Cellular & Molecular Immunology

Genetic ablation approaches are routinely used to establish gene function, but these are not beyond limitations. The intracellularly expressed camelid single-domain antibodies (sdAbs), or nanobodies, can specifically disrupt molecular interactions and, therefore, help ascertain their role in the process of cellular differentiation. The approach has not been evaluated in differentiating T cells or the stimulating DCs during viral infection. We modified the intracellular response of Galectin-3 (Gal-3) using an -Gal-3 intrabody (IB) in antigen-specific CD8+ T cells and assessed their differentiation patterns during a resolving Influenza A virus encoding SIINFEKL epitope (IAV: WSN-SIINFEKL). The -Gal-3 IB expressors, compared to the cells genetically depleted of Gal-3, exhibit a significantly prolonged activation, enhanced proliferation, and elevated cytokine production following in vitro stimulation. The -Gal-3 IB expressing cells show enhanced functionality and generate an efficient effector response, favoring the generation of memory precursor effector cells (MPECs: CD127hiKLRG1lo) over short-lived effector cells (SLECs: CD127loKLRG1hi) in IAV-infected animals. Such a differentiation pattern results in improved differentiation of effector memory (CD44hiCD62LloCCR7lo) cells amongst the -Gal-3 IB-expressing cells. The generated memory cells are efficiently recalled upon challenge infection with MHV68-SIINFEKL and help control the infection better. Therefore, modifying the intracellular response of Gal-3 using a sdAb could improve the primary and memory response of antigen-specific CD8+ T cells.

Objective: Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) frequently present as overlap syndromes, characterized by shared sexual dimorphism and elevated intestinal Veillonella dispar (V. dispar) abundance, yet exhibiting distinct hallmark pathological manifestations. This study aimed to elucidate the shared pathogenesis, phenotypic differentiation mechanisms and sex-specific predisposition of AIH and PBC induced by V. dispar. Methods: Clean-grade and germ-free (GF) mice were employed to establish AIH and PBC models. Model induction involved oral gavage of V. dispar and intraperitoneal injection of either liver-specific antigen S100 (for AIH) or a pyruvate dehydrogenase complex E2 subunit (PDC-E2) mimetic peptide (for PBC). Single-cell RNA sequencing, metabolomics, transmission electron microscopy, western blotting, and flow cytometry were utilized to elucidate the underlying mechanisms. Results: V. dispar successfully induced autoimmune liver disease-like features in mice, characterized by significant intrahepatic B cell infiltration. Mechanistically, V. dispar caused systemic arginine reduction, leading to intrinsic apoptosis of gonadal stromal cells and a subsequent reduction in testosterone. This decreased testosterone weakened its inhibitory effect on B cell activating factor (BAFF) secretion, thereby amplifying B cell-mediated immune responses. Furthermore, in the presence of S100 or PDC-E2 mimetic peptide, V. dispar also facilitated Th17 cell activation, which guided the phenotypic differentiation into AIH or PBC, respectively. Consistent with these findings, our clinical observations revealed that patients with AIH and PBC tended to harbor enriched V. dispar, along with lower serum arginine and testosterone. In addition, elevated serum levels of BAFF and IL-17 were also observed in these patients. Conclusion: V. dispar induces reduced testosterone levels and upregulation of BAFF, leading to intrahepatic B cell expansion, which serves as the common pathogenic basis for AIH and PBC. The presence of S100 and PDC-E2 subsequently drives further maturation of these expanded B cells and promotes Th17 cell activation, thereby determining the phenotypic divergence between AIH and PBC.

