PubMed Health⌕ Search

Biomedical subjects

Jennelle M Kyd

Publications and source records attributed to Jennelle M Kyd.

17 recordsLinked to original sources
PubMed2006

Comparison of mucosal and parenteral immunisation in two animal models of pneumococcal infection: otitis media and acute pneumonia.

Bacterial clearance and immune responses in a mouse model of pneumonia and a rat model of otitis media following parenteral or mucosal immunisation in both models were compared. Both the immunisation routes were equally effective in inducing bacterial clearance from the lung, upregulated the recruitment of white cells and lead to an increase in the concentration of TNF-alpha, IL-1beta and specific antibody in the bronchoalveolar lavage. Both the routes of immunisation enhanced clearance of bacteria from the middle ear. Parenteral immunisation was most effective overall in enhancing bacterial clearance and recruiting white cells to the middle ear. Both the routes significantly suppressed the levels of TNF-alpha in the middle ear lavage. Mucosal immunisation induced a Streptococcus pneumoniae-specific IgA antibody response. Both the animal models gave highly reproducible disease and provided high levels of sensitivity for testing the efficacy of candidate vaccine antigens. Differences observed in the inflammatory responses require further study.

Animals↗
PubMed2006

A demonstration of the use of ultra-performance liquid chromatography-mass spectrometry [UPLC/MS] in the determination of amphetamine-type substances and ketamine for forensic and toxicological analysis.

We have recently seen the emergence of ultra-performance liquid chromatography (UPLC) coupled to mass spectrometry as an alternative to traditional high-performance liquid chromatography techniques. The strengths of UPLC technology promote the ability to separate and identify drug compounds with significant gains in resolution and sensitivity and marked reductions in the overall time of analysis. As increased throughput is the desire of the practical toxicology laboratory, the aim of this study was to trial commercially available technology by assessment of the separation of several commonly encountered amphetamine-type substances. From injection of a poly-drug reference standard and whole blood extract, we successfully separated and identified amphetamine, methamphetamine, ephedrine, pseudoephedrine, phentermine, MDA, MDMA, MDEA and ketamine in less than 3 min using the Acquity UPLC-Micromass Quattro Micro API MS instrumentation (Waters Corporation, USA). In addition to this significant reduction in overall run time, all peaks exhibited acceptable resolution using selected ion recording (SIR), with analysis indicating the capability to separate 5-11 peaks in 1.75 min using the current system parameters. From this introductory data, it is therefore indicated that the technological advancements defining ultra-performance liquid chromatography will allow it to serve as a powerful analytical tool for rapid throughput analysis.

Amphetamines↗
PubMed2006

Enterocyte and M-cell transport of native and heat-denatured bovine beta-lactoglobulin: significance of heat denaturation.

The three-dimensional structure, digestibility, and immunological properties of bovine beta-lactoglobulin (beta-lg) are modified by heat treatments used in processing of liquid milk products. Because it is not known if such treatments also modify the intestinal transport properties of beta-lg, the transport of native and heat-denatured bovine beta-lg was investigated in experimental cell models using Caco-2 cells and M cells. Transport of beta-lg labeled with a fluorescent marker was followed with fluorometric measurements, electrophoretic analyses, and fluorescence microscopy. The data show that both cell types transported native beta-lg more efficiently than they did heat-denatured beta-lg. In addition, M cells transported native beta-lg more than Caco-2 cells. Transport of native and heat-denatured beta-lg was transcellular. The electrophoretic data also suggest that heat-denatured beta-lg may have degraded more than native beta-lg during the transport.

Animals↗
PubMed2006

Product ion mass spectra of amphetamine-type substances, designer analogues, and ketamine using ultra-performance liquid chromatography/tandem mass spectrometry.

This paper describes the application of ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) technology to separate and identify amphetamine-type substances (amphetamine, methamphetamine), common and novel designer analogues (MDA, MDMA, PMA, 4-MTA, MBDB), and ketamine using Acquity UPLC/Micromass Quattro Micro API mass spectrometer instrumentation (Waters Corporation, USA). From injection of drug reference standards, it was demonstrated that these compounds can be identified by product ion mass spectra in less than 4 min total analysis time, indicating that the technological advancements associated with UPLC/MS/MS allow it to serve as a powerful analytical tool for high-throughput testing. In addition to demonstrating the separation and response of these drug compounds under the stated UPLC/MS/MS conditions, we believe the acquired product ion spectra will be a beneficial reference to laboratories interested in incorporating the use of this technology in the routine analysis of drugs of abuse.

Amphetamines↗
PubMed2006

Microbial pattern recognition receptors mediate M-cell uptake of a gram-negative bacterium.

