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The receptor‐binding domain (RBD) of the SARS‐CoV‐2 virus spike protein has emerged as a promising target for the generation of neutralizing antibodies. Although the RBD subunit is more stable than its encoding mRNA, RBD is poorly immunogenic. It is hypothesized that this limitation can be overcome by sustained coadministration with a more potent and optimized adjuvant than standard adjuvants. One such candidate adjuvant, cGAMP, exhibits promising potency via activation of the antiviral STING pathway. Unfortunately, delivery of cGAMP as a therapeutic exhibits poor performance due to poor pharmacokinetics and pharmacodynamics from rapid excretion and degradation. To overcome these limitations, it is sought to create an artificial immunological niche enabling the slow release of cGAMP and RBD to mimic natural infections in which immune‐activating molecules are colocalized with antigen. Specifically, through coencapsulation of cGAMP and RBD in an injectable polymer‐nanoparticle (PNP) hydrogel, the cGAMP‐adjuvanted hydrogel vaccine elicits more potent, durable, and broad antibody responses with improved neutralization as compared to dose‐matched bolus controls and hydrogel‐based vaccines lacking cGAMP. The cGAMP‐adjuvanted hydrogel platform can be further explored for the delivery of other antigens to enhance immunity against a broad range of pathogens. [ABSTRACT FROM AUTHOR]

Objective: Antibodies against citrullinated fibrinogen (anti-Cit-fibrinogen) have been implicated in rheumatoid arthritis (RA) and associated with cardiovascular risk in RA. The objective of this study was to examine the association between anti-Cit-fibrinogens and coronary artery disease (CAD) outcomes.Methods: We performed the study in an RA cohort based in a large academic institution linked with electronic medical record data containing information on CAD outcomes from medical record review. Using a published bead-based assay method, we measured 10 types of anti-Cit-fibrinogens. We applied a score test to determine the association between the anti-Cit-fibrinogens as a group with CAD outcomes. Principal components analysis (PCA) was performed to assess whether the anti-Cit-fibrinogens clustered into groups. Each group was then additionally tested for association with CAD. Sensitivity analyses were also performed using a published International Classification of Disease, Ninth Revision code group for ischemic heart disease (IHD) as the outcome.Results: We studied 1,006 RA subjects (mean ± SD age 61.0 ± 13.0 years; 72.2% anti-cyclic citrullinated peptide positive). As a group, anti-Cit-fibrinogen was associated with CAD (P = 1.1 × 10-4 ). From the PCA analysis, we observed 3 main groups, of which only 1 group, containing 7 of the 10 anti-Cit-fibrinogens, was significantly associated with CAD outcomes (P = 0.015). In the sensitivity analysis, all anti-Cit-fibrinogens as a group remained significantly associated with IHD (P = 2.9 × 10-4 ).Conclusion: Anti-Cit-fibrinogen antibodies as a group were associated with CAD outcomes in our RA cohort, with the strongest signal for association arising from a subset of the autoantibodies. [ABSTRACT FROM AUTHOR]

Abstract: Idiopathic pulmonary arterial hypertension (IPAH) is a devastating pulmonary vascular disease in which autoimmune and inflammatory phenomena are implicated. B cells and autoantibodies have been associated with IPAH and identified as potential therapeutic targets. However, the specific populations of B cells involved and their roles in disease pathogenesis are not clearly defined. We aimed to assess the levels of activated B cells (plasmablasts) in IPAH, and to characterize recombinant antibodies derived from these plasmablasts. Blood plasmablasts are elevated in IPAH, remain elevated over time, and produce IgA autoantibodies. Single‐cell sequencing of plasmablasts in IPAH revealed repertoires of affinity‐matured antibodies with small clonal expansions, consistent with an ongoing autoimmune response. Recombinant antibodies representative of these clonal lineages bound known autoantigen targets and displayed an unexpectedly high degree of polyreactivity. Representative IPAH plasmablast recombinant antibodies stimulated human umbilical vein endothelial cells to produce cytokines and overexpress the adhesion molecule ICAM‐1. Together, our results demonstrate an ongoing adaptive autoimmune response involving IgA plasmablasts that produce anti‐endothelial cell autoantibodies in IPAH. These antibodies stimulate endothelial cell production of cytokines and adhesion molecules, which may contribute to disease pathogenesis. These findings suggest a role for mucosally‐driven autoimmunity and autoimmune injury in the pathogenesis of IPAH. [ABSTRACT FROM AUTHOR]