Background: Patients receiving anti-TNF treatment for chronic inflammatory disease display impaired antibody responses, but it remains unclear how immune memory formation is affected. We evaluated antibody responses and memory B cells (Bmem) after COVID-19 booster vaccination in inflammatory bowel disease (IBD) patients receiving anti-TNF treatment. Methodology: Blood was sampled at baseline, 1, and 6 months after WH1/BA.5 bivalent or XBB.1.5 monovalent vaccination from 27 IBD patients receiving intravenous anti-TNF and 44 controls. Neutralizing antibodies were measured using an infectious virus assay. SARS-CoV-2 spike receptor binding domain (RBD)-specific serum IgG was quantified by ELISA, and RBD-specific Bmem were immunophenotyped by flow cytometry using recombinant proteins from ancestral, Omicron BA.1, BA.5, XBB.1.5, and JN.1 variants. Results: Serum IgG to vaccine RBD and neutralizing antibodies in patients increased pre to 1 month post-vaccination, but were lower than controls. Ancestral-, BA.5- and XBB.1.5-specific Bmem increased after vaccination but were significantly lower in patients than controls. Within RBD-specific Bmem, frequencies of recently activated CD21lo cells were increased after vaccination, and were higher in patients than controls. Fewer antigen-specific Bmem in patients expressed IgG4, and more expressed IgG3 or IgD following vaccination. Following vaccination, more RBD-specific Bmem recognized multiple viral variants. However, patients had fewer Bmem that could bind to subvariants than controls. Conclusion: Antibody and Bmem responses to COVID-19 booster vaccination in anti-TNF-treated IBD patients displayed reduced capacity, durability and cross-reactivity, suggesting impaired immune memory for protection against breakthrough infection. This supports the recommendation for annual booster vaccination to prevent severe disease and viral spread.

Inflammatory Bowel Disease (IBD) is rising worldwide and requires the development of preventative strategies to lower its incidence. Circadian rhythms, daily cycles of physiology, have been shown to be implicated in IBD in both clinical and laboratory studies. We tested if a 12-hour Time-Restricted Feeding (TRF) dietary regimen, that improves circadian rhythms, could ameliorate colitis using a mouse model of disease. We find that TRF indeed protects mice from the damaging effects of colitis, and boosts the rhythmic expression of transcripts related to the clock, cell proliferation, and barrier function. Under TRF, mice exhibit lower disease symptoms, changes in microbiota, and reduced inflammatory tissue damage. These outcomes are not clock-dependent: colitis in Bmal1 mutants without circadian rhythms is also rescued by TRF. However, in this context alterations to the transcriptome are distinct from that found in clock-wildtype controls. Together our data support the translation of a 12-hour TRF in IBD, and highlight clock-dependent and nutrition-dependent changes accompanying colitis rescue.

Purpose: To investigate the incidence, clinical features, and risk factors for SARS-CoV-2 nucleic acid re-positivity in recovered COVID-19 patients. Methods: We enrolled 441 convalescent COVID-19 patients from the rehabilitation ward of the Fifth Hospital of Shijiazhuang between January and April 2021. Based on nucleic acid test results, patients were categorized into repositive (n = 69) and non-repositive (n = 372) groups. Demographic, clinical, laboratory, and imaging data were compared between groups. Logistic regression was used to identify factors associated with re-positivity. Results: The overall re-positivity rate was 15.65%. Compared with the non-repositive group, the repositive group presented with a significantly higher proportion of moderate disease severity (72.46% vs. 50.54%) and a lower proportion of patients under 14 years old (7.25% vs. 23.66%). Additionally, multi-lobar involvement ([&ge;] 3 lobes) during the acute phase was more common in the repositive group (43.48% vs. 26.61%), with all differences being statistically significant (P < 0.001). Laboratory analysis revealed that repositive patients had significantly lower lymphocyte and eosinophil counts, as well as reduced albumin (ALB), aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, and albumin/globulin (A/G) ratio. Furthermore, circulating CD3+, CD4+, and CD8+ T-cell counts were markedly decreased. In contrast, the neutrophil-to-lymphocyte ratio (NLR), immunoglobulin M (IgM), immunoglobulin A (IgA), and neutralizing antibody (NAb) levels were significantly elevated in re-positive patients (all P < 0.05). Multivariate logistic regression analysis identified the CD8+ as independent risk factors for re-positivity. Conclusion: In convalescent patients, SARS-CoV-2 RNA re-positivity correlates with distinct clinical and immunological characteristics. The CD8+ T-cell level is an independent predictor, highlighting that dysregulated immune and inflammatory responses contribute to delayed viral clearance.

