Biology subjects

Goldenring, J. R.

Publications and source records attributed to Goldenring, J. R..

14 recordsLinked to original sources

bioRxiv2026

A unique intestinal epithelial cell that expresses canonical lymphoid genes

Enterocytes and intestinal secretory cells harbor innate immunity. However, certain transcriptional programs -even beyond rearranged T- and B-cell receptor genes- are considered the exclusive purview of adaptive immune cells, including abundant and diverse intestinal intra-epithelial lymphocytes (IELs). Here, we identify and characterize columnar intestinal secretory cells that co-express classic epithelial and lymphoid genes, including Ptprc, Cd3e, Cd8a, and Gzma/b but not T- or B-cell receptors. These previously unrecognized epithelium-derived lymphoid-like cells (EDLCs) differ from any known resident cell type, including IELs or tuft cells. Rare in healthy mouse and human intestines, their numbers increase upon IL-25 stimulation or IL-10 receptor deficiency in vivo and upon IL-13 stimulation in vitro. EDLC chromatin is uniquely accessible at thousands of cis-elements, including lymphoid and epithelial loci. These findings reveal a transcriptionally and epigenetically distinct intestinal epithelial derivative that expresses prominent lymphoid character.

cell biology↗

bioRxiv2026

PKA/CIP4 SIGNALING REGULATES CIP4 RELOCATION IN ACTIVATED NATURAL KILLER CELLS

Natural killer (NK) cells are cytotoxic lymphocytes of the innate immune system that eliminate virus-infected and transformed cells through the formation of a specialized immune synapse. Effective target cell killing requires coordinated plasma membrane remodeling and dynamic reorganization of the actin and microtubule cytoskeletons, enabling centrosome polarization and directed secretion of lytic granules. The scaffold protein CIP4 has emerged as an important regulator of cytoskeletal coordination in NK cells, yet how its subcellular localization is controlled during NK cell activation is unknown. CIP4 contains a unique protein kinase A (PKA) phosphorylation site (threonine 225, T225) within its F-BAR domain, a domain that mediates interactions with microtubules and the plasma membrane. We hypothesized that localized PKA signaling controls CIP4 redistribution during immune synapse assembly. To test this hypothesis, we analyzed CIP4 localization and phosphorylation in NK cells engaged with sensitive target cells using biochemical and imaging approaches. We show that NK-target cell interaction enhances PKA activity and promotes phosphorylation of CIP4, coinciding with its delocalization from microtubules and accumulation at the immune synapse. Importantly, this relocalization process requires the PKA-anchoring protein AKAP350, which positions PKA and CIP4 within the same protein complex, thereby facilitating CIP4 phosphorylation. Consistently, pharmacological inhibition of PKA prevented CIP4 delocalization from microtubules and reduced its accumulation at the immune synapse. The non-phosphorylatable CIP4 mutant T225A displayed increased association with microtubules compared with a phosphomimetic mutant, identifying phosphorylation at T225 as a key determinant of CIP4 spatial regulation. Together, these findings identify a signaling mechanism that links compartmentalized PKA activity to the spatial control of CIP4 during immune synapse formation, providing new insight into the molecular mechanisms governing immune synapse maturation.

immunology↗

bioRxiv2025

Coronavirus membrane protein with a fluorescent protein tag enables tracking of virus particles in live cells

Coronavirus particles assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and exit from host cells via secretory organelles that are not well defined. The interplay between viral components and intracellular transport pathways that facilitate assembly and egress are not fully understood and recent studies suggest that multiple pathways maybe involved. Reverse genetics was used to develop a model system to further understand the assembly and egress processes. Mouse hepatitis coronavirus (MHV-A59) was genetically engineered to express the membrane (M) protein fused to green fluorescent protein (M-GFP), with the chimeric gene cloned in place of the open reading frame (ORF) 4 coding region in the RNA genome. The recovered M-GFP virus also expresses wild-type (WT) M protein (M WT) from its native ORF. The M-GFP virus exhibited morphology and growth properties like WT virus. M-GFP and WT M proteins colocalized early in infection, but less M-GFP trafficked toward the cell surface at later times, suggesting that the fusion protein is incorporated less efficiently into virus particles. M-GFP was stably expressed through at least four virus passages. Early passage virus M-GFP virus particles were visualized by confocal and Total Internal Reflection Fluorescence (TIRF) microscopy in live cells. The fluorescently labeled virus particles represent a new tool for coronavirus intracellular trafficking and egress studies. Such studies can also help provide a more detailed understanding of infection and disease processes to provide new insight for development of new therapeutic strategies. IMPORTANCECoronavirus assembly, intracellular transport, egress, and the virus-host interactions involved in these processes are not fully understood. The M protein is the most abundant virion structural component, which forms the scaffold for assembly of the viral envelope. It facilitates incorporation of the viral nucleocapsid and the other viral membrane proteins, spike (S) and envelope (E). In this study we engineered M protein tagged with GFP, which is expressed along with wild-type (WT) M from the viral genome. M-GFP interacted with WT M protein and co-assembled into virus particles. The resulting fluorescently labeled coronavirus particles open opportunities to use state of the art microscopy to monitor virus assembly, trafficking, and egress in live cells to facilitate deeper understanding of the molecular and cell biology of these processes. The ability to visualize particles also opens opportunities to help further understanding of steps in viral replication and pathogenesis for potential therapeutic targets.

