A leukocyte immune-type receptor specific polyclonal antibody recognizes goldfish kidney leukocytes and activates the MAPK pathway in isolated goldfish kidney neutrophil-like cells.

Leukocyte immune-type receptors (LITRs) belong to a large family of teleost immunoregulatory receptors that share phylogenetic and syntenic relationships with mammalian Fc receptor-like molecules (FCRLs). Recently, several putative stimulatory Carassius auratus (Ca)-LITR transcripts, including CaLITR3, have been identified in goldfish. CaLITR3 has four extracellular immunoglobulin-like (Ig-like) domains, a transmembrane domain containing a positively charged histidine residue, and a short cytoplasmic tail region. Additionally, the calitr3 transcript is highly expressed by goldfish primary kidney neutrophils (PKNs) and macrophages (PKMs). To further investigate the immunoregulatory potential of CaLITR3 in goldfish myeloid cells, we developed and characterized a CaLITR3-epitope-specific polyclonal antibody (anti-CaL3.D1 pAb). We show that the anti-CaL3.D1 pAb stains various hematopoietic cell types within the goldfish kidney, as well as in PKNs and PKMs. Moreover, cross-linking of the anti-CaL3.D1-pAb on PKN membranes induces phosphorylation of p38 and ERK1/2, critical components of the MAPK pathway involved in controlling a wide variety of innate immune effector responses such as NETosis, respiratory burst, and cytokine release. These findings support the stimulatory potential of CaLITR3 proteins as activators of fish granulocytes and pave the way for a more in-depth examination of the immunoregulatory functions of CaLITRs in goldfish myeloid cells.

Current evidence and therapeutic implication of PANoptosis in cancer.

Regulated cell death (RCD) is considered a critical pathway in cancer therapy, contributing to eliminating cancer cells and influencing treatment outcomes. The application of RCD in cancer treatment is marked by its potential in targeted therapy and immunotherapy. As a type of RCD, PANoptosis has emerged as a unique form of programmed cell death (PCD) characterized by features of pyroptosis, apoptosis, and necroptosis but cannot be fully explained by any of these pathways alone. It is regulated by a multi-protein complex called the PANoptosome. As a relatively new concept first described in 2019, PANoptosis has been shown to play a role in many diseases, including cancer, infection, and inflammation. This study reviews the application of PCD in cancer, particularly the emergence and implication of PANoptosis in developing therapeutic strategies for cancer. Studies have shown that the characterization of PANoptosis patterns in cancer can predict survival and response to immunotherapy and chemotherapy, highlighting the potential for PANoptosis to be used as a therapeutic target in cancer treatment. It also plays a role in limiting the spread of cancer cells. PANoptosis allows for the elimination of cancer cells by multiple cell death pathways and has the potential to address various challenges in cancer treatment, including drug resistance and immune evasion. Moreover, active investigation of the mechanisms and potential therapeutic agents that can induce PANoptosis in cancer cells is likely to yield effective cancer treatments and improve patient outcomes. Research on PANoptosis is still ongoing, but it is a rapidly evolving field with the potential to lead to new treatments for various diseases, including cancer.

Self-reported continuing professional development needs of medical laboratory professionals in Ghana.

