Layering vaccination with antibiotic therapy results in protection and clearance of Burkholderia pseudomallei in Balb/c mice.

Melioidosis is a disease that is difficult to treat due to the causative organism, Burkholderia pseudomallei being inherently antibiotic resistant and it having the ability to invade, survive, and replicate in an intracellular environment. Combination therapy approaches are routinely being evaluated in animal models with the aim of improving the level of protection and clearance of colonizing bacteria detected. In this study, a subunit vaccine layered with the antibiotic finafloxacin was evaluated in vivo against an inhalational infection with B. pseudomallei in Balb/c mice. Groups of mice vaccinated, infected, and euthanized at antibiotic initiation had a reduced bacterial load compared to those that had not been immunized. In addition, the subunit vaccine provided a synergistic effect when it was delivered with a CpG ODN and finafloxacin was initiated at 48 h post-challenge. Vaccination was also shown to improve the outcome, in a composite measure of survival and clearance. In summary, layering a subunit vaccine with the antibiotic finafloxacin is a promising therapeutic alternative for use in the treatment of B. pseudomallei infections.

Exploring the Inclusion of Person-Centered Care Domains in Stroke Transitions of Care Interventions: A Scientific Statement From the American Heart Association.

BACKGROUND: Health care teams along the stroke recovery continuum have a responsibility to support care transitions and return to the community. Ideally, individualized care will consider patient and family preferences, best available evidence, and health care professional input. Person-centered care can improve patient-practitioner interactions through shared decision-making in which health professionals and institutions are sensitive to those for whom they provide care. However, it is unclear how the concepts of person-centered care have been described in reports of stroke transitional care interventions. METHODS: A secondary analysis of a systematic review and meta-analysis was undertaken. We retrieved all included articles (n=17) and evaluated the extent to which each intervention explicitly addressed 7 domains of person-centered care: alignment of care with patients' values, preferences, and needs; coordination of care; information and education; physical comfort; emotional support; family and friend involvement; and smooth transition and continuity of care. RESULTS: Most of the articles included some aspects of person-centeredness; we found that certain domains were not addressed in the descriptions of transitional care interventions, and no articles mentioned all 7 domains of person-centered care. We identified 3 implications for practice and research: (1) delineating person-centered care components when reporting interventions, (2) elucidating social and cultural factors relevant to the study sample and intervention, and (3) clearly describing the role of family and nonmedical support in the intervention. CONCLUSIONS: There is still room for greater consistency in the reporting of person-centeredness in stroke transitions of care interventions, despite a long-standing definition and conceptualization of person-centered care in academic and clinically focused literature.

Augmenting TCR signal strength and ICOS costimulation results in metabolically fit and therapeutically potent human CAR Th17 cells.

IL-17-producing antigen-specific human T cells elicit potent antitumor activity in mice. Yet, refinement of this approach is needed to position it for clinical use. While activation signal strength regulates IL-17 production by CD4+ T cells, the degree to which T cell antigen receptor (TCR) and costimulation signal strength influences Th17 immunity remains unknown. We discovered that decreasing TCR/costimulation signal strength by incremental reduction of αCD3/costimulation beads progressively altered Th17 phenotype. Moreover, Th17 cells stimulated with αCD3/inducible costimulator (ICOS) beads produced more IL-17A, IFNγ, IL-2, and IL-22 than those stimulated with αCD3/CD28 beads. Compared with Th17 cells stimulated with the standard, strong signal strength (three beads per T cell), Th17 cells propagated with 30-fold fewer αCD3/ICOS beads were less reliant on glucose and favored the central carbon pathway for bioenergetics, marked by abundant intracellular phosphoenolpyruvate (PEP). Importantly, Th17 cells stimulated with weak αCD3/ICOS beads and redirected with a chimeric antigen receptor that recognizes mesothelin were more effective at clearing human mesothelioma. Less effective CAR Th17 cells generated with high αCD3/ICOS beads were rescued by overexpressing phosphoenolpyruvate carboxykinase 1 (PCK1), a PEP regulator. Thus, Th17 therapy can be improved by using fewer activation beads during manufacturing, a finding that is cost effective and directly translatable to patients.

Exploring the experiences of adults with stroke in virtual community-based stroke programs: a qualitative descriptive study.

