Prime-Pull Immunization of Mice with a BcfA-Adjuvanted Vaccine Elicits Sustained Mucosal Immunity That Prevents SARS-CoV-2 Infection and Pathology.

Vaccines against SARS-CoV-2 that induce mucosal immunity capable of preventing infection and disease remain urgently needed. In this study, we demonstrate the efficacy of Bordetella colonization factor A (BcfA), a novel bacteria-derived protein adjuvant, in SARS-CoV-2 spike-based prime-pull immunizations. We show that i.m. priming of mice with an aluminum hydroxide- and BcfA-adjuvanted spike subunit vaccine, followed by a BcfA-adjuvanted mucosal booster, generated Th17-polarized CD4+ tissue-resident memory T cells and neutralizing Abs. Immunization with this heterologous vaccine prevented weight loss following challenge with mouse-adapted SARS-CoV-2 (MA10) and reduced viral replication in the respiratory tract. Histopathology showed a strong leukocyte and polymorphonuclear cell infiltrate without epithelial damage in mice immunized with BcfA-containing vaccines. Importantly, neutralizing Abs and tissue-resident memory T cells were maintained until 3 mo postbooster. Viral load in the nose of mice challenged with the MA10 virus at this time point was significantly reduced compared with naive challenged mice and mice immunized with an aluminum hydroxide-adjuvanted vaccine. We show that vaccines adjuvanted with alum and BcfA, delivered through a heterologous prime-pull regimen, provide sustained protection against SARS-CoV-2 infection.

Bps polysaccharide of Bordetella pertussis resists antimicrobial peptides by functioning as a dual surface shield and decoy and converts Escherichia coli into a respiratory pathogen.

Infections and disease caused by the obligate human pathogen Bordetella pertussis (Bp) are increasing, despite widespread vaccinations. The current acellular pertussis vaccines remain ineffective against nasopharyngeal colonization, carriage, and transmission. In this work, we tested the hypothesis that Bordetella polysaccharide (Bps), a member of the poly-ß-1,6-N-acetyl-D-glucosamine (PNAG/PGA) family of polysaccharides promotes respiratory tract colonization of Bp by resisting killing by antimicrobial peptides (AMPs). Genetic deletion of the bpsA-D locus, as well as treatment with the specific glycoside hydrolase Dispersin B, increased susceptibility to AMP-mediated killing. Bps was found to be both cell surface-associated and released during laboratory growth and mouse infections. Addition of bacterial supernatants containing Bps and purified Bps increased B. pertussis resistance to AMPs. By utilizing ELISA, immunoblot and flow cytometry assays, we show that Bps functions as a dual surface shield and decoy. Co-inoculation of C57BL/6J mice with a Bps-proficient strain enhanced respiratory tract survival of the Bps-deficient strain. In combination, the presented results highlight the critical role of Bps as a central driver of B. pertussis pathogenesis. Heterologous production of Bps in a non-pathogenic E. coli K12 strain increased AMP resistance in vitro, and augmented bacterial survival and pathology in the mouse respiratory tract. These studies can serve as a foundation for other PNAG/PGA polysaccharides and for the development of an effective Bp vaccine that includes Bps.

Targeting OCT3 attenuates doxorubicin-induced cardiac injury.

Doxorubicin is a commonly used anticancer agent that can cause debilitating and irreversible cardiac injury. The initiating mechanisms contributing to this side effect remain unknown, and current preventative strategies offer only modest protection. Using stem-cell-derived cardiomyocytes from patients receiving doxorubicin, we probed the transcriptomic landscape of solute carriers and identified organic cation transporter 3 (OCT3) (SLC22A3) as a critical transporter regulating the cardiac accumulation of doxorubicin. Functional validation studies in heterologous overexpression models confirmed that doxorubicin is transported into cardiomyocytes by OCT3 and that deficiency of OCT3 protected mice from acute and chronic doxorubicin-related changes in cardiovascular function and genetic pathways associated with cardiac damage. To provide proof-of-principle and demonstrate translational relevance of this transport mechanism, we identified several pharmacological inhibitors of OCT3, including nilotinib, and found that pharmacological targeting of OCT3 can also preserve cardiovascular function following treatment with doxorubicin without affecting its plasma levels or antitumor effects in multiple models of leukemia and breast cancer. Finally, we identified a previously unrecognized, OCT3-dependent pathway of doxorubicin-induced cardiotoxicity that results in a downstream signaling cascade involving the calcium-binding proteins S100A8 and S100A9. These collective findings not only shed light on the etiology of doxorubicin-induced cardiotoxicity, but also are of potential translational relevance and provide a rationale for the implementation of a targeted intervention strategy to prevent this debilitating side effect.