BACKGROUND: Because of the essential nature of the work of medical laboratory professionals, continuing development in knowledge and skills is indispensable. The study aimed at identifying and prioritizing the development and training needs of medical laboratory professionals in Ghana. This is expected to help in developing focused continuing professional development (CPD) that meets the needs of practitioners as well as the changing medical trends. METHODS: An online cross-sectional survey in February 2022 using a structured questionnaire was conducted. Respondents were asked questions that collected demographic and work-related data about them, their participation, preference, and challenges in being part of CPDs. Finally, a list of topics based on (i) quality management systems, (ii) technical competence, (iii) laboratory management, leadership, and coaching, (iv) pathophysiology, and (iv) data interpretation and research were asked with the option to rate them on a 3-point scale (most, moderate, and least) in order of importance. RESULTS: A total of 316 medical laboratory professionals participated in the study. Overall, the most frequently selected topics for training based on domains for CPD training and ranking as most important were (i) quality management systems, (mean = 80.59 ± 9.024; 95% CI = 73.04-88.13); (ii) pathophysiology, data interpretation, and research (mean = 78.0 ± 6.973; 95% CI = 73.97-82.03); (iii) technical competence (mean = 73.97 ± 10.65; 95% CI = 66.35-81.59); and (iv) laboratory management, leadership, and coaching (mean = 72.82 ± 9.719; 95% CI = 67.44-78.2). The factors affecting the choice of training needs included the medical laboratory professionals' current place of work, years in service, the reason for attending CPD activities, the period for attending the last CPD, being in a supervisory role, and the number of staff being supervised. Face-to-face presentations, training workshops, and hands-on workshops were the most preferred modes of CPD delivery with financial implications and workload/time constraints being the main challenges impeding CPD participation. CONCLUSION: The identified needs will help in developing CPD programs that address what medical laboratory professionals prioritize as training needs. Stakeholders should incorporate these training needs into future programs and address the challenges highlighted in this study to have more relevant training for medical laboratory professionals.

HBV Infection Is an Intermediate-Risk Disease, Whereas Anaemia Is a Mild-to-Moderate Public Health Problem in Young Ghanaian Adults: A Four-Year Retrospective Analysis of Students' Medical Records.

Background: In sub-Saharan Africa, malaria, chronic viral diseases, nutritional deficiencies, and haemoglobinopathies are common causes of anaemia. Continual surveillance data is required to situate the anaemia and infectious disease burden within a given population. This study determined the 4-year trends of anaemia, hepatitis B virus (HBV), and HCV infections and factors associated with anaemia in young Ghanaian adults. Methods: This retrospective study analysed the medical records of 21,716 fresh students at the University of Cape Coast. Data was presented as percentages and line graphs to show the yearly trends in anaemia, HBV, and HCV infections. Binary logistic regression was used to determine the increased odds of anaemia in participants. Results: Although the 4-year anaemia prevalence was 14.2% (95% CI: 0.1403-0.1498), anaemia prevalence in women and men were 24.1% (95% CI: 0.2387-0.2562) and 6.6% (95% CI:0.0616-0.0705), respectively. Anaemia prevalence consistently remained mild (males) and moderate (females) public health problem over the four-year period. Adolescents were more represented in the anaemic group (18.7% prevalence), 70.9% of them being females. The prevalence of HBV and HCV infections were 5.4% (95% CI:0.0506-0.0567) and 0.9% (95% CI: 0.0082-0.0108), respectively; only 0.1% of participants had HBV and HCV coinfection. Males were more represented in both HBV (71.2%) and HCV (63.7%) infection groups. Moreover, 15.8% of the participants who were seropositive for HBsAg self-reported having previously been vaccinated, suggesting a breakthrough infection and/or vaccine nonresponse. Furthermore, female (COR: 4.545; p < 0.001), teenagers (COR: 1.697; p < 0.001), 20-29 years (COR: 1.221; p = 0.035), and positive sickling slide test (COR: 1.176; p = 0.003) were statistically significantly associated with increased odds of anaemia. Conclusion: Intentional preventative public health campaigns regarding anaemia, HBV, and HCV infection should, respectively, target females and young adult males to increase chances of making real change in behavioural attitudes in these at-risk groups.

Candidiasis profile at the outpatient department of the university of cape coast hospital in the central region of Ghana: a retrospective study.