BACKGROUND: Stroke is among the top contributors to disability and can impact an individual's cognition, physical functioning, and mental health. Since the COVID-19 pandemic, several community-based organizations have started delivering stroke programs virtually. However, participants' experiences in these programs remain understudied, and evidence-based guidelines to inform and optimize virtual stroke program development and delivery are lacking. Thus, this study aimed to describe the perspectives and experiences of individuals with stroke who participated in virtual community-based organization stroke programs, including perceived access and participation facilitators and barriers and suggestions for improving these programs. METHODS: A qualitative descriptive design was used to gather participant experiences through semi-structured interviews. Audio-recorded interviews were conducted on Zoom and transcribed verbatim. Adult participants who had experienced a stroke and attended at least one Canadian virtual community-based organization stroke program were recruited. Data were analyzed using inductive thematic analysis. RESULTS: Twelve participants (32-69 years, 2-23 years post-stroke, eight women and four men) participated in this study. Five themes were identified: (1) motives to join virtual community-based organization stroke programs, including gaining peer connections, knowledge and information; (2) perceived barriers to accessing and participating in virtual community-based organization stroke programs, including technology inequities, difficulties navigating technology, and inadequate facilitation; (3) perceived facilitators to accessing and participating in virtual community-based organization stroke programs, including remote access, virtual platform features and program leader characteristics/skills; (4) unmet needs during virtual community-based organization stroke programs, including in-person connection and individualized support; and (5) suggestions and preferences for improving virtual community-based organization stroke programs, including program facilitation, content and format. CONCLUSIONS: Study findings highlight opportunities to improve virtual community-based organization stroke programs to optimize participant experiences and outcomes. Addressing the barriers and suggestions identified in this study may improve virtual community-based organization stroke programs' access and quality.

Comparison of Experimental Middle East Respiratory Syndrome Coronavirus Infection Acquired by Three Individual Routes of Infection in the Common Marmoset.

Two strains of Middle East respiratory syndrome coronavirus (MERS-CoV), England 1 and Erasmus Medical Centre/2012 (EMC/2012), were used to challenge common marmosets (Callithrix jacchus) by three routes of infection: aerosol, oral, and intranasal. Animals challenged by the intranasal and aerosol routes presented with mild, transient disease, while those challenged by the oral route presented with a subclinical immunological response. Animals challenged with MERS-CoV strain EMC/2012 by the aerosol route responded with primary and/or secondary pyrexia. Marmosets had minimal to mild multifocal interstitial pneumonia, with the greatest relative severity being observed in animals challenged by the aerosol route. Viable virus was isolated from the host in throat swabs and lung tissue. The transient disease described is consistent with a successful host response and was characterized by the upregulation of macrophage and neutrophil function observed in all animals at the time of euthanasia. IMPORTANCE Middle East respiratory syndrome is caused by a human coronavirus, MERS-CoV, similar to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Humans typically exhibit fever, cough, shortness of breath, gastrointestinal issues, and breathing difficulties, which can lead to pneumonia and/or renal complications. This emerging disease resulted in the first human lethal cases in 2012 and has a case fatality rate of approximately 36%. Consequently, there is a need for medical countermeasures and appropriate animal models for their assessment. This work has demonstrated the requirement for higher concentrations of virus to cause overt disease. Challenge by the aerosol, intranasal, and oral routes resulted in no or mild disease, but all animals had an immunological response. This shows that an appropriate early immunological response is able to control the disease.

Exploring barriers to SARS-CoV-2 testing uptake in underserved black communities in Louisiana.

OBJECTIVE: To collect qualitative data on approaches that can potentially reduce barriers to, and create strategies for, increasing SARS-CoV-2 testing uptake in underserved Black communities in Louisiana. METHODS: A series of eight focus groups, including 41 participants, were conducted in primarily Black communities. The Nominal Group Technique (NGT) was used to determine perceptions of COVID-19 as a disease, access to testing, and barriers limiting testing uptake. RESULTS: Common barriers to SARS-CoV-2 testing were identified as lack of transportation, misinformation/lack of information, lack of time/long wait times, fear of the test being uncomfortable and/or testing positive, the cost of testing, and lack of computer/smartphone/internet. The most impactful approaches identified to increase testing uptake included providing testing within the local communities; testing specifically in heavily traveled areas such as supermarkets, churches, schools, and so forth; providing incentives; engaging local celebrities; and providing information to the community through health fairs, or through churches and schools. The strategies that were deemed to be the easiest to implement revolved around communication about testing, with suggested strategies involving churches, local celebrities or expert leaders, social media, text messages, public service announcements, post cards, or putting up signs in neighborhoods. Providing transportation to testing sites, providing incentives, and bringing the testing to neighborhoods and schools were also identified as easy to implement strategies. CONCLUSIONS: Several strategies to increase testing uptake were identified in this population. These strategies need to be tested for effectiveness in real-world settings using experimental and observational study designs.