Caspase-11 regulates lung inflammation in response to house dust mites.

Asthma is an inflammatory lung disorder characterized by mucus hypersecretion, cellular infiltration, and bronchial hyper-responsiveness. House dust mites (HDM) are the most prevalent cause of allergic sensitization. Canonical and noncanonical inflammasomes are multiprotein complexes that assemble in response to pathogen or danger-associated molecular patterns (PAMPs or DAMPs). Murine caspase-11 engages the noncanonical inflammasome. We addressed the role of caspase-11 in mediating host responses to HDM and subsequent allergic inflammation using caspase-11-/- mice, which lack caspase-11 while express caspase-1. We found that HDM induce caspase-11 expression in vitro. The presence of IL-4 and IL-13 promote caspase-11 expression. Additionally, caspase-11-/- macrophages show reduced release of IL-6, IL-12, and KC, and express lower levels of costimulatory molecules (e.g., CD40, CD86 and MHCII) in response to HDM stimulation. Notably, HDM sensitization of caspase-11-/- mice resulted in similar levels of IgE responses and hypothermia in response to nasal HDM challenge compared to WT. However, analysis of cell numbers and cytokines in bronchiolar alveolar lavage fluid (BALF) and histopathology of representative lung segments demonstrate altered inflammatory responses and reduced neutrophilia in the airways of the caspase-11-/- mice. These findings indicate that caspase-11 regulates airway inflammation in response to HDM exposure.

Moderately pathogenic maternal influenza A virus infection disrupts placental integrity but spares the fetal brain.

Maternal infection during pregnancy is a known risk factor for offspring mental health disorders. Animal models of maternal immune activation (MIA) have implicated specific cellular and molecular etiologies of psychiatric illness, but most rely on pathogen mimetics. Here, we developed a mouse model of live H3N2 influenza A virus (IAV) infection during pregnancy that induces a robust inflammatory response but is sublethal to both dams and offspring. We observed classic indicators of lung inflammation and severely diminished weight gain in IAV-infected dams. This was accompanied by immune cell infiltration in the placenta and partial breakdown of placental integrity. However, indications of fetal neuroinflammation were absent. Further hallmarks of mimetic-induced MIA, including enhanced circulating maternal IL-17A, were also absent. Respiratory IAV infection did result in an upregulation in intestinal expression of transcription factor RORγt, master regulator of a subset of T lymphocytes, TH17 cells, which are heavily implicated in MIA-induced etiologies. Nonetheless, subsequent augmentation in IL-17A production and concomitant overt intestinal injury was not evident. Our results suggest that mild or moderately pathogenic IAV infection during pregnancy does not inflame the developing fetal brain, and highlight the importance of live pathogen infection models for the study of MIA.

Bordetella Colonization Factor A (BcfA) Elicits Protective Immunity against Bordetella bronchiseptica in the Absence of an Additional Adjuvant.

Bordetella bronchiseptica is an etiologic agent of respiratory diseases in animals and humans. Despite the widespread use of veterinary B. bronchiseptica vaccines, there is limited information on their composition and relative efficacy and on the immune responses that they elicit. Furthermore, human B. bronchiseptica vaccines are not available. We leveraged the dual antigenic and adjuvant functions of Bordetella colonization factor A (BcfA) to develop acellular B. bronchiseptica vaccines in the absence of an additional adjuvant. BALB/c mice immunized with BcfA alone or a trivalent vaccine containing BcfA and the Bordetella antigens FHA and Prn were equally protected against challenge with a prototype B. bronchiseptica strain. The trivalent vaccine protected mice significantly better than the canine vaccine Bronchicine and provided protection against a B. bronchiseptica strain isolated from a dog with kennel cough. Th1/17-polarized immune responses correlate with long-lasting protection against bordetellae and other respiratory pathogens. Notably, BcfA strongly attenuated the Th2 responses elicited by FHA and Prn, resulting in Th1/17-skewed responses in inherently Th2-skewed BALB/c mice. Thus, BcfA functions as both an antigen and an adjuvant, providing protection as a single-component vaccine. BcfA-adjuvanted vaccines may improve the efficacy and durability of vaccines against bordetellae and other pathogens.

