1
|
Bhat TA, Kalathil SG, Leigh N, Hutson A, Goniewicz ML, Thanavala YM. Do alternative tobacco products induce less adverse respiratory risk than cigarettes? Respir Res 2023; 24:261. [PMID: 37907902 PMCID: PMC10617138 DOI: 10.1186/s12931-023-02568-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/18/2023] [Indexed: 11/02/2023] Open
Abstract
RATIONALE Due to the relatively short existence of alternative tobacco products, gaps exist in our current understanding of their long-term respiratory health effects. We therefore undertook the first-ever side-by-side comparison of the impact of chronic inhalation of aerosols emitted from electronic cigarettes (EC) and heated tobacco products (HTP), and combustible cigarettes (CC) smoke. OBJECTIVES To evaluate the potential differential effects of alternative tobacco products on lung inflammatory responses and efficacy of vaccination in comparison to CC. METHODS Mice were exposed to emissions from EC, HTP, CC, or air for 8 weeks. BAL and lung tissue were analyzed for markers of inflammation, lung damage, and oxidative stress. Another group was exposed for 12 weeks and vaccinated and challenged with a bacterial respiratory infection. Antibody titers in BAL and sera and pulmonary bacterial clearance were assessed. MAIN RESULTS EC- and HTP-aerosols significantly augmented lung immune cell infiltrates equivalent to that achieved following CC-exposure. HTP and CC significantly increased neutrophil numbers compared to EC. All products augmented numbers of B cells, T cells, and pro-inflammatory IL17A+ T cells in the lungs. Decreased lung antioxidant activity and lung epithelial and endothelial damage was induced by all products. EC and HTP differentially augmented inflammatory cytokines/chemokines in the BAL. Generation of immunity following vaccination was impaired by EC and HTP but to a lesser extent than CC, with a CC > HTP > EC hierarchy of suppression of pulmonary bacterial clearance. CONCLUSIONS HTP and EC-aerosols induced a proinflammatory pulmonary microenvironment, lung damage, and suppressed efficacy of vaccination.
Collapse
Affiliation(s)
- Tariq A Bhat
- Department of Immunology, Roswell Park Comprehensive Cancer Center, 665 Elm Street, Buffalo, NY, 14263, USA
- Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Suresh G Kalathil
- Department of Immunology, Roswell Park Comprehensive Cancer Center, 665 Elm Street, Buffalo, NY, 14263, USA
| | - Noel Leigh
- Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Alan Hutson
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Maciej L Goniewicz
- Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Yasmin M Thanavala
- Department of Immunology, Roswell Park Comprehensive Cancer Center, 665 Elm Street, Buffalo, NY, 14263, USA.
| |
Collapse
|
2
|
Roles of the Tol/Pal System in Bacterial Pathogenesis and Its Application to Antibacterial Therapy. Vaccines (Basel) 2022; 10:vaccines10030422. [PMID: 35335056 PMCID: PMC8953051 DOI: 10.3390/vaccines10030422] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 01/27/2023] Open
Abstract
The Tol/Pal system (also written as “The Tol-Pal system”) is a set of protein complexes produced by most Gram-negative bacteria. It comprises the inner membrane-associated and the outer membrane-anchored subunits composed of the TolA, TolQ, and TolR proteins and the TolB and Pal proteins, respectively. Although the Tol/Pal system was first defined as bacterial proteins involved in colicin uptake of Escherichia coli, its global roles have been characterized in several studies as mentioned in this article. Pathogenesis of many Gram-negative pathogens is sustained by the Tol/Pal system. It is also essential for cell growth and fitness in some pathogens. Therefore, the Tol/Pal system is proposed as a potential target for antimicrobial chemotherapy. Although the tol/pal mutants are low in virulence, they still have the ability to stimulate the immune system. The Pal protein is highly immunogenic and induces both adaptive and innate immune responses. Therefore, the tol/pal mutant strains and Pal proteins also have potential vaccine properties. For these reasons, the Tol/Pal system represents a promising research target in the development of antibacterial therapeutic strategies for refractory infections caused by multi-drug-resistant (MDR), Gram-negative pathogens. In this paper, we summarize studies on the Tol/Pal system associated with bacterial pathogenesis and vaccine development.
Collapse
|
3
|
Szczepaniak J, Press C, Kleanthous C. The multifarious roles of Tol-Pal in Gram-negative bacteria. FEMS Microbiol Rev 2021; 44:490-506. [PMID: 32472934 PMCID: PMC7391070 DOI: 10.1093/femsre/fuaa018] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/28/2020] [Indexed: 12/15/2022] Open
Abstract
In the 1960s several groups reported the isolation and preliminary genetic mapping of
Escherichia coli strains tolerant towards the
action of colicins. These pioneering studies kick-started two new fields in bacteriology;
one centred on how bacteriocins like colicins exploit the Tol (or more commonly Tol-Pal)
system to kill bacteria, the other on the physiological role of this cell
envelope-spanning assembly. The following half century has seen significant advances in
the first of these fields whereas the second has remained elusive, until recently. Here,
we review work that begins to shed light on Tol-Pal function in Gram-negative bacteria.
What emerges from these studies is that Tol-Pal is an energised system with fundamental,
interlinked roles in cell division – coordinating the re-structuring of peptidoglycan at
division sites and stabilising the connection between the outer membrane and underlying
cell wall. This latter role is achieved by Tol-Pal exploiting the proton motive force to
catalyse the accumulation of the outer membrane peptidoglycan associated lipoprotein Pal
at division sites while simultaneously mobilising Pal molecules from around the cell.