INTRODUCTION: Vulvovaginal candidiasis (VVC) is a public health problem with an estimated 138 million women globally experiencing recurrent VVC annually. The microscopic diagnosis of VVC has low sensitivity, but it remains an essential tool for diagnosis as the microbiological culture methods are limited to advanced clinical microbiology laboratories in developing countries. The study retrospectively analyzed the presence of red blood cells (RBCs), epithelial cells (ECs), pus cells (PCs) and Candida albicans positive in wet mount preparation of urine or high vaginal swabs (HVS) samples to test for their sensitivity and specificity for the diagnosis of candidiasis. METHODS: The study is a retrospective analysis at the Outpatient Department of the University of Cape Coast between 2013 and 2020. All urine and high vagina swabs (HVS) cultures samples using Sabourauds dextrose agar with wet mount data were analyzed. 2 × 2 contingency diagnostic test was used to ascertain the diagnostic accuracy of red blood cells (RBCs), epithelial cells (ECs), pus cells (PCs), and Candida albicans positive in wet mount preparation of urine or high vaginal swabs (HVS) samples for the diagnosis of candidiasis. The association of candidiasis among patients' demographics was analyzed using relative risk (RR) analysis. RESULTS: The high prevalence of candida infection was among female subjects 97.1% (831/856) compared to males 2.9% (25/856). The microscopic profiles which characterized candida infection were pus cells 96.4% (825/856), epithelial cells 98.7% (845/856), red blood cells (RBCs) 7.6% (65/856) and Candida albicans positive 63.2% (541/856). There was a lower risk of Candida infections among male patients compared to female patients RR (95% CI) = 0.061 (0.041-0.088). The sensitivity (95%) for detecting Candida albicans positive and red blood cells (0.62 (0.59-0.65)), Candida albicans positive and pus cells (0.75 (0.72-0.78)) and Candida albicans positive and epithelial cells (0.95 (0.92-0.96)) with corresponding specificity (95% CI) of 0.63 (0.60-0.67), 0.69 (0.66-0.72) and 0.74 (0.71-0.76) were detected among the high vaginal swab samples. CONCLUSION: In conclusion, the study has shown that the presence of PCs, ECs, RBCs or ratio of RBCs/ECs and RBCs/PCs in the wet mount preparation from urine or HVS can enhance microscopic diagnosis of VVC cases.

Mesenchymal stem cell-derived exosome mitigates colitis via the modulation of the gut metagenomics-metabolomics-farnesoid X receptor axis.

Inflammatory bowel disease (IBD) is associated with chronic gut immune dysregulation and altered microbiome and metabolite composition. Bile acids and their receptors such as the farnesoid X receptor (FXR) form a crucial component of the chemical communications between the intestinal microbiota and the host immune system; thus, alterations in the bile acid pool affect intestinal homeostasis and exacerbate IBD. Considering the promising therapeutic effect of mesenchymal stem cell-derived exosomes (MSC-Ex) on IBD, this study assessed the regulatory effect of MSC-Ex on the gut bacteria composition and diversity, metabolites, and their related functions and pathways, as well as key inflammatory and anti-inflammatory cytokines during the mitigation of IBD. The dextran sulfate sodium (DSS)-induced IBD model of BABL/C mice was established, consisting of three groups: control, DSS, and MSC-Ex groups. Post administration of MSC-Ex, the effect was evaluated via hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), qRT-PCR, and western blotting. Mice fecal samples were obtained for metagenomics and metabolomics analysis via 16S rRNA gene sequencing and UHPLC/Q-TOF-MS respectively. Results showed that MSC-Ex mitigated colitis by significantly relieving the macroscopic and microscopic features of inflammation, modulating the gut metagenomics and metabolomics profile, and increasing colonic FXR. MSC-Ex improved the gut microbiota composition by significantly restoring the structure of OTUs and colitis-induced reduction in α-diversity, increasing the abundance of 'healthy' bacteria, decreasing disease-associated bacteria, decreasing detrimental functions, and enhancing other vital cellular functions. For the first time, we demonstrate that MSC-Ex mitigates colitis in mice by modulating the gut metagenomics-metabolomics-FXR axis, thus providing potential therapeutic targets.

The gut metagenomics and metabolomics signature in patients with inflammatory bowel disease.