Patient Voices in Rheumatic Immune-related Adverse Events.

Patients with cancer considering immune checkpoint inhibitor (ICI) therapy often look for health information and peer support through online communities. The authors used social media content analysis to obtain the perspectives of patients receiving ICI treatment about immune-related adverse events (irAEs), with particular focus on rheumatological symptoms. The most reported rheumatic symptom was joint pain. Other commonly reported symptoms included muscle pain, joint stiffness, arthritis, myositis, bone pain, back pain, and tendon/ligament pain. A few users reported development of rheumatic diseases. The authors' analyses allowed for cataloging and assessment of patient and caregiver experiences with ICI therapy and rheumatic irAEs.

Neurotoxic, inflammatory, and mucosecretory responses in the nasal airways of mice repeatedly exposed to the macrocyclic trichothecene mycotoxin roridin A: dose-response and persistence of injury.

Macrocyclic trichothecene mycotoxins encountered in water-damaged buildings have been suggested to contribute to illnesses of the upper respiratory tract. Here, the authors characterized the adverse effects of repeated exposures to roridin A (RA), a representative macrocyclic trichothecene, on the nasal airways of mice and assessed the persistence of these effects. Young, adult, female C57BL/6 mice were exposed to single daily, intranasal, instillations of RA (0.4, 2, 10, or 50 microg/kg body weight [bw]) in saline (50 microl) or saline alone (controls) over 3 weeks or 250 microg/kg RA over 2 weeks. Histopathologic, immunohistochemical, and morphometric analyses of nasal airways conducted 24 hr after the last instillation revealed that the lowest-effect level was 10 microg/kg bw. RA exposure induced a dose-dependent, neutrophilic rhinitis with mucus hypersecretion, atrophy and exfoliation of nasal transitional and respiratory epithelium, olfactory epithelial atrophy and loss of olfactory sensory neurons (OSNs). In a second study, the persistence of lesions in mice instilled with 250 microg/kg bw RA was assessed. Nasal inflammation and excess luminal mucus were resolved after 3 weeks, but OSN loss was still evident in olfactory epithelium (OE). These results suggest that nasal inflammation, mucus hypersecretion, and olfactory neurotoxicity could be important adverse health effects associated with short-term, repeated, airborne exposures to macrocyclic trichothecenes.

Veterinarians in biomedical research: building national capacity.

This Executive Summary provides the conclusions from the presentations and discussions at the conference Veterinarians in Biomedical Research-Building National Capacity, a meeting coordinated by the AAVMC and held at the National Institutes of Health (NIH), Bethesda, MD, August 1-4, 2007.

Inflammation and neuroprotection in traumatic brain injury.