These studies begin to explain the diverse phenotypic outcomes of tol-pal
mutations, point to other cell envelope roles Tol-Pal may have and raise many new
questions.
Collapse
Affiliation(s)
- Joanna Szczepaniak
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Cara Press
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Colin Kleanthous
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| |
Collapse
|
4
|
Bhat TA, Kalathil SG, Bogner PN, Lehmann PV, Thatcher TH, Sime PJ, Thanavala Y. AT-RvD1 Mitigates Secondhand Smoke-Exacerbated Pulmonary Inflammation and Restores Secondhand Smoke-Suppressed Antibacterial Immunity. THE JOURNAL OF IMMUNOLOGY 2021; 206:1348-1360. [PMID: 33558371 DOI: 10.4049/jimmunol.2001228] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/09/2021] [Indexed: 02/07/2023]
Abstract
Cigarette smoke is a potent proinflammatory trigger contributing to acute lung injury and the development of chronic lung diseases via mechanisms that include the impairment of inflammation resolution. We have previously demonstrated that secondhand smoke (SHS) exposure exacerbates bacterial infection-induced pulmonary inflammation and suppresses immune responses. It is now recognized that resolution of inflammation is a bioactive process mediated by lipid-derived specialized proresolving mediators that counterregulate proinflammatory signaling and promote resolution pathways. We therefore hypothesized that proresolving mediators could reduce the burden of inflammation due to chronic lung infection following SHS exposure and restore normal immune responses to respiratory pathogens. To address this question, we exposed mice to SHS followed by chronic infection with nontypeable Haemophilus influenzae (NTHI). Some groups of mice were treated with aspirin-triggered resolvin D1 (AT-RvD1) during the latter half of the smoke exposure period or during a period of smoking cessation and before infection. Treatment with AT-RvD1 markedly reduced the recruitment of neutrophils, macrophages, and T cells in lung tissue and bronchoalveolar lavage and levels of proinflammatory cytokines in the bronchoalveolar lavage. Additionally, treatment with AT-RvD1 improved Ab titers against the NTHI outer membrane lipoprotein Ag P6 following infection. Furthermore, treatment with AT-RvD1 prior to classically adjuvanted immunization with P6 increased Ag-specific Ab titers, resulting in rapid clearance of NTHI from the lungs after acute challenge. Collectively, we have demonstrated that AT-RvD1 potently reverses the detrimental effects of SHS on pulmonary inflammation and immunity and thus could be beneficial in reducing lung injury associated with smoke exposure and infection.
Collapse
Affiliation(s)
- Tariq A Bhat
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263
| | | | - Paul N Bogner
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, NY 14263
| | | | - Thomas H Thatcher
- Department of Medicine, University of Rochester, Rochester, NY 14620; and.,Department of Environmental Medicine, University of Rochester, Rochester, NY 14620
| | - Patricia J Sime
- Department of Medicine, University of Rochester, Rochester, NY 14620; and.,Department of Environmental Medicine, University of Rochester, Rochester, NY 14620
| | - Yasmin Thanavala
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263;
| |
Collapse
|
5
|
Bhat TA, Kalathil SG, Bogner PN, Miller A, Lehmann PV, Thatcher TH, Phipps RP, Sime PJ, Thanavala Y. Secondhand Smoke Induces Inflammation and Impairs Immunity to Respiratory Infections. THE JOURNAL OF IMMUNOLOGY 2018; 200:2927-2940. [PMID: 29555783 DOI: 10.4049/jimmunol.1701417] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 02/16/2018] [Indexed: 12/29/2022]
Abstract
Despite advocacy to reduce smoking-related diseases, >1 billion people worldwide continue to smoke. Smoking is immunosuppressive and an important etiological factor in the development of several human disorders including respiratory diseases like chronic obstructive pulmonary disease. However, there is a critical gap in the knowledge of the role of secondhand smoke (SHS) in inflammation and immunity. We therefore studied the influence of SHS on pulmonary inflammation and immune responses to respiratory infection by nontypeable Haemophilus influenzae (NTHI) recurrently found in chronic obstructive pulmonary disease patients. Chronic SHS-exposed mice were chronically infected with NTHI and pulmonary inflammation was evaluated by histology. Immune cell numbers and cytokines were measured by flow cytometry and ELISA, respectively. Chronic SHS exposure impaired NTHI P6 Ag-specific B and T cell responses following chronic NTHI infection as measured by ELISPOT assays, reduced the production of Abs in serum and bronchoalveolar lavage, and enhanced albumin leak into the bronchoalveolar lavage as determined by ELISA. Histopathological examination of lungs revealed lymphocytic accumulation surrounding airways and bronchovasculature following chronic SHS exposure and chronic infection. Chronic SHS exposure enhanced the levels of inflammatory cytokines IL-17A, IL-6, IL-1β, and TNF-α in the lungs, and impaired the generation of adaptive immunity following either chronic infection or P6 vaccination. Chronic SHS exposure diminished bacterial clearance from the lungs after acute NTHI challenge, whereas P6 vaccination improved clearance equivalent to the level seen in air-exposed, non-vaccinated mice. Our study provides unequivocal evidence that SHS exposure has long-term detrimental effects on the pulmonary inflammatory microenvironment and immunity to infection and vaccination.