microbiology↗

bioRxiv2025

CLASP1/2 REGULATE IMMUNE SYNAPSE MATURATION IN NATURAL KILLER CELLS

Natural killer (NK) cells are the first line of defense against viral infections and tumors. Their cytotoxic activity relies on the formation of an immune synapse (IS) with target cells. The lymphocyte function-associated antigen (LFA)-1 plays a central role in NK cell cytotoxicity by modulating NK-IS assembly and maturation. LFA-1 organization at the IS involves a Golgi-dependent mechanism, which has not been completely elucidated. CLIP-associating proteins (CLASP) 1/2 are microtubule plus-tip interacting proteins that control the dynamics of Golgi derived microtubules (GDMTs). In the present study, we found that CLASP1/2 depletion impaired LFA-1 organization at the IS and inhibited the polarization of the centrosome and the lytic granules towards the target cell. Our results also revealed the role of the Golgi apparatus as a microtubule organizing center (MTOC) in these cells. Furthermore, we found that, similarly to what was described in other cell types, NK cells require CLASP1/2 and AKAP350 for efficient nucleation of microtubules at the Golgi. Overall, this study uncovers the role of CLASP1/2 in the maturation of the lytic IS in NK cells, and presents evidence supporting the contribution of GDMTs in this process. Summary sentenceThe Golgi apparatus (GA) functions as a microtubule-organizing center (MTOC) in NK cells. During the recognition of tumoral cells by NK cells, CLASP1/2-mediated stabilization of GA-derived microtubules (GDMTs) facilitates vesicular LFA-1 (LFA-1v) trafficking toward the interaction surface, thereby promoting the immune synapse (IS) maturation.

immunology↗

bioRxiv2024

Altered cellular metabolic pathway and epithelial cell maturation induced by MYO5B defects are partially reversible by LPAR5 activation

Functional loss of the motor protein, Myosin Vb (MYO5B), induces various defects in intestinal epithelial function and causes a congenital diarrheal disorder, microvillus inclusion disease (MVID). Utilizing the MVID model mice, Vil1-CreERT2;Myo5bflox/flox (MYO5B{Delta}IEC) and Vil1-CreERT2;Myo5bflox/G519R(MYO5B(G519R)), we previously reported that functional MYO5B loss disrupts progenitor cell differentiation and enterocyte maturation that result in villus blunting and deadly malabsorption symptoms. In this study, we determined that both absence and a point mutation of MYO5B impair lipid metabolism and alter mitochondrial structure, which may underlie the progenitor cell malfunction observed in MVID intestine. Along with a decrease in fatty acid oxidation, the lipogenesis pathway was enhanced in the MYO5B{Delta}IEC small intestine. Consistent with these observations in vivo, RNA-sequencing of enteroids generated from two MVID mouse strains showed similar downregulation of energy metabolic enzymes, including mitochondrial oxidative phosphorylation genes. In our previous studies, lysophosphatidic acid (LPA) signaling ameliorates epithelial cell defects in MYO5B{Delta}IEC tissues and enteroids. The present study demonstrates that the highly soluble LPAR5-preferred agonist, Compound-1, improved sodium transporter localization and absorptive function, and tuft cell differentiation in patient-modeled MVID animals that carry independent mutations in MYO5B. Body weight loss in male MYO5B(G519R) mice was ameliorated by Compound-1. These observations suggest that Compound-1 treatment has a trophic effect on intestine with MYO5B functional loss through epithelial cell-autonomous pathways that may improve the differentiation of progenitor cells and the maturation of enterocytes. Targeting LPAR5 may represent an effective therapeutic approach for treatment of MVID symptoms induced by different point mutations in MYO5B. NEW & NOTEWOTHYThis study demonstrates the importance of MYO5B for cellular lipid metabolism and mitochondria in intestinal epithelial cells, a previously unexplored function of MYO5B. Alterations in cellular metabolism may underlie the progenitor cell malfunction observed in microvillus inclusion disease (MVID). To examine the therapeutic potential of progenitor-targeted treatments, the effects of LPAR5-preferred agonist, Compound-1, was investigated utilizing several MVID model mice and enteroids. Our observations suggests that Compound-1 may provide a therapeutic approach for treating MVID. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/610579v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@54b5borg.highwire.dtl.DTLVardef@1966a5aorg.highwire.dtl.DTLVardef@2073f1org.highwire.dtl.DTLVardef@9c12e1_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2024