Echovirus 18 (E18) is a predominant pathogen causing aseptic meningitis in children, and post-E18 infection frequently triggers myasthenia gravis-like autoimmune neurological damage. This pathological process relies on neonatal Fc receptor (FcRn)-mediated IgG transcytosis across mucosal barriers, and FcRn also acts as an essential functional receptor required for E18 attachment and uncoating during host cell invasion. At present, no E18-specific prophylactic vaccine has been clinically approved, and anti-FcRn monoclonal antibodies are the available therapeutics to alleviate autoantibody-mediated tissue injury. We constructed an integrated automated phylogenetic pipeline named evolution_conservation, which enables rapid tracing of the evolutionary position and genetic relatedness of clinical isolates to identify closely related strains from previous outbreaks. Serving as an in silico alternative to animal experiments, this pipeline supports reference-guided vaccine design and longitudinal comparative assessment of vaccine safety and efficacy, facilitates identification of patient populations presenting rare post-viral sequelae, and accelerates clinical trial progression. In this study, we inserted the pre-screened linear epitope E18-3 into a truncated hepatitis B core (HBc) scaffold to generate chimeric virus-like particles (VLPs). A non-invasive floss-based gingival mucosal immunization mouse model was established, with subcutaneous Freunds adjuvant immunization set as the control group. ELISA results confirmed that gingival mucosal delivery of particulate HBc-E18-3 VLPs alone could induce sustained high levels of antigen-specific intestinal IgG in vivo. Drawing on research paradigms of therapeutic neoantigen vaccines for tumor recurrence prevention, the evolution_conservation bioinformatic pipeline and mucosal VLP platform described herein establish an innovative framework for developing antigen-competitive prophylactic and therapeutic vaccines targeting FcRn for myasthenia gravis and autoimmune encephalitis.

Formation of autoantibodies to transglutaminase 2 (TG2) in celiac disease likely involves TG2-gluten complexes that allow gluten-specific CD4+ T cells to provide help to TG2-specific B cells. To investigate whether TG2 derived from intestinal epithelial cells (IECs) contributes to this process, we generated mice with inducible IEC-specific expression of TG2 fused to a deamidated gluten peptide (DGP) containing a T-cell epitope. Upon induction, the TG2-DGP fusion protein was expressed in IECs and released into the intestinal lumen. In HLA-DQ2.5 transgenic mice with activated gluten-specific CD4+ T cells and naive TG2-specific B cells, expression of TG2-DGP was immunogenic and drove the production of intestinal and systemic anti-TG2 autoantibodies. TG2-specific B cells predominantly expanded in Peyers patches, suggesting that their priming and subsequent differentiation into lamina propria TG2-specific IgA+ plasma cells occurs in gut-associated lymphoid tissues. The findings demonstrate immunogenicity of IEC-derived TG2-DGP fusion antigen supporting the notion of a pathogenic role for luminal TG2 in driving anti-TG2 autoimmunity in celiac disease.

IgM is the most ancient antibody isotype, playing an important role in both circulatory and mucosal immune responses across vertebrates, yet structural characterization of its polymeric forms is limited outside of mammals. Here, we report the cryo-electron microscopy structure of mallard duck secretory (S) IgM at 3.37-[A] resolution. The structure revealed a pentameric core globally similar to human SIgM, supporting the view that pentameric IgM is subject to strong evolutionary constraints. However, compared to mammalian structures, we observed species-specific differences at molecular interfaces. Surface plasmon resonance binding assays characterizing secretory component (SC)-IgM interactions supported structural observations and, when compared to IgA binding, revealed isotype-specific contributions from the avian SC N-terminal extension. Together, these findings establish a comparative structural framework for polymeric IgM across vertebrates and provide insight into how avian SIgM-specific features may support mucosal immunity in birds.

