Transcutaneous immunization as preventative and therapeutic regimens to protect against experimental otitis media due to nontypeable Haemophilus influenzae

We have developed three nontypeable Haemophilus influenzae (NTHI) adhesin-derived immunogens that are significantly efficacious against experimental otitis media (OM) due to NTHI when delivered parenterally. We now expanded our preventative immunization strategies to include transcutaneous immunization (TCI) as a less invasive, but potentially equally efficacious, regimen to prevent OM due to NTHI. Additionally, we examined the potential of TCI as a therapeutic immunization regimen to resolve ongoing experimental OM. Preventative immunization with NTHI outer membrane protein (OMP) P5- and type IV pilus-targeted immunogens, delivered with the adjuvant LT(R192G-L211A), induced significantly earlier clearance of NTHI from the nasopharynges and middle ears of challenged chinchillas compared with receipt of immunogen or adjuvant alone. Moreover, therapeutic immunization resulted in significant resolution of established NTHI biofilms from the middle ear space of animals compared with controls. These data advocate TCI with the adhesin-directed immunogens as an efficacious regimen for prevention and resolution of experimental NTHI-induced OM

Non-typeable Haemophilus Influenzae detection in the lower airways of patients with lung cancer and chronic obstructive pulmonary disease

Background: Chronic airway inflammation and hypersensitivity to bacterial infection may contribute to lung cancer pathogenesis. Previous studies have demonstrated that nontypeable Haemophilus influenzae (NTHi) is the most common colonizing bacteria in the lower airways of patients with COPD. The objective of this study was to determine the presence of NTHi and immunoglobulin concentrations in patients with lung cancer, COPD and controls. Methods: Serum and bronchial wash samples were collected from patients undergoing diagnostic bronchoscopy. Total IgE, IgG and specific NTHi IgG were measured by enzyme linked immunosorbent assay. Bronchial wash samples were examined for the presence of NTHi via PCR. Results: Out of the 60 patients: 20 had confirmed Lung Cancer, 27 had COPD only and 13 were used as Controls. NTHi was detected in the lower airways of all three groups (Lung Cancer 20%; COPD 22% and Controls 15%). Total IgE was highest in Lung Cancer subjects followed by COPD and control subjects (mean ± SD: 870 ± 944, 381 ± 442, 159 ± 115). Likewise total IgG was higher in Lung cancer (Mean ± SD: 6.99 ± 1.8) patients compared to COPD (Mean ± SD: 5.43 ± 2). Conclusions: The lack of difference in NTHi and specific antibodies between the three groups makes it less likely that NTHi has an important pathogenetic role in subjects with Lung Cancer. However the detection of higher IgE antibody in Lung Cancer subjects identifies a possible mechanism for carcinogenesis in these subjects and warrants further study.Griffith Health, School of MedicineFull Tex

Coherence and recurrency: maintenance, control and integration in working memory

Working memory (WM), including a ‘central executive’, is used to guide behavior by internal goals or intentions. We suggest that WM is best described as a set of three interdependent functions which are implemented in the prefrontal cortex (PFC). These functions are maintenance, control of attention and integration. A model for the maintenance function is presented, and we will argue that this model can be extended to incorporate the other functions as well. Maintenance is the capacity to briefly maintain information in the absence of corresponding input, and even in the face of distracting information. We will argue that maintenance is based on recurrent loops between PFC and posterior parts of the brain, and probably within PFC as well. In these loops information can be held temporarily in an active form. We show that a model based on these structural ideas is capable of maintaining a limited number of neural patterns. Not the size, but the coherence of patterns (i.e., a chunking principle based on synchronous firing of interconnected cell assemblies) determines the maintenance capacity. A mechanism that optimizes coherent pattern segregation, also poses a limit to the number of assemblies (about four) that can concurrently reverberate. Top-down attentional control (in perception, action and memory retrieval) can be modelled by the modulation and re-entry of top-down information to posterior parts of the brain. Hierarchically organized modules in PFC create the possibility for information integration. We argue that large-scale multimodal integration of information creates an ‘episodic buffer’, and may even suffice for implementing a central executive

Cellular immunity in adenoids and blood of otitis media-prone children

Middle ear infections (otitis media, OM) are a major burden on health services worldwide. More than 80% of children will have suffered with an OM infection by 3 years of age. Of these juveniles, almost 40% will develop recurring infections, with little relief experienced from antibiotic therapies. This research project aims to improve the understanding of the immune-regulation of OM in children, with a specific focus on the cellular pathways driving immune-suppression and infection tolerance in OM-prone children. The study described here involves two cohorts of non-OM prone children and OM prone children. Patients scheduled for adenoidectomy due to clinical reasons, including adenoid hypertrophy and OM, were recruited into the study for the collection of their clinical data and tissue samples including adenoids, blood, nasopharyngeal and saliva aspirates. The tissue samples and clinical data were used to determine immune differences between the two cohorts through the analysis of both clinical microbiology and immune cell responses to OM pathogens. Understanding cellular immune regulation in OM has the potential to identify physiological factors that may be used to influence adenoidectomy, immunotherapy and vaccine treatments for OM. This approach aims to enable children to experience a quicker recovery from infection, possibly avoiding the progression to chronic disease. This would result in an overall improved quality of life due to reduced adverse side effects experienced that are associated with prolonged OM-related disease