IMPORTANCE: Traumatic brain injury (TBI) is a significant public health concern that affects individuals in all demographics. With increasing interest in the medical and public communities, understanding the inflammatory mechanisms that drive the pathologic and consequent cognitive outcomes can inform future research and clinical decisions for patients with TBI. OBJECTIVES: To review known inflammatory mechanisms in TBI and to highlight clinical trials and neuroprotective therapeutic manipulations of pathologic and inflammatory mechanisms of TBI. EVIDENCE REVIEW: We searched articles in PubMed published between 1960 and August 1, 2014, using the following keywords: traumatic brain injury, sterile injury, inflammation, astrocytes, microglia, monocytes, macrophages, neutrophils, T cells, reactive oxygen species, alarmins, danger-associated molecular patterns, purinergic receptors, neuroprotection, and clinical trials. Previous clinical trials or therapeutic studies that involved manipulation of the discussed mechanisms were considered for inclusion. The final list of selected studies was assembled based on novelty and direct relevance to the primary focus of this review. FINDINGS: Traumatic brain injury is a diverse group of sterile injuries induced by primary and secondary mechanisms that give rise to cell death, inflammation, and neurologic dysfunction in patients of all demographics. Pathogenesis is driven by complex, interacting mechanisms that include reactive oxygen species, ion channel and gap junction signaling, purinergic receptor signaling, excitotoxic neurotransmitter signaling, perturbations in calcium homeostasis, and damage-associated molecular pattern molecules, among others. Central nervous system resident and peripherally derived inflammatory cells respond to TBI and can provide neuroprotection or participate in maladaptive secondary injury reactions. The exact contribution of inflammatory cells to a TBI lesion is dictated by their anatomical positioning as well as the local cues to which they are exposed. CONCLUSIONS AND RELEVANCE: The mechanisms that drive TBI lesion development as well as those that promote repair are exceedingly complex and often superimposed. Because pathogenic mechanisms can diversify over time or even differ based on the injury type, it is important that neuroprotective therapeutics be developed and administered with these variables in mind. Due to its complexity, TBI has proven particularly challenging to treat; however, a number of promising therapeutic approaches are now under pre-clinical development, and recent clinical trials have even yielded a few successes. Given the worldwide impact of TBI on the human population, it is imperative that research remains active in this area and that we continue to develop therapeutics to improve outcome in afflicted patients.

In vivo dynamics of innate immune sentinels in the CNS.

The innate immune system is comprised of cellular sentinels that often serve as the first responders to injury and invading pathogens. Our basic understanding of innate immunity is derived from research conducted in peripheral lymphoid tissues. However, it is now recognized that most non-lymphoid tissues throughout the body are equipped with specialized innate immune cells that are uniquely adapted to the niches in which they reside. The central nervous system (CNS) is a particularly interesting compartment because it contains a population of post-mitotic cells (neurons) that are intolerant of robust, cytopathic inflammatory responses observed in many peripheral tissues. Thus, evolutionary adaptations have fitted the CNS with a unique array of innate immune sentinels that facilitate the development of local inflammatory responses but attempt to do so in a manner that preserves the integrity of its post-mitotic residents. Interestingly, studies have even suggested that CNS resident innate immune cells contribute to the homeostasis of this compartment and promote neural activity. In this review we discuss recent advances in our understanding of CNS innate immune sentinels and how novel imaging approaches such as intravital two-photon laser scanning microscopy (TPLSM) have shed light on these cells during states of health and disease.

Investigation into diagnostic agreement using automated computer-assisted histopathology pattern recognition image analysis.

The extent to which histopathology pattern recognition image analysis (PRIA) agrees with microscopic assessment has not been established. Thus, a commercial PRIA platform was evaluated in two applications using whole-slide images. Substantial agreement, lacking significant constant or proportional errors, between PRIA and manual morphometric image segmentation was obtained for pulmonary metastatic cancer areas (Passing/Bablok regression). Bland-Altman analysis indicated heteroscedastic measurements and tendency toward increasing variance with increasing tumor burden, but no significant trend in mean bias. The average between-methods percent tumor content difference was -0.64. Analysis of between-methods measurement differences relative to the percent tumor magnitude revealed that method disagreement had an impact primarily in the smallest measurements (tumor burden <3%). Regression-based 95% limits of agreement indicated substantial agreement for method interchangeability. Repeated measures revealed concordance correlation of >0.988, indicating high reproducibility for both methods, yet PRIA reproducibility was superior (C.V.: PRIA = 7.4, manual = 17.1). Evaluation of PRIA on morphologically complex teratomas led to diagnostic agreement with pathologist assessments of pluripotency on subsets of teratomas. Accommodation of the diversity of teratoma histologic features frequently resulted in detrimental trade-offs, increasing PRIA error elsewhere in images. PRIA error was nonrandom and influenced by variations in histomorphology. File-size limitations encountered while training algorithms and consequences of spectral image processing dominance contributed to diagnostic inaccuracies experienced for some teratomas. PRIA appeared better suited for tissues with limited phenotypic diversity. Technical improvements may enhance diagnostic agreement, and consistent pathologist input will benefit further development and application of PRIA.