Inflammatory bowel disease (IBD), a chronic gut immune dysregulation and dysbiosis condition is rapidly increasing in global incidence. Regardless, there is a lack of ideal diagnostic markers, while conventional treatment provides scarce desired results, thus, the exploration for better options. Changes in the gut microbial composition and metabolites either lead to or are caused by the immune dysregulation that characterizes IBD. This study examined the fecal metagenomics and metabolomic changes in IBD patients. A total of 30 fecal samples were collected from 15 IBD patients and 15 healthy controls for 16S rDNA gene sequencing and UHPLC/Q-TOF-MS detection of metabolomics. Results showed that there was a severe perturbation of gut bacteria community composition, diversity, metabolites, and associated functions and metabolic pathways in IBD. This included a significantly decreased abundance of Bacteroidetes and Firmicutes, increased disease-associated phyla such as Proteobacteria and Actinobacteria, and increased Escherichia coli and Klebsiella pneumoniae in IBD. A total of 3146 metabolites were detected out of which 135 were differentially expressed between IBD and controls. Metabolites with high sensitivity and specificity in differentiating IBD from healthy individuals included 6,7,4'-trihydroxyisoflavone and thyroxine 4'-o-.beta.-d-glucuronide (AUC = 0.92), normorphine and salvinorin a (AUC = 0.90), and trichostachine (AUC = 0.91). Moreover, the IBD group had significantly affected pathways including primary bile acid biosynthesis, vitamin digestion and absorption, and carbohydrate metabolism. This study reveals that the combined evaluation of metabolites and fecal microbiome can be useful to discriminate between healthy subjects and IBD patients and consequently serve as therapeutic and diagnostic targets.

Self-amplifying mRNA SARS-CoV-2 vaccines raise cross-reactive immune response to variants and prevent infection in animal models.

The spike (S) protein of SARS-CoV-2 plays a crucial role in cell entry, and the nucleocapsid (N) protein is highly conserved among human coronavirus homologs. For potentially broad effectiveness against both original virus and emerging variants, we developed Alphavirus-based self-amplifying mRNA (sa-mRNA) SARS-CoV-2 vaccines: an sa-mRNA S encoding a full-length S protein stabilized in a prefusion conformation and an sa-mRNA S-N co-expressing S and N proteins for the original virus. We show that these sa-mRNA SARS-CoV-2 vaccines raised potent neutralizing antibody responses in mice against not only the original virus but also the Alpha, Beta, Gamma, and Delta variants. sa-mRNA S vaccines against the Alpha and Beta variants also raised robust cross-reactive neutralizing antibody responses against their homologous viruses and heterologous variants. sa-mRNA S and sa-mRNA S-N vaccines elicited Th1-dominant, antigen-specific CD4+ T cell responses to S and N proteins and robust and broad CD8+ T cell responses to S protein. Hamsters immunized with either vaccine were fully protected from lung infection and showed significant reduction of viral load in upper respiratory tract. Our findings demonstrate that sa-mRNA SARS-CoV-2 vaccines are potent in animal models with potential to be highly effective against SARS-CoV-2 infection in humans.

Antibiotic-resistant pathogenic bacterial isolates from patients attending the outpatient department of university of Cape Coast hospital, Ghana: A retrospective study between 2013-2015.

