Systemic Compartments Research Articles

CLINICAL MANAGEMENT SNAKEBITES OF COMMUNITY CARE UNIT: A SINGLE-CENTER RETROSPECTIVE STUDY IN LOPBURI, CENTRAL THAILAND

Background: Snakebite, a neglected tropical disease, might result in severe clinical outcomes. Objectives: This study presents a retrospective analysis of snakebite data from a community hospital in Lopburi, Central Thailand, and also assesses snakebite distribution and clinical management to lower mortality and morbidity in the community setting. Methods: A cross-sectional retrospective study used data from October 1, 2014, to August 30, 2023, to determine the epidemiology, clinical profile, and management of snakebite patients who visited Pattananikom Hospital. Results: The study included 225 snakebite patients with a median age of 39 (IQR 26-53 years), and 64.4% were male. The responsible species for half of the bite cases were unidentified (54.2%). Among 103 confirmed snakebites with identified species, there were 24 cobras (23.3%), 23 Russell’s vipers (22.3%), 16 green pit vipers (15.5%), 4 Malayan pit vipers (3.9%), 2 Malayan kraits (1.9%), and 34 (33.0%) other nonvenomous snakes. Notably, 10 out of 24 patients (41.7%) encountering cobras were diagnosed with venom ophthalmia. For bites caused by unknown snakes, two patients experienced compartment syndrome, one had dyspnea, and one had ptosis. Thirteen patients, also bitten by unidentified snakes and eligible for antivenom, went untreated due to a shortage of polyvalent antivenom, resulting in referrals. From 2021 to 2023, 20 patients (55.6% of 36) were referred (p=0.026). Of the patients with thrombocytopenia, eight (57.1% of 14) were referred (p=0.001), as were all cases with systemic bleeding, dyspnea, ptosis, or compartment syndrome. Moreover, prophylactic antibiotics (amoxicillin-clavulanate) were routinely prescribed (82.7%). Conclusion: Snakebites have been referred to more frequently in the last three years. Even though the origins of most cases are unknown and often lead to referrals, there is a notable shortage of polyvalent antivenoms. This scarcity has the potential to delay treatment and increase the risk of mortality. This study highlights the need for improved antivenom access in community hospitals to mitigate delays and reduce mortality.

Distinct distribution and responses of IgM+, IgT1+ and IgT2+ B cells in common carp.

In teleosts, the immunoglobulin classes produced by B cells are IgM, IgD, and IgT/IgZ. IgT was initially described as an immunoglobulin specialized in mucosal responses; accumulating evidence, however, shows that it is also involved in systemic immune responses. Two types of IgT/IgZ (IgT1 and IgT2) were previously described in common carp, but their further characterization was hampered by the lack of specific tool. In the current study, we developed and validated polyclonal antibodies against carp IgT1 and IgT2 and used them in combination with well validated monoclonal antibody against carp IgM (WCI12), to study the distribution of IgM+, IgT1+ and IgT2+ B cells or their secreted immunoglobulins in various mucosal and systemic organs of carp. Finally, we also preliminary assessed the B cell response to infection with the blood-borne parasite Trypanoplasma borreli. Using these tools, we report on the distinct expression of soluble immunoglobulins in systemic and mucosal compartments. IgT1 and IgM were expressed in mucosal as well as systemic organs and responded to systemic parasitic infection, whereas IgT2 was preferentially expressed at mucosal sites and did not respond to systemic infections. By studying the distribution of B cells in different organs, compartmentalization of the three B cell subtypes was observed in gills and gut, whereas splenic B cells appeared as organized clusters around ellipsoids. Our results provide insights into the distribution and to some extent the function of B cells in carp, indicating that our newly developed tools are valuable for future studies aiming at the further characterization of immune responses of carp to infections and vaccination.