Collapse
Affiliation(s)
- Tariq A Bhat
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263
| | | | - Paul N Bogner
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, NY 14263
| | - Austin Miller
- Department of Biostatistics, Roswell Park Cancer Institute, Buffalo, NY 14263
| | | | - Thomas H Thatcher
- Department of Medicine, University of Rochester, Rochester, NY 14620; and
| | - Richard P Phipps
- Department of Medicine, University of Rochester, Rochester, NY 14620; and.,Department of Environmental Medicine, University of Rochester, Rochester, NY 14620
| | - Patricia J Sime
- Department of Medicine, University of Rochester, Rochester, NY 14620; and.,Department of Environmental Medicine, University of Rochester, Rochester, NY 14620
| | - Yasmin Thanavala
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263;
| |
Collapse
|
6
|
Khan MN, Ren D, Kaur R, Basha S, Zagursky R, Pichichero ME. Developing a vaccine to prevent otitis media caused by nontypeable Haemophilus influenzae. Expert Rev Vaccines 2016; 15:863-78. [PMID: 26894630 DOI: 10.1586/14760584.2016.1156539] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi) is a predominant organism of the upper respiratory nasopharyngeal microbiota. Its disease spectrum includes otitis media, sinusitis, non-bacteremic pneumonia and invasive infections. Protein-based vaccines to prevent NTHi infections are needed to alleviate these infections in children and vulnerable populations such as the elderly and those with chronic obstructive pulmonary disease (COPD). One NTHi protein is included in a pneumococcal conjugate vaccine and has been shown to provide efficacy. Our lab has been interested in understanding the immunogenicity of NTHi vaccine candidates P6, protein D and OMP26 for preventing acute otitis media in young children. We expect that continued investigation and progress in the development of an efficacious protein based vaccine against NTHi infections is achievable in the near future.
Collapse
Affiliation(s)
- M Nadeem Khan
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Dabin Ren
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Ravinder Kaur
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Saleem Basha
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Robert Zagursky
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Michael E Pichichero
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| |
Collapse
|
7
|
Serum Concentrations of Antibodies against Outer Membrane Protein P6, Protein D, and T- and B-Cell Combined Antigenic Epitopes of Nontypeable Haemophilus influenzae in Children and Adults of Different Ages. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 23:155-61. [PMID: 26677200 DOI: 10.1128/cvi.00506-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/07/2015] [Indexed: 12/22/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi) is one of the most common etiologies of acute otitis media, rhinosinusitis, and pneumonia. Outer membrane proteins (OMPs) are the main focus in new vaccine development against NTHi, as the H. influenzae type b (Hib) vaccine does not cover noncapsulated NTHi. The OMPs P6 and protein D are the most promising candidate antigens for an NTHi vaccine, and low antibody levels against them in serum may be correlated with infection caused by NTHi. In the current study, we measured the antibody titers against P6, protein D, and their T- and B-cell combined peptide epitopes in healthy individuals of different ages. We found that children <1 month old had the lowest antibody levels against NTHi P6, protein D, and their T- and B-cell combined antigenic epitopes. Antibody titers increased at ages 1 to 6 months, peaked at 7 months to 3 years, and remained high at 4 to 6 years. The antibody titers started to decrease after 6 years and were the lowest in the 21- to 30-year group. The geometric mean titers (GMTs) of T- and B-cell combined antigenic epitopes in P6 and protein D were positively correlated with those of the protein antigens. Among 12 peptides tested, P6-61, P6-123, and protein D-167 epitopes were better recognized than others in human serum. These findings might contribute to the development of an effective serotype-independent vaccine for H. influenzae.
Collapse
|
8
|
Lugade AA, Bogner PN, Thatcher TH, Sime PJ, Phipps RP, Thanavala Y. Cigarette smoke exposure exacerbates lung inflammation and compromises immunity to bacterial infection. THE JOURNAL OF IMMUNOLOGY 2014; 192:5226-35. [PMID: 24752444 DOI: 10.4049/jimmunol.1302584] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The detrimental impact of tobacco on human health is clearly recognized, and despite aggressive efforts to prevent smoking, close to one billion individuals worldwide continue to smoke. People with chronic obstructive pulmonary disease are susceptible to recurrent respiratory infections with pathogens, including nontypeable Haemophilus influenzae (NTHI), yet the reasons for this increased susceptibility are poorly understood. Because mortality rapidly increases with multiple exacerbations, development of protective immunity is critical to improving patient survival. Acute NTHI infection has been studied in the context of cigarette smoke exposure, but this is the first study, to our knowledge, to investigate chronic infection and the generation of adaptive immune responses to NTHI after chronic smoke exposure. After chronic NTHI infection, mice that had previously been exposed to cigarette smoke developed increased lung inflammation and compromised adaptive immunity relative to air-exposed controls. Importantly, NTHI-specific T cells from mice exposed to cigarette smoke produced lower levels of IFN-γ and IL-4, and B cells produced reduced levels of Abs against outer-membrane lipoprotein P6, with impaired IgG1, IgG2a, and IgA class switching. However, production of IL-17, which is associated with neutrophilic inflammation, was enhanced. Interestingly, cigarette smoke-exposed mice exhibited a similar defect in the generation of adaptive immunity after immunization with P6. Our study has conclusively demonstrated that cigarette smoke exposure has a profound suppressive effect on the generation of adaptive immune responses to NTHI and suggests the mechanism by which prior cigarette smoke exposure predisposes chronic obstructive pulmonary disease patients to recurrent infections, leading to exacerbations and contributing to mortality.
