Document text
Principal Investigator: Jason G Cyster
Organization: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
Fiscal Year: 2024
Award: $562,480
Funding agency: National Institute of Allergy and Infectious Diseases
Project Summary/Abstract
The intestinal immune system plays crucial roles in maintaining tissue and microbiome homeostasis
and in protecting from pathogens. Two major classes of intestinal immune cells are the intraepithelial
lymphocytes (IEL) and IgA producing cells. The factors controlling the compartmentalization and homeostasis
of immune cells in different intestinal niches are incompletely understood.
G-protein coupled receptors (GPCRs) have diverse actions in recruiting and retaining cells in tissues.
Chemoattractant receptors couple to Gαi and have critical roles in cell recruitment to the gut. Recent studies
have identified important roles for Gα13-coupled receptors in organizing lymphoid niches, but their function in
the intestinal immune system is poorly understood. In preliminary data we find that removal of Gα13 from
hematopoietic cells leads to a deficiency of γδT and αβT IEL. In Aim 1, we will define how Gα13-signaling
contributes to IEL compartmentalization and function. Lineage specific Cre lines will enable dissection of
subset selective effects and tamoxifen-inducible TCRδ-CreERT2 will be used to define the stage(s) when
Gα13 is required in the γδT IEL compartment. CD8αβ T cells will be differentiated in vitro in the presence of
retinoic acid and TGFβ to induce a gut tropic α4β7+ CCR9+ state and used in transfer experiments to dissect
the mechanism by which Gα13-deficiency impacts on CD8αβ TCRαβ IELs. The role of downstream factors
Ahrgef1, RhoA and ROCK will be investigated as well as possible cross talk with AHR. The impact of Gα13-
deficiency on the response to intestinal pathogens will be studied.
In Aim 2, the GPCRs acting upstream of Gα13 in IEL will be characterized. Our prior work showed that
GPR18 is important for IEL competitiveness. We will test the dependence of GPR18 function on Gα13
signaling. GPR55, a lysophosphatidylinositol responsive Gα13-coupled receptor, restrains IEL interaction with
the epithelium. We will test the possibility that in the absence of Gα13, GPR55 becomes dominantly coupled to
Gαi, leading to IEL mispositioning and loss. CRISPR-based knockout in retroviral bone marrow chimeras will
be used to identify further Gα13-coupled receptors contributing to IEL homeostasis.
During our study of conditional Gα13-deficient mice we observed an exaggerated IgA response in
mesenteric lymph nodes (MLNs) but not Peyer’s patches. Individual MLNs drain different regions of the
intestine. In Aim 3, we will examine the impact of Gα13 deficiency in each MLN type. We will identify the
stage(s) during IgA+ GC B cell generation that Gα13 acts and perform microscopy and cell contact-tracing
studies to characterize the cell-cell interactions determining the magnitude of the MLN IgA response.
These studies will advance our understanding of cues and signaling pathways acting to promote
intestinal lymphocyte homeostasis and function. Given that GPCRs are the most drugged class of molecules,
our studies are likely to lead to new opportunities to identify therapies for gut inflammatory diseases.
Terms: <ARHGEF1><ARHGEF1 gene><ATRA><Abscission><Adhesions><Autoregulation><B blood cells><B cell><B cells><B-Cells><B-Lymphocytes><B-cell><Blood Plasma Cell><Body Tissues><Bone Marrow><Bone Marrow Reticuloendothelial System><Bone-Derived Transforming Growth Factor><C-C CKR-9><CC-CKR-9><CCL25><CCL25 gene><CCR-9><CCR9><CCR9 gene><CD8><CD8B><CD8B1><CD8B1 gene><CRISPR><CRISPR/Cas system><Cell Body><Cell Communication><Cell Communication and Signaling><Cell Compartmentation><Cell Compartmentations><Cell Count><Cell Interaction><Cell Number><Cell Signaling><Cell-to-Cell Interaction><Cells><Chemoattractant Receptor><Chemokine Receptor Gene><Chemokine, CC Motif, Ligand 25><Chemotactic Cytokines><Chemotactic Peptide Receptor><Chemotaxis><Chimera><Chimera organism><Class Switching><Class Switchings><Clinical><Clustered Regularly Interspaced Short Palindromic Repeats><Communicable Disease Contact Tracing><Contact Tracing><Coupled><Cues><Data><Dendritic