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Canesso, M. C. C.

Publications and source records attributed to Canesso, M. C. C..

7 recordsLinked to original sources

Eosinophil-epithelial interactions mediate protective intestinal remodeling during food allergy

Food allergies are associated with progressive gastrointestinal symptoms driven by exacerbated mucosal type-2 immunity. Here, we investigated whether cellular interactions between the gut epithelium and innate immune cells regulate the severity of allergic symptoms in mice. Using the BALB/c OVA-alum food allergy model, we observed that repeated oral allergen challenges remodel the gut epithelium, expanding tuft cells, while shifting the intestinal stem cell niche toward a fetal-like repair state. Using uLIPSTIC, we systematically characterized in vivo immune-epithelial interactions and found that eosinophils and mast cells directly interact with intestinal epithelial cells (iECs) in an allergen challenge-dependent manner. Epithelial subset-specific uLIPSTIC provided further resolution and revealed that eosinophils and mast cells contact enteroendocrine cells and Paneth cells in a regionally compartmentalized manner. Allergic challenge was associated with rapid eosinophil migration towards the crypts and modulation of iEC differentiation. Depletion of eosinophils using two independent approaches reversed key markers of food allergy-associated epithelial remodeling, while exacerbating allergic diarrhea and mortality from anaphylactic shock. These findings establish eosinophils as orchestrators of protective epithelial remodeling in food allergies.

immunology↗

Identification of distinct cDC2 subpopulations that direct microbiota-specific T cell differentiation

How the complex network of intestinal antigen presenting cells (APCs) instructs CD4+ T cell responses against the microbiota remains unclear. Here, we use Labeling Immune Partnerships by SorTagging Intercellular Contacts (LIPSTIC) to characterize the APCs that prime CD4+ T cells recognizing the commensal bacterium Akkermansia muciniphila. A. muciniphila-specific T cells engaged multiple transcriptionally distinct migratory cDC2 subpopulations, both at homeostasis, when A. muciniphila promotes TFH differentiation, and during inflammation, when it also drives TH1 and TH17 differentiation. The identity of these subpopulations was unchanged by inflammation; however, the distribution of presentation across the subpopulations shifted, with increased presentation by inflammatory cDC2s favoring TH1 and TH17 polarization. These results reveal how distinct T cell differentiation trajectories can be determined through varied interactions with multiple, functionally distinct subpopulations of APCs.

immunology↗

A Specialized CD107a+ Macrophage Subset Drives Selective Mycobacterial Phagocytosis

Macrophages are essential for pathogen clearance, yet phagocytic specialization among subsets is poorly defined. Bone marrow-derived macrophages cultured with L929 supernatant or M-CSF separate into FSCloSSCloF4/80loCD11blo (FSCloSSClo) and FSChiSSChiF4/80hiCD11bhi (FSChiSSChi) subsets. Transcriptomic and functional analyses reveal that FSCloSSClo cells possess a hyperphagocytic program driven by enhanced actin cytoskeleton regulators (e.g., Arp2/3) and pro-inflammatory signaling (NF-{kappa}B). These cells excel at internalizing Mycobacterium tuberculosis virulent H37Rv and BCG through actin-mediated, cytochalasin D-sensitive mechanisms. High surface CD107a (LAMP1) expression marks this hyperphagocytic subset and correlates strongly with mycobacterial uptake. FSCloSSClo macrophages produce more TNF and IL-6 upon mycobacterial or TLR2/TLR5 stimulation yet retain IFN-{gamma}-mediated killing capacity. In vivo, CD107a alveolar macrophages in BCG-infected lungs preferentially capture bacilli and upregulate CD195, recapitulating the in vitro phenotype. These findings establish CD107a as a key surface marker of a hyperphagocytic macrophage subset and highlight its role in selective mycobacterial phagocytosis, providing new mechanistic understanding relevant to tuberculosis host defense and therapeutic development. HighlightsO_LIBone marrow-derived FSCloSSCloF4/80loCD11blo macrophage subset excels at M. tuberculosis and BCG uptake C_LIO_LIHyperphagocytic macrophages mount rapid pro-inflammatory TNF/IL-6 responses C_LIO_LICD107a (LAMP1) identifies a pre-existing hyperphagocytic macrophage subset in vitro and in vivo C_LIO_LIBCG infection triggers CD195 (CCR5) upregulation selectively on CD107a alveolar macrophages C_LI

immunology↗

Dietary protein shapes the profile and repertoire of intestinal CD4+ T cells

The intestinal immune system must tolerate food antigens to avoid allergy, a process requiring CD4+ T cells. Combining antigenically defined diets with gnotobiotic models, we show that food and microbiota distinctly influence the profile and T cell receptor repertoire of intestinal CD4+ T cells. Independent of the microbiota, dietary proteins contributed to accumulation and clonal selection of antigen-experienced CD4+ T cells at the intestinal epithelium, imprinting a tissue specialized transcriptional program including cytotoxic genes on both conventional and regulatory CD4+ T cells (Tregs). This steady state CD4+ T cell response to food was disrupted by inflammatory challenge, and protection against food allergy in this context was associated with Treg clonal expansion and decreased pro-inflammatory gene expression. Finally, we identified both steady state epithelium-adapted CD4+ T cells and tolerance-induced Tregs that recognize dietary antigens, suggesting that both cell types may be critical for preventing inappropriate immune responses to food.