Objective: The location and mechanisms involved in the initial generation of autoantibodies to citrullinated and noncitrullinated proteins/peptides during the natural history of rheumatoid arthritis (RA) development is incompletely understood. This study sought to explore individual antibody responses to citrullinated and noncitrullinated proteins/peptides in the sputum and associations with neutrophil extracellular traps (NETs) in subjects at risk for the future development of RA. Methods: Serum and sputum samples were obtained from 41 RA‐free subjects who were considered at risk for the development of RA based on familial or serologic risk factors, from 20 subjects classified as having RA, and from 22 healthy control subjects. Samples were evaluated using a bead‐based array for IgG reactivity to 29 citrullinated proteins/peptides and 21 noncitrullinated proteins/peptides. Cutoff levels for antibody positivity were established in a separate control group. NET levels in the sputum were measured using sandwich enzyme‐linked immunosorbent assays that quantitate DNA–myeloperoxidase and DNA–neutrophil elastase complexes. Results: In at‐risk subjects, antibody responses to the citrullinated forms of fibrinogen, apolipoprotein E, and fibronectin were highly prevalent. The most citrulline‐specific antibodies in the sputum of at‐risk subjects were those to fibrinogen, vimentin, and peptides of fibrinogen A and apolipoprotein A1. Patterns of sputum autoantibody positivity differed between at‐risk subjects and subjects with RA. In at‐risk subjects, increasing sputum NET levels significantly correlated with several citrullinated and some noncitrullinated antibody reactivities. Conclusion: These findings suggest that sputum antibody reactivity to particular citrullinated and noncitrullinated proteins/peptides is specific for RA and for subjects at risk of RA, and the association of these proteins/peptides with NETs may be a key feature of early RA–related autoimmunity in the lung. These results further support the hypothesis that the lung plays a role in early RA–related autoimmunity. [ABSTRACT FROM AUTHOR]

Objective Patients with rheumatoid arthritis (RA) develop autoantibodies against a spectrum of antigens, but the clinical significance of these autoantibodies is unclear. Using a phenome-wide association study (PheWAS) approach, we examined the association between autoantibodies and clinical subphenotypes of RA. Methods This study was conducted in a cohort of RA patients identified from the electronic medical records (EMRs) of 2 tertiary care centers. Using a published multiplex bead assay, we measured 36 autoantibodies targeting epitopes implicated in RA. We extracted all International Classification of Diseases, Ninth Revision (ICD-9) codes for each subject and grouped them into disease categories (PheWAS codes), using a published method. We tested for the association of each autoantibody (grouped by the targeted protein) with PheWAS codes. To determine significant associations (at a false discovery rate [FDR] of ≤0.1), we reviewed the medical records of 50 patients with each PheWAS code to determine positive predictive values (PPVs). Results We studied 1,006 RA patients; the mean ± SD age of the patients was 61.0 ± 12.9 years, and 79.0% were female. A total of 3,568 unique ICD-9 codes were grouped into 625 PheWAS codes; the 206 PheWAS codes with a prevalence of ≥3% were studied. Using the PheWAS method, we identified 24 significant associations of autoantibodies to epitopes at an FDR of ≤0.1. The associations that were strongest and had the highest PPV for the PheWAS code were autoantibodies against fibronectin and obesity ( P = 6.1 × 10−4, PPV 100%), and that between fibrinogen and pneumonopathy ( P = 2.7 × 10−4, PPV 96%). Pneumonopathy codes included diagnoses for cryptogenic organizing pneumonia and obliterative bronchiolitis. Conclusion We demonstrated application of a bioinformatics method, the PheWAS, to screen for the clinical significance of RA-related autoantibodies. Using the PheWAS approach, we identified potentially significant links between variations in the levels of autoantibodies and comorbidities of interest in RA. [ABSTRACT FROM AUTHOR]

Objectives. Cigarette smoking is a major risk factor for RA and has been associated with increased disease severity and lower rates of disease remission. We hypothesized that inflammation and disease activity would be associated with smoking status and this would be related to levels of ACPA. Methods. RA patients from the Veterans Affairs RA registry were studied (n = 1466): 76.9% anti-CCP2 positive, 89% male, median age 63 years (interquartile range 57-72), median disease duration 8.45 years (interquartile range 2.8-18). Baseline serum samples were evaluated for levels of anti-CCP2, RF, 19 distinct ACPAs and 17 cytokines. Smoking status at baseline was recorded as current, former or never. The association of smoking status with cytokines, autoantibodies and disease activity (DAS28) was evaluated. Results. Among anti-CCP-positive RA patients, RA-associated cytokines (false-discovery rates q < 0.1%) and DAS28 (P < 0.01) were higher in current smokers compared with former or never smokers. DAS28 and cytokine levels were similar between former and never smokers. In contrast, ACPA concentrations were higher among both current and former smokers compared with never smokers, and levels of ACPA were not associated with DAS28 or cytokine levels. Conclusion. Among anti-CCP2-positive RA patients, current smoking status is associated with elevations in pro-inflammatory cytokines and increased RA disease activity. Similar levels of inflammation and disease activity among former and never smokers suggests that the detrimental effects of smoking could be ameliorated through tobacco cessation. The effect of tobacco cessation on RA disease activity should be evaluated prospectively. [ABSTRACT FROM AUTHOR]