Profile of immune response during nasal challenge with dermatophagoides pteronyssinus in subjects with allergic airway diseases

BackgroundT lymphocyte helper (Th) 2 plays the main role in pathogenesis of allergic airway diseases (AAD). Recent studies showed that interleukin (IL) 33, Th17 and Th22 also may be involved in allergic inflammation. The aim is to evaluate cytokine level before and after nasal challenge with Dermatophagoides pteronyssinus in patients with AAD.MethodsPatients with persistent allergic rhinitis (AR) with or without allergic asthma (AA) allergic to house dust mite and healthy individuals underwent nasal challenge with Dermatophagoides pteronyssinus. Measurements of IL-13, IL-17, IL-22 and IL-33 in serum and nasal lavage were performed before, 2 and 22 h after nasal challenge by ELISA.Results. Ten patients with AR only, 6 patients with AR and AA and 7 healthy individuals were involved in the study. Serum IL-22 level significantly increased in patients with AR and AA and nasal lavage IL-22 tended to increase in patients with AAD after nasal challenge. Serum IL-13 level tended to increase in patients with AR and AA. IL-13 level in nasal lavage fluid decreased at 22 h after nasal challenge in patients with AR only. IL-17 level in serum and nasal lavage decreased in patients with AAD. Serum IL-33 tended to increase after nasal challenge whereas IL-33 in nasal lavage significantly decreased.ConclusionCytokine profile differs between local and systemic compartments and between patients with allergic rhinitis only and patients with allergic rhinitis and asthma after nasal challenge.

The Complex Immune Cell Composition and Cellular Interaction in the Alveolar Compartment of Patients with Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) is characterized by protein rich edema due to alveolar-capillary barrier dysfunction caused by inflammatory processes. Currently, our understanding of the inflammatory response in patients with ARDS is mainly based on assessment of the systemic compartment and preclinical studies. Investigations into the intricate network of immune cells and their critical functions in the alveolar compartment remain limited. However, with recent improvements in single cell analyses, our comprehensive understanding of the interactions between immune cells in the lungs has improved. In this review, we summarize the current knowledge about the cellular composition and interactions of different immune cell types within the alveolar space of patients with ARDS. Neutrophils and macrophages are the predominant immune cells in the alveolar space of ARDS patients. Yet, all immune cells present, including lymphocytes, participate in complex interactions, coordinate recruitment, modulate the lifespan and control apoptosis through various signaling pathways. Moreover, the cellular composition of alveolar immune cells is associated with clinical outcomes of ARDS patients. In conclusion, this synthesis advances our understanding of ARDS immunology, emphasizing the crucial role of immune cells within the alveolar space. Associations between cellular composition and clinical outcomes highlight the significance of exploring distinct alveolar immune cell subsets. Such exploration holds promise for uncovering novel therapeutic targets in ARDS pathophysiology, presenting avenues for enhancing clinical management and treatment strategies for ARDS patients. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Therapeutic effects of oral benzoic acid application during acute murine campylobacteriosis.

Serious risks to human health are posed by acute campylobacteriosis, an enteritis syndrome caused by oral infection with the food-borne bacterial enteropathogen Campylobacter jejuni. Since the risk for developing post-infectious autoimmune complications is intertwined with the severity of enteritis, the search of disease-mitigating compounds is highly demanded. Given that benzoic acid is an organic acid with well-studied health-promoting including anti-inflammatory effects we tested in our present study whether the compound might be a therapeutic option to alleviate acute murine campylobacteriosis. Therefore, microbiota-depleted IL-10-/- mice were perorally infected with C. jejuni and received benzoic acid through the drinking water from day 2 until day 6 post-infection. The results revealed that benzoic acid treatment did not affect C. jejuni colonization in the gastrointestinal tract, but alleviated clinical signs of acute campylobacteriosis, particularly diarrheal and wasting symptoms. In addition, benzoic acid mitigated apoptotic cell responses in the colonic epithelia and led to reduced pro-inflammatory immune reactions in intestinal, extra-intestinal, and systemic compartments tested on day 6 post-infection. Hence, our preclinical placebo-controlled intervention trial revealed that benzoic acid constitutes a promising therapeutic option for treating acute campylobacteriosis in an antibiotic-independent fashion and in consequence, also for reducing the risk of post-infectious autoimmune diseases.

