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Jallow S, Cutland CL, Masbou AK, Adrian P, Madhi SA. Maternal HIV infection associated with reduced transplacental transfer of measles antibodies and increased susceptibility to disease. J Clin Virol 2017; 94:50-56. [PMID: 28759772 DOI: 10.1016/j.jcv.2017.07.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/08/2017] [Accepted: 07/16/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Transplacental transfer of measles antibodies from mother to fetus is important in protecting against measles during early infancy. Changes in population immunity against measles in adults, including waning of immunity among HIV-infected pregnant women, could affect passive immunity acquired in utero by newborns. OBJECTIVES To evaluate the effect of maternal HIV infection on transplacental transfer of measles antibody in mother-newborn dyads in a setting of high maternal HIV prevalence. STUDY DESIGN Serum at birth was obtained from 303 mother-newborn dyads, including 196 HIV-infected and 107 HIV-uninfected women, and tested for measles IgG antibodies by ELISA. Seronegativity was defined as antibody levels <150mIU/ml and seroprotective titers as ≥330mIU/ml. RESULTS HIV-infected and -uninfected women had similar measles antibody titers, however, cord-blood titers were lower among HIV-exposed (788.06mIU/ml) compared to HIV- unexposed newborns (1306.6mIU/ml; p≤0.001), due to lower transplacental antibody transfer ratio in HIV-exposed (0.63) than in HIV-unexposed newborns (0.97; p≤0.001). Maternal age <25years of age was associated with lower antibody titers and lower percentage with seroprotective titer, as well as less likelihood of their newborns having seroprotective titers (70.2% vs. 86.5%; p=0.001). CONCLUSIONS Lower levels of measles antibody in HIV-exposed newborns and in younger women <25years old, increases the susceptibility of their newborns to developing measles. This suggest a need to re-evaluate measles immunization of women of child bearing age and the timing of measles vaccination among infants in settings with a high prevalence of maternal HIV-infection.
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Affiliation(s)
- Sabelle Jallow
- Respiratory and Meningeal Pathogens Unit, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa; Centre for Vaccines and Immunology, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.
| | - Clare L Cutland
- Respiratory and Meningeal Pathogens Unit, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | | | - Peter Adrian
- Respiratory and Meningeal Pathogens Unit, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | - Shabir A Madhi
- Respiratory and Meningeal Pathogens Unit, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa; Centre for Vaccines and Immunology, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
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Noh Y, Shim BS, Cheon IS, Rho S, Kim HJ, Choi Y, Kang CY, Chang J, Song MK, Kim JO. Neonatal immunization with respiratory syncytial virus glycoprotein fragment induces protective immunity in the presence of maternal antibodies in mice. Viral Immunol 2013; 26:268-76. [PMID: 23869549 DOI: 10.1089/vim.2012.0087] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infections in infants and the elderly worldwide. The significant morbidity and mortality associated with this infection underscores the urgent need for development of RSV vaccine. In this study, we first show that intranasal administration of RSV glycoprotein core fragment (Gcf) to neonatal mice can induce systemic humoral immune responses and protective immunity against RSV without causing lung eosinophilia, although antibody response was shifted to a Th2 response. Next, we examined whether the presence of maternal anti-RSV antibodies would affect the responsiveness and protection efficacy of Gcf in newborn mice, since infants can possess RSV-specific maternal antibodies due to frequent RSV re-infections to adults. Intranasal administration of Gcf induced antibody response and increased IFNγ secretion and protected mice against RSV challenge without severe lung eosinophilia, even in the presence of high levels of RSV-specific maternal antibodies. Thus, our findings suggest that Gcf may be an effective and safe RSV vaccine during the neonatal period.