Cryo-EM of AKAP350 reveals fibrillar clusters and a potential association with DNA

Protein kinase A (PKA) is a promiscuous serine/threonine kinase that phosphorylates a broad-spectrum of effectors involved in vital processes such as glucose, glycogen, and lipid metabolism. Its activity is thus tightly controlled by a family of eukaryotic scaffolding proteins known as the A-kinase anchoring proteins (AKAPs) that confine PKA signaling to specific compartments in the cell. AKAP350 (the protein encoded by AKAP9) is a massive scaffolding protein that anchors PKA to the Golgi apparatus and the centrosome where it nucleates macromolecular signaling hubs that control microtubule nucleation and dynamics. Here, we have expressed and purified full-length AKAP350 from HEK293F cells in a functional conformation. Electron cryo-microscopy (cryo-EM) of the purified protein revealed polydisperse particles forming fibrillar clusters around 50 nm in diameter, and long, thin filaments that reconstructed into double-stranded DNA. Tomographic reconstruction of a tilt series of the purified protein by electron cryo-tomography (cryo-ET) further elucidated these fibrillar clusters as 3D bundles of entangled filaments. Mass spectrometry and DNA sequencing confirmed the co-purification of DNA and DNA binding proteins such as nuclear factor 1 B (NFIB) and nucleolin (NCL). Pulldown of NFIB and NCL, but not of CEP290, CDK5RAP2, and CEP170 was diminished in the presence of DNase-I, suggesting that AKAP350 interaction with these two proteins is mediated by DNA. Overall, this study has achieved a quality purification of AKAP350 from which a previously uncharacterized interaction landscape with DNA and DNA binding proteins was discovered.

biochemistry↗

bioRxiv2023

Concerted epithelial and stromal changes during progression of Barrett's Esophagus to invasive adenocarcinoma exposed by multi-scale, multi-omics analysis

Esophageal adenocarcinoma arises from Barretts esophagus, a precancerous metaplastic replacement of squamous by columnar epithelium in response to chronic inflammation. Multi-omics profiling, integrating single-cell transcriptomics, extracellular matrix proteomics, tissue-mechanics and spatial proteomics of 64 samples from 12 patients paths of progression from squamous epithelium through metaplasia, dysplasia to adenocarcinoma, revealed shared and patient-specific progression characteristics. The classic metaplastic replacement of epithelial cells was paralleled by metaplastic changes in stromal cells, ECM and tissue stiffness. Strikingly, this change in tissue state at metaplasia was already accompanied by appearance of fibroblasts with characteristics of carcinoma-associated fibroblasts and of an NK cell-associated immunosuppressive microenvironment. Thus, Barretts esophagus progresses as a coordinated multi-component system, supporting treatment paradigms that go beyond targeting cancerous cells to incorporating stromal reprogramming. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=187 SRC="FIGDIR/small/544265v1_ufig1.gif" ALT="Figure 1"> View larger version (62K): org.highwire.dtl.DTLVardef@64c375org.highwire.dtl.DTLVardef@15c6ef2org.highwire.dtl.DTLVardef@177dee0org.highwire.dtl.DTLVardef@c945e7_HPS_FORMAT_FIGEXP M_FIG Graphical AbstractTo obtain a comprehensive picture of the coordinated changes in epithelial, stromal and immune compartments during development of Barretts-associated esophageal adenocarcinoma, patient-matched samples corresponding to various phases of disease progression were collected from 12 patients, each of which had at a given time point lesions at multiple stages progression (matched-normal, metaplasia, dysplasia, and carcinoma). Matched "normal" gastric tissues were also collected. These sample were analyzed by single cell RNA-sequencing (scRNAseq) for single-cell resolution transcriptomics and Copy Number Variant (CNV), by proteomics for extracellular matrix (ECM) proteins, by Atomic Force Microscopy (AFM for tissue stiffness and by CODEX spatial proteomics imaging The integrative multi-omics analysis exposed drastic alterations in cell type composition and shifts in cell states in all three compartments. A large subpopulation of fibroblasts absent in the normal esophagus and characteristic of dysplasia and adenocarcinoma sample, that based on markers would indeed be considered cancer associated fibroblasts (CAF), appeared already in the metaplastic phase. This fibroblast subpopulation had transcriptomes virtually indistinguishable with fibroblasts of the cancer free gastric epithelium in these patients C_FIG