Uropathogenic Escherichia coli (E. coli) is an important urinary tract infection (UTI) that has been associated with both complicated and uncomplicated disease conditions. The global emergence of multiple drug-resistant (MDR) and extended-spectrum ß-lactamase (ESBL) is of public health concern as the resistance limits the current treatment options. The objective of this study was to analyze the antibiotic-resistant patterns among the uropathogenic E. coli isolates at the University of Cape Coast (UCC) hospital between 2013 and 2015 as baseline data to understand the current antibiotic resistance situation within UCC and its environs. A retrospective cross-sectional study of bacteria isolates at UCC hospital from January 2013 to December 2015 were analyzed. A standard biochemical and antibiotic susceptibility tests were performed using Kirby-Bauer NCCLs modified disc diffusion technique. The network of interaction between pathogenic isolates and antibiotic resistance was performed using Cytoscape software. Statistical significance was tested using ANOVA and one-sample Wilcoxon test. The overall E. coli prevalence was 15.76% (32/203); females had the highest infection of 17.33% (26/150) compared to male subjects who had 11.32% (6/53) out of all the pathogenic infections. The E. coli prevalence among the age categories were 2/21 (9.52%), 27/154 (17.53%) and 4/21 (19.05%) among ≤20 years, 21-40 years and 41-60 years respectively. The isolated resistant pathogens exhibited different antibiotic resistance patterns. An interaction network of nodes connecting to other nodes indicating positive correlations between the pathogens and antibiotic resistance was established. Escherichia coli, Citrobacter spp, Klebsiella spp among other isolated pathogens formed higher centrality in the network of interaction with antibiotic resistance. The individual E. coli isolates showed a significant difference in the mean ± SD (95% CI) pattern of antibiotic resistance, 2.409±1.205 (1.828-2.990), χ2 = 36.68, p<0.0001. In conclusion, the study reports the interaction of E. coli isolates at UCC hospital and its antibiotic-resistant status between 2013 and 2015. This data forms the baseline information for assessing the current antibiotic status in UCC and its environs.

Psychological impact of COVID-19 on diabetes mellitus patients in Cape Coast, Ghana: a cross-sectional study.

INTRODUCTION: COVID-19 pandemic has had a greater psychological impact on patients with chronic ailments such as diabetes mellitus, tuberculosis, and HIV/AIDS compared to those without chronic conditions. We explored the psychological impacts of COVID-19 among people living with diabetes mellitus in Ghana. METHODS: this study employed a hospital-based cross-sectional design involving 157 diabetes mellitus patients aged 20 years and above. We assessed diabetes distress by the seventeen-item diabetes stress (DDS17) scale and COVID-19 worries by 3 specific benchmarks: "worry about overly affected due to diabetes if infected with COVID-19", "worry about people with diabetes characterized as a risk group" and "worry about not able to manage diabetes if infected with COVID-19". A close-ended questionnaire was used in data collection. RESULTS: of 157 diabetic patients interviewed, the majority had type 2 diabetes mellitus with known complications and only 42.7% were managing COVID-19 symptoms. The participants showed moderate to high level of COVID-19 specific worry, moderate fear of isolation, and low level of diabetes-associated distress. About 33.8% of the study population expressed a sense of worry towards the pandemic. The logistic regression showed that age, employment status, and presence of other chronic diseases were significantly associated with worries about being overly affected if infected with COVID-19 due to their diabetes status. Age and sex were associated with worries about people with diabetes being characterized as a risk group and age, sex and employment status were associated with participants who were worried about not being able to manage diabetes if infected with COVID-19. CONCLUSION: the general trend indicates a sense of worry among diabetes patients during the COVID-19 pandemic which is associated with poorer psychological health. Clients' education and counseling on COVID-19 are necessary to address some of their concerns to minimize the level of anxiety and emotional stress in these individuals.

Assessment of malaria diagnostic methods and treatments at a Ghanaian health facility.

INTRODUCTION: it has been more than a decade since the World Health Organization (WHO) recommended parasitological confirmation of malaria before treatment begins. Light microscopy and rapid diagnostic tests are currently being used for diagnosing malaria in routine clinical care settings. Many clinicians have however raised questions about the competencies of laboratory staff who perform these tests and the performance of these diagnostic methods. This study aimed at assessing the performance of microscopy and two rapid diagnostic test kits in the hands of routine laboratory staff compared to expert microscopy as well as assess the performance of clinical diagnosis. METHODS: this was a cross sectional study involving 799 participants of all ages who visited the out patient department of the University of Cape Coast Hospital with symptoms suggestive of malaria. RESULTS: when the different methods were compared to expert microscopy, the rapid diagnostic test kits had the highest sensitivities, Wondfo 94.83% (95% CI: 85.62-98.20) and CareStart 91.38 (95% CI: 81.02-97.14). Microscopy by laboratory staff had a sensitivity of 68.79 (95% CI: 55.46-80.46) whilst clinical diagnosis had the lowest sensitivity of 17.24 (95% CI: 8.59-29.43). Cohen´s kappa coefficient was used to measure the level of agreement of the methods with expert microscopy. Microscopy by laboratory staff, CareStart and Wondfo showed substantial measures of agreement (k = 0.737, 0.683, and 0.691 respectively). CONCLUSION: these findings suggest that clinical diagnosis is highly unreliable whilst rapid diagnostic tests and microscopy performed by routine laboratory staff could be trusted by clinicians as reliable diagnostic methods.