Objective The disease process in rheumatoid arthritis (RA) starts years before the clinical diagnosis is made, and elevated levels of disease-specific autoantibodies can be detected during this period. Early responses to known or novel autoantigens likely drive the eventual production of pathogenic autoimmunity. Importantly, the presence of disease-specific autoantibodies can identify individuals who are at high risk of developing RA but who do not currently have arthritis. The goal of the current study was to characterize plasmablasts from individuals at risk of developing RA. Methods We investigated antibody-secreting plasmablasts derived from a well-characterized cohort of individuals who were at risk of developing RA, based on RA-related serum autoantibody positivity, as compared to patients with early (<1 year) seropositive RA as well as healthy control subjects. The plasmablast antibody repertoires of at-risk subjects were analyzed using DNA barcode-based methods with paired heavy- and light-chain gene sequencing. Cells were single-cell sorted, the cell- and plate-specific DNA barcodes were sequentially added, and next-generation sequencing was performed. Results Total plasmablast levels were similar in the antibody-positive (1%) and control (0.4-1.6%) groups. However, increased frequencies of IgA+ versus IgG+ plasmablasts were observed in the antibody-positive group (39% IgA+ and 37% IgG+) as compared to other groups (1-9% IgA+ and 71-87% IgG+). Paired antibody sequences from antibody-positive subjects revealed cross-isotype clonal families and similar sequence characteristics in the IgA and IgG plasmablast repertoires. Antibody-positive individuals also demonstrated elevated serum levels of IgA isotype anti-cyclic citrullinated peptide 3 antibodies. Conclusion The IgA plasmablast dominance in these antibody-positive individuals suggests that a subset of RA-related autoantibodies may arise from mucosal immune responses and may be involved in early disease pathogenesis in individuals who are at risk of developing RA. [ABSTRACT FROM AUTHOR]

Chemokines and cytokines are key signaling molecules that orchestrate the trafficking of immune cells, direct them to sites of tissue injury and inflammation and modulate their states of activation and effector cell function. We have measured, using a multiplex-based approach, the levels of 58 immune mediators and 7 acute phase markers in sera derived from of a cohort of patients diagnosed with acute Lyme disease and matched controls. This analysis identified a cytokine signature associated with the early stages of infection and allowed us to identify two subsets (mediator-high and mediator-low) of acute Lyme patients with distinct cytokine signatures that also differed significantly (p<0.0005) in symptom presentation. In particular, the T cell chemokines CXCL9 (MIG), CXCL10 (IP-10) and CCL19 (MIP3B) were coordinately increased in the mediator-high group and levels of these chemokines could be associated with seroconversion status and elevated liver function tests (p = 0.027 and p = 0.021 respectively). There was also upregulation of acute phase proteins including CRP and serum amyloid A. Consistent with the role of CXCL9/CXCL10 in attracting immune cells to the site of infection, CXCR3+ CD4 T cells are reduced in the blood of early acute Lyme disease (p = 0.01) and the decrease correlates with chemokine levels (p = 0.0375). The levels of CXCL9/10 did not relate to the size or number of skin lesions but elevated levels of serum CXCL9/CXCL10 were associated with elevated liver enzymes levels. Collectively these results indicate that the levels of serum chemokines and the levels of expression of their respective chemokine receptors on T cell subsets may prove to be informative biomarkers for Lyme disease and related to specific disease manifestations. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a prototypical autoimmune arthritis affecting nearly 1% of the world population and is a significant cause of worldwide disability. Though prior studies have demonstrated the appearance of RA-related autoantibodies years before the onset of clinical RA, the pattern of immunologic events preceding the development of RA remains unclear. To characterize the evolution of the autoantibody response in the preclinical phase of RA, we used a novel multiplex autoantigen array to evaluate development of the anti-citrullinated protein antibodies (ACPA) and to determine if epitope spread correlates with rise in serum cytokines and imminent onset of clinical RA. To do so, we utilized a cohort of 81 patients with clinical RA for whom stored serum was available from 1-12 years prior to disease onset. We evaluated the accumulation of ACPA subtypes over time and correlated this accumulation with elevations in serum cytokines. We then used logistic regression to identify a profile of biomarkers which predicts the imminent onset of clinical RA (defined as within 2 years of testing). We observed a time-dependent expansion of ACPA specificity with the number of ACPA subtypes. At the earliest timepoints, we found autoantibodies targeting several innate immune ligands including citrullinated histones, fibrinogen, and biglycan, thus providing insights into the earliest autoantigen targets and potential mechanisms underlying the onset and development of autoimmunity in RA. Additionally, expansion of the ACPA response strongly predicted elevations in many inflammatory cytokines including TNF-α, IL-6, IL-12p70, and IFN-γ. Thus, we observe that the preclinical phase of RA is characterized by an accumulation of multiple autoantibody specificities reflecting the process of epitope spread. Epitope expansion is closely correlated with the appearance of preclinical inflammation, and we identify a biomarker profile including autoantibodies and cytokines which predicts the imminent onset of clinical arthritis. [ABSTRACT FROM AUTHOR]

Abstract: Efficient syntheses of tripodal thioethers have been achieved by ionic thiol-ene reactions of 1,3,5-triacryloylhexahydro-1,3,5-triazine (TAT) with a variety of commercially available thiols. The reactions are complete within minutes and give the products in high yields (63−96%) and high purity without a complex workup. The thiol-ene reactions tolerate a wide range of functionality, including hydroxy, amino, carboxylate, and trimethoxylsilyl groups. The amino acid cysteine is also an excellent substrate for this reaction. [Copyright &y& Elsevier]