial communities from neonates of allergic mothers to neonates of non-allergic mothers was sufficient to confer responsiveness to allergen in the recipient pups. In contrast, neonates of allergic mothers were not protected from development of allergy by transfer of donor lung microbial communities from either neonates of non-allergic mothers or neonates of αT-supplemented allergic mothers. These data suggest that the dysbiotic lung microbiota is dominant and sufficient for enhanced neonate responsiveness to allergen. Importantly, infants within the INHANCE cohort with an anti-inflammatory profile of tocopherol isoforms had an altered microbiome composition compared to infants with a pro-inflammatory profile of tocopherol isoforms. These data may inform design of future studies for approaches in the prevention or intervention in asthma and allergic disease early in life.Item Evidence that High Affinity IgE Can Develop in the Germinal Center in the Absence of an IgG1-switched Intermediate(American Association of Immunologists, 2023) Chen, Qiang; Liu, Hong; Luling, Noelle; Reinke, Julia; Dent, Alexander L.; Microbiology and Immunology, School of MedicineHigh affinity allergen-specific IgE is essential for the severe allergic anaphylaxis response. High affinity antibodies (Abs) are formed by successive rounds of selection of Ag-specific B cells in the germinal center (GC), however several studies have shown that IgE+ GC B cells are impaired in their ability to undergo selection in the GC. A pathway, known as the “indirect switching pathway” for IgE, has been described whereby Ag-specific B cells initially switch to the IgG1 isotype and undergo affinity selection in the GC, with a secondary switch to the IgE isotype after affinity selection. In previous work, using a food allergy model in mice, we investigated how high affinity IgE develops in the GC but we did not test the indirect switching model. Here we analyzed the importance of the indirect switching pathway by constructing IgG1-cre Bcl6-fl/fl mice. In these mice, once B cells switch to IgG1, they delete Bcl6 and thus cannot enter or persist in the GC. When we tested IgG1-cre Bcl6-fl/fl mice with our food allergy model, we found that as expected, IgG1 Abs had decreased affinity, but unexpectedly the affinity of IgE for allergen was unchanged. IgG1-cre Bcl6-fl/fl mice underwent anaphylaxis in response to allergen, consistent with the formation of high affinity IgE. Thus, in a food allergy response, high affinity IgE can be efficiently formed in the absence of indirect switching to IgG1, either by direct selection of IgE+ GC B cells or indirect selection of IgM+ GC B cells that later switch to IgE.Item Factors affecting adherence to intranasal treatment for allergic rhinitis: A qualitative study(Wiley, 2022-11-29) Fox, Meha G.; Cass, Lauren M.; Sykes, Kevin J.; Cummings, Emily L.; Fassas, Scott N.; Nallani, Rohit; Smith, Josh B.; Chiu, Alexander G.; Villwock, Jennifer A.; Medicine, School of MedicineObjective: To determine the facilitators of and barriers to adherence to use of intranasal pharmacotherapy (daily intranasal corticosteroids and/or antihistamine, and nasal saline irrigation [NSI]), for allergic rhinitis (AR). Methods: Patients were recruited from an academic tertiary care rhinology and allergy clinic. Semi-structured interviews were conducted after the initial visit and/or 4-6 weeks following treatment. Transcribed interviews were analyzed using a grounded theory, inductive approach to elucidate themes regarding patient adherence to AR treatment. Results: A total of 32 patients (12 male, 20 female; age 22-78) participated (seven at initial visit, seven at follow-up visit, and 18 at both). Memory triggers, such as linking nasal routine to existing daily activities or medications, were identified by patients as the most helpful strategy for adherence at initial and follow-up visits. Logistical obstacles related to NSI (messy, takes time, etc.) was the most common concept discussed at follow-up. Patients modified the regimen based on side effects experienced or perceived efficacy. Conclusions: Memory triggers help patients adhere to nasal routines. Logistical obstacles related to NSI can deter from use. Health care providers should address both concepts during patient counseling. Nudge-based interventions that incorporate these concepts may help improve adherence to AR treatment.Item Follicular helper T cells mediate IgE antibody response to airborne allergens(Elsevier, 2017-01) Kobayashi, Takao; Iijima, Koji; Dent, Alexander L.; Kita, Hirohito; Microbiology and Immunology, School of MedicineBACKGROUND: TH2 cells have long been believed to play a pivotal role in allergic immune responses, including IgE antibody production and type 2 cytokine-mediated inflammation and pathology. A new T-cell subset, follicular helper T (TFH) cells, is specialized in supporting B-cell maturation and antibody production. OBJECTIVE: We sought to investigate the roles of TFH cells in allergic immune responses. METHODS: Naive mice were exposed to cytokines or natural allergens through the airways. Development of allergic immune responses was analyzed by collecting draining lymph nodes and sera and by challenging the animals. Cytokine reporter mice and gene-deficient mice were used to dissect the immunologic mechanisms. RESULTS: We observed the development of IL-4-producing TFH cells and TH2 cells in draining lymph nodes after airway exposure to IL-1 family cytokines or natural allergens. TFH and TH2 cells demonstrated unique phenotypes, tissue localization, and cytokine responses. TFH cells supported the sustained production of IgE antibody in vivo in the absence of other T-cell subsets or even when TH2 cell functions were severely compromised. Conversely, conditional deficiency of the master regulator Bcl6 in CD4+ T cells resulted in a marked reduction in TFH cell numbers and IgE antibody levels, but type 2 cytokine responses and eosinophilic inflammation in the airways remained unaffected. CONCLUSION: TFH cells play critical roles in the regulation of IgE antibody production. Allergic immune responses to airborne allergens likely involve 2 distinct subsets of IL-4-producing CD4+ T cells, namely TFH and Th2 cells.