Guillain-Barre syndrome (GBS) is an autoimmune polyneuropathy that is the leading cause of nonpoliovirus-associated acute flaccid paralysis worldwide. In most cases, GBS occurs following an infection, most commonly Campylobacter jejuni, through the induction of antibodies recognizing bacterial ganglioside-mimicking lipooligosaccharides that cross-react with human neuronal gangliosides. This post-infectious autoimmune cascade causes neuropathy, from which patients can recover as their anti-ganglioside antibody titers diminish and immunostimulation decreases. In this study, we find 10% of clinically confirmed GBS patients maintain high titers of circulating anti-ganglioside antibodies more than one decade after recovery. These antibodies no longer cause neuropathy compared to acute sera from the same patients using a human pluripotent stem cell-derived sensory neuron model with human complement. We found both IgG subclass and glycoform differences between paired acute and recovered GBS patient sera, including anti-inflammatory modifications on isolated anti-GM1 ganglioside antibodies. Together, these data suggest that patients with GBS select for non-pathogenic variants of autoantibodies that are no longer capable of damaging their neurons, but may still protect against C. jejuni infection.

Respiratory infections remain a relevant global health concern nowadays. The rapid dissemination and high mutational ratio of some pathogens, amid human demographic drivers, increases their pandemic potential. On the other hand, some bacterial infections have re-emerged with new resistant variants, supporting the need of updated or more potent vaccines. The development of nasal vaccines, with the capacity to efficiently induce immune response at the respiratory tract and systemic compartments, constitutes an appealing strategy to tackle respiratory infections, including tuberculosis. In this work, two synthetic compounds, the ODN-39M and the peptide LALF32-51, are evaluated as nasal vaccine adjuvants for the Ag85B antigen from Mycobacterium tuberculosis. The capacity of such adjuvants to enhance the immune response at systemic and mucosal compartments following intranasal immunization was assessed in Balb/C mice. The ODN-39M was able to potentiate the immune response, showing preferentially a Th1 pattern. The vaccine preparation containing this CpG adjuvant plus Ag85B induces potent cell-mediated and high IgA specific antibody response in lungs, along with systemic immunity. A preliminary study of the interaction between the ODN-39M with the NALT immune cells shows the early recruitment of lymphoid cells, and the increase of CD69 activation marker, mainly in B and dendritic cells. Although further studies should be done to reach a deeper understanding of NALT functioning, including the development of local innate response, the current data enrich the scarce reports focused on this compartment and support the use of the ODN-39M as a potent and potentially safe adjuvant option for future nasal vaccines.

Dendritic cells (DCs) are key orchestrators of anti-tumor adaptive immune responses. Their function is tightly regulated by galectins, a family of carbohydrate-biding proteins that decode extracellular glycans into intracellular signaling. Here, we show that exposure to melanoma-conditioned media (CM) induces loss of galectin-9 (gal-9) at the DC surface. Notably, gal-9 loss, independent of transcriptional regulation, was associated with the acquisition of an immunosuppressive phenotype in CD14cDC2 cells following tumor exposure, with higher-molecular weight fractions of the melanoma secretome as mediators. Notably, gal-9 depletion was mirrored with a reduction in gal-9 ligands on the cell surface, particularly GalNAc-containing glycoepitopes, pointing towards a melanoma-exploited gal-9-glycan axis as a DC-evasive strategy. Interestingly, restoring gal-9 surface levels in CM-exposed CD14cDC2 cells prevented the expansion of regulatory T cells (Tregs), postulating gal-9 as a novel immunomodulatory molecule in DC-mediated Treg induction during melanoma progression. Altogether, our data suggest that melanoma-derived factors remodel the DC glycan-gal-9 axis to enhance T cell differentiation towards regulatory phenotypes and dampen anti-tumor immunity. This identifies the gal-9/glycan axis in CD14cDC2 cells as a vulnerable node in melanoma immune evasion and as a potential therapeutic target.