The Innate Immune Response in the Marmoset during the Acute Pneumonic Disease Caused by Burkholderia pseudomallei.

Burkholderia pseudomallei is the causative agent of melioidosis, a severe human infection that is difficult to treat with antibiotics and for which there is no effective vaccine. Development of novel treatments rely upon appropriately characterized animal models. The common marmoset (Callithrix jacchus) has been established at Defense Science and Technology laboratories (DSTL) as a model of melioidosis. Further analysis was performed on samples generated in these studies to provide a description of the innate immune response. Many of the immunological features described, (migration/activation of neutrophils and macrophages, activation of T cells, elevation of key cytokines IFNγ, TNF-α, IL-6, and IL-1ß) have been observed in acute melioidosis human cases and correlated with prognosis. Expression of the MHCII marker (HLA-DR) on neutrophils showed potential as a diagnostic with 80% accuracy when comparing pre- and postchallenge levels in paired blood samples. Discriminant analysis of cell surface, activation markers on neutrophils combined with levels of key cytokines, differentiated between disease states from single blood samples with 78% accuracy. These key markers have utility as a prototype postexposure, presymptomatic diagnostic. Ultimately, these data further validate the use of the marmoset as a suitable model for determining efficacy of medical countermeasures against B. pseudomallei.

Efficacy of Co-Trimoxazole against Experimental Melioidosis Acquired by Different Routes of Infection.

Burkholderia pseudomallei is the causative agent of melioidosis and presents with diverse clinical manifestations. Naturally occurring infection occurs following contamination of cuts or skin abrasions, or ingestion of contaminated water, and occasionally through inhalational of infected soil or water particles. The influence of the route of disease acquisition on the efficacy of medical countermeasures has not been explored in humans or in appropriate animal models. The efficacy of co-trimoxazole against melioidosis acquired by different routes of exposure was assessed in postexposure prophylaxis (PEP) and treatment studies in marmoset models of melioidosis. Following challenge with B. pseudomallei by the inhalational, subcutaneous, or ingestion routes of administration, animals were given co-trimoxazole at 12 hourly intervals for 14 days, starting either 6 h postchallenge or at the onset of fever. Animals were then observed for 28 days. All animals that received antibiotic 6 h postchallenge survived the duration of dosing. All animals that received antibiotics at the onset of fever completed the treatment, but 10%, 57%, and 60% of those with ingestion, subcutaneous, and inhalation challenge relapsed, respectively. Bacteriological and histological differences were observed between placebo-control animals and those that relapsed. Immunological profiles indicate difference between animals given placebo and those that relapsed or survived the duration of the study. A broad T-cell activation was observed in animals that survived. Overall, these data suggest the efficacy of co-trimoxazole, as measured in the incidence of relapse, differs depending on the disease-acquisition route. Therefore, there are implications in treating this disease in regions of endemicity.

Assessment of Walking Speed and Distance Post-Stroke Increases After Providing a Theory-Based Toolkit.