The receptors involved in the sampling of particulate microbial antigens by the gut are largely unknown. Here we demonstrate for the first time in an in vitro M-cell model and in situ in isolated murine intestinal segments that the receptors TLR-4, PAF-R, and alpha5beta1 integrin are all involved in mediating bacterial uptake associated with transcytosis. The pattern of expression of TLR-4 and alpha5beta1 integrin differed between M cells and enterocytes. There was increased apical expression of TLR-4 in M-cell cultures, and it was present on the apical surface of murine M cells but not enterocytes in situ. In contrast, PAF-R was expressed equally by both cell types in vitro and was abundantly expressed throughout the intestinal epithelium. Inhibition of TLR-4 and PAF-R, but not TLR-2, reduced gram-negative bacterial uptake by both cell types, whereas inhibition of the apically expressed alpha5beta1 integrin significantly reduced the ability of M cells to translocate bacteria. Hence, the involvement of each receptor was dependent not only on differences in the level of receptor expression but the cellular localization. Using bacteria that had mutations that affected the bacterial lipooligosaccharide structure indicated that the oligosaccharide moiety was important in bacterial uptake. Taken together, the data suggest that pathogen-associated molecular pattern interactions with pattern recognition receptors are key factors in M-cell recognition of intestinal antigens for mucosal immune priming.

Animals↗
PubMed2005

Impact of saliva collection methods on sIgA and cortisol assays and acceptability to participants.

In community-based studies of stress and immunity, saliva samples offer a non-intrusive way of gathering biological data. Cotton-based devices are widely used in cortisol research, but some may affect assay results. We compared assay reliability and perceived acceptability of three saliva collection methods: passive, cotton 'salivettes' and cellulose-cotton tip 'eyespears'. Compared to passive collection, salivettes reduced the concentration of cortisol (p = .001) and sIgA (p = .002). Eyespears did not reduce cortisol or sIgA concentration, and showed less interference in the rank ordering of cortisol (r(eyespear with passive) = .90) and sIgA scores (r(eyespear with passive) = .96) compared to salivettes (r cortisol(salivette with passive) = .79; r sIgA(salivette with passive) = .66). The comfort and acceptability of both cotton-based devices were rated positively. Cotton-cellulose eyespears could offer methodological advantages for collecting saliva to measure cortisol and sIgA levels, and, because they can be held during sampling, may be useful for research with children and the frail elderly.

Adult↗
PubMed2005

Vaccines for otitis media: proposals for overcoming obstacles to progress.

Otitis media is a common problem with enormous morbidity worldwide. The development of vaccines to prevent otitis media would have an important human and economic impact. A striking lack of progress in the development, production and clinical testing of vaccines to prevent otitis media has occurred in the past decade. This review outlines a series of specific proposals intended to advance vaccine development for otitis media.

Bacterial Vaccines↗
PubMed2005

Mucosal immunisation with novel Streptococcus pneumoniae protein antigens enhances bacterial clearance in an acute mouse lung infection model.

Streptococcus pneumoniae contains many proteins that have not been evaluated as potential protective vaccine antigens. In this study we isolated proteins from a serotype 3 strain of S. pneumoniae for use in mouse immunisation studies. Separation of the protein mix was achieved by SDS-PAGE electrophoresis followed by electro-elution to isolate individual proteins. This procedure successfully separated 21 fractions from which six proteins were selected based on purity and quantity and were initially denoted by their molecular masses: 14-, 34-, 38-, 48-, 57- and 75-kDa. The immunogenicity of these proteins was investigated in a mucosal immunisation model in mice involving a primary inoculation to the intestinal Peyer's patches followed by an intra-tracheal boost two weeks later. The immune response was assessed by enhancement of pulmonary clearance of infection, recruitment of phagocytes to the lungs and induction of an antibody response. Two of the proteins, the 14-kDa identified as a L7/L12 ribosomal protein, and the 34-kDa identified as glyceraldehyde-3-phosphate dehydrogenase resulted in up to 99% and 94%, respectively, enhanced clearance of infection within 5 h following pulmonary challenge with S. pneumoniae. This study has shown that novel pneumococcal proteins have the potential to be vaccine candidates to enhance clearance of an acute mucosal S. pneumoniae infection.

Amino Acid Sequence↗
PubMed2005

Bacterial otitis media: a vaccine preventable disease?

