Resident memory T cells in tumor-distant tissues fortify against metastasis formation.

As a critical machinery for rapid pathogen removal, resident memory T cells (TRMs) are locally generated after the initial encounter. However, their development accompanying tumorigenesis remains elusive. Using a murine breast cancer model, we show that TRMs develop in the tumor, the contralateral mammary mucosa, and the pre-metastatic lung. Single-cell RNA sequencing of TRMs reveals two phenotypically distinct populations representing their active versus quiescent phases. These TRMs in different tissue compartments share the same TCR clonotypes and transcriptomes with a subset of intratumoral effector/effector memory T cells (TEff/EMs), indicating their developmental ontogeny. Furthermore, CXCL16 is highly produced by tumor cells and CXCR6- TEff/EMs are the major subset preferentially egressing the tumor to form distant TRMs. Functionally, releasing CXCR6 retention in the primary tumor amplifies tumor-derived TRMs in the lung and leads to superior protection against metastases. This immunologic fortification suggests a potential strategy to prevent metastasis in clinical oncology.

Distinct associations of sputum and oral microbiota with atopic, immunologic, and clinical features in mild asthma.

BACKGROUND: Whether microbiome characteristics of induced sputum or oral samples demonstrate unique relationships to features of atopy or mild asthma in adults is unknown. OBJECTIVE: We sought to determine sputum and oral microbiota relationships to clinical or immunologic features in mild atopic asthma and the impact on the microbiota of inhaled corticosteroid (ICS) treatment administered to ICS-naive subjects with asthma. METHODS: Bacterial microbiota profiles were analyzed in induced sputum and oral wash samples from 32 subjects with mild atopic asthma before and after inhaled fluticasone treatment, 18 atopic subjects without asthma, and 16 nonatopic healthy subjects in a multicenter study (NCT01537133). Associations with clinical and immunologic features were examined, including markers of atopy, type 2 inflammation, immune cell populations, and cytokines. RESULTS: Sputum bacterial burden inversely associated with bronchial expression of type 2 (T2)-related genes. Differences in specific sputum microbiota also associated with T2-low asthma phenotype, a subgroup of whom displayed elevations in lung inflammatory mediators and reduced sputum bacterial diversity. Differences in specific oral microbiota were more reflective of atopic status. After ICS treatment of patients with asthma, the compositional structure of sputum microbiota showed greater deviation from baseline in ICS nonresponders than in ICS responders. CONCLUSIONS: Novel associations of sputum and oral microbiota to immunologic features were observed in this cohort of subjects with or without ICS-naive mild asthma. These findings confirm and extend our previous report of reduced bronchial bacterial burden and compositional complexity in subjects with T2-high asthma, with additional identification of a T2-low subgroup with a distinct microbiota-immunologic relationship.

Synthesis and Biological Evaluation of Subglutinol Analogs for Immunomodulatory Agents.

Autoimmune diseases are chronic inflammatory diseases associated with high morbidity and mortality. Treatment options for autoimmune diseases have increased over the past several decades, but they are, in general, limited in their clinical efficacy due to high toxicity and lack of selectivity. Thus, efforts must be made to identify new immunomodulatory agents that are effective through a novel mechanism to circumvent existing side effects. To define the structural requirements of subglutinols for immunomodulatory activity and to provide guiding principles on future therapeutic development, we prepared and evaluated several subglutinol analogs for their immunomodulatory activities. Our efforts identified a subglutinol analog with reduced structural complexity as a potential lead compound for future autoimmune drug development. Our study will provide an important framework for the design of potent and nontoxic immunomodulating agents derived from subglutinols.

Bacterial biogeography of adult airways in atopic asthma.

BACKGROUND: Perturbations to the composition and function of bronchial bacterial communities appear to contribute to the pathophysiology of asthma. Unraveling the nature and mechanisms of these complex associations will require large longitudinal studies, for which bronchoscopy is poorly suited. Studies of samples obtained by sputum induction and nasopharyngeal brushing or lavage have also reported asthma-associated microbiota characteristics. It remains unknown, however, whether the microbiota detected in these less-invasive sample types reflect the composition of bronchial microbiota in asthma. RESULTS: Bacterial microbiota in paired protected bronchial brushings (BB; n = 45), induced sputum (IS; n = 45), oral wash (OW; n = 45), and nasal brushings (NB; n = 27) from adults with mild atopic asthma (AA), atopy without asthma (ANA), and healthy controls (HC) were profiled using 16S rRNA gene sequencing. Though microbiota composition varied with sample type (p < 0.001), compositional similarity was greatest for BB-IS, particularly in AAs and ANAs. The abundance of genera detected in BB correlated with those detected in IS and OW (r median [IQR] 0.869 [0.748-0.942] and 0.822 [0.687-0.909] respectively), but not with those in NB (r = 0.004 [- 0.003-0.011]). The number of taxa shared between IS-BB and NB-BB was greater in AAs than in HCs (p < 0.05) and included taxa previously associated with asthma. Of the genera abundant in NB, only Moraxella correlated positively with abundance in BB; specific members of this genus were shared between the two compartments only in AAs. Relative abundance of Moraxella in NB of AAs correlated negatively with that of Corynebacterium but positively with markers of eosinophilic inflammation in the blood and BAL fluid. The genus, Corynebacterium, trended to dominate all NB samples of HCs but only half of AAs (p = 0.07), in whom abundance of this genus was negatively associated with markers of eosinophilic inflammation. CONCLUSIONS: Induced sputum is superior to nasal brush or oral wash for assessing bronchial microbiota composition in asthmatic adults. Although compositionally similar to the bronchial microbiota, the microbiota in induced sputum are distinct, reflecting enrichment of oral bacteria. Specific bacterial genera are shared between the nasal and the bronchial mucosa which are associated with markers of systemic and bronchial inflammation.

Alternative splicing of interleukin-33 and type 2 inflammation in asthma.

Type 2 inflammation occurs in a large subgroup of asthmatics, and novel cytokine-directed therapies are being developed to treat this population. In mouse models, interleukin-33 (IL-33) activates lung resident innate lymphoid type 2 cells (ILC2s) to initiate airway type 2 inflammation. In human asthma, which is chronic and difficult to model, the role of IL-33 and the target cells responsible for persistent type 2 inflammation remain undefined. Full-length IL-33 is a nuclear protein and may function as an "alarmin" during cell death, a process that is uncommon in chronic stable asthma. We demonstrate a previously unidentified mechanism of IL-33 activity that involves alternative transcript splicing, which may operate in stable asthma. In human airway epithelial cells, alternative splicing of the IL-33 transcript is consistently present, and the deletion of exons 3 and 4 (Δ exon 3,4) confers cytoplasmic localization and facilitates extracellular secretion, while retaining signaling capacity. In nonexacerbating asthmatics, the expression of Δ exon 3,4 is strongly associated with airway type 2 inflammation, whereas full-length IL-33 is not. To further define the extracellular role of IL-33 in stable asthma, we sought to determine the cellular targets of its activity. Comprehensive flow cytometry and RNA sequencing of sputum cells suggest basophils and mast cells, not ILC2s, are the cellular sources of type 2 cytokines in chronic asthma. We conclude that IL-33 isoforms activate basophils and mast cells to drive type 2 inflammation in chronic stable asthma, and novel IL-33 inhibitors will need to block all biologically active isoforms.