BACKGROUND AND PURPOSE: While underutilized, poststroke administration of the 10-m walk test (10mWT) and 6-minute walk test (6MWT) can improve care and is considered best practice. We aimed to evaluate provision of a toolkit designed to increase use of these tests by physical therapists (PTs). METHODS: In a before-and-after study, 54 PTs and professional leaders in 9 hospitals were provided a toolkit and access to a clinical expert over a 5-month period. The toolkit comprised a guide, smartphone app, and video, and described how to set up walkways, implement learning sessions, administer walk tests, and interpret and apply test results clinically. The proportion of hospital visits for which each walk test score was documented at least once (based on abstracted health records of ambulatory patients) were compared over 8-month periods pre- and post-intervention using generalized mixed models. RESULTS: Data from 347 and 375 pre- and postintervention hospital visits, respectively, were analyzed. Compared with preintervention, the odds of implementing the 10mWT were 12 times greater (odds ratio [OR] = 12.4, 95% confidence interval [CI] 5.8, 26.3), and of implementing the 6MWT were approximately 4 times greater (OR = 3.9, 95% CI 2.3, 6.7), post-intervention, after adjusting for hospital setting, ambulation ability, presence of aphasia and cognitive impairment, and provider-level clustering. Unadjusted change in the percentage of visits for which the 10mWT/6MWT was documented at least once was smallest in acute care settings (2.0/3.8%), and largest in inpatient and outpatient rehabilitation settings (28.0/19.9% and 29.4/23.4%, respectively). DISCUSSION AND CONCLUSIONS: Providing a comprehensive toolkit to hospitals with professional leaders likely contributed to increasing 10mWT and 6MWT administration during inpatient and outpatient stroke rehabilitation.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A390 ).

Colonoscopy Screening and Polyp Detection in the Southeastern United States.

Screening colonoscopy is recommended for polyp detection and colorectal cancer prevention for those aged 50-75 years. The aim of this study was to determine colon polyp incidence rates detected through screening colonoscopies in the Southeast United States. A retrospective chart review was conducted to determine polyp rates. Charts with a diagnostic code of "screening" colonoscopy were reviewed for age, gender, number of polyps, and type of polyps. The number of charts reviewed was 534, with a total of 239 found to have polyps. Polyp type was defined as hyperplastic and adenomatous, with all adenomatous types grouped together. Descriptive statistics were used for data analysis. The median age of participants was 62 years with 58% being male. The combined rate of colon polyp detection was 44.6%. Seventy percent of the overall sample was found to have at least one polyp. From 16% to 20% of the study population had mixed (adenomatous and hyperplastic) polyps. This study supports the need for continued screening colonoscopies for polyp detection and removal. Education is key and nurses are often the ones who have the greatest educational opportunity. This study indicates the need for further research that may support colorectal cancer screening beginning at an earlier age.

Supported self-management as a model for end-of-life care in the setting of malignant bowel obstruction: A qualitative study.

OBJECTIVE: Women with advanced gynecologic cancer and malignant bowel obstruction (MBO) undergo repeated hospitalizations, experience feelings of isolation and abandonment, and often die in acute settings. Innovative outpatient models of care are needed to address the unmet needs of this population at the end-of-life. We implemented a novel supported self-management (SMS) program focused on increasing patients' skill and confidence in managing MBO proactively in the ambulatory setting. METHODS: We performed a qualitative descriptive study embedded in a prospective single-arm evaluative trial (Clinicaltrials.gov ID: NCT03260647) to understand the impact of this program on patients' sense of support, degree of distress, quality of care, and capacity to self-manage. Semi-structured interviews were completed and analysed using the Chronic Care Model as a theoretical framework. Data saturation was confirmed after 15 interviews. RESULTS: Fifteen patients (age range: 47-82) with diagnoses of advanced ovarian, endometrial, and cervical cancer were interviewed; 10 had died by end of follow-up, with a median interval from interview to death of 5 months. Patients were able to self-manage the: (i) medical aspects; (ii) psychological consequences, and (iii) changes in life roles and expectations resulting from their condition. Patients felt greatly supported, less isolated, and secure in their knowledge and ability to access care due to SMS. While patients understood their disease was not curative they did not fully appreciate that MBO signalled a significantly poorer prognosis. CONCLUSION: Outpatient SMS interventions can be successfully implemented even for rapidly fatal conditions at the end-of-life and offer significant benefit to gynecologic cancer patients with MBO. Counselling should focus on the specific trajectory of MBO, and early palliative care referrals should be standard practice.

Defining the characteristics of intermediate care models including transitional care: an international Delphi study.