Collapse
Affiliation(s)
- Amit A Lugade
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263
| | - Paul N Bogner
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, NY 14263
| | - Thomas H Thatcher
- Department of Medicine, University of Rochester, Rochester, NY 14620; and
| | - Patricia J Sime
- Department of Medicine, University of Rochester, Rochester, NY 14620; and Department of Environmental Medicine, University of Rochester, Rochester, NY 14620
| | - Richard P Phipps
- Department of Medicine, University of Rochester, Rochester, NY 14620; and Department of Environmental Medicine, University of Rochester, Rochester, NY 14620
| | - Yasmin Thanavala
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263;
| |
Collapse
|
9
|
Abstract
Otitis media is a major cause of morbidity in 80% of all children less than 3 years of age and often goes undiagnosed in the general population. There is evidence to suggest that the incidence of otitis media is increasing. The major cause of otitis media is infection of the middle ear with microbes from the nasopharynx. The anatomical orientation of the eustachian tube, in association with a number of risk factors, predisposes infants and young children to the infection. Bacteria are responsible for approximately 70% of cases of acute otitis media, with Streptococcus pneumoniae, nontypeable Haemophilus influenzae and Moraxella catarrhalis predominating as the causative agents. The respiratory viruses, respiratory syncytial virus, rhinovirus, parainfluenza and influenza, account for 30% of acute otitis media cases. Over the past decade, there has been a profound increase in the reported resistance to antibiotics, which, with increased disease burden, has focussed attention on vaccine development for otitis media. A polymicrobial formulation containing antigens from all major pathogens would have the greatest potential to deliver a sustained reduction in the disease burden globally. The disappointing outcomes for otitis media seen with the polysaccharide pneumococcal conjugate vaccine have raised major challenges for the vaccination strategy. Clearly, more knowledge is required concerning immune mechanisms in the middle ear, as well as vaccine formulations containing antigens that are more representative of the polymicrobial nature of the disease. Antigens that have been extensively tested in animal models are now available for testing in human subjects.
Collapse
Affiliation(s)
- Allan W Cripps
- Griffith University, School of Medicine, Gold Coast Campus, PMB 50, Gold Coast, MC, QLD, 9726, Australia.
| | | |
Collapse
|
10
|
See SB, Thomas WR. Protective anti-outer membrane protein immunity against Pasteurella pneumotropica infection of mice. Microbes Infect 2013; 15:470-9. [PMID: 23624107 DOI: 10.1016/j.micinf.2013.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 07/31/2012] [Accepted: 04/15/2013] [Indexed: 10/26/2022]
Abstract
The ability of recombinant outer membrane proteins of Pasteurella pneumotropica to vaccinate against the infections of mice was studied. The proteins examined were the homologues of the P4, P6, P26, and D15 proteins of Haemophilus influenzae. Intranasal vaccination with P4 and P6 produced protection against pneumonia. P6 vaccination, which was most studied, reduced the peak bacteria load in lungs by 50-fold and caused a rapid resolution of an infection that lasted for at least 5 days in unvaccinated animals. Protection could be partially transferred with CD4(+) T cells and pulmonary challenge with the P6 antigen induced interferon-γ and the Th17 cytokine IL-21. This is the first demonstration of the ability of a recombinant P6 to mediate protective immunity to a pathogen in its natural host and it is proposed that it would not only have utility for mouse breeding but also for investigating how to improve the efficacy of vaccination with homologous proteins for related species.
Collapse
Affiliation(s)
- Sarah B See
- Division of Molecular Biotechnology, Centre for Child Health Research, Telethon Institute of Child Health Research, University of Western Australia, West Perth 6872, Australia.
| | | |
Collapse
|
11
|
Santos CA, Beloti LL, Toledo MAS, Crucello A, Favaro MTP, Mendes JS, Santiago AS, Azzoni AR, Souza AP. A novel protein refolding protocol for the solubilization and purification of recombinant peptidoglycan-associated lipoprotein from Xylella fastidiosa overexpressed in Escherichia coli. Protein Expr Purif 2012; 82:284-9. [PMID: 22306742 DOI: 10.1016/j.pep.2012.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 01/17/2012] [Accepted: 01/18/2012] [Indexed: 10/14/2022]
Abstract
Xylella fastidiosa is a Gram-negative xylem-limited plant pathogenic bacterium responsible for several economically important crop diseases. Here, we present a novel and efficient protein refolding protocol for the solubilization and purification of recombinant X. fastidiosa peptidoglycan-associated lipoprotein (XfPal). Pal is an outer membrane protein that plays important roles in maintaining the integrity of the cell envelope and in bacterial pathogenicity. Because Pal has a highly hydrophobic N-terminal domain, the heterologous expression studies necessary for structural and functional protein characterization are laborious once the recombinant protein is present in inclusion bodies. Our protocol based on the denaturation of the XfPal-enriched inclusion bodies with 8M urea followed by buffer-exchange steps via dialysis proved effective for the solubilization and subsequent purification of XfPal, allowing us to obtain a large amount of relatively pure and folded protein. In addition, XfPal was biochemically and functionally characterized. The method for purification reported herein is valuable for further research on the three-dimensional structure and function of Pal and other outer membrane proteins and can contribute to a better understanding of the role of these proteins in bacterial pathogenicity, especially with regard to the plant pathogen X. fastidiosa.