Immunogenicity and safety of an Entamoeba histolytica adjuvanted protein vaccine candidate (LecA+GLA-3M-052 liposomes) in rhesus macaques

ABSTRACT Entamoeba histolytica, the causative agent of amebiasis, is one of the top three parasitic causes of mortality worldwide. However, no vaccine exists against amebiasis. Using a lead candidate vaccine containing the LecA fragment of Gal-lectin and GLA-3M-052 liposome adjuvant, we immunized rhesus macaques via intranasal or intramuscular routes. The vaccine elicited high-avidity functional humoral responses as seen by the inhibition of amebic attachment to mammalian target cells by plasma and stool antibodies. Importantly, antigen-specific IFN-γ-secreting peripheral blood mononuclear cells (PBMCs) and IgG/IgA memory B cells (BMEM) were detected in immunized animals. Furthermore, antigen-specific antibody and cellular responses were maintained for at least 8 months after the final immunization as observed by robust LecA-specific BMEM as well as IFN-γ+ PBMC responses. Overall, both intranasal and intramuscular immunizations elicited a durable and functional response in systemic and mucosal compartments, which supports advancing the LecA+GLA-3M-052 liposome vaccine candidate to clinical testing.

Pharmacokinetic Modeling of the Effect of Tariquidar on Ondansetron Disposition into the Central Nervous System

PurposeSerotonin (5-HT3) receptor antagonists are promising agents for treatment of neuropathic pain. However, insufficient drug exposure at the central nervous system (CNS) might result in lack of efficacy. The goal of this study was to evaluate the impact of administration of a Pgp inhibitor (tariquidar) on ondansetron exposure in the brain, spinal cord, and cerebrospinal fluid in a wild-type rat model.MethodsOndansetron (10 mg/kg) and tariquidar (7.5 mg/kg) were administered intravenously, plasma and tissue samples were collected and analyzed by HPLC. A mathematical model with brain, spinal cord, cerebrospinal fluid and two systemic disposition compartments was developed to describe the data.ResultsThe results demonstrate that tariquidar at 7.5 mg/kg resulted in a complete inhibition of Pgp efflux of ondansetron in the brain and spinal cord. The compartmental model successfully captured pharmacokinetics of ondansetron in wild type and Pgp knockout (KO) animals receiving the drug alone or in wild type animals receiving the ondansetron and tariquidar combination.ConclusionsThe study provided important quantitative information on enhancement of CNS exposure to ondansetron using co-administration of Pgp Inhibitor in a rat model, which will be further utilized in conducting a clinical study. Tariquidar co-administration resulted in ondansetron CNS exposure comparable to observed in Pgp KO rats. Results also highlighted the effect of tariquidar on plasma disposition of ondansetron, which may not be dependent on Pgp inhibition, and should be evaluated in future studies.

Distinct pulmonary and systemic effects of dexamethasone in severe COVID-19

Dexamethasone is the standard of care for critically ill patients with COVID-19, but the mechanisms by which it decreases mortality and its immunological effects in this setting are not understood. Here we perform bulk and single-cell RNA sequencing of samples from the lower respiratory tract and blood, and assess plasma cytokine profiling to study the effects of dexamethasone on both systemic and pulmonary immune cell compartments. In blood samples, dexamethasone is associated with decreased expression of genes associated with T cell activation, including TNFSFR4 and IL21R. We also identify decreased expression of several immune pathways, including major histocompatibility complex-II signaling, selectin P ligand signaling, and T cell recruitment by intercellular adhesion molecule and integrin activation, suggesting these are potential mechanisms of the therapeutic benefit of steroids in COVID-19. We identify additional compartment- and cell- specific differences in the effect of dexamethasone that are reproducible in publicly available datasets, including steroid-resistant interferon pathway expression in the respiratory tract, which may be additional therapeutic targets. In summary, we demonstrate compartment-specific effects of dexamethasone in critically ill COVID-19 patients, providing mechanistic insights with potential therapeutic relevance. Our results highlight the importance of studying compartmentalized inflammation in critically ill patients.