Otitis media (OM) is the most common childhood illness for which medical advice is sought. Whilst the disease rarely results in death, there is a significant level of morbidity and economic burden on the community. Although the causes of OM are multifactoral, bacterial and viral infections are the single most important cause. Bacteria responsible for infections of the middle ear are predominantly, nontypeable Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Antibiotics have been widely used to treat children who present to a medical clinic with OM. However, given the high prevalence of this disease and the increasing incidence of microbial resistance to antibiotics, there is a need to develop alternative therapeutic strategies such as vaccination. Pneumococcal polysaccharide vaccination has produced disappointing results for effectiveness in preventing OM and there is evidence of an increased incidence of disease due to non-vaccine serotypes. An efficacious vaccine for bacterial OM would require combining protective protein antigens from all three causative bacteria. A combined bacterial-viral vaccine formulation would produce the most profound and sustained impact on reducing the global incidence of OM.

Acute Disease↗
PubMed2005

Characterization of a novel porin protein from Moraxella catarrhalis and identification of an immunodominant surface loop.

Moraxella catarrhalis is a gram-negative bacterium that is mainly responsible for respiratory tract infections. In this study we report a novel outer membrane protein (OMP), designated M35, with a molecular mass of 36.1 kDa. This protein was structurally homologous to classic gram-negative porins, such as OMP C from Escherichia coli and OMP K36 from Klebsiella pneumoniae, with a predicted structure of 8 surface loops and 16 antiparallel beta-sheets. The DNA sequences of the genes from 18 diverse clinical isolates showed that the gene was highly conserved (99.6 to 100% of nucleotides), with only one isolate (ID78LN266) having base variations that resulted in amino acid substitutions. Electrophoresis and analysis of recognition of the protein using mouse anti-M35 sera showed that M35 was expressed on the bacterial surface and constitutively expressed across M. catarrhalis isolates, with only ID78LN266 showing poor antibody recognition. Our results showed that the single amino acid mutation in loop 3 significantly affected antibody recognition, indicating that loop 3 appeared to contain an immunodominant B-cell epitope. The antibody specificity to loop 3 may be a potential mechanism for evasion of host immune responses targeted to M35, since loop 3 should theoretically orientate into the porin channel. Thus, M35 is a highly conserved, surface-expressed protein that is of significance for its potential functional role as an M. catarrhalis porin and is of interest as a vaccine candidate.

Bacterial Outer Membrane Proteins↗
PubMed2003

Pseudomonas aeruginosa-specific IgG1 and IgG2 subclasses in enhancement of pulmonary clearance following passive immunisation in the rat.

Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen, which causes serious debilitating infections in patients with compromised lung function. The mechanism by which P. aeruginosa is cleared from the lung is not fully defined, although our previous studies have established a role for cellular immunity in protection against P. aeruginosa infections. This study aimed to evaluate the role of P. aeruginosa-specific IgG in protection against P. aeruginosa in a rat model of acute pulmonary infection. Immunoaffinity chromatography was used to purify total rat IgG from rat immune serum (rats immunised with P. aeruginosa) and non-immune serum. Untreated recipient rats were injected intravenously with different concentrations of pure IgG prepared from serum of unimmunised rats (non-immune IgG) or from rats immunised intestinally with killed P. aeruginosa (immune IgG) and infected intratracheally with P. aeruginosa 18 h later. The protective capability of the purified IgG against P. aeruginosa was assessed by measurement of reduction in P. aeruginosa infection in the lung 4 h after instillation of bacteria. Enhanced bacterial clearance induced by IgG was determined to be dose-dependent with a 1 mg dose failing to enhance clearance, whereas 5 mg of immune IgG enhanced clearance from the airways and the lung tissue. Measurement of the IgG1, IgG2a and IgG2b isotypes in serum and the lung lavage following transfer of P. aeruginosa-specific IgG found that all three were present. These results demonstrate that anti-P. aeruginosa IgG can enhance bacterial clearance from the airways in an acute infection and identify an important role for IgG in acute respiratory infections caused by P. aeruginosa.

Acute Disease↗
PubMed2003

Construction of recombinant S-layer proteins (rSbsA) and their expression in bacterial ghosts--a delivery system for the nontypeable Haemophilus influenzae antigen Omp26.

This study has investigated the feasibility of a combination of recombinant surface layer (S-layer) proteins and empty bacterial cell envelopes (ghosts) to deliver candidate antigens for a vaccine against nontypeable Haemophilus influenzae (NTHi) infections. The S-layer gene sbsA from Bacillus stearothermophilus PV72 was used for the construction of fusion proteins. Fusion of maltose binding protein (MBP) to the N-terminus of SbsA allowed expression of the S-layer in the periplasm of Escherichia coli. The outer membrane protein (Omp) 26 of NTHi was inserted into the N-terminal and C-terminal regions of SbsA. The presence of the fused antigen Omp26 was demonstrated by Western blot experiments using anti-Omp26 antisera. Electron microscopy showed that the recombinant SbsA maintained the ability to self-assemble into sheet-like and cylindrical structures. Recombinant E. coli cell envelopes (ghosts) were produced by the expression of SbsA/Omp26 fusion proteins prior to gene E-mediated lysis. Intraperitoneal immunization with these recombinant bacterial ghosts induced an Omp26-specific antibody response in BALB/c mice. These results demonstrate that the NTHi antigen, Omp26, was expressed in the S-layer self-assembly product and this construct was immunogenic for Omp26 when administered to mice in bacterial cell envelopes.