To characterize anti-nucleocapsid (anti-N) IgG binding antibody responses following first PCR-confirmed SARS-CoV-2 infections in a highly vaccinated population, we evaluated antibody boosting and durability in a longitudinal cohort in Michigan. Among 113 participants with paired pre- and post-infection serum specimens tested using a multiplex electrochemiluminescence assay, SARS-CoV-2 infection induced substantial boosting of anti-N IgG concentrations; approximately 80% of participants becoming anti-N seropositive following infection, and 81% of participants demonstrating at least a 4-fold rise in antibody concentrations following infection. Population-level analyses of 66 participants with post-infection serum specimens collected 52-120 days after infection demonstrated sustained anti-N IgG concentrations over time, with no evidence of substantial decline. These findings demonstrate robust boosting and sustained infection-induced anti-N IgG responses in a highly vaccinated population through four months following SARS-CoV-2 infection. This supports the use of anti-N antibodies for longitudinal serosurveillance, including those who are vaccinated.

BackgroundLupus nephritis remains a major cause of chronic kidney disease and kidney failure in systemic lupus erythematosus. Glucocorticoids are central to treatment but are limited by systemic toxicity. We evaluated whether a previously characterized collagen IV 3-targeted liposomal nanoparticle formulation carrying low-dose prednisolone could attenuate established lupus nephritis in MRL/lpr mice. MethodsFemale MRL/lpr mice with disease present at treatment initiation and C57BL/6J control mice received saline or collagen IV 3-targeted prednisolone-loaded nanoparticles (Col4-3-Pred-NPs). Renal outcomes were assessed by longitudinal proteinuria, glomerular filtration rate (GFR), survival, kidney histopathology, renal IgG and C3d deposition, dUTP/TUNEL-associated injury staining, and renal cytokine/chemokine profiling. Body weight, food and water intake, and blood glucose were monitored as measures of general condition and preliminary tolerability. ResultsCol4-3-Pred-NPs improved survival in MRL/lpr mice, reduced cumulative proteinuria burden, and attenuated terminal GFR decline compared with saline-treated MRL/lpr controls. Treatment reduced glomerular and tubulointerstitial injury, lowered composite EGTI histopathology scores, decreased terminal kidney enlargement, reduced glomerular IgG deposition and renal dUTP-positive injury signals, and reduced renal signals for IL-28A/B, IL-7, PD-ECGF, IL-11, CCL6/C10, and IL-15. C3d deposition was not significantly altered. Nanoparticle treatment was not associated with sustained treatment-related increases in blood glucose or body-weight loss during the measured study period. ConclusionsCollagen IV 3-targeted liposomal delivery of low-dose prednisolone attenuated established lupus nephritis in MRL/lpr mice and improved renal structural, functional, inflammatory, and survival outcomes. These findings support further evaluation of glomerulus-targeted nanotherapy as a potential strategy to improve the precision and therapeutic index of glucocorticoid treatment in lupus nephritis.

Background. Persistent SARS-CoV-2 antigen is a leading hypothesis for post-acute sequelae of SARS-CoV-2 infection (PASC), commonly known as Long COVID. Impaired Fc-mediated antiviral antibody function could contribute to inefficient clearance of infected cells and viral antigen despite preserved antibody levels. Therefore, we tested whether PASC is associated with altered Fc{gamma} receptor-mediated antibody function and differences in IgG1 Fc fucosylation, a major regulator of Fc effector function. Methods. Serum samples from RECOVER-Adult participants with prior SARS-CoV-2 infection (99 PASC, 139 non-PASC) were analyzed for anti-SARS-CoV-2 spike receptor-binding domain (RBD) IgG and subclasses, Fc{gamma}RIIIa- and Fc{gamma}RIIa-mediated reporter activity as surrogate measures of antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), anti-RBD IgG1 Fc glycosylation, and circulating fucose-modifying enzymes. Results. Despite higher anti-RBD IgG and IgG1 abundance, PASC sera showed lower ADCC- and ADCP-associated Fc{gamma}R reporter activity, including after normalization for antibody abundance. Anti-RBD IgG1 showed greater fucosylation in PASC samples (30 PASC, 34 non-PASC). Serum FUCA2 was lower in PASC samples (24 PASC, 34 non-PASC), whereas FUCA1 and soluble CD16a levels did not differ between the two groups. Conclusion. PASC is associated with impaired antiviral IgG Fc function, increased IgG1 Fc fucosylation, and reduced circulating FUCA2, identifying a glycoimmune axis that may contribute to impaired Fc-dependent antigen clearance and represents a potentially targetable pathway in Long COVID.