Airway and Systemic Immunoglobulin Profiling and Immune Response in Adult Asthma

IntroductionImmunoglobulins play a vital role in host immune response and in the pathogenesis of conditions like asthma. Therapeutic agents such as monoclonal antibodies target specific elements of the asthmatic inflammatory cascade. Decisions to utilize these medications are often based on systemic inflammatory profiling without direct insight into the airway inflammatory profile. We sought to investigate the relationship between immunoglobulin and cytokine profiles in the airway and systemic immune compartments of adult asthmatics.MethodsBlood sampling and bronchoscopy with bronchoalveolar lavage (BAL) were performed in 76 well-defined adult asthmatics. Antibody and cytokine profiles were measured in both BAL and serum using ELISA and quantibody arrays.ResultsThere was no relationship between BAL and serum levels of IgE. This is of significance in an asthma population. For some analytes, correlation analysis was significant (P < 0.05) indicating representativeness of our cohort and experimental setup in those cases. Nevertheless, the predictive power (r2) of the BAL-to-serum comparisons was mostly low except for TNF-α (r2 = 0.73) when assuming a simple (linear) relationship.ConclusionThis study highlights the importance of sample site when investigating the roles of immunoglobulins and cytokines in disease pathogenesis and suggests that both localized and systemic immune responses are at play. The prescription of asthma monoclonal therapy is generally based on systemic evaluation of cytokine and immunoglobulin levels. Our research suggests that this approach may not fully reflect the pathophysiology of the disease and may provide insight into why some patients respond to these targeted therapies while others do not.

Polymeric Caffeic Acid Acts as an Antigen Delivery Carrier for Mucosal Vaccine Formulation by Forming a Complex with an Antigenic Protein.

The development of mucosal vaccines, which can generate antigen-specific immune responses in both the systemic and mucosal compartments, has been recognized as an effective strategy for combating infectious diseases caused by pathogenic microbes. Our recent research has focused on creating a nasal vaccine system in mice using enzymatically polymerized caffeic acid (pCA). However, we do not yet understand the molecular mechanisms by which pCA stimulates antigen-specific mucosal immune responses. In this study, we hypothesized that pCA might activate mucosal immunity at the site of administration based on our previous findings that pCA possesses immune-activating properties. However, contrary to our initial hypothesis, the intranasal administration of pCA did not enhance the expression of various genes involved in mucosal immune responses, including the enhancement of IgA responses. Therefore, we investigated whether pCA forms a complex with antigenic proteins and enhances antigen delivery to mucosal dendritic cells located in the lamina propria beneath the mucosal epithelial layer. Data from gel filtration chromatography indicated that pCA forms a complex with the antigenic protein ovalbumin (OVA). Furthermore, we examined the promotion of OVA delivery to nasal mucosal dendritic cells (mDCs) after the intranasal administration of pCA in combination with OVA and found that OVA uptake by mDCs was increased. Therefore, the data from gel filtration chromatography and flow cytometry imply that pCA enhances antigen-specific antibody production in both mucosal and systemic compartments by serving as an antigen-delivery vehicle.

Intranasal administration of unadjuvanted SARS-CoV-2 spike antigen boosts antigen-specific immune responses induced by parenteral protein subunit vaccine prime in mice and hamsters.