Influenza Virus Infects and Depletes Activated Adaptive Immune Responders.

Influenza infections cause several million cases of severe respiratory illness, hospitalizations, and hundreds of thousands of deaths globally. Secondary infections are a leading cause of influenza's high morbidity and mortality, and significantly factored into the severity of the 1918, 1968, and 2009 pandemics. Furthermore, there is an increased incidence of other respiratory infections even in vaccinated individuals during influenza season. Putative mechanisms responsible for vaccine failures against influenza as well as other respiratory infections during influenza season are investigated. Peripheral blood mononuclear cells (PBMCs) are used from influenza vaccinated individuals to assess antigen-specific responses to influenza, measles, and varicella. The observations made in humans to a mouse model to unravel the mechanism is confirmed and extended. Infection with influenza virus suppresses an ongoing adaptive response to vaccination against influenza as well as other respiratory pathogens, i.e., Adenovirus and Streptococcus pneumoniae by preferentially infecting and killing activated lymphocytes which express elevated levels of sialic acid receptors. These findings propose a new mechanism for the high incidence of secondary respiratory infections due to bacteria and other viruses as well as vaccine failures to influenza and other respiratory pathogens even in immune individuals due to influenza viral infections.

Standard-Dose Intradermal Influenza Vaccine Elicits Cellular Immune Responses Similar to Those of Intramuscular Vaccine in Men With and Those Without HIV Infection.

BACKGROUND: Human immunodeficiency virus (HIV)-infected persons are at a higher risk of severe influenza. Although we have shown that a standard-dose intradermal influenza vaccine versus a standard-dose intramuscular influenza vaccine does not result in differences in hemagglutination-inhibition titers in this population, a comprehensive examination of cell-mediated immune responses remains lacking. METHODS: Serological, antigen-specific B-cell, and interleukin 2-, interferon γ-, and tumor necrosis factor α-secreting T-cell responses were assessed in 79 HIV-infected men and 79 HIV-uninfected men. RESULTS: The route of vaccination did not affect the immunoglobulin A and immunoglobulin G (IgG) plasmablast or memory B-cell response, although these were severely impaired in the group with a CD4+ T-cell count of <200 cells/µL. The frequencies of IgG memory B cells measured on day 28 after vaccination were highest in the HIV-uninfected group, followed by the group with a CD4+ T-cell count of ≥200 cells/µL and the group with a CD4+ T-cell count of <200 cells/µL. The route of vaccination did not affect the CD4+ or CD8+ T-cell responses measured at various times after vaccination. CONCLUSIONS: The route of vaccination had no effect on antibody responses, antibody avidity, T-cell responses, or B-cell responses in HIV-infected or HIV-uninfected subjects. With the serological and cellular immune responses to influenza vaccination being impaired in HIV-infected individuals with a CD4+ T-cell count of <200 cells/µL, passive immunization strategies need to be explored to protect this population. CLINICAL TRIALS REGISTRATION: NCT01538940.

Evaluation of urinalysis parameters and antimicrobial susceptibility of uropathogens among out-patients at University of Cape Coast Hospital.