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Affiliation(s)
- Youran Noh
- Laboratory Science Division , International Vaccine Institute, Seoul, Korea
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3
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Chan PKS, Lee N, Zaman M, Adisasmito W, Coker R, Hanshaoworakul W, Gasimov V, Oner AF, Dogan N, Tsang O, Phommasack B, Touch S, Bamgboye E, Swenson A, Toovey S, Dreyer NA. Determinants of antiviral effectiveness in influenza virus A subtype H5N1. J Infect Dis 2012; 206:1359-66. [PMID: 22927451 DOI: 10.1093/infdis/jis509] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Oseltamivir is widely used as treatment for influenza virus A subtype H5N1 (hereafter, "H5N1") infection but, like any intervention, is not always effective. METHODS We used Avian Influenza Registry data from 10 countries to examine the risk of death in 215 patients with confirmed H5N1 infection who were treated with oseltamivir, according to viral clade, age, respiratory failure, and adjunctive treatment with corticosteroids or antibiotics. RESULTS The median age of infected individuals was 18 years, and 50% were male. The highest fatality rate occurred in a country with clade 2.1 virus circulation, and the lowest occurred in countries with clade 2.2 virus circulation (P < .001). In univariate analyses, age of ≤5 years and treatment ≤2 days after symptom onset were protective against fatality. When accounting for all risk factors, early initiation of oseltamivir was found to be particularly effective in individuals without respiratory failure (odds ratio, 0.17; P = .04). Patients who had advanced respiratory failure requiring ventilatory support at the time of oseltamivir initiation were more likely to die from the episode of H5N1 infection than patients who did not (P < .001). Adjunctive therapy did not improve the likelihood of surviving the episode. CONCLUSIONS Oseltamivir is especially effective for treating H5N1 infection when given early and before onset of respiratory failure. The effect of viral clade on fatality and treatment response deserves further investigation.
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Affiliation(s)
- Paul K S Chan
- Faculty of Medicine, Chinese University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
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Abstract
Vaccines for early-life immunization are a crucial biomedical intervention to reduce global morbidity and mortality, yet their developmental path has been largely ad hoc, empiric, and inconsistent. Immune responses of human newborns and infants are distinct and cannot be predicted from those of human adults or animal models. Therefore, understanding and modeling age-specific human immune responses will be vital to the rational design and development of safe and effective vaccines for newborns and infants.
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5
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Immunization and challenge experiments with a new modified live bovine herpesvirus type 1 marker vaccine prototype adjuvanted with a co-polymer. Vaccine 2010; 28:5871-7. [DOI: 10.1016/j.vaccine.2010.06.057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 06/16/2010] [Accepted: 06/16/2010] [Indexed: 11/22/2022]
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6
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Skerry CM, Cassidy JP, English K, Feunou-Feunou P, Locht C, Mahon BP. A live attenuated Bordetella pertussis candidate vaccine does not cause disseminating infection in gamma interferon receptor knockout mice. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2009; 16:1344-51. [PMID: 19625486 PMCID: PMC2745004 DOI: 10.1128/cvi.00082-09] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Revised: 05/04/2009] [Accepted: 06/29/2009] [Indexed: 11/20/2022]
Abstract
Bordetella pertussis is the cause of whooping cough and responsible for 300,000 infant deaths per annum. Current vaccines require 6 months to confer optimal immunity on infants, the population at highest risk. Recently, an attenuated strain of B. pertussis (BPZE1) has been developed to be used as a low-cost, live, intranasal, single-dose vaccine for newborns. Preclinical proof of concept has been established; however, it is necessary to evaluate the safety of BPZE1, especially in immunodeficient models, prior to human clinical trials. Here, the preclinical safety of BPZE1 was examined in well-characterized murine models. Immunocompetent and gamma interferon (IFN-gamma) receptor knockout mice were challenged by aerosol with either virulent B. pertussis or BPZE1. The two strains colonized the lung at equal levels, but inflammation was associated with carriage of only virulent bacteria. Virulent bacteria disseminated to the liver of IFN-gamma receptor-deficient mice, resulting in atypical pathology. In contrast, attenuated BPZE1 did not disseminate in either immunocompetent or immunodeficient mice and did not induce atypical pathology. In neonatal challenge models, virulent B. pertussis infection resulted in significant mortality of both immunodeficient and immunocompetent mice, whereas no mortality was observed for any neonatal mice challenged with BPZE1. BPZE1 was shown to elicit strong IFN-gamma responses in mice, equivalent to those elicited by the virulent streptomycin-resistant B. pertussis Tohama I derivative BPSM, also inducing immunoglobulin G2a, a process requiring TH1 cytokines in mice. These data indicate that a live attenuated whooping cough vaccine candidate shows no signs of disseminating infection in preclinical models but rather evokes an immunological profile associated with optimal protection against disease.