With the continued transmission of SARS-CoV-2 across widely vaccinated populations, it remains important to develop new vaccines and vaccination strategies capable of providing protective immunity and limiting the spread of disease. Heterologous prime-boost vaccination based on the selection of different vaccine formulations and administration routes for priming and booster doses presents a promising strategy for inducing broader immune responses in key systemic and respiratory mucosal compartments. Intranasal vaccination can induce mucosal immune responses at the site of SARS-CoV-2 infection; however, the lack of clinically approved mucosal adjuvants makes it difficult to induce robust immune responses with protein subunit vaccines. Herein, we evaluated the immunogenicity of heterologous prime-boost regimens in mice and hamsters based on a parenteral vaccination of the antigen in combination with sulfated lactosylarchaeol (SLA) archaeosomes, a liposome adjuvant comprised of a single semisynthetic archaeal lipid, followed by an intranasally administered unadjuvanted SARS-CoV-2 spike antigen. Intranasal administration of unadjuvanted spike to mice and hamsters increased serum spike-specific IgG titers and spike-neutralizing activity compared with nonboosted animals. Spike-specific IgA responses were also detected in the bronchoalveolar lavage fluid in the lungs of mice that received an intranasal boost. In hamsters, the intranasal boost showed high efficacy against SARS-CoV-2 infection by protecting from body weight loss and reducing viral titers in the lungs and nasal turbinate. Overall, our heterologous intramuscular prime-intranasal boost with SLA-adjuvanted and unadjuvanted spike, respectively, demonstrated the potential of protein subunit formulations to promote antigen-specific systemic and mucosal immune responses.

Host-microbiome associations in saliva predict COVID-19 severity.

Established evidence indicates that oral microbiota plays a crucial role in modulating host immune responses to viral infection. Following severe acute respiratory syndrome coronavirus 2, there are coordinated microbiome and inflammatory responses within the mucosal and systemic compartments that are unknown. The specific roles the oral microbiota and inflammatory cytokines play in the pathogenesis of coronavirus disease 2019 (COVID-19) are yet to be explored. Here, we evaluated the relationships between the salivary microbiome and host parameters in different groups of COVID-19 severity based on their oxygen requirement. Saliva and blood samples (n = 80) were collected from COVID-19 and from noninfected individuals. We characterized the oral microbiomes using 16S ribosomal RNA gene sequencing and evaluated saliva and serum cytokines and chemokines using multiplex analysis. Alpha diversity of the salivary microbial community was negatively associated with COVID-19 severity, while diversity increased with health. Integrated cytokine evaluations of saliva and serum showed that the oral host response was distinct from the systemic response. The hierarchical classification of COVID-19 status and respiratory severity using multiple modalities separately (i.e. microbiome, salivary cytokines, and systemic cytokines) and simultaneously (i.e. multimodal perturbation analyses) revealed that the microbiome perturbation analysis was the most informative for predicting COVID-19 status and severity, followed by the multimodal. Our findings suggest that oral microbiome and salivary cytokines may be predictive of COVID-19 status and severity, whereas atypical local mucosal immune suppression and systemic hyperinflammation provide new cues to understand the pathogenesis in immunologically compromised populations.

Intranasal delivery of Salmonella OMVs decorated with Chlamydia trachomatis antigens induces specific local and systemic immune responses

ABSTRACT Chlamydia trachomatis is an obligate intracellular pathogen responsible for the most prevalent bacterial sexually transmitted disease globally. The high prevalence of chlamydial infections underscores the urgent need for licensed and effective vaccines to prevent transmission in populations. Bacterial outer membrane vesicles (OMVs) have emerged as promising mucosal vaccine carriers due to their inherent adjuvant properties and the ability to display heterologous antigens. In this proof-of-concept study, we evaluated the immunogenicity of Salmonella OMVs decorated with C. trachomatis MOMP-derived CTH522 or HtrA antigens in mice. Following a prime-boost intranasal vaccination approach, two OMV-based C. trachomatis vaccines elicited significant humoral responses specific to the antigens in both systemic and vaginal compartments. Furthermore, we demonstrated strong antigen-specific IFN-γ and IL17a responses in splenocytes and cervical lymph node cells of vaccinated mice, indicating CD4+ Th1 and Th17 biased immune responses. Notably, the OMV-CTH522 vaccine also induced the production of spleen-derived CD8+ T cells expressing IFN-γ. In conclusion, these results highlight the potential of OMV-based C. trachomatis vaccines for successful use in future challenge studies and demonstrate the suitability of our modular OMV platform for intranasal vaccine applications.