Collapse
Affiliation(s)
- Clelton A Santos
- Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas, Campinas, SP, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Simkins SG, Knapp SL, Brough GH, Lenz KL, Barley-Maloney L, Baker JP, Dekking L, Wai H, Dixon EP. Generation of monoclonal antibodies to the AML1-ETO fusion protein: strategies for overcoming high homology. Hybridoma (Larchmt) 2011; 30:433-43. [PMID: 22008070 DOI: 10.1089/hyb.2011.0037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The chromosomal translocation t(8;21) often found in acute myeloid leukemia generates an oncogenic fusion protein AML1-ETO. This chimeric oncoprotein disrupts wild-type AML1 function and dysregulates genes important for normal myelopoiesis. Monoclonal antibodies that can capture and detect the AML1-ETO fusion protein would help with early diagnosis and treatment prognosis of acute myeloid leukemia. We report the development of murine monoclonal antibodies (MAbs) that specifically bind epitopes encoded by either AML1 or ETO. Since alignment to the human ETO protein indicated almost 100% homology to the mouse ortholog, a strategy was needed to instruct humoral immunity in mice to focus and respond to self-epitopes. Our strategy to develop capture/detector reagents involved producing MAbs that would bind to epitopes within the non-fused myelopic protein (i.e., either AML1 or ETO). This included a process to select antibodies for their ability to also recognize the translocated chromosomal AML1-ETO fusion protein and to identify complementary capture/detector antibody pairs. Construction of a peptide hapten-carrier complex and use of a rapid immunization protocol resulted in IgM-IgG ETO specific MAbs. These MAbs bound specifically to a recombinant form of AML1-ETO fusion protein expressed in HEK and to an endogenous AML1-ETO form of the fusion protein expressed in Kasumi-1. We report the development of murine hybridoma MAbs derived from immunizations with a peptide "self-epitope." Our findings provide a potential strategy to instruct humoral immunity in mice to focus and respond to self-epitopes. This strategy has been validated with the oncogenic fusion protein AML1-ETO involved in acute myeloid leukemia.
Collapse
Affiliation(s)
- Stephen G Simkins
- BD Diagnostics, Women's Health and Cancer, Durham, North Carolina, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Lugade AA, Vethanayagam RR, Nasirikenari M, Bogner PN, Segal BH, Thanavala Y. Nrf2 regulates chronic lung inflammation and B-cell responses to nontypeable Haemophilus influenzae. Am J Respir Cell Mol Biol 2011; 45:557-65. [PMID: 21216970 PMCID: PMC3175582 DOI: 10.1165/rcmb.2010-0321oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 12/17/2010] [Indexed: 12/12/2022] Open
Abstract
Nrf2 is a leucine zipper transcription factor that protects against oxidant-induced injury. Nontypeable Haemophilus influenzae is responsible for frequent disease exacerbations in patients with chronic obstructive pulmonary disease and is responsible for causing otitis media in young children. We hypothesized that Nrf2 would limit inflammatory responses to nontypeable H. influenzae. The objective of this study was to assess the role of Nrf2 in chronic lung inflammation and regulation of immune responses to nontypeable H. influenzae in mice. Wild-type (C57BL/6) mice and Nrf2(-/-) mice were instilled by oropharyngeal aspiration of 1 × 10(6) colony-forming units of live, nontypeable H. influenzae (NTHI) twice a week for 4 to 16 consecutive weeks to generate a chronic inflammatory milieu within the lungs that models chronic bronchitis. Nrf2(-/-) mice had increased lymphocytic airway inflammation compared with WT mice after NTHI challenge. Although the extent of NTHI-induced peribronchovascular inflammation did not significantly differ between the genotypes, plasma cell infiltration was significantly more abundant in Nrf2(-/-) mice. Most strikingly, Nrf2(-/-) mice generated significantly enhanced and persistent levels of serum antibodies against P6, a key outer membrane protein of NTHI. Lung dendritic cells from Nrf2(-/-) mice challenged with NTHI had increased activation markers compared with dendritic cells from similarly treated WT mice. Nrf2 regulates NTHI-induced airway inflammation characterized by lymphocytic and plasma cell infiltration and the activation of lung dendritic cells and B-cell responses in mice. Nrf2 may be a potential therapeutic target in limiting the bacterial infection-induced airway inflammation that drives exacerbations of chronic obstructive pulmonary disease.
Collapse
Affiliation(s)
- Amit A. Lugade
- Departments of Immunology, Roswell Park Cancer Institute, Buffalo, New York
| | | | - Mehrab Nasirikenari
- Departments of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York
| | - Paul N. Bogner
- Departments of Pathology, Roswell Park Cancer Institute, Buffalo, New York
| | - Brahm H. Segal
- Departments of Immunology, Roswell Park Cancer Institute, Buffalo, New York
- Departments of Medicine, Roswell Park Cancer Institute, Buffalo, New York
| | - Yasmin Thanavala
- Departments of Immunology, Roswell Park Cancer Institute, Buffalo, New York
| |
Collapse
|
14
|
Lugade AA, Bianchi-Smiraglia A, Pradhan V, Elkin G, Murphy TF, Thanavala Y. Lipid motif of a bacterial antigen mediates immune responses via TLR2 signaling. PLoS One 2011; 6:e19781. [PMID: 21611194 PMCID: PMC3096640 DOI: 10.1371/journal.pone.0019781] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 04/04/2011] [Indexed: 01/21/2023] Open
Abstract
The cross-talk between the innate and the adaptive immune system is facilitated
by the initial interaction of antigen with dendritic cells. As DCs express a
large array of TLRs, evidence has accumulated that engagement of these molecules
contributes to the activation of adaptive immunity. We have evaluated the
immunostimulatory role of the highly-conserved outer membrane lipoprotein P6
from non-typeable Haemophilus influenzae (NTHI) to determine
whether the presence of the lipid motif plays a critical role on its
immunogenicity. We undertook a systematic analysis of the role that the lipid
motif plays in the activation of DCs and the subsequent stimulation of
antigen-specific T and B cells. To facilitate our studies, recombinant P6
protein that lacked the lipid motif was generated. Mice immunized with
non-lipidated rP6 were unable to elicit high titers of anti-P6 Ig. Expression of
the lipid motif on P6 was also required for proliferation and cytokine secretion
by antigen-specific T cells. Upregulation of T cell costimulatory molecules was
abrogated in DCs exposed to non-lipidated rP6 and in
TLR2−/− DCs exposed to native P6, thereby resulting
in diminished adaptive immune responses. Absence of either the lipid motif on
the antigen or TLR2 expression resulted in diminished cytokine production from
stimulated DCs. Collectively; our data suggest that the lipid motif of the
lipoprotein antigen is essential for triggering TLR2 signaling and effective
stimulation of APCs. Our studies establish the pivotal role of a bacterial lipid
motif on activating both innate and adaptive immune responses to an otherwise
poorly immunogenic protein antigen.