BACKGROUND: Although there is growing utilisation of intermediate care to improve the health and well-being of older adults with complex care needs, there is no international agreement on how it is defined, limiting comparability between studies and reducing the ability to scale effective interventions. AIM: To identify and define the characteristics of intermediate care models. METHODS: A scoping review, a modified two-round electronic Delphi study involving 27 multi-professional experts from 13 countries, and a virtual consensus meeting were conducted. RESULTS: Sixty-six records were included in the scoping review, which identified four main themes: transitions, components, benefits and interchangeability. These formed the basis of the first round of the Delphi survey. After Round 2, 16 statements were agreed, refined and collapsed further. Consensus was established for 10 statements addressing the definitions, purpose, target populations, approach to care and organisation of intermediate care models. DISCUSSION: There was agreement that intermediate care represents time-limited services which ensure continuity and quality of care, promote recovery, restore independence and confidence at the interface between home and acute services, with transitional care representing a subset of intermediate care. Models are best delivered by an interdisciplinary team within an integrated health and social care system where a single contact point optimises service access, communication and coordination. CONCLUSIONS: This study identified key defining features of intermediate care to improve understanding and to support comparisons between models and studies evaluating them. More research is required to develop operational definitions for use in different healthcare systems.

U.S. Media Enjoyment without Strong Media Literacy Undermines Adolescents' and Mothers' Reported Efforts to Reduce Unhealthy Eating in Jamaica.

We investigate whether media literacy and media use can moderate the association between U.S. media enjoyment and unhealthy eating among remotely acculturating "Americanized" adolescents and their mothers in Jamaica (n = 164 individuals/82 dyads; Madolescent.age  = 12.83, SD = 0.48, 48% female; Mmother_age  = 39.25, SD = 5.71). Socioeconomically diverse participants completed questionnaires reporting their degree of enjoyment of U.S. media (i.e., remote acculturation), media literacy (i.e., critical thinking about food media/advertising), and adherence to national dietary guidelines to reduce sugar/fat. Multilevel modeling showed that enjoying U.S. media and consuming high levels of U.S. TV plus Jamaican TV are associated with lower efforts to reduce sugar and fat. However, high media literacy, whether one's own or a close family member's, weakens or nullifies that association.

Global Analysis of Genes Essential for Francisella tularensis Schu S4 Growth In Vitro and for Fitness during Competitive Infection of Fischer 344 Rats.

The highly virulent intracellular pathogen Francisella tularensis is a Gram-negative bacterium that has a wide host range, including humans, and is the causative agent of tularemia. To identify new therapeutic drug targets and vaccine candidates and investigate the genetic basis of Francisella virulence in the Fischer 344 rat, we have constructed an F. tularensis Schu S4 transposon library. This library consists of more than 300,000 unique transposon mutants and represents a transposon insertion for every 6 bp of the genome. A transposon-directed insertion site sequencing (TraDIS) approach was used to identify 453 genes essential for growth in vitro Many of these essential genes were mapped to key metabolic pathways, including glycolysis/gluconeogenesis, peptidoglycan synthesis, fatty acid biosynthesis, and the tricarboxylic acid (TCA) cycle. Additionally, 163 genes were identified as required for fitness during colonization of the Fischer 344 rat spleen. This in vivo selection screen was validated through the generation of marked deletion mutants that were individually assessed within a competitive index study against the wild-type F. tularensis Schu S4 strain.IMPORTANCE The intracellular bacterial pathogen Francisella tularensis causes a disease in humans characterized by the rapid onset of nonspecific symptoms such as swollen lymph glands, fever, and headaches. F. tularensis is one of the most infectious bacteria known and following pulmonary exposure can have a mortality rate exceeding 50% if left untreated. The low infectious dose of this organism and concerns surrounding its potential as a biological weapon have heightened the need for effective and safe therapies. To expand the repertoire of targets for therapeutic development, we initiated a genome-wide analysis. This study has identified genes that are important for F. tularensis under in vitro and in vivo conditions, providing candidates that can be evaluated for vaccine or antibacterial development.

Novel immunotherapies for hematologic malignancies.

