Immunological characterisation of truncated lipooligosaccharide-outer membrane protein based conjugate vaccine against Moraxella catarrhalis and nontypeable Haemophilus influenzae.

In this study, we conjugated wild-type and truncated M. catarrhalis detoxified-LOS to a recombinant modified OMP26, rOMP26VTAL. Vaccination of mice with these conjugates resulted in a significant increase in anti-LOS and anti-rOMP26VTAL IgG levels. Importantly, mouse antisera showed complement-mediated bactericidal activity against all M. catarrhalis serotype A and B strains and a NTHi strain tested. Serotypes A &B make up more than 90% of isolates. These data suggest that the LOS and OMP based conjugate can be used as vaccine components and require further investigation in animal models. PMID: 31668366 [PubMed - as supplied by publisher]
Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research

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AbstractAll infective bacterial species need to conquer the innate immune system in order to colonize and survive in their hosts. The human respiratory pathogensHaemophilus influenzae andMoraxella catarrhalis are no exceptions, and have developed sophisticated mechanisms to evade complement ÔÇÉmediated killing. Both bacterial species carry lipooligosaccharides preventing complement attacks, and attract and utilize host complement regulators C4b binding protein and Factor H to inhibit the classical and alternative pathways of complement activation, respectively. In addition, the regulat or of the terminal pathway of complem...
Source: FEBS Letters - Category: Biochemistry Authors: Tags: REVIEW ARTICLE Source Type: research
Conclusions and significance: This case-control study demonstrated that the presence of COM plus biofilm was associated with a given microbiota which contained more Firmicutes. Our study allows a better understanding of physiopathological mechanisms involved in chronic otitis media and paves the way for further investigations. PMID: 32049553 [PubMed - as supplied by publisher]
Source: Acta Oto-Laryngologica - Category: ENT & OMF Authors: Tags: Acta Otolaryngol Source Type: research
Abstract Otitis media (OM) is a very common pediatric disease and nontypeable Haemophilus influenzae (NTHI) is the predominant causative agent. We've developed a chimeric immunogen, chimV4, that simultaneously targets two NTHI adhesins, OMP P5 and the type IV pilus. Transcutaneous immunization (TCI) via bandaid with chimV4 plus the adjuvant dmLT provides significant protection against experimental NTHI-induced OM in chinchilla models. Herein, we now examined the durability and boostability of the induced immune response. Bandaid immunization with chimV4+dmLT followed by two sequential middle ear challenges with NT...
Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research
Conclusions: Presence of bacterial otopathogen, specifically nontypeable H. influenzae, in the middle ear during VTI was a predictor of children at-risk of repeat VTI. Here, we identify a modifiable microbiologic factor for repeat VTI that can be targeted to improve clinical management of rAOM.
Source: The Pediatric Infectious Disease Journal - Category: Infectious Diseases Tags: Original Studies Source Type: research
In this study, we assessed the role M. catarrhalis plays in the co-colonization and persistence of the other major otopathogens, Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi). We characterized both monomicrobial and polymicrobial biofilms using an in vitro nasopharyngeal colonization model. Biofilm assays were designed to mimic the nasopharynx and bacterial persistence was quantified over time. NTHi showed a steady and significant decline in viability over 20–48 h when this organism was in a dual species biofilm with S. pneumoniae. However, when M. catarrhalis was present in the polymicrobia...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
A comprehensive understanding about the pathogenesis of otitis media (OM), one of the most common pediatric diseases, has the potential to alleviate a substantial disease burden across the globe. Advancements in genetic and bioinformatic detection methods, as well as a growing interest in the microbiome, has enhanced the capability of researchers to investigate the interplay between host genes, host microbiome, invading bacteria, and resulting OM susceptibility. Early studies deciphering the role of genetics in OM susceptibility assessed the heritability of the phenotype in twin and triplet studies, followed by linkage stu...
Source: Frontiers in Genetics - Category: Genetics & Stem Cells Source Type: research
Conclusions: In many cases, pediatric AOM was found to constitute a respiratory polymicrobial infection. Multiplex PCR was useful to detect multiple respiratory viruses and bacteria in AOM. To understand intractable AOM, further studies regarding the clinical features of each viral and bacterial coinfection are required.
Source: The Pediatric Infectious Disease Journal - Category: Infectious Diseases Tags: Original Studies Source Type: research
Nontypeable Haemophilus influenzae (NTHi) is a major pathogen causing acute otitis media (AOM). The pathology of AOM increases during long-term infection in the middle ear (ME), but the host cellular immune response to bacterial infection in this inflamed environment is poorly understood. Using the Junbo mouse, a characterized NTHi infection model, we analyzed the cellular response to NTHi infection in the Junbo mouse middle ear fluid (MEF). NTHi infection increased the total cell number and significantly decreased the proportion of live cells in the MEF at day 1, and this further decreased gradually on each day up to day ...
Source: Infection and Immunity - Category: Infectious Diseases Authors: Tags: Host Response and Inflammation Source Type: research
Nontypeable Haemophilus influenzae (NTHi) efficiently colonizes the human nasopharynx asymptomatically but also causes respiratory mucosal infections, including otitis media, sinusitis, and bronchitis. The lipooligosaccharide (LOS) on the cell surface of NTHi displays complex glycans that mimic host structures, allowing it to evade immune recognition. However, LOS glycans are also targets of host adaptive and innate responses. To aid in evasion of these responses, LOS structures exhibit interstrain heterogeneity and are also subject to phase variation, the random on/off switching of gene expression, generating intrastrain ...
Source: Infection and Immunity - Category: Infectious Diseases Authors: Tags: Molecular Pathogenesis Source Type: research
Conclusions: The PHiD-CV vaccination program in Brazil has resulted in important reductions of pneumococcal disease and substantial cost savings. Instead of switching PCVs, expanding vaccine coverage or investing in other health care interventions would be a more efficient use of resources to improve the health of the population in Brazil.
Source: The Pediatric Infectious Disease Journal - Category: Infectious Diseases Tags: Vaccine Reports Source Type: research
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