BACKGROUND: Urinary tract infection (UTI) is a major global public health issue. The gold standard for diagnosing UTI is urine culture. This is however labour intensive and time consuming. Many prescribers therefore rely on urinalysis in diagnosing UTI. This study sought to evaluate the performance of some parameters of urinalysis as predictors of urine culture positivity. The common causative agents and their antibiotic susceptibility patterns were also determined. METHODS: A cross sectional study was carried out at the University of Cape Coast Hospital from July 2017 - December 2017 among out-patients. The performance characteristics of leukocyte esterase (3+) and nitrite reactions were estimated and compared with urine culture. Antimicrobial susceptibility tests were done using disc diffusion technique described by Kirby-Bauer. RESULTS: Prevalence of UTI in this study was 30.0% (64/213). The most prevalent pathogen was E. coli (20, 31.2%), followed by S. saprophyticus (9, 14.1%). Most of the bacteria (52, 94.5%) were sensitive to amikacin, followed by ciprofloxacin (42, 76.3%). The most sensitive (94.4%) of the parameters was pus cells [>5 white blood cells (WBC) per high power field (HPF)] and the least sensitive was the nitrite test (21.0%). The leukocyte esterase test showed the highest accuracy of 91.1%. CONCLUSION: The study supports the recommendation of the use of oral ciprofloxacin as the first line treatment of uncomplicated UTI by the Ghana Standard Treatment Guidelines (2017). FUNDING: No funding was provided for this study.

Nasal delivery of H5N1 avian influenza vaccine formulated with GenJet™ or in vivo-jetPEI® induces enhanced serological, cellular and protective immune responses.

Avian influenza virus infection is a serious public health threat and preventive vaccination is the most cost-effective public health intervention strategy. Unfortunately, currently available unadjuvanted avian influenza vaccines are poorly immunogenic and alternative vaccine formulations and delivery strategies are in urgent need to reduce the high risk of avian influenza pandemics. Cationic polymers have been widely used as vectors for gene delivery in vitro and in vivo. In this study, we formulated H5N1 influenza vaccines with GenJet™ or in vivo-jetPEI®, and showed that these formulations significantly enhanced the immunogenicity of H5N1 vaccines and conferred protective immunity in a mouse model. Detailed analyses of adaptive immune responses revealed that both formulations induced mixed TH1/TH2 antigen-specific CD4 T-cell responses, antigen-specific cytotoxic CD8 T-cell and memory B-cell responses. Our findings suggest that cationic polymers merit future development as potential adjuvants for mucosal delivery of poorly immunogenic vaccines.

Adenovirus vector-based multi-epitope vaccine provides partial protection against H5, H7, and H9 avian influenza viruses.

The emergence of H5, H7, and H9 avian influenza virus subtypes in humans reveals their pandemic potential. Although human-to-human transmission has been limited, the genetic reassortment of the avian and human/porcine influenza viruses or mutations in some of the genes resulting in virus replication in the upper respiratory tract of humans could generate novel pandemic influenza viruses. Current vaccines do not provide cross protection against antigenically distinct strains of the H5, H7, and H9 influenza viruses. Therefore, newer vaccine approaches are needed to overcome these potential threats. We developed an egg-independent, adenovirus vector-based, multi-epitope (ME) vaccine approach using the relatively conserved immunogenic domains of the H5N1 influenza virus [M2 ectodomain (M2e), hemagglutinin (HA) fusion domain (HFD), T-cell epitope of nucleoprotein (TNP). and HA α-helix domain (HαD)]. Our ME vaccine induced humoral and cell-mediated immune responses and caused a significant reduction in the viral loads in the lungs of vaccinated mice that were challenged with antigenically distinct H5, H7, or H9 avian influenza viruses. These results suggest that our ME vaccine approach provided broad protection against the avian influenza viruses. Further improvement of this vaccine will lead to a pre-pandemic vaccine that may lower morbidity, hinder transmission, and prevent mortality in a pandemic situation before a strain-matched vaccine becomes available.