cancer biology↗

bioRxiv2023

Golgi organization is a determinant of stem cell function in the small intestine

Cell-to-cell signalling between niche and stem cells regulates tissue regeneration. While the identity of many mediating factors is known, it is largely unknown whether stem cells optimize their receptiveness to niche signals according to the niche organization. Here, we show that Lgr5+ small intestinal stem cells (ISCs) regulate the morphology and orientation of their secretory apparatus to match the niche architecture, and to increase transport efficiency of niche signal receptors. Unlike the progenitor cells lacking lateral niche contacts, ISCs orient Golgi apparatus laterally towards Paneth cells of the epithelial niche, and divide Golgi into multiple stacks reflecting the number of Paneth cell contacts. Stem cells with a higher number of lateral Golgi transported Epidermal growth factor receptor (Egfr) with a higher efficiency than cells with one Golgi. The lateral Golgi orientation and enhanced Egfr transport required A-kinase anchor protein 9 (Akap9), and was necessary for normal regenerative capacity in vitro. Moreover, reduced Akap9 in aged ISCs renders ISCs insensitive to niche-dependent modulation of Golgi stack number and transport efficiency. Our results reveal stem cell-specific Golgi complex configuration that facilitates efficient niche signal reception and tissue regeneration, which is compromised in the aged epithelium.

cell biology↗

bioRxiv2023

The MYO1B and MYO5B motor proteins and the SNX27 sorting nexin regulate membrane mucin MUC17 trafficking in enterocytes

A dense glycocalyx, composed of the megaDalton-sized membrane mucin MUC17, coats the microvilli in the apical brush border of transporting intestinal epithelial cells, called enterocytes. The establishment of the MUC17-based glycocalyx in the mouse small intestine occurs at the critical suckling-weaning transition. The enterocytic glycocalyx extends 1 {micro}m into the intestinal lumen and prevents the gut bacteria from directly attaching to the enterocytes. To date, the mechanism behind apical targeting of MUC17 to the brush border remains unknown. Here, we show that the actin-based motor proteins MYO1B and MYO5B, and the sorting nexin SNX27 regulate the intracellular trafficking of MUC17 in enterocytes. We demonstrate that MUC17 turnover at the brush border is slow and controlled by MYO1B and SNX27. Furthermore, we report that MYO1B regulates MUC17 protein levels in enterocytes, whereas MYO5B specifically governs MUC17 levels at the brush border. Together, our results extend our understanding of the intracellular trafficking of membrane mucins and provide mechanistic insights into how defective trafficking pathways render enterocytes sensitive to bacterial invasion.

cell biology↗

bioRxiv2023

Therapy Development for Microvillus Inclusion Disease using Patient-derived Enteroids