Cells><Dependence><Differentiation in cell culture><Disease><Disorder><Dissection><Epithelium><Excision><Extirpation><F-Chemotactic Peptide Receptor><Formyl Peptide Receptors><G Protein-Complex Receptor><G Protein-Coupled Receptor Genes><G-Protein-Coupled Receptors><GPCR><GPR-9-6><GPR18><GPR18 receptor><GPR55><GPR55 receptor><Gene Expression Monitoring><Gene Expression Pattern Analysis><Gene Expression Profiling><Gene Targeting><Generations><Germinal Center><Guanine Nucleotide Exchange Factor, 115-kD><Hematopoietic><Heterotrimeric G-Proteins><Heterotrimeric GTP-Binding Proteins><Homeostasis><Homolog of Mouse LSC><Homologous Chemotactic Cytokines><IgA><Image><Immune><Immune Diseases><Immune Disorders><Immune Dysfunction><Immune System Diseases><Immune System Disorder><Immune System Dysfunction><Immune System and Related Disorders><Immune Tolerance><Immune system><Immunes><Immunity><Immunodeficiency and Immunosuppression Disorders><Immunoglobulin A><Immunoglobulin Class Switching><Immunoglobulin Class Switchings><Immunoglobulin Isotype-Switch Recombination><Immunoglobulin Switch Recombination><Immunologic Diseases><Immunologic Tolerance><Immunological Diseases><Immunological Dysfunction><Immunological System Dysfunction><Immunosuppressants><Immunosuppressive Agents><Immunosuppressive drug><Immunosuppressive treatment><In vitro cell differentiation><Individual><Infection><Infectious Disease Contact Tracing><Inflammatory><Integrins><Integrins Extracellular Matrix><Intercrines><Intestinal><Intestines><Intracellular Communication and Signaling><Isotype Switching><Isotype Switchings><Knock-out><Knockout><LSC gene><LSC protein><LYT3><Lamina Propria><Ligands><Lymphatic Tissue><Lymphatic cell><Lymphocyte><Lymphocytic><Lymphoid><Lymphoid Tissue><Mediating><Mice><Mice Mammals><Microscopy><Milk Growth Factor><Molecular><Mucosa><Mucosal Tissue><Mucous Membrane><Murine><Mus><Myeloid Cells><N-Formylmethionyl Peptide Receptor><N-formyl Hexapeptide Receptor><P115-RHOGEF><Peyer's Patches><Phenotype><Physiological Homeostasis><Plasma Cells><Plasmacytes><Platelet Transforming Growth Factor><Play><Population><Position><Positioning Attribute><Receptor Protein><Removal><Retinoic Acid><Rho Guanine Nucleotide Exchange Factor 1><Role><SCYA25><SIS cytokines><Signal Pathway><Signal Transduction><Signal Transduction Systems><Signaling><Small Inducible Cytokine Subfamily A, Member 25><Small Intestines><Structure of germinal center of lymph node><Surgical Removal><Switch Recombination><System><T-Cells><T-Lymphocyte><TECK><TGF B><TGF-beta><TGF-β><TGFbeta><TGFβ><Tamoxifen><Testing><Thymus><Thymus Gland><Thymus Proper><Thymus Reticuloendothelial System><Thymus-Expressed Chemokine><Tissues><Trans Vitamin A Acid><Transcript Expression Analyses><Transcript Expression Analysis><Transforming Growth Factor beta><Transforming Growth Factor-Beta Family Gene><Tretinoin><Tretinoinum><Veiled Cells><Vitamin A Acid><Work><all-trans-Retinoic Acid><all-trans-Vitamin A acid><analyze gene expression><biological signal transduction><bowel><chemoattractant cytokine><chemokine><chemokine receptor><chimeras><develop therapy><differentiation in culture><differentiation in vitro><draining lymph node><enteral pathogen><enteric pathogen><enteropathogen><experiment><experimental research><experimental study><experiments><fMet-Leu-Phe receptor><firewall><gene expression analysis><gene expression assay><gut microbes><gut microbial species><hemopoietic><imaging><immune suppressive agent><immune suppressor><immune system tolerance><immune unresponsiveness><immunological paralysis><immunosuppressive substance><immunosuppressor><in vitro cellular differentiation><intervention development><intestinal barrier><intestinal microbes><intestinal mucosal barrier><intestinal pathogen><intestine pathogen><intra-vital imaging><intraepithelial><intravital imaging><knockout gene><lymph cell><lysoPI><lysophosphatidylinositol><mesenteric lymph node><mesentery lymph node><microbiome><p115 rhoGEF><pathogen><plasmocyte><receptor><recruit><regional lymph node><resection><response><restraint><rho><rho guanine nucleotide exchange factor p115><small bowel><social role><therapy development><thymus derived lymphocyte><trans-Retinoic Acid><transcriptional profiling><treatment development>