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Affiliation(s)
- Ciaran M Skerry
- Institute of Immunology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
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7
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Sacco RE. DNA vaccines against infectious agents: recent strategies for enhancing immune responses. Expert Opin Ther Pat 2008. [DOI: 10.1517/13543776.18.4.365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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8
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Jónsdóttir I. Maturation of Mucosal Immune Responses and Influence of Maternal Antibodies. J Comp Pathol 2007; 137 Suppl 1:S20-6. [PMID: 17559864 DOI: 10.1016/j.jcpa.2007.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The mucosae represent the primary point of contact between the major respiratory and enteric pathogens and the innate and adaptive immune response. The microanatomy and function of the mucosal immune system is now well-characterized, in particular the major effector mechanism that involves the production and translocation of secretory immunoglobulin A (IgA). Mucosal delivery of antigen has the potential to induce potent local and systemic immunity, although such responses may differ between neonatal, infant and adult mice. In younger animals mucosal immune responses are Th2 biased, whereas in adults there is a broader Th1 and Th2 responsiveness. There is much interest in the development of mucosally delivered vaccines which can be tailored to enhance Th1 immunity or to avoid potential interference from maternally derived antibodies (MDA). Accordingly, a range of mucosal adjuvants (particularly those derived from bacteria) has been tested, and live recombinant vectored vaccines may also be effectively delivered by this route.
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Affiliation(s)
- I Jónsdóttir
- Department of Immunology, Landspitali University Hospital, University of Iceland and de CODE genetics, Hringbraut, 101 Reykjavík, Iceland.
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9
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Silber JL, Chan ISF, Wang WW, Matthews H, Kuter BJ. Immunogenicity of Oka/Merck varicella vaccine in children vaccinated at 12-14 months of age versus 15-23 months of age. Pediatr Infect Dis J 2007; 26:572-6. [PMID: 17596796 DOI: 10.1097/inf.0b013e318060d33d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Recent reports suggest that breakthrough varicella may be more common in children when the Oka/Merck varicella vaccine is given at 12-14 months of age than when it is given at older ages. An analysis of 5 postlicensure clinical trials with this vaccine was conducted to evaluate immune response relative to the age of the vaccine recipient. METHODS In 5 clinical trials, 3771 children, 12 through 23 months of age with no history of varicella, received an injection of varicella vaccine. Varicella-zoster virus (VZV) antibody was measured 6 weeks postvaccination by glycoprotein enzyme-linked immunosorbent assay (gpELISA), an assay that correlates with neutralizing antibody. Endpoints evaluated were the response rate (percent of subjects with VZV antibody > or =5 gpELISA units/mL, a titer shown to correlate with protection) and geometric mean titer (GMT) of VZV antibody. Each endpoint was compared across 3 age groups (12-14, 15-17, and 18-23 months of age). Response rates by initial VZV serostatus were evaluated for children vaccinated at 12-14 months of age to assess whether maternal antibody had an impact on the immune response. RESULTS The response rates were similar among 12-14, 15-17, and 18-23 month olds (93.8, 90.8, and 93.1%, respectively); GMTs were significantly higher among the 12-14 month olds (15.1, 13.5, and 13.7 gpELISA units/mL, respectively). Among children 12-14 months of age, response rates and GMTs were similar regardless of their prevaccination VZV serostatus. CONCLUSIONS Oka/Merck varicella vaccine is highly immunogenic when given to children 12-14 months of age. The immunogenicity profile is similar to that of children 15-17 and 18-23 months of age. The presence of low titers of VZV antibody before vaccination did not influence vaccine response in 12-14 month olds. These results support current recommendations for universal varicella vaccination beginning at 12 months of age.