Repetitive cytosolic Ca2+ spikes in pancreatic acinar cells, elicited by low (physiological) concentrations of acetylcholine (ACh), cholecystokinin (CCK) and gastrin releasing peptide (GRP), control secretion of digestive enzymes, whereas high-intensity stimulation induces sustained Ca2+ elevation initiating acute pancreatitis. Since inositol trisphosphate (IP3) was discovered as an intracellular Ca2+ releasing messenger, it has been assumed that a major class of G-protein coupled receptors relies on this pathway. We have now compared the mechanisms of action of the three physiological stimulants, all acting on different receptors, but each coupled to the IP3 pathway. Low concentrations of CCK and GRP cannot elicit Ca2+ signals without co-operation of an additional intracellular mechanism. CCK-elicited Ca2+ signalling requires activation of intracellular receptors for nicotinic acid adenine dinucleotide phosphate (NAADP), whereas this is not the case for the action of GRP that nevertheless relies on the operation of CD38, the enzyme involved in the synthesis of both cyclic ADP ribose and NAADP. Even Ca2+ signals elicited by ACh are partially dependent on CD38. It is engagement of these additional non-IP3 pathways that allows low concentrations of secretagogues to elicit safe Ca2+ spiking and therefore secretion, obviating the need for potentially toxic high levels of secretagogues.

Acute respiratory distress syndrome (ARDS) is marked by severe pulmonary edema and concomitant hypoxia, affecting hundreds of thousands of people a year, especially those in critical care conditions or suffering from septic shock. Previous studies have implicated that the ketogenic diet, a high-fat and low-carbohydrate diet, modulates inflammatory responses. However, the impact of the ketogenic diet on septic ARDS outcomes is unknown. Here, we demonstrated that mice on a ketogenic diet showed strikingly reduced lung injury and inflammation compared to those on a control diet during a murine model of endotoxin-induced lung injury, induced by intratracheal lipopolysaccharide (LPS) injection. Immune mass cytometry studies on lung tissue indicated that the ketogenic diet reduces immune cell infiltration. Treating mice with beta-hydroxybutyrate (BHB), the primary metabolite of ketogenesis, after the onset of ARDS reduced pulmonary edema and lung inflammation, as well as NF-kB activity, suggesting strong therapeutic potential. By multiplex analysis in bronchial alveolar lavage fluid, we observed that the ketogenic diet or BHB administration attenuates the chemotaxis and activation of immune cells. Altogether, our findings reveal that the ketogenic diet provides lung protection during endotoxin-induced lung injury through BHB.

Monkeypox, caused by MPXV, has become a global public health concern; however, the T-cell immunity against MPXV following smallpox vaccination remains unclear. In this study, we screened the immunogenicity of 21 predicted MPXV epitopes and compared immune responses between young and elderly groups. Two immunogenic CD8 T-cell epitopes, M15 and M17, were identified, both of which effectively stimulated specific immune responses, with significantly stronger responses observed in the young group. Notably, this study provides the first evidence that smallpox vaccination induces CD8 T-cell immunity that cross-recognizes the MPXV epitopes M15 and M17 and remains detectable for more than four decades after vaccination, as demonstrated in vaccinated individuals aged 53-75. These findings provide experimental evidence for understanding the cross-protective mechanisms of the smallpox vaccine and informing monkeypox vaccine development.

