Biology subjects

Munoz-Sandoval, P.

Publications and source records attributed to Munoz-Sandoval, P..

3 recordsLinked to original sources

bioRxiv2026

Allergen-responsive T helper type 2 cells revealed by high-dimensional profiling in allergen challenged human airways

Asthma is a chronic inflammatory disease affecting over 300 million people worldwide. This disease has multiple underlying etiologies, and a major endotype of asthma is characterized by cellular and molecular signatures of type 2 (allergic) inflammation. In this study we conducted bronchoscopies with airway segmental allergen challenge in allergic asthmatics to dissect airway responses to allergen. Using mass cytometry and single-cell RNA sequencing, we characterized with high resolution the airway immune landscape before and after allergen challenge and the heterogeneity present between subjects. This heterogeneity generally falls along a type 1/ type 2 axis. In type 2 high individuals, we identified allergen-reactive Th2 cells by using TCR sequences to barcode clonal T cell populations in single-cell genomic and activation-induced marker expression assays. These potentially pathogenic Th2 cell clones were present systemically and expanded following allergen challenge, connecting local lung inflammation to systemic clonal Th2 cell dynamics. Th2 cell airway ingress was coordinated with myeloid cell expression of T cell chemoattractants including CCL17 and CCL22. This study provides insight into the molecular and cellular components of allergen-induced tissue inflammation in asthma. Deeper resolution of the T cell response to aeroallergens may inform novel diagnostic and therapeutic strategies for asthma and other allergic airway diseases.

immunology↗

bioRxiv2023

The lncRNA Malat1 Inhibits miR-15/16 to Enhance Cytotoxic T Cell Activation and Memory Cell Formation

Proper activation of cytotoxic T cells via the T cell receptor and the costimulatory receptor CD28 is essential for adaptive immunity against viruses, many intracellular bacteria and cancers. Through biochemical analysis of RNA:protein interactions, we uncovered a non-coding RNA circuit regulating activation and differentiation of cytotoxic T cells composed of the long non-coding RNA Malat1 (Metastasis Associated Lung Adenocarcinoma Transcript 1) and the microRNA family miR-15/16. miR-15/16 is a widely and highly expressed tumor suppressor miRNA family important for cell proliferation and survival. miR-15/16 also play important roles in T cell responses to viral infection, including the regulation of antigen-specific T cell expansion and T cell memory. Comparative Argonaute-2 high throughput sequencing of crosslinking immunoprecipitation (Ago2 HITS-CLIP, or AHC) combined with gene expression profiling in normal and miR-15/16-deficient T cells revealed a large network of several hundred direct miR-15/16 target mRNAs, many with functional relevance for T cell activation, survival and memory formation. Among these targets, the long non-coding RNA Malat1 contained the largest absolute magnitude miR-15/16-dependent AHC peak in T cells. This binding site was also among the strongest lncRNA:miRNA interactions detected in the T cell transcriptome. We used CRISPR targeting with homology directed repair to generate mice with a 5-nucleotide mutation in the miR-15/16 binding site in Malat1. This mutation interrupted Malat1:miR-15/16 interaction, and enhanced the repression of other miR-15/16 target genes, including CD28. Interrupting Malat1 interaction with miR-15/16 decreased cytotoxic T cell activation, including the expression of IL-2 and a broader CD28-responsive gene program. Accordingly, Malat1 mutation diminished memory cell persistence following LCMV Armstrong and Listeria monocytogenes infection. This study marks a significant advance in the study of long noncoding RNAs in the immune system by ascribing cell-intrinsic, sequence-specific in vivo function to Malat1. These findings have implications for T cell-mediated autoimmune diseases, antiviral and anti-tumor immunity, as well as lung adenocarcinoma and other malignancies where Malat1 is overexpressed. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=197 SRC="FIGDIR/small/536843v2_figu1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1ebb1bborg.highwire.dtl.DTLVardef@e19c29org.highwire.dtl.DTLVardef@1d3568forg.highwire.dtl.DTLVardef@1d7d69b_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2020

Global Absence and Targeting of Protective Immune States in Severe COVID-19.

While SARS-CoV-2 infection has pleiotropic and systemic effects in some patients, many others experience milder symptoms. We sought a holistic understanding of the severe/mild distinction in COVID-19 pathology, and its origins. We performed a whole-blood preserving single-cell analysis protocol to integrate contributions from all major cell types including neutrophils, monocytes, platelets, lymphocytes and the contents of serum. Patients with mild COVID-19 disease display a coordinated pattern of interferon-stimulated gene (ISG) expression across every cell population and these cells are systemically absent in patients with severe disease. Severe COVID-19 patients also paradoxically produce very high anti-SARS-CoV-2 antibody titers and have lower viral load as compared to mild disease. Examination of the serum from severe patients demonstrates that they uniquely produce antibodies with multiple patterns of specificity against interferon-stimulated cells and that those antibodies functionally block the production of the mild disease-associated ISG-expressing cells. Overzealous and auto-directed antibody responses pit the immune system against itself in many COVID-19 patients and this defines targets for immunotherapies to allow immune systems to provide viral defense. One Sentence SummaryIn severe COVID-19 patients, the immune system fails to generate cells that define mild disease; antibodies in their serum actively prevents the successful production of those cells.

immunology↗