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van Drunen Littel-van den Hurk S, Mapletoft JW, Arsic N, Kovacs-Nolan J. Immunopathology of RSV infection: prospects for developing vaccines without this complication. Rev Med Virol 2007; 17:5-34. [PMID: 17004293 DOI: 10.1002/rmv.518] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Respiratory syncytial virus is the most important cause of lower respiratory tract infection in infants and young children. RSV clinical disease varies from rhinitis and otitis media to bronchiolitis and pneumonia. An increased incidence of asthma later in life has been associated with the more severe lower respiratory tract infections. Despite its importance as a pathogen, there is no licensed vaccine against RSV. This is due to a number of factors complicating the development of an effective and safe vaccine. The immunity to natural RSV infection is incomplete as re-infections occur in all age groups, which makes it challenging to design a protective vaccine. Second, the primary target population is the newborn infant, which has a relatively immature immune system and maternal antibodies that can interfere with vaccination. Finally, some vaccines have resulted in a predisposition for exacerbated pulmonary disease in infants, which was attributed to an imbalanced Th2-biased immune response, although the exact cause has not been elucidated. This makes it difficult to proceed with vaccine testing in infants. It is likely that an effective and safe vaccine needs to elicit a balanced immune response, including RSV-specific neutralising antibodies, CD8 T-cells, Th1/Th2 CD4 T-cells and preferably secretory IgA. Subunit vaccines formulated with appropriate adjuvants may be adequate for previously exposed individuals. However, intranasally delivered genetically engineered attenuated or vectored vaccines are currently most promising for newborns, as they are expected to induce a balanced immune response similar to that elicited to natural infection and not be subject to interference from maternal antibodies. Maternal vaccination may be the optimal strategy to protect the very young infants.
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MESH Headings
- Adult
- Animals
- Antibody Formation
- Child, Preschool
- Female
- Humans
- Immunity, Active
- Immunity, Cellular
- Immunity, Innate
- Immunity, Maternally-Acquired
- Infant
- Infant, Newborn
- Pregnancy
- Respiratory Syncytial Virus Infections/immunology
- Respiratory Syncytial Virus Infections/prevention & control
- Respiratory Syncytial Virus Vaccines/administration & dosage
- Respiratory Syncytial Virus Vaccines/adverse effects
- Respiratory Syncytial Virus Vaccines/immunology
- Respiratory Syncytial Virus, Human/immunology
- Vaccination/methods
- Vaccination/trends
- Vaccines, Subunit/administration & dosage
- Vaccines, Subunit/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/immunology
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Zimmerman AD, Boots RE, Valli JL, Chase CCL. Evaluation of protection against virulent bovine viral diarrhea virus type 2 in calves that had maternal antibodies and were vaccinated with a modified-live vaccine. J Am Vet Med Assoc 2006; 228:1757-61. [PMID: 16740078 DOI: 10.2460/javma.228.11.1757] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the efficacy of an adjuvanted modified-live bovine viral diarrhea virus (BVDV) vaccine against challenge with a virulent type 2 BVDV strain in calves with or without maternal antibodies against the virus. DESIGN Challenge study. ANIMALS 23 crossbred dairy calves. PROCEDURES Calves were fed colostrum containing antibodies against BVDV or colostrum without anti-BVDV antibodies within 6 hours of birth and again 8 to 12 hours after the first feeding. Calves were vaccinated with a commercial modified-live virus combination vaccine or a sham vaccine at approximately 5 weeks of age and challenged with virulent type 2 BVDV 3.5 months after vaccination. Clinical signs of BVDV infection, development of viremia, and variation in WBC counts were recorded for 14 days after challenge exposure. RESULTS Calves that received colostrum free of anti-BVDV antibodies and were vaccinated with the sham vaccine developed severe disease (4 of the 7 calves died or were euthanatized). Calves that received colostrum free of anti-BVDV antibodies and were vaccinated and calves that received colostrum with anti-BVDV antibodies and were vaccinated developed only mild or no clinical signs of disease. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the modified-live virus vaccine induced a strong protective immune response in young calves, even when plasma concentrations of maternal antibody were high. In addition, all vaccinated calves were protected against viral shedding, whereas control calves vaccinated with the sham vaccine shed virus for an extended period of time.