Animals↗
PubMed2003

Immunisation with non-integral OMPs promotes pulmonary clearance of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an opportunistic bacterial pathogen that can cause fatal acute lung infections in critically ill individuals. Lung damage due to chronic infections in cystic fibrosis sufferers is the major cause of morbidity and mortality in this group. The bacterium produces various immunomodulatory products that enable it to survive in the lung. Innate and increasing resistance to antibiotic therapy shown by this organism heightens the need for development of a vaccine. This study reports the identification of six non-integral protein antigens; Pa13, azurin, acyl carrier protein (ACP), amidase, aminopeptidase and KatE, purified from a mucoid strain of P. aeruginosa. N-terminal amino acid sequencing was used to identify these proteins and, based on their ascribed functions, determined that their normal cellular location was cytosolic. A rat model of acute pulmonary infection was used to investigate the ability of these protein antigens to enhance pulmonary clearance of a live P. aeruginosa challenge. Mucosal immunisation with four of the six antigens significantly enhanced bacterial clearance from both the lavage fluid and lung tissue. The greatest level of clearance was demonstrated for the antigens; KatE, aminopeptidase and amidase. Enhanced bacterial clearance was maintained when the antigens amidase and aminopeptidase were produced in recombinant form. When delivered parenterally, aminopeptidase demonstrated its continued efficacy as a vaccine candidate. This study has demonstrated that non-integral outer membrane proteins are antigenic and protective and warrant further investigation as potential components of a vaccine.

Amino Acid Sequence↗
PubMed2003

Efficacy of the 26-kilodalton outer membrane protein and two P5 fimbrin-derived immunogens to induce clearance of nontypeable Haemophilus influenzae from the rat middle ear and lungs as well as from the chinchilla middle ear and nasopharynx.

The rat middle ear and lung clearance model has been used to show that the nontypeable Haemophilus influenzae 26-kDa outer membrane protein OMP26 is highly efficacious as a mucosal immunogen, inducing significantly enhanced clearance in immunized rats upon direct challenge of these two anatomic sites. Similarly, the chinchilla model of middle ear and nasopharyngeal clearance has been used to show that two P5 fimbrin adhesin-derived immunogens, LB1 and lipoprotein D (LPD)-LB1(f)(2,1,3), are highly efficacious as parenteral immunogens. Both induced significantly augmented clearance of nontypeable H. influenzae upon challenge of these sites. Here, these three nontypeable H. influenzae immunogens in addition to six bovine serum albumin and keyhole limpet hemocyanin conjugates of the synthetic peptide LB1(f) were assayed for relative efficacy in the reciprocal rodent model system. OMP26 was assayed in the chinchilla host by a parenteral immunization route, with clearance of the middle ear and nasopharynx used as outcome measures. Both LB1 and LPD-LB1(f)(2,1,3) were assayed in the rat host with a mucosal immunization route and clearance of nontypeable H. influenzae from the lungs and middle ears as outcome measures. Both of the immunogens were found to induce a high-titered and specific immune responses in the heterologous host system. Moreover, each was found to be highly efficacious in the reciprocal host system, providing strong support for the continued development and inclusion of both OMP26 and P5 fimbrin-derived peptides as candidate vaccine antigens directed at otitis media caused by nontypeable H. influenzae.

Amino Acid Sequence↗
PubMed2003

Mucosal immunization against respiratory bacterial pathogens.

Bacterial respiratory diseases remain a major cause of morbidity and mortality throughout the world. The young and the elderly are particularly susceptible to the pathogens that cause these diseases. Therapeutic approaches remain dependent upon antibiotics contributing to the persistent increases in antibiotic resistance. The main causes of respiratory disease discussed in this review are Mycobacterium tuberculosis, Corynebacterium diphtheriae, Bordatella pertussis, Streptococcus pneumoniae, non-typeable Haemophilus influenzae, Moraxella catarrhalis and Pseudomonas aeruginosa. All these organisms initiate disease at the mucosal surface of the respiratory tract and thus the efficacy of the host's response to infection needs to be optimal at this site. Vaccines available for diseases caused by many of these pathogens have limitations in accessibility or efficacy, highlighting the need for improvements in approaches and products. The most significant challenges in both therapy and prevention of disease induced by bacteria in the respiratory tract remain the development of non-injectable vaccines and delivery systems/immunization regimens that improve mucosal immunity.

Animals↗