The immune system is designed to discriminate between self and tumor tissue. Through genetic recombination, there is fundamentally no limit to the number of tumor antigens that immune cells can recognize. Yet, tumors use a variety of immunosuppressive mechanisms to evade immunity. Insight into how the immune system interacts with tumors is expanding rapidly and has accelerated the translation of immunotherapies into medical breakthroughs. Herein, we appraise novel strategies that exploit the patient's immune system to kill cancer. We review various forms of immune-based therapies, which have shown significant promise in patients with hematologic malignancies, including (i) conventional monoclonal therapies like rituximab; (ii) engineered monoclonal antibodies called bispecific T-cell engagers; (iii) monoclonal antibodies and pharmaceutical drugs that block inhibitory T-cell pathways (i.e. PD-1, CTLA-4, and IDO); and (iv) adoptive cell transfer therapy with T cells engineered to express chimeric antigen receptors or T-cell receptors. We also assess the idea of using these therapies in combination and conclude by suggesting multi-prong approaches to improve treatment outcomes and curative responses in patients.

Burkholderia pseudomallei sequencing identifies genomic clades with distinct recombination, accessory, and epigenetic profiles.

Burkholderia pseudomallei (Bp) is the causative agent of the infectious disease melioidosis. To investigate population diversity, recombination, and horizontal gene transfer in closely related Bp isolates, we performed whole-genome sequencing (WGS) on 106 clinical, animal, and environmental strains from a restricted Asian locale. Whole-genome phylogenies resolved multiple genomic clades of Bp, largely congruent with multilocus sequence typing (MLST). We discovered widespread recombination in the Bp core genome, involving hundreds of regions associated with multiple haplotypes. Highly recombinant regions exhibited functional enrichments that may contribute to virulence. We observed clade-specific patterns of recombination and accessory gene exchange, and provide evidence that this is likely due to ongoing recombination between clade members. Reciprocally, interclade exchanges were rarely observed, suggesting mechanisms restricting gene flow between clades. Interrogation of accessory elements revealed that each clade harbored a distinct complement of restriction-modification (RM) systems, predicted to cause clade-specific patterns of DNA methylation. Using methylome sequencing, we confirmed that representative strains from separate clades indeed exhibit distinct methylation profiles. Finally, using an E. coli system, we demonstrate that Bp RM systems can inhibit uptake of non-self DNA. Our data suggest that RM systems borne on mobile elements, besides preventing foreign DNA invasion, may also contribute to limiting exchanges of genetic material between individuals of the same species. Genomic clades may thus represent functional units of genetic isolation in Bp, modulating intraspecies genetic diversity.

Addressing the Evidence Gap in Stroke Rehabilitation for Complex Patients: A Preliminary Research Agenda.

Evidence suggests that a stroke occurs in isolation (no comorbid conditions) in less than 6% of patients. Multimorbidity, compounded by psychosocial issues, makes treatment and recovery for stroke increasingly complex. Recent research and health policy documents called for a better understanding of the needs of this patient population, and for the development and testing of models of care that meet their needs. A research agenda specific to complexity is required. The primary objective of the think tank was to identify and prioritize research questions that meet the information needs of stakeholders, and to develop a research agenda specific to stroke rehabilitation and patient complexity. A modified Delphi and World Café approach underpinned the think tank meeting, approaches well recognized to foster interaction, dialogue, and collaboration between stakeholders. Forty-three researchers, clinicians, and policymakers attended a 2-day meeting. Initial question-generating activities resulted in 120 potential research questions. Sixteen high-priority research questions were identified, focusing on predetermined complexity characteristics-multimorbidity, social determinants, patient characteristics, social supports, and system factors. The final questions are presented as a prioritized research framework. An emergent result of this activity is the development of a complexity and stroke rehabilitation research network. The research agenda reflects topics of importance to stakeholders working with stroke patients with increasingly complex care needs. This robust process resulted in a preliminary research agenda that could provide policymakers with the evidence needed to make improvements toward better-organized services, better coordination between settings, improved patient outcomes, and lower system costs.

Effects of an In-Frame Deletion of the 6k Gene Locus from the Genome of Ross River Virus.