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12
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Jaspan HB, Lawn SD, Safrit JT, Bekker LG. The maturing immune system: implications for development and testing HIV-1 vaccines for children and adolescents. AIDS 2006; 20:483-94. [PMID: 16470112 DOI: 10.1097/01.aids.0000210602.40267.60] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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13
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Yang YW, Wei AC, Shen SS. The immunogenicity-enhancing effect of emulsion vaccine adjuvants is independent of the dispersion type and antigen release rate--a revisit of the role of the hydrophile-lipophile balance (HLB) value. Vaccine 2005; 23:2665-75. [PMID: 15780450 DOI: 10.1016/j.vaccine.2004.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2004] [Accepted: 09/07/2004] [Indexed: 10/26/2022]
Abstract
Effective antigen delivery is one of the most important issues in vaccine development. It has been suggested that adjuvant action results from a depot effect by prolonging the duration of the interaction between antigen and cells, and thus is related to the antigen-releasing properties of emulsion adjuvants. The objective of this study was to investigate the effect of the dispersion properties of emulsion-type vaccine adjuvants on the immune response with the aim of optimizing vaccine adjuvant formulation. Emulsion-type adjuvants with various dispersion properties of either the oil-in-water or water-in-oil type were prepared using emulsifiers with various hydrophilic-hydrophobic balance (HLB) values. The physicochemical properties of the emulsions, including the conductivity and viscosity, and antigen release rates were then determined. Cell death induced by the vaccine adjuvants was examined in EL4 cells by Annexin V/propidium iodide (PI) staining and flow cytometric analysis. Mice were immunized with or without the adjuvants and the immunogenicity-enhancing effect of the adjuvants determined by measuring antibody production using an enzyme linked immunosorbent assay. The conductivity, viscosity, and antigen release rates varied widely among emulsions containing emulsifiers with different HLB values. However, the magnitude of the antigen-specific antibody response was similar in most emulsions adjuvants containing Spans or Tweens. L121-adjuvant, the control adjuvant inducing the strongest apoptosis in vitro, was shown to stimulate the highest antibody response in vivo. The results obtained in this study indicate that the immunogenicity-enhancing effect of emulsion adjuvants is independent of the dispersion type and the antigen release rate of the vaccine delivery system.
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Affiliation(s)
- Ya-Wun Yang
- School of Pharmacy, College of Medicine, National Taiwan University, 1, Jen-Ai Road, Section , Taipei 100, Taiwan, ROC.
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Ennis DP, Cassidy JP, Mahon BP. Whole-cell pertussis vaccine protects against Bordetella pertussis exacerbation of allergic asthma. Immunol Lett 2005; 97:91-100. [PMID: 15626480 DOI: 10.1016/j.imlet.2004.10.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Revised: 10/01/2004] [Accepted: 10/04/2004] [Indexed: 12/11/2022]
Abstract
The prevalence of asthma and allergic disease has increased in many countries and there has been speculation that immunization promotes allergic sensitization. Bordetella pertussis infection exacerbates allergic asthmatic responses. We investigated whether whole-cell pertussis vaccine (Pw) enhanced or prevented B. pertussis induced exacerbation of allergic asthma. Groups of mice were immunized with Pw, infected with B. pertussis and/or sensitized to ovalbumin. Immunological, pathological and physiological changes were measured to assess the impact of Pw immunization on immune deviation and airway function. Pw immunization modulated ovalbumin-specific serum IgE production, and reduced local and systemic IL-13 and other cytokine responses to sensitizing allergen. Histopathological examination revealed Pw immunization reduced the severity of airway pathology and decreased bronchial hyperreactivity to methacholine exposure. Pw does not enhance airway IL-13 and consequently does not enhance but protects against the exacerbation of allergic responses. We find no evidence of Pw contributing to allergic asthma, but rather provide evidence of a mechanism whereby whole-cell pertussis vaccination has a protective role.