Regulatory T lymphocytes are associated with increased nasopharyngeal colonization in children

Objectives: Regulatory T lymphocytes (Treg) have been linked to survival of commensal bacteria at mucosal sites, but their presence and role in chronic otitis media (COM) and their response to otopathogens has not been evaluated previously. We investigated the association between Treg lymphocytes and otopathogens in COM prone and non-COM prone children. Methods: Forty children, 2 to 7 years of age, scheduled for adenoidectomy were enrolled into COM (n = 20) or non-COM (n = 20) groups. Adenoid biopsy and nasopharyngeal aspirate bacteriology were assessed by conventional culture techniques. Peripheral blood and adenoid lymphocytes were stained with viability stain, monoclonal anti-CD19, anti-CD3, anti-CD4, anti-CD8, anti-CD25 and anti-CD127. Cells were stained intracellularly with monoclonal anti-FoxP3 and then quantified by flow cytometry. Results: Children with nasopharyngeal otopathogen-positive culture had significantly more circulating CD3+CD4+FoxP3+CD25hi+CD127lo+ lymphocytes (M = 4.4%) compared to culture-negative children (M = 3.1%, p = 0.005). Circulating CD19+ lymphocytes were significantly increased in children with positive Moraxella catarrhalis nasopharyngeal culture (M = 12.4%) compared to culture-negative children (M = 8.6%, p = 0.006). Adenoid-derived lymphocytes were not significantly different in children with any positive nasopharyngeal culture compared to negative culture. Lymphocyte subsets were not significantly different between COM and non-COM prone children. Conclusion: Clinically-detectable otopathogen nasopharyngeal culture is positively associated with Treg lymphocytes, potentially inducing suppressive effector responses to promote colonization and infection chronicity. This finding supports further investigation of Treg lymphocyte activity and influence on upper airway colonization of young children

Dynamics of nasopharyngeal colonisation and correlations with lymphocyte populations in the adenoid & peripheral blood of chronic otitis media-prone children

Aim: Nasopharyngeal cultures of chronic otitis media (COM)-prone and non COM-prone children were correlated with blood and adenoid lymphocyte populations to evaluate microbe-host relationships relating to the pathogenesis of COM. The clinical significance of nasopharyngeal aspirate (NPA) culture as a screening tool for adenoid culture was also assessed. Methodology: Forty children scheduled for adenoidectomy were enrolled into COM-prone or non COM-prone groups (for each, n = 20). Conventional culture was performed for adenoid biopsy and NPA bacteriology. Peripheral blood and adenoid mononuclear cells (PBMC and AdMNC, respectively) were stained with viability stain, monoclonal anti-CD19, anti-CD3, anti-CD4, anti-CD8, anti-CD25 and anti-CD127. Cells were permeabilised, fixed and intracellularly stained with monoclonal anti-FoxP3 and quantified by flow cytometry. Results: Streptococcus pneumoniae, Staphylococcus aureus, Moraxella catarrhalisand non-typeable Haemophilus influenzae (NTHi) were positive in 44%, 39%, 22% and 22% of COM-prone children with no significant differences compared to non COM-prone children. S. pneumoniae NPA culture was a significant predictor of S. pneumoniae culture at the adenoid (OR = 39.30, CI = 3.68 – 419.28, p = 0.002). Children with positive otopathogen nasopharyngeal culture had significantly more FoxP3+ CD25hi+ CD127lo+ PBMC (M = 4.4%) compared to otopathogen culture negative children (M = 3.1%, p = 0.005). Conclusion: Otopathogens are positively associated with regulatory T cells, potentially inducing a suppressive effector response to promote colonisation and infection chronicity, thus supporting further investigation of their influence on lymphocyte activity. S. pneumoniae NPA cultures may be of direct clinical benefit to clinicians in making diagnoses and recommendations for prophylactic antibiotic therapies in COM

Nontypeable <i>Haemophilus influenzae</i> as a Pathogen in Children

Nontypeable Haemophilus influenzae is a significant pathogen in children, causing otitis media, sinusitis, conjunctivitis, pneumonia, and occasionally invasive infections. H. influenzae type b conjugate vaccines have no effect on infections caused by nontypeable strains because nontypeable strains are nonencapsulated. Approximately, one-third of episodes of otitis media are caused by nontypeable H. influenzae and the bacterium is the most common cause of recurrent otitis media. Recent progress in elucidating molecular mechanisms of pathogenesis, understanding the role of biofilms in otitis media and an increasing understanding of immune responses have potential for development of novel strategies to improve prevention and treatment of otitis media caused by nontypeable H. influenzae. Feasibility of vaccination for prevention of otitis media due to nontypeable H. influenzae was recently demonstrated in a clinical trial with a vaccine that included the surface virulence factor, protein D