Collapse
Affiliation(s)
- Amit A. Lugade
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New
York, United States of America
| | - Anna Bianchi-Smiraglia
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New
York, United States of America
- Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo,
New York, United States of America
| | - Vandana Pradhan
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New
York, United States of America
| | - Galina Elkin
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New
York, United States of America
| | - Timothy F. Murphy
- Department of Medicine, University at Buffalo, State University of New
York, Buffalo, New York, United States of America
| | - Yasmin Thanavala
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New
York, United States of America
- * E-mail:
| |
Collapse
|
15
|
Lugade AA, Bogner PN, Murphy TF, Thanavala Y. The role of TLR2 and bacterial lipoprotein in enhancing airway inflammation and immunity. Front Immunol 2011; 2:10. [PMID: 22566801 PMCID: PMC3342052 DOI: 10.3389/fimmu.2011.00010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 04/12/2011] [Indexed: 12/20/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHI) colonizes the lower respiratory tract of patients with chronic obstructive pulmonary disease and also causes exacerbations of the disease. The 16-kDa lipoprotein P6 has been widely studied as a potential vaccine antigen due to its highly conserved expression amongst NTHI strains. Although P6 is known to induce potent inflammatory responses, its role in the pathogenesis of NTHI infection in vivo has not been examined. Additionally, the presence of an amino-terminal lipid motif on P6 serves to activate host Toll-like receptor 2 (TLR2) signaling. The role of host TLR2 and NTHI expression of the lipoprotein P6 on the induction of airway inflammation and generation of adaptive immune responses following chronic NTHI stimulation was evaluated with TLR2-deficient mice and a P6-deficient NTHI strain. Absence of either host TLR2 or bacterial P6 resulted in diminished levels of immune cell infiltration within lungs of mice exposed to NTHI. Pro-inflammatory cytokine secretion was also reduced in lungs that did not express TLR2 or were exposed to NTHI devoid of P6. Induction of specific antibodies to P6 was severely limited in TLR2-deficient mice. Although mice exposed to the P6-deficient NTHI strain were capable of generating antibodies to other surface antigens of NTHI, these levels were lower compared to those observed in mice exposed to P6-expressing NTHI. Therefore, cognate interaction between host TLR2 and bacterial P6 serves to enhance lung inflammation and elicit robust adaptive immune responses during NTHI exposure. Strategies to limit NTHI inflammation while simultaneously promoting robust immune responses may benefit from targeting the TLR2:P6 signaling axis.
Collapse
Affiliation(s)
- Amit A Lugade
- Department of Immunology, Roswell Park Cancer Institute Buffalo, NY, USA
| | | | | | | |
Collapse
|
16
|
Kodama S, Hirano T, Noda K, Umemoto S, Suzuki M. Nasal immunization with plasmid DNA encoding P6 protein and immunostimulatory complexes elicits nontypeable Haemophilus influenzae-specific long-term mucosal immune responses in the nasopharynx. Vaccine 2011; 29:1881-90. [PMID: 21237276 DOI: 10.1016/j.vaccine.2010.12.129] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 11/26/2010] [Accepted: 12/30/2010] [Indexed: 11/16/2022]
Abstract
Nasal vaccination is an effective therapeutic regimen for preventing upper respiratory infection, while DNA vaccines represent a new approach for controlling infectious diseases. Here, we examined the efficacy of nasally administered DNA vaccine on upper respiratory infections. A DNA plasmid encoding the P6 outer membrane protein of nontypeable Haemophilus influenzae (NTHi) was constructed. Mice were immunized 3 times intranasally with the DNA plasmid and Matrix-M, an immunostimulatory complex adjuvant. P6-specific immune responses were examined using purified P6 protein. Nasal-associated lymphoid tissue (NALT) CD4(+) T cells were purified and incubated with feeder cells in the presence of P6, and the expression of cytokine mRNA was examined. In addition, NTHi challenges were performed and the level of NTHi was quantified in nasal washes. P6-specific nasal wash IgA and serum IgG were elevated following immunization with the DNA plasmid and Matrix-M. The number of specific IgA-producing cells increased in the nasal passages of the immunized mice. In addition to Th1 and Th2 cytokine expression, IL-17 was detected in P6-specific NALT CD4(+) T cells. Moreover, DNA vaccination enhanced bacterial clearance. These findings suggest that a successful DNA vaccination protocol has been developed for inducing in vivo immune responses against NTHi. Nasal vaccination with P6 DNA vaccine and Matrix-M might be a new effective regimen for the induction of specific protective immunity in the upper respiratory tract.