Efforts to develop a universal influenza vaccine have primarily focused on the surface-exposed viral hemagglutinin (HA), but neuraminidase (NA) is an additional target for cross-reactive, protective responses. Here, we used hyperglycosylation as an immunogen design approach to reshape anti-NA humoral immunity toward conserved antigenic regions. Iterative design produced a hyperglycosylated NA immunogen that retained enzymatic activity and reactivity to a conformation-specific antibody recognizing the conserved catalytic site. In mice, the hyperglycosylated immunogen elicited serum antibody responses of comparable magnitude to those elicited by the wild-type NA immunogen. However, serum antibodies elicited by the hyperglycosylated immunogen had increased breadth, recognizing N2 NAs from H2N2 and H3N2 viruses spanning nearly 65 years of antigenic drift, as well as a heterosubtypic N9 NA. Single B cell analyses identified a monoclonal antibody that competed with a component of the serum antibody response elicited by the hyperglycosylated immunogen, and structural characterization showed that it recognizes a previously undefined, conserved epitope at the NA tetramer interface. Passive transfer of this interface-directed antibody partially protected mice against lethal heterologous influenza challenge. Collectively, these data show that glycan shielding can reshape and enrich humoral responses toward a conserved antigenic region on NA. The immunogen and hyperglycosylation design strategy described here provide a template for developing next- generation NA-based influenza vaccines. ONE SENTENCE SUMMARYA hyperglycosylated influenza neuraminidase immunogen reshapes humoral immunity and elicits antibodies targeting a conserved tetramer-interface epitope.

The decline in first-phase insulin response (FPIR) during the presymptomatic period of type 1 diabetes (T1D) is well established. In-situ functional studies with pancreas tissue slices showed that {beta}-cell loss of glucose-responsiveness was independent of T-cell infiltration into islets in recent-onset T1D cases. However, the mechanisms driving {beta}-cell dysfunction before the onset of T1D remain unclear. In pancreas tissue from donors across the natural history of T1D, we utilized an in-situ, whole-islet phenotypical and transcriptomic approach to unravel novel targets in the glucose-stimulus coupled secretion pathway that are similarly impaired in T-cell infiltrated and non-infiltrated islets. Specifically, we observed that islets from autoantibody positive (single(s) or multiple(m) AAb+) donors exhibited activation of post-transcriptional gene regulation along with reduced protein translation, processing in the endoplasmic reticulum (ER), and ER stress. Disrupted mitochondrial metabolism and bioenergetics were prominent in islets from multiple AAb+ and T1D donors with disease durations [&le;]7 years. In addition, T1D islets presented reduced mitochondrial protein import, quality control, and dynamics, together with downregulated genes in insulin secretory pathways. During infiltration, these pathways remain dysregulated while immune/inflammatory transcripts were increased. These studies identified novel mechanisms of {beta}-cell dysregulation before symptomatic onset and independent of T-cell infiltration in T1D pathogenesis.

Acute lung injury (ALI) is a severe inflammatory syndrome frequently complicated by brain injury, which worsens outcomes. Here, we explored whether regulation of the lung-brain axis represents a therapeutic strategy for the management of ALI. We show that intranasal administration of Fritillaria taipaiensis-derived exosome-like nanovesicles (Ft-ELNs) ameliorates LPS-induced ALI and ALI-associated hypothalamic inflammation in mice. Ft-ELNs preferentially accumulate in the lungs, inhibiting TRPV1 in both the lungs and the hypothalamus to establish the lung-brain axis. In parallel, Ft-ELNs primarily regulate systemic humoral immunity by inhibiting the VEGFR1/PI3K/AKT/NF?B signaling pathway. In vitro experiments further confirmed that Ft-ELNs are efficiently internalized by alveolar epithelial MLE-12 cells, exerting protective effects by suppressing VEGFR1 expression. Mechanistically, we identified Ft-miR1 of Ft-ELNs as the key functional effector that directly targets the Flt1 3'UTR to inhibit VEGFR1 expression. These data suggest that Ft-ELNs attenuate lung-brain axis inflammation by targeting VEGFR1 and may hold potential as novel therapeutic agents for the treatment of severe ALI.