Abstract 6397: Immune profiling for improving responsiveness to ipilimumab plus nivolumab checkpoint blockade treatment in patients with metastatic melanoma

Abstract Background:aCTLA-4 and aPD-1 combination therapy has significantly improved clinical outcomes in patients with metastatic melanoma, with 50%-60% of patients responding to treatment, but predictors of response and treatment induced immunological effects are poorly characterized. Identifying circulating immune populations as biomarkers could reveal crucial insights into the mechanisms driving treatment success. Methods:Using unbiased single-cell profiling (with cytometry by Time-Of-Flight, CyTOF), we characterized the systemic immune compartments of over 250 peripheral blood mononuclear samples from 89 patients with advanced melanoma before and during combination therapy. We evaluated the association between circulating immune populations and clinical outcome using nonparametric Mann-Whitney tests, and investigated the prognostic values of these features using survival analysis. Additionally, we assessed treatment-induced immunological effects, providing insights into the dynamic changes within the immune system during therapy. Results:We characterized circulating T cells, NK cells, B cells, and monocytes from peripheral blood. Following combination therapy, there was a shift from naïve and central memory T cells to effector populations in both CD4+ and CD8+ T cells compartments. There was also a broad activation observed in both adaptive and innate populations, characterized by an elevation of multiple co-stimulatory and co-inhibitory molecules. Lower CD8+ NK cell populations prior to combination therapy were predictive of durable clinical benefit (DCB). Pre-treatment measurements of Tregs were not predictive of outcome, but higher Tregs one month after starting therapy, as well as increases of Tregs from pre to post treatment, predicted better progression free survival (PFS) and overall survival (OS). Starting from early on treatment, higher “exhausted-like” CD8+ T cells, characterized by positive expression of at least two co-inhibitory markers, is associated with resistance. Conclusions:aCTLA-4 and aPD-1 combination therapy led to a longitudinal shift from naïve and central memory to effector phenotypes in T cells, along with a broad activation in both adaptive and innate populations. Within innate immune compartment, favorable clinical outcome was associated with lower CD8+ NK cells, capable of regulating proliferation and activation of CD4+ T cells. Interestingly, one month after the start of the therapy, the increase in Tregs and a decrease in 'exhausted-like' CD8+ T populations are associated with a better response. Collectively, these analyses suggest potential treatment-specific correlates of efficacy and may enable biomarker-selected patient populations in future. Citation Format: Joanna Baginska, Jiajia Chen, Giuseppe Tarantino, Anita Giobbie-Hurder, Jason L. Weirather, Mariano Severgnini, Michael Manos, Kelly Burke, Janice D. Russell, Martha Brainard, Elizabeth Gabriel, Ryan Brennick, Matthew Nazzaro, Emma Hathaway, Marta Holovatska, Claire Manuszak, Srinika Ranashinge, David Liu, F. Stephen Hodi. Immune profiling for improving responsiveness to ipilimumab plus nivolumab checkpoint blockade treatment in patients with metastatic melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6397.

In silico design and analysis of a multiepitope vaccine against Chlamydia.

Chlamydia trachomatis (Ct) is the most common sexually transmitted bacterial infection worldwide, potentially leading to severe pathologies including pelvic inflammatory disease, ectopic pregnancy, and tubal infertility if left untreated. Current strategies, including screening and antibiotics, have limited effectiveness due to high rates of asymptomatic cases and logistical challenges. A multiepitope prophylactic vaccine could afford long-term protection against infection. Immunoinformatic analyses were employed to design a multiepitope Chlamydia vaccine antigen. B- and T-cell epitopes from five highly conserved and immunogenic Ct antigens were predicted and selected for the vaccine design. The final construct, adjuvanted with cholera toxin A1 subunit (CTA1), was further screened for immunogenicity. CTA1-MECA (multiepitope Chlamydia trachomatis antigen) was identified as antigenic and nonallergenic. A tertiary structure was predicted, refined, and validated as a good quality model. Molecular docking exhibited strong interactions between the vaccine and toll-like receptor 4 (TLR4). Additionally, immune responses consistent with protection including IFN-γ, IgG+IgM antibodies, and T- and B-cell responses were predicted following vaccination in an immune simulation. Expression of the construct in an Escherichia coli expression vector proved efficient. To further validate the vaccine efficacy, we assessed its immunogenicity in mice. Immunization with CTA1-MECA elicited high levels of Chlamydia-specific antibodies in mucosal and systemic compartments.