Collapse
Affiliation(s)
- Satoru Kodama
- Department of Otolaryngology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hazama-cho, Yufu, Oita 879-5593, Japan.
| | | | | | | | | |
Collapse
|
17
|
Wiertsema SP, Leach AJ. Theories of otitis media pathogenesis, with a focus on Indigenous children. Med J Aust 2010; 191:S50-4. [PMID: 19883357 DOI: 10.5694/j.1326-5377.2009.tb02927.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 09/01/2009] [Indexed: 11/17/2022]
Abstract
Otitis media is a common childhood illness associated with hearing loss, social disadvantage and medical costs. Prevalence and severity are high among Indigenous children. Respiratory bacterial and viral pathogens ascend the eustachian tube from the nasopharynx to the middle ear, causing inflammation, fluid accumulation, and bulging of the tympanic membrane, with or without pain. Among Australian Indigenous children, ear disease commences earlier in life, and involves multiple strains of bacterial pathogens at high density that persist longer. Persistent nasal discharge, overcrowded living conditions (particularly exposure to many children) and poor facilities for washing children perpetuate a vicious cycle of transmission and infection. Risk factors include environmental tobacco smoke, season, lack of breastfeeding, younger age and immature immune system, and possibly genetic factors. The innate immune system is a critical first response to infection, particularly as passive maternal antibodies decline and during the maturation of the infant adaptive immune response. The relative contributions of innate factors to protection from otitis media are currently not well understood. A diversity of antibodies that target strain-specific and conserved antigens are generated in response to natural exposure to otitis media pathogens (or to vaccines). Deficiencies in these antibodies may explain susceptibility to recurrent infections. Incremental contributions from all these elements are likely to be important in otitis media susceptibility versus protection. Effective medical and social strategies to prevent early age of onset are urgently needed.
Collapse
Affiliation(s)
- Selma P Wiertsema
- School of Paediatrics and Child Health, University of Western Australia, Perth, WA, Australia.
| | | |
Collapse
|
18
|
Use of Moraxella catarrhalis lipooligosaccharide mutants to identify specific oligosaccharide epitopes recognized by human serum antibodies. Infect Immun 2009; 77:4548-58. [PMID: 19651870 DOI: 10.1128/iai.00294-09] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Moraxella catarrhalis is a causative agent of otitis media in children and lower respiratory tract infections in adults suffering from chronic obstructive pulmonary disease (COPD). This strict human pathogen continues to be a significant cause of disease in this broad spectrum of patients because there is no available vaccine. Although numerous putative vaccine antigens have been described, little is known about the human immune response to M. catarrhalis infection in vivo. Human serum antibodies are directed at a number of surface proteins, and lipooligosaccharides (LOS) and detoxified LOS may be an effective immunogen in mice. In this study, we used a specific LOS-based enzyme-linked immunosorbent assay (ELISA), containing the three major M. catarrhalis serotypes together with a complete series of truncated LOS mutants, to detect the development of new antibodies to specific regions of the oligosaccharide molecule. We compared serum samples from COPD patients who had recently cleared an M. catarrhalis infection to serum samples collected prior to their infection. Variability in the antibody response to LOS was observed, as some patients developed serotype-specific antibodies, others developed antibodies to the LOS of each serotype, others developed broadly cross-reactive antibodies, and some did not develop new antibodies. These newly developed human antibodies are directed at both side chains and core structures in the LOS molecule. This LOS-based ELISA can be used to dissect the human antibody response to both internal and external carbohydrate epitopes, thus providing a better understanding of the humoral immune response to M. catarrhalis LOS epitopes developed during natural infection.
Collapse
|
19
|
Godlewska R, Wiśniewska K, Pietras Z, Jagusztyn-Krynicka EK. Peptidoglycan-associated lipoprotein (Pal) of Gram-negative bacteria: function, structure, role in pathogenesis and potential application in immunoprophylaxis. FEMS Microbiol Lett 2009; 298:1-11. [PMID: 19519769 DOI: 10.1111/j.1574-6968.2009.01659.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The protein Pal (peptidoglycan-associated lipoprotein) is anchored in the outer membrane (OM) of Gram-negative bacteria and interacts with Tol proteins. Tol-Pal proteins form two complexes: the first is composed of three inner membrane Tol proteins (TolA, TolQ and TolR); the second consists of the TolB and Pal proteins linked to the cell's OM. These complexes interact with one another forming a multiprotein membrane-spanning system. It has recently been demonstrated that Pal is essential for bacterial survival and pathogenesis, although its role in virulence has not been clearly defined. This review summarizes the available data concerning the structure and function of Pal and its role in pathogenesis.