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Affiliation(s)
- Darren P Ennis
- Mucosal Immunology Laboratory, Institute of Immunology, NUI Maynooth, Ireland
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15
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Otero M, Calarota SA, Felber B, Laddy D, Pavlakis G, Boyer JD, Weiner DB. Resiquimod is a modest adjuvant for HIV-1 gag-based genetic immunization in a mouse model. Vaccine 2004; 22:1782-90. [PMID: 15068862 DOI: 10.1016/j.vaccine.2004.01.037] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA vaccines have been effective at generating useful immune responses in many animal species. However, it is clearly desirable to increase their potency. The identification of adjuvants that increase their cell-mediated immune (CMI) response is therefore an important goal. Resiquimod is an imiquimod analog proven to activate dendritic cells through TLR-7. The adjuvant capacity of resiquimod has not, to our knowledge, been studied in the context of genetic immunization. Here, we studied resiquimod as an adjuvant for plasmid vaccine therapy by intra-muscular immunization of BALB/c mice with HIV-1 gag DNA vaccine without and with several concentrations of resiquimod (ranging from 5-100nM). We observed that resiquimod moderately enhanced IFN-gamma production as measured by a peptide-based ELISPOT assay compared to that obtained in mice immunized with DNA gag only. Antigen-specific T-cell proliferation studies showed a several-fold increase in the stimulation index in mice immunized with DNA gag +50 nM of resiquimod as compared to mice receiving DNA gag alone. Antibody titer also increased, while the antibody isotyping data showed a strong Th1 biased type response. Analysis of cytokine production in serum samples demonstrated a stronger Th1 cytokine bias in the presence of resiquimod. Furthermore, relevant increase in IL-4 production, as measured by ELISPOT assay, was not observed. Our results show that resiquimod can have modest adjuvant activity, in a DNA formulation, driving the immune system towards a cell-mediated immune response. Additional studies involving this adjuvant for DNA vaccines are underway.
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Affiliation(s)
- Miguel Otero
- Department of Pathology, School of Medicine, University of Pennsylvania, 422 Curie Blvd., 505 Stellar-Chance Bldg., Philadelphia, PA 19104-6100, USA
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Lee KY, Chun E, Seong BL. Investigation of antigen delivery route in vivo and imune-boosting effects mediated by pH-sensitive liposomes encapsulated with K(b)-restricted CTL epitope. Biochem Biophys Res Commun 2002; 292:682-8. [PMID: 11922620 DOI: 10.1006/bbrc.2002.6711] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using fluorescein isothiocyanate (FITC)-conjugated H-2K(b) CTL epitope (SIINFEKL) as a model system, we investigated the antigen delivery route by pH-sensitive liposomes in vivo. Fluorescence was initially detected in lymph nodes at 3 h after immunization, and its intensity reached a peak value in superticial inguinal lymph node at 9 h. No trace could be detected in spleen even with prolonged monitoring for up to 24 h. These results strongly suggest that the presentation of CTL-peptide antigen vehicled by pH-sensitive liposomes exclusively occurs in lymph nodes. In mice immunized with the H-2K(b) CTL epitope encapsulated pH-sensitive liposomes, peptide-specific CTL response was detected at day 3. The response was strongly augmented by the second immunization and persisted up to at least 45 days. These results suggest that pH-sensitive liposome formula functions as a potential adjuvant of peptide antigens and is useful for the induction of antigen specific CTLsv in vivo.
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Affiliation(s)
- Ki-Young Lee
- Department of Biotechnology, College of Engineering and Bioproducts Research Center, Yonsei University, 134 Shinchon-Dong, Seodaemun-Gu, Seoul, 120-749, South Korea
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