UNLABELLED: The alphaviral6kgene region encodes the two structural proteins 6K protein and, due to a ribosomal frameshift event, the transframe protein (TF). Here, we characterized the role of the6kproteins in the arthritogenic alphavirus Ross River virus (RRV) in infected cells and in mice, using a novel6kin-frame deletion mutant. Comprehensive microscopic analysis revealed that the6kproteins were predominantly localized at the endoplasmic reticulum of RRV-infected cells. RRV virions that lack the6kproteins 6K and TF [RRV-(Δ6K)] were more vulnerable to changes in pH, and the corresponding virus had increased sensitivity to a higher temperature. While the6kdeletion did not reduce RRV particle production in BHK-21 cells, it affected virion release from the host cell. Subsequentin vivostudies demonstrated that RRV-(Δ6K) caused a milder disease than wild-type virus, with viral titers being reduced in infected mice. Immunization of mice with RRV-(Δ6K) resulted in a reduced viral load and accelerated viral elimination upon secondary infection with wild-type RRV or another alphavirus, chikungunya virus (CHIKV). Our results show that the6kproteins may contribute to alphaviral disease manifestations and suggest that manipulation of the6kgene may be a potential strategy to facilitate viral vaccine development. IMPORTANCE: Arthritogenic alphaviruses, such as chikungunya virus (CHIKV) and Ross River virus (RRV), cause epidemics of debilitating rheumatic disease in areas where they are endemic and can emerge in new regions worldwide. RRV is of considerable medical significance in Australia, where it is the leading cause of arboviral disease. The mechanisms by which alphaviruses persist and cause disease in the host are ill defined. This paper describes the phenotypic properties of an RRV6kdeletion mutant. The absence of the6kgene reduced virion release from infected cells and also reduced the severity of disease and viral titers in infected mice. Immunization with the mutant virus protected mice against viremia not only upon exposure to RRV but also upon challenge with CHIKV. These findings could lead to the development of safer and more immunogenic alphavirus vectors for vaccine delivery.

The inducible costimulator augments Tc17 cell responses to self and tumor tissue.

The inducible costimulator (ICOS) plays a key role in the development of Th17 cells, but its role in the development and antitumor activity of IL-17-producing CD8(+) T cells (Tc17) remains unknown. We found that ICOS costimulation was important for the functional maintenance, but not differentiation, of Tc17 cells in vitro. Blocking the ICOS pathway using an antagonist mAb or by using recipient mice genetically deficient in the ICOS ligand reduced the antitumor activity of adoptively transferred Tc17 cells. Conversely, activating Tc17 cells with an ICOS agonist in vitro enhanced their capacity to eradicate melanoma and induce autoimmune vitiligo when infused into mice. However, ICOS stimulation did not augment the antitumor activity of IL-2 expanded T cells. Additional investigation revealed that ICOS stimulation not only increased IL-2Rα, CXCR3, and IL-23R expression on Tc17 cells, but also dampened their expression of suppressive molecule CD39. Although Tc17 cells activated with an ICOS agonist cosecreted heightened IL-17A, IL-9, and IFN-γ, their therapeutic effectiveness was critically dependent on IFN-γ production. Depletion of IL-17A and IL-9 had little impact on antitumor Tc17 cells activated with an ICOS agonist. Collectively, our work reveals that the ICOS pathway potentiates the antitumor activity of adoptively transferred Tc17 cells. This work has major implications for the design of vaccine, Ab and cell-based therapies for autoimmunity, infectious disease, and cancer.

Role of envelope N-linked glycosylation in Ross River virus virulence and transmission.

With an expanding geographical range and no specific treatments, human arthritogenic alphaviral disease poses a significant problem worldwide. Previous in vitro work with Ross River virus (RRV) demonstrated that alphaviral N-linked glycosylation contributes to type I IFN (IFN-αß) induction in myeloid dendritic cells. This study further evaluated the role of alphaviral N-linked glycans in vivo, assessing the effect of glycosylation on pathogenesis in a mouse model of RRV-induced disease and on viral infection and dissemination in a common mosquito vector, Aedes vigilax. A viral mutant lacking the E1-141 glycosylation site was attenuated for virus-induced disease, with reduced myositis and higher levels of IFN-γ induction at peak disease contributing to improved viral clearance, suggesting that glycosylation of the E1 glycoprotein plays a major role in the pathogenesis of RRV. Interestingly, RRV lacking E2-200 glycan had significantly reduced replication in the mosquito vector A. vigilax, whereas loss of either of the E1 or E2-262 glycans had little effect on the competence of the mosquito vector. Overall, these results indicate that glycosylation of the E1 and E2 glycoproteins of RRV provides important determinants of viral virulence and immunopathology in the mammalian host and replication in the mosquito vector.