Microvillus Inclusion Disease (MVID), caused by loss-of-function mutations in the motor protein Myosin Vb (MYO5B), is a severe infantile disease characterized by diarrhea, malabsorption, and acid-base instability, requiring intensive parenteral support for nutritional and fluid management. Human patient-derived enteroids represent a model for investigation of monogenic epithelial disorders but are a rare resource from MVID patients. We developed human enteroids with different loss-of function MYO5B variants and showed that they recapitulated the structural changes found in native MVID enterocytes. Multiplex Immunofluorescence imaging of patient duodenal tissues revealed patient-specific changes in localization of brush border transporters. Functional analysis of electrolyte transport revealed profound loss of Na+/H+ exchange (NHE) activity in MVID patient enteroids with near-normal chloride secretion. The chloride channel-blocking anti-diarrheal drug, Crofelemer, dose-dependently inhibited agonist-mediated fluid secretion. MVID enteroids exhibited altered differentiation and maturation versus healthy enteroids. Inhibition of Notch signaling with the {gamma}-secretase inhibitor, DAPT, recovered apical brush border structure and functional Na+/H+ exchange activity in MVID enteroids. Transcriptomic analysis revealed potential pathways involved in the rescue of MVID cells including serum- and glucocorticoid-induced protein kinase 2 (SGK2), and NHE regulatory factor 3 (NHERF3). These results demonstrate the utility of patient-derived enteroids for developing therapeutic approaches to MVID. Conflict-of-interest statementThe authors have declared that no conflict of interest exists.

cell biology↗

bioRxiv2022

Toxin-mediated downregulation of absorptive ion transporters NHE3, DRA, and SGLT1 in the colon contributes to diarrhea associated with Clostridioides difficile infection.

Background & AimClostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea and pseudomembranous colitis. Two protein toxins, TcdA and TcdB, produced by C. difficile are the major determinants of disease. However, the physiological cause of diarrhea associated with CDI is not well understood. We investigated the effects of CDI on paracellular permeability and apical ion transporters. MethodsWe studied intestinal permeability and apical membrane transporters in female C57BL/6J mice. Ussing chambers were used to measure regional differences in paracellular permeability and ion transporter function in intestinal mucosa. Intestinal tissues were collected from mice and analyzed by immunofluorescence microscopy and RNA-sequencing. ResultsCDI increased intestinal permeability through the size-selective leak pathway in vivo, but permeability was not increased at the sites of pathological damage. Chloride secretion was reduced in the cecum during infection by decreased CaCC function. Infected mice had decreased SGLT1 (also called SLC5A1) activity in the cecum and colon along with diminished apical abundance and an increase in luminal glucose. SGLT1 and DRA (also called SLC26A3) expression was ablated by either TcdA or TcdB, but NHE3 (also called SLC9A3) was decreased in a TcdB-dependent manner. Finally, expression of these three ion transporters was drastically reduced at the transcriptional level. ConclusionsCDI increases intestinal permeability and decreases apical abundance of NHE3, SGLT1, and DRA. This combination may cause a dysfunction in water and solute absorption in the lower gastrointestinal tract, leading to osmotic diarrhea. These findings may open novel pathways for attenuating CDI-associated diarrhea. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=185 HEIGHT=200 SRC="FIGDIR/small/516162v1_ufig1.gif" ALT="Figure 1"> View larger version (69K): org.highwire.dtl.DTLVardef@e6e23corg.highwire.dtl.DTLVardef@ed6bborg.highwire.dtl.DTLVardef@33adcaorg.highwire.dtl.DTLVardef@d6e359_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2021

Single-cell transcriptomics reveals a conserved metaplasia program in pancreatic injury

BACKGROUND & AIMSAcinar to ductal metaplasia (ADM) occurs in the pancreas in response to tissue injury and is a potential precursor for adenocarcinoma. The goal of these studies was to define the populations arising from ADM, the associated transcriptional changes, and markers of disease progression. METHODSAcinar cells were lineage-traced with enhanced yellow fluorescent protein (EYFP) to follow their fate upon injury. Transcripts of over 13,000 EYFP+ cells were determined using single-cell RNA sequencing (scRNA-seq). Developmental trajectories were generated. Data were compared to gastric metaplasia, KrasG12D-induced neoplasia, and human pancreatitis. Results were confirmed by immunostaining and electron microscopy. KrasG12D was expressed in injury-induced ADM using several inducible Cre drivers. Surgical specimens of chronic pancreatitis from 15 patients were evaluated by immunostaining. RESULTSscRNA-seq of ADM revealed emergence of a mucin/ductal population resembling gastric pyloric metaplasia. Lineage trajectories suggest that some pyloric metaplasia cells can generate tuft and enteroendocrine cells (EECs). Comparison to KrasG12D-induced ADM identifies populations associated with disease progression. Activation of KrasG12D expression in HNF1B+ or POU2F3+ ADM populations leads to neoplastic transformation and formation of MUC5AC+ gastric-pit-like cells. Human pancreatitis samples also harbor pyloric metaplasia with a similar transcriptional phenotype. CONCLUSIONSUnder conditions of chronic injury, acinar cells undergo a pyloric-type metaplasia to mucinous progenitor-like populations, which seed disparate tuft cell and EEC lineages. ADM-derived EEC subtypes are diverse. KrasG12D expression is sufficient to drive neoplasia from injury-induced ADM and offers an alternative origin for tumorigenesis. This program is conserved in human pancreatitis, providing insight into early events in pancreas diseases.