immunology↗

Universal recording of cell-cell contacts in vivo for interaction-based transcriptomics

Cellular interactions are essential for tissue organization and functionality. In particular, immune cells rely on direct and usually transient interactions with other immune and non-immune populations to specify and regulate their function. To study these "kiss-and-run" interactions directly in vivo, we previously developed LIPSTIC (Labeling Immune Partnerships by SorTagging Intercellular Contacts), an approach that uses enzymatic transfer of a labeled substrate between the molecular partners CD40L and CD40 to label interacting cells. Reliance on this pathway limited the use of LIPSTIC to measuring interactions between CD4+ helper T cells and antigen presenting cells, however. Here, we report the development of a universal version of LIPSTIC (uLIPSTIC), which can record physical interactions both among immune cells and between immune and non-immune populations irrespective of the receptors and ligands involved. We show that uLIPSTIC can be used, among other things, to monitor the priming of CD8+ T cells by dendritic cells, reveal the cellular partners of regulatory T cells in steady state, and identify germinal center (GC)-resident T follicular helper (Tfh) cells based on their ability to interact cognately with GC B cells. By coupling uLIPSTIC with single-cell transcriptomics, we build a catalog of the immune populations that physically interact with intestinal epithelial cells (IECs) and find evidence of stepwise acquisition of the ability to interact with IECs as CD4+ T cells adapt to residence in the intestinal tissue. Thus, uLIPSTIC provides a broadly useful technology for measuring and understanding cell-cell interactions across multiple biological systems.

immunology↗

Identification of dendritic cell-T cell interactions driving immune responses to food

The intestinal immune system must concomitantly tolerate food and commensals and protect against pathogens. Dendritic cells (DCs) orchestrate these immune responses by presenting luminal antigens and inducing functional differentiation of CD4+ T cells into regulatory (pTreg) or pro-inflammatory (Th) subsets. However, the exact nature of the DCs inducing tolerance or inflammation to dietary antigens has been difficult to define. Using an intestine-adapted Labeling Immune Partnerships by SorTagging Intercellular Contacts (LIPSTIC) combined with single-cell transcriptomics, we characterized DCs presenting dietary antigens in the context of tolerance or infection. At steady-state, migratory cDC1 and cDC2 DCs, but not resident DCs, were found to present dietary antigen to cognate CD4+ T cells. Whereas cDC2s promoted T cell activation, only cDC1s induced their differentiation into pTregs. Infection with the helminth Strongyloides venezuelensis abrogated cDC1 presentation of dietary antigens, preventing pTreg and oral tolerance induction. In contrast, Heligmosomoides polygyrus infection only partially affected cDC1s, allowing oral tolerance to be maintained. An expanded population of cDC2s that induced type-2 immunity during both helminth infections did not present dietary antigens, demonstrating that compartmentalized presentation of luminal antigens can prevent food-specific Th2 responses during inflammatory conditions. Our data uncover novel cellular mechanisms by which tolerance to food is induced and can be disrupted during infections.

immunology↗

Neuroimmune circuits involved in β-lactoglobulin-induced food allergy

Cows milk allergy is the most prevalent food allergy that usually begins early in life and {beta}- lactoglobulin (BLG) is the milk component with the highest allergenicity. It has been described that ovalbumin (OVA)-induced food allergy in mice is associated with anxiety and aversive behavior. However, it is yet to be determined whether altered behavior is a general component of food allergy or whether it is specific for some types of allergens. Thus, we investigated behavioral and neuroimmune circuits triggered by allergic sensitization to BLG. We found a neuroimmune conflict between aversion and reward in a model of food allergy induced to BLG. Mice sensitized to BLG did not present aversive behavior when the allergen was used for sensitization and oral challenge. Mice allergic to BLG preferred to drink the allergen-containing solution over water even though they presented high levels of specific IgE, inflammatory cells in the intestinal mucosa and significant weight loss. When sensitized to OVA and orally challenged with the same antigen, mice had display neuron activation in the amygdala suggesting an anxiety-related sensation. On the other hand, OVA-sensitized mice showed preference to consume a mixture of BLG and OVA during oral challenge in spite of their aversion to OVA. Consumption of OVA-BLG solution was associated with neuron activation in the nucleus accumbens, suggesting a reward sensation. Thus, the aversive behavior observed in food allergy to OVA does not apply to all antigens and some allergens may induce preference rather than aversion. Our study provides new insights into the neuroimmune conflicts regarding preference and avoidance to a common antigen associated with food allergy.

immunology↗