CD18-mediated adhesion is required for lung inflammation induced by mononuclear cell-derived extracellular vesicles

Neri, T.; Scalise, V.; Passalacqua, I.; Giusti, I.; Balia, C.; D'Alessandro, D.; Berrettini, S.; Pedrinelli, R.; Paggiaro, P.; Dolo, V.; Celi, A.

doi:10.1101/158121

bioRxiv · 10.1101/158121

CD18-mediated adhesion is required for lung inflammation induced by mononuclear cell-derived extracellular vesicles

Neri, T.·Scalise, V.·Passalacqua, I.·Giusti, I.·Balia, C.·D'Alessandro, D.·Berrettini, S.·Pedrinelli, R.·Paggiaro, P.·Dolo, V.·Celi, A.

View original source ↗Export metadata ↓

Abstract

Extracellular vesicles are submicron vesicles that upregulate the synthesis of proinflammatory mediators by lung epithelial cells.\n\nWe investigated whether these structures adhere to lung epithelial cells, and whether adhesion is a prerequisite for their proinflammatory activity.\n\nExtracellular vesicles were generated by stimulation of normal human mononuclear cells with the calcium ionophore A23187, and labelled with carboxyfluorescein diacetate succinimidyl ester. Adhesion of vesicles to monolayers of immortalized bronchial epithelial cells (16HBE) and alveolar cells (A549) was analysed by fluorescence microscopy. The role of candidate adhesion receptors was evaluated with inhibitory monoclonal antibodies and soluble peptides. The synthesis of proinflammatory mediators was assessed by ELISA.\n\nTransmission electron microscopy confirmed the generation of closed vesicles with an approximate size range between 50 and 600 nm. Adhesion of extracellular vesicles to epithelial cells was minimal in baseline conditions and was upregulated upon stimulation of the latter with tumour necrosis factor-. Adhesion was blocked by an anti-CD18 antibody and by peptides containing the sequence RGD. The same molecules also blocked the upregulation of the synthesis of interleukin-8 and monocyte chemotactic protein-1 induced by extracellular vesicles.\n\nSummary statementExtracellular vesicles upregulate the synthesis of proinflammatory mediators by lung epithelial cells. CD18-mediated adhesion to target cells is required for this proinflammatory effect and might represent a target for anti-inflammatory therapy.

Source connections

Published article ↗

Explore related subjects

immunology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Neri, T., Scalise, V., Passalacqua, I., Giusti, I., Balia, C., D'Alessandro, D., Berrettini, S., Pedrinelli, R., Paggiaro, P., Dolo, V., Celi, A.. 2017-06-30. CD18-mediated adhesion is required for lung inflammation induced by mononuclear cell-derived extracellular vesicles. https://doi.org/10.1101/158121

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

CD19-CAR T-cell therapy resets the EBV+ autoreactive B cell repertoire in autoimmune disease

Epstein-Barr virus (EBV) reprograms autoreactive B cells into activated antigen-presenting cells that drive pathogenic T- and B-cell responses in autoimmune disease. Using EBV B-cell sequencing (EBV-seq), we profiled EBV+ B cells in patients treated with CD19 chimeric antigen receptor (CAR) T cells (systemic lupus, n=6; idiopathic inflammatory myopathies, n=3; systemic sclerosis, n=3) or rituximab (n=15). CAR T cells, but not rituximab, depleted EBV+ B cells, resetting the repertoire toward a naive state: predominantly IgM+ with minimal somatic hypermutation. Post-rituximab B-cells remained class-switched, hypermutated, and activated. Monoclonal antibodies cloned from EBV+ B cells lost autoreactivity after CAR T cells but not rituximab. Sustained drug-free remission occurred in 8/12 CAR-treated but 0/15 rituximab-treated patients. EBV+ B cells were predominantly Latency III and resisted anti-CD20 and anti-CD19 antibodies, yet were killed by CAR T cells and T-cell engagers. CD19-CAR T-cell therapy resets the autoreactive EBV+ B-cell repertoire, which may underlie sustained drug-free remission.

immunology↗

bioRxiv2026

A minimal two-residue C-terminal truncation of AID in adult-onset hyper-IgM syndrome type 2 (HIGM2)

Activation-induced cytidine deaminase (AID), encoded by AICDA, facilitates class-switch recombination (CSR) and somatic hypermutation (SHM) in activated B cells. Loss of AID function causes hyper-IgM syndrome type 2 (HIGM2). While typically autosomal recessive, three C-terminal truncation variants have been reported to act in autosomal dominant manner. We describe a novel heterozygous AICDA nonsense variant, c.589G>T (p.G197*), that truncates the final two C-terminal residues of AID and results in adult-onset HIGM2. Single-cell sequencing of primary patient B cells revealed a complete block in CSR and a [~]10-fold reduction in SHM. AICDA mRNA expression was balanced between wild-type and variant alleles, yet AID protein abundance was reduced to [~]56% with normal subcellular localization. Remarkably, inducible germinal center (iGB) cultures restored CSR in purified naive patient B cells. CRISPR-Cas9 editing of healthy donor B cells confirmed that the iGB platform can rescue B cells harboring heterozygous, but not homozygous, AICDA variants. These results demonstrate that even a two-amino-acid truncation at the AID C-terminus is sufficient to disrupt its function and cause HIGM2.

immunology↗

bioRxiv2026

Defining the Functional Consequence of the Human Ocular Microbiome

The ocular surface is one of the body's most environmentally exposed mucosal barriers, yet it is considered low biomass and harbors orders of magnitude fewer bacteria than microbe-rich sites like the gut. This has cast doubt on whether a functional core ocular microbiome exists at all. Having previously defined a protective gd T cell and IL-17 axis engaged by the murine commensal Corynebacterium mastitidis, we asked whether human-derived bacteria could do the same. Pairing sequencing and culturomics of healthy human conjunctiva from two geographically distinct cohorts, we define a stable core microbiome and identify Corynebacterium bovis as a consistent eye-resident commensal rather than a transient contaminant. In humans, C. bovis elicits a non-pathogenic response marked by IL-17 secretion by {gamma}{delta} T cells and circulating C. bovis-specific IgG, which suggests commensalism rather than pathology. Colonizing mice with human C. bovis strains from Pittsburgh or Miami reproduced this program and conferred protection against ocular infection with Staphylococcus aureus. Together, these findings identify C. bovis as a human-derived ocular commensal that can drive protective {gamma}{delta} T cell immunity, translating a mechanism previously defined only in mice into human relevance and a rational target against sight-threatening infection.

immunology↗