cell biology↗

bioRxiv2021

Human colorectal pre-cancer atlas identifies distinct molecular programs underlying two major subclasses of pre-malignant tumors

Most colorectal cancers (CRCs) develop from either adenomas (ADs) or sessile serrated lesions (SSLs). The origins and molecular landscapes of these histologically distinct pre-cancerous polyps remain incompletely understood. Here, we present an atlas at single-cell resolution of sporadic conventional tubular/tubulovillous ADs, SSLs, hyperplastic polyps (HPs), microsatellite stable (MSS) and unstable (MSI-H) CRC, and normal colonic mucosa. Using single-cell transcriptomics and multiplex imaging, we studied 69 datasets from 33 participants. We also examined separate sets of 66 and 274 polyps for RNA and targeted gene sequencing, respectively. We performed multiplex imaging on a tissue microarray of 14 ADs and 15 CRCs, and we integrated pre-cancer polyp data with published single-cell and The Cancer Genome Atlas (TCGA) bulk CRC data to establish potential polyp-cancer relationships. Striking differences were observed between ADs and SSLs that extended to MSS and MSI-H CRCs, respectively, reflecting their distinct origins and trajectories. ADs arose from WNT pathway dysregulation in stem cells, which aberrantly expanded and expressed a Hippo and ASCL2 regenerative program. In marked contrast, SSLs were depleted of stem cell-like populations and instead exhibited a program of gastric metaplasia in the setting of elevated cytotoxic inflammation. Using subtype-specific gene regulatory networks and shared genetic variant analysis, we implicated serrated polyps, including some HPs conventionally considered benign, as arising from a metaplastic program in committed absorptive cells. ADs and SSLs displayed distinct patterns of immune cell infiltration that may influence their natural history. Our multi-omic atlas provides novel insights into the malignant potential of colorectal polyps and serves as a framework for precision surveillance and prevention of sporadic CRC.

cancer biology↗

bioRxiv2020

AKAP350 REGULATES CYTOSKELETON REMODELLING AND LFA-1 ORGANIZATION DURING NK CYTOLYTIC RESPONSE

The elimination of transformed and viral infected cells by natural killer (NK) cells requires the formation of a specialized junction between NK and target cells, generally denominated immunological synapse (IS). After initial recognition, the IS enables the directed secretion of lytic granules content into the susceptible target cell. The lymphocyte function-associated antigen (LFA)-1 regulates NK effector function by enabling NK-IS assembly and maturation. The pathways underlying LFA-1 accumulation at the IS in NK cells have not been elucidated so far. A kinase anchoring protein 350 (AKAP350) is a centrosome/Golgi associated protein with a central role in the regulation of Golgi organization and microtubule dynamics. In T cells, AKAP350 participates in LFA-1 activation by mechanisms that remain elusive. We first investigated AKAP350 participation in NK cytolytic activity. Our results showed that the decrease in AKAP350 levels by expression of specific shRNAs (AKAP350KD) inhibited NK-YTS cytolytic activity, without affecting NK:target cell conjugate formation. The impairment of NK effector function in AKAP350KD cells correlated with decreased LFA-1 clustering and defective IS maturation. AKAP350KD cells that were exclusively activated via LFA-1 showed impaired LFA-1 organization and deficient lytic granule translocation as well. In NK AKAP350KD cells, activation signaling through Vav1 was preserved up to 10 min of interaction with target cells, but significantly decreased afterwards. Experiments in YTS and in ex vivo NK cells revealed the existence of an intracellular pool of LFA-1 vesicles, which partially associated with the Golgi apparatus. Upon NK cell activation, this LFA-1 pool redistributed to the IS in a Golgi-AKAP350-dependent manner. Disruption of Golgi integrity or alteration of microtubule dynamics impaired LFA-1 localization at the IS. Therefore, this study reveals the existence of a Golgi/AKAP350 dependent trafficking pathway for LFA-1, which is relevant for LFA-1 organization at NK-lytic IS and, concomitantly, for NK cytolytic function.

cell biology↗