An Adjuvanted A(H5N1) Subvirion Vaccine Elicits Virus-Specific Antibody Response and Improves Protection Against Lethal Influenza Viral Challenge in Mouse Model of Protein Energy Malnutrition.

Background: Protein energy malnutrition (PEM) increases susceptibility to infectious diseases, including influenza infection, but no studies have addressed the potential influences of PEM on the immunogenicity and protective efficacy of avian influenza A(H5N1) vaccine. Methods: We investigated the role of PEM on vaccine-mediated protection after a lethal challenge with recombinant A(H5N1) virus using isocaloric diets providing either adequate protein (AP; 18% protein) or very low protein (VLP; 2% protein) in an established murine model of influenza vaccination. Results: We demonstrated that mice maintained on a VLP diet succumb to lethal challenge at greater rates than mice maintained on an AP diet, despite comparable immunization regimens. Importantly, there was no virus-induced mortality in both VLP and AP groups of mice when either group was immunized with adjuvanted low-dose A(H5N1) subvirion vaccine. Conclusions: Our results suggest that adjuvanted vaccination in populations where PEM is endemic may be one strategy to boost vaccination-promoted immunity and improve outcomes associated with highly pathogenic A(H5N1).

RIG-I ligand enhances the immunogenicity of recombinant H7HA protein.

Avian H7N9 influenza virus infection with fatal outcomes continues to pose a pandemic threat and highly immunogenic vaccines are urgently needed. In this report we show that baculovirus-derived recombinant H7 hemagglutinin protein, when delivered with RIG-I ligand, induced enhanced antibody and T cell responses and conferred protection against lethal challenge with a homologous H7N9 virus. These findings indicate the potential utility of RIG-I ligands as vaccine adjuvants to increase the immunogenicity of recombinant H7 hemagglutinin.

NADPH Oxidase 1 Is Associated with Altered Host Survival and T Cell Phenotypes after Influenza A Virus Infection in Mice.

The role of the reactive oxygen species-producing NADPH oxidase family of enzymes in the pathology of influenza A virus infection remains enigmatic. Previous reports implicated NADPH oxidase 2 in influenza A virus-induced inflammation. In contrast, NADPH oxidase 1 (Nox1) was reported to decrease inflammation in mice within 7 days post-influenza A virus infection. However, the effect of NADPH oxidase 1 on lethality and adaptive immunity after influenza A virus challenge has not been explored. Here we report improved survival and decreased morbidity in mice with catalytically inactive NADPH oxidase 1 (Nox1*/Y) compared with controls after challenge with A/PR/8/34 influenza A virus. While changes in lung inflammation were not obvious between Nox1*/Y and control mice, we observed alterations in the T cell response to influenza A virus by day 15 post-infection, including increased interleukin-7 receptor-expressing virus-specific CD8+ T cells in lungs and draining lymph nodes of Nox1*/Y, and increased cytokine-producing T cells in lungs and spleen. Furthermore, a greater percentage of conventional and interstitial dendritic cells from Nox1*/Y draining lymph nodes expressed the co-stimulatory ligand CD40 within 6 days post-infection. Results indicate that NADPH oxidase 1 modulates the innate and adaptive cellular immune response to influenza virus infection, while also playing a role in host survival. Results suggest that NADPH oxidase 1 inhibitors may be beneficial as adjunct therapeutics during acute influenza infection.

A highly immunogenic vaccine against A/H7N9 influenza virus.

Since the first case of human infection in March 2013, continued reports of H7N9 cases highlight a potential pandemic threat. Highly immunogenic vaccines to this virus are urgently needed to protect vulnerable populations who lack protective immunity. In this study, an egg- and adjuvant-independent adenoviral vector-based, hemagglutinin H7 subtype influenza vaccine (HAd-H7HA) demonstrated enhanced cell-mediated immunity as well as serum antibody responses in a mouse model. Most importantly, this vaccine provided complete protection against homologous A/H7N9 viral challenge suggesting its potential utility as a pandemic vaccine.