Collapse
Affiliation(s)
- Renata Godlewska
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | | | | | | |
Collapse
|
20
|
Pang B, Winn D, Johnson R, Hong W, West-Barnette S, Kock N, Swords WE. Lipooligosaccharides containing phosphorylcholine delay pulmonary clearance of nontypeable Haemophilus influenzae. Infect Immun 2008; 76:2037-43. [PMID: 18347044 PMCID: PMC2346676 DOI: 10.1128/iai.01716-07] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 01/25/2008] [Accepted: 03/06/2008] [Indexed: 11/20/2022] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi) causes pulmonary infections in patients with chronic obstructive pulmonary disease and other mucociliary clearance defects. Like many bacteria inhabiting mucosal surfaces, NTHi produces lipooligosaccharide (LOS) endotoxins that lack the O side chain. Persistent NTHi populations express a discrete subset of LOS glycoforms, including those containing phosphorylcholine (PCho). In this study, we compared two NTHi strains with isogenic mutants lacking PCho for clearance from mice following pulmonary infection. Consistent with data from other model systems, populations of the strains NTHi 2019 and NTHi 86-028NP recovered from mouse lung contained an increased proportion of PCho+ variants compared to that in the inocula. PCho- mutants were more rapidly cleared. Serial passage of NTHi increased both PCho content and bacterial resistance to clearance, and no such increases were observed for PCho- mutants. Increased PCho content was also observed in NTHi populations within non-endotoxin-responsive C3H/HeJ and Toll-like receptor 4 null (TLR4-/-) mice, albeit at later times postinfection. Changes in bacterial subpopulations and clearance were unaffected in TLR2-/- mice compared to the subpopulations in and clearance from mice of the parental strain. The clearance of PCho- mutants occurred at earlier time points in both strain backgrounds and in all types of mice. Comparison of bacterial populations in lung tissue cryosections by immunofluorescent staining showed sparse bacteria within the air spaces of C57BL/6 mice and large bacterial aggregates within the lungs of MyD88-/- mice. These results indicate that PCho promotes bacterial resistance to pulmonary clearance early in infection in a manner that is at least partially independent of the TLR4 pathway.
Collapse
Affiliation(s)
- Bing Pang
- Department of Microbiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
| | | | | | | | | | | | | |
Collapse
|
21
|
Nomura Y, Abe Y, Ishida Y, Kobayashi H, Harabuchi Y. Promiscuous peptides on the nontypeable Haemophilus influenzae P6 outer membrane protein. J Clin Immunol 2008; 28:361-9. [PMID: 18379862 DOI: 10.1007/s10875-008-9189-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Accepted: 02/15/2008] [Indexed: 01/27/2023]
Abstract
INTRODUCTION P6 outer membrane protein is one of the candidates for a vaccine formulation against nontypeable Haemophilus influenzae (NTHi) infection. As otitis-prone children who have recurrent episodes of acute otitis media because of NTHi show an impaired immune response to P6, an innovative approach to vaccination is required to augment their immune response. RESULTS AND DISCUSSION We previously identified human HLA-DR9-restricted T cell epitope peptide and highly immunogenic analog peptides on P6 for peptide vaccine candidates. To develop a vaccine formulation effective in the general population, we identified promiscuous T cell epitope peptides (p41-55, p71-85) on P6. In addition to stimulating with potentially promiscuous peptides (p30-44, p45-59) selected using a computer algorithm, we established peptide-specific T cell lines which respond to P6. CONCLUSION Our present results indicate that these peptides would be candidates for a widely applicable peptide vaccine formulation.
Collapse
Affiliation(s)
- Yuka Nomura
- Department of Otolaryngology-Head and Neck Surgery, Asahikawa Medical College, Midorigaoka E2-1-1-1, Asahikawa, Hokkaido 078-8510, Japan
| | | | | | | | | |
Collapse
|
22
|
Holyoak GR, Smith CM, Boyette R, Montelongo M, Wray JH, Ayalew S, Duggan VE, Confer AW. Serum antibodies in mares and foals to Actinobacillus equuli whole cells, outer membrane proteins, and Aqx toxin. Vet Immunol Immunopathol 2007; 118:310-6. [PMID: 17604847 DOI: 10.1016/j.vetimm.2007.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 04/24/2007] [Accepted: 05/30/2007] [Indexed: 11/28/2022]
Abstract
Actinobacillus equuli is carried in the alimentary tract of mares and can cause severe septicemia of neonatal foals. A hemolytic subspecies, A. equuli subsp. haemolyticus, and a non-hemolytic subspecies, A. equuli subsp. equuli, have been identified. Hemolytic strains produce the RTX toxin Aqx. The purpose of this study was to demonstrate sequentially in two sets of mare-foal pairs antibodies to A. equuli whole bacterial cells, outer membrane proteins, and recombinant Aqx and to compare the transfer of antibodies to these antigens between mares and their foals. Two mare/foal sets of sera were evaluated. Cohort A consisted of 18 mare-foal pairs obtained in the spring of 2005. Cohort B consisted of 10 mare-foal pairs obtained in the spring of 2006. For both sets, mare and foal sera were obtained immediately after foaling and prior to nursing (time 0) as well as at 12 and 24h and daily thereafter for 7 days. For Cohort B, sera were also obtained 30 days after birth. At parturition all mares had detectable antibodies to A. equuli whole cells and outer membranes; however, of those mares, two in Cohort A had undetectable antibodies to Aqx and their foals likewise had undetectable anti-Aqx antibodies. Antibodies against whole cells, outer membrane proteins, and Aqx were readily transferred from mares to foals. In most cases, there were significant correlations (p<0.05) between antibodies against whole cells, outer membrane proteins, and Aqx in mares' sera at the time of parturition and foal sera 24 after birth. Antibodies against the three antigen preparations had declined insignificantly (p>0.05) by day 30.
Collapse
Affiliation(s)
- G R Holyoak
- Department of Veterinary Clinical Sciences, Boren Veterinary Medical Teaching Hospital, Oklahoma State University, Center for Veterinary Health Sciences, Stillwater, OK 74078, USA
| | | | | | | | | | | | | | | |
Collapse
|