Alterations of Hemostatic Molecular Markers During Acute Large Vessel Occlusion Stroke.

This study aimed to investigate regional levels of TAT (thrombin-antithrombin complex), PIC (plasmin-α2 plasmin inhibitor complex), t-PAIC (tissue plasminogen activator-plasminogen activator inhibitor complex), sTM (soluble thrombomodulin), and D-dimer, along with their associations with clinical and procedural characteristics in patients with acute ischemic stroke undergoing endovascular thrombectomy. We retrospectively analyzed 166 consecutive patients with acute ischemic stroke (62±11.54 years of age, 34.3% women) using prospectively maintained clinical databases and blood samples from local ischemic (proximal to thrombus) and systemic (femoral artery, self-control) arterial compartments. Levels of TAT, PIC, t-PAIC, and D-dimer were significantly elevated, whereas sTM was significantly reduced, in local ischemic regions compared with their systemic levels. Each 1-unit increase in ischemic TAT (adjusted odds ratio [aOR], 1.086 [95% CI, 1.03-1.145]; P=0.002; area under the curve [AUC], 0.833) and PIC (aOR, 1.337 [95% CI, 1.087-1.644]; P=0.006; AUC, 0.771) correlated significantly with higher symptomatic intracranial hemorrhage risk. Additionally, each 1-unit increase in ischemic TAT (aOR, 1.076 [95% CI, 1.016-1.139]; P=0.013; AUC, 0.797), PIC (aOR, 1.554 [95% CI, 1.194-2.022]; P=0.001; AUC, 0.798), and sTM (aOR, 0.769 [95% CI, 0.615-0.961]; P=0.021; AUC, 0.756) was significantly associated with an increased risk of an unfavorable 90-day outcome (modified Rankin scale of 3-6). These hemostatic molecules, individually or combined, significantly improved the predictive power of conventional risk factors, as evidenced by significant increases in net reclassification improvement and integrated discrimination improvement (all P<0.01). We observed a hyperactive state of the coagulation-fibrinolysis system within the local ischemic region during hyperacute stroke. Rapid automated measurement of hemostatic molecular markers, particularly TAT, PIC, and sTM, during intra-arterial procedures may provide additional information for stroke risk stratification and therapeutic decision-making, and warrants further investigation.

Addition of Mucoadhesive Agent to Enzymatically Polymerized Caffeic Acid-Based Nasal Vaccine Formulation Attenuates Antigen-Specific Antibody Responses in Mice.

Mucosal vaccination is a promising strategy for combating infectious diseases caused by pathogenic microbes, as it can generate antigen-specific immune responses in both systemic and mucosal compartments. In our recent study, we developed a nasal vaccine system for Streptococcus pneumoniae infections in mice using enzymatically polymerized polyphenols such as caffeic acid. However, the efficacy of this mucosal vaccine system is approximately 70%, indicating a need for improvement. To address this issue, we hypothesized that incorporating a mucoadhesive agent that enhances mucosal absorption into a polyphenol-based mucosal vaccine system would improve vaccine efficacy. Contrary to our expectations, we found that adding a mucoadhesive agent, hydrophobically modified hydroxypropylmethylcellulose, to the vaccine system reduced the stimulation of antigen-specific antibody responses in both the mucosal (more than 90% reduction; P < 0.05) and systemic compartments (more than 80% reduction; P < 0.05). Although the addition of the mucoadhesive agent may have interfered with the interaction between the mucosal epithelium and the vaccine system, the underlying mechanism remains unclear, and further research is needed to fully understand the mechanisms involved.

Impact of maternal Bifidobacterium breve M-16V and scGOS/lcFOS supplementation during pregnancy and lactation on the maternal immune system and milk composition.

Maternal synbiotic supplementation during pregnancy and lactation can significantly influence the immune system. Prebiotics and probiotics have a positive impact on the immune system by preventing or ameliorating among others intestinal disorders. This study focused on the immunomodulatory effects of B. breve M-16V and short chain galacto-oligosaccharides (scGOS)/long chain fructo-oligosachairdes (lcFOS), including systemic and mucosal compartments and milk composition. Lewis rats were orally administered with the synbiotic or vehicle during pregnancy (21 days) and lactation (21 days). At the weaning day, small intestine (SI), mammary gland (MG), adipose tissue, milk, mesenteric lymph nodes (MLN), salivary gland (SG), feces and cecal content were collected from the mothers. The immunoglobulinome profile showed increased IgG2c in plasma and milk, as well as elevated sIgA in feces at weaning. The supplementation improved lipid metabolism through enhanced brown adipose tissue activity and reinforced the intestinal barrier by increasing the expression of Muc3, Cldn4, and Ocln. The higher production of short chain fatty acids in the cecum and increased Bifidobacterium counts suggest a potential positive impact on the gastrointestinal tract. These findings indicate that maternal synbiotic supplementation during gestation and lactation improves their immunological status and improved milk composition.

Pneumonic Plague Protection Induced by a Monophosphoryl Lipid A Decorated Yersinia Outer-Membrane-Vesicle Vaccine.

A new Yersinia pseudotuberculosis mutant strain, YptbS46, carrying the lpxE insertion and pmrF-J deletion is constructed and shown to exclusively produce monophosphoryl lipid A (MPLA) having adjuvant properties. Outer membrane vesicles (OMVs) isolated from YptbS46 harboring an lcrV expression plasmid, pSMV13, are designated OMV46-LcrV, which contained MPLA and high amounts of LcrV (Low Calcium response V) and displayed low activation of Toll-like receptor 4 (TLR4). Intramuscular prime-boost immunization with 30µg of of OMV46-LcrV exhibited substantially reduced reactogenicity than the parent OMV44-LcrV and conferred complete protection to mice against a high-dose of respiratory Y. pestis challenge. OMV46-LcrV immunization induced robust adaptive responses in both lung mucosal and systemic compartments and orchestrated innate immunity in the lung, which are correlated with rapid bacterial clearance and unremarkable lung damage during Y. pestis challenge. Additionally, OMV46-LcrV immunization conferred long-term protection. Moreover, immunization with reduced doses of OMV46-LcrV exhibited further lower reactogenicity and still provided great protection against pneumonic plague. The studies strongly demonstrate the feasibility of OMV46-LcrV as a new type of plague vaccine candidate.

Utility of nasal swabs for assessing mucosal immune responses towards SARS-CoV-2

SARS-CoV-2 has caused millions of infections worldwide since its emergence in 2019. Understanding how infection and vaccination induce mucosal immune responses and how they fluctuate over time is important, especially since they are key in preventing infection and reducing disease severity. We established a novel methodology for assessing SARS-CoV-2 cytokine and antibody responses at the nasal epithelium by using nasopharyngeal swabs collected longitudinally before and after either SARS-CoV-2 infection or vaccination. We then compared responses between mucosal and systemic compartments. We demonstrate that cytokine and antibody profiles differ between compartments. Nasal cytokines show a wound healing phenotype while plasma cytokines are consistent with pro-inflammatory pathways. We found that nasal IgA and IgG have different kinetics after infection, with IgA peaking first. Although vaccination results in low nasal IgA, IgG induction persists for up to 180 days post-vaccination. This research highlights the importance of studying mucosal responses in addition to systemic responses to respiratory infections. The methods described herein can be used to further mucosal vaccine development by giving us a better understanding of immunity at the nasal epithelium providing a simpler, alternative clinical practice to studying mucosal responses to infection.