scholarly journals Protective immunity to heartwater (Cowdria ruminantium infection) is acquired after vaccination with in vitro-attenuated rickettsiae.

1991 ◽  
Vol 59 (2) ◽  
pp. 729-731 ◽  
Author(s):  
F Jongejan
Keyword(s):  
Protective Immunity ◽  
Cowdria Ruminantium

scholarly journals The avian haemophili.

1989 ◽  
Vol 2 (3) ◽  
pp. 270-277 ◽  
Author(s):  
P J Blackall
Keyword(s):  
Causative Agent ◽  
Protective Immunity ◽  
In Vitro Growth ◽  
Phenotypic Properties ◽  
Infectious Coryza ◽  
The Common ◽  
Recent Attention

There are four currently recognized taxa to accommodate the avian haemophili: Haemophilus paragallinarum, Pasteurella avium, Pasteurella volantium, and Pasteurella species A (the last three being formerly united as Haemophilus avium). A range of other taxa has also been recognized, but they have been neither named nor assigned to a genus. All of these various taxa, legitimate and otherwise, have the common characteristic of requiring V factor, but not X factor, for in vitro growth. Several recent studies have established the phenotypic properties that allow the differentiation of the recognized taxa, both named and unnamed. The serological properties of H. paragallinarum, the causative agent of infectious coryza of chickens, has received considerable recent attention. In contrast, many questions on the pathogenicity and virulence mechanisms of H. paragallinarum remain unanswered. Another area requiring further work is the identification of those antigens responsible for inducing protective immunity in vaccinated or naturally infected chickens.

scholarly journals Expression d’interleukine 6 après infection par Cowdria ruminantium de cellules endothéliales de cerveau bovin

1993 ◽  
Vol 46 (1-2) ◽  
pp. 195-195
Author(s):  
Albert Bensaïd ◽  
S. Bourdoulous ◽  
D. Lerhun ◽  
D. Calvez ◽  
L. Droogman ◽  
...  
Keyword(s):  
Cowdria Ruminantium ◽  
Phase Aiguë ◽  
Cellules T

Les interleukines sont des médiateurs protéiques solubles qui peuvent déclencher une activation cellulaire. D’abord impliquée dans l’activation des cellules T dans la production d’immunoglobulines par les cellules B, l’interleukine 6 (IL6) provoque aussi l’induction de protéines de la phase aiguë par les hépatocytes. Ainsi, l’IL6 est impliquée dans les processus inflammatoires qui sont en grande partie responsables de la pathogénie de la cowdriose. Originellement produit par des macrophages et des cellules endothéliales activées, l’IL6 agit comme un stimulant de la réponse immunitaire. Néanmoins, quand elle est produite constamment et en grandes quantités, l’IL6 provoque des réactions inflammatoires non contrôlées. Afin de tester si l’IL6 est impliquée dans la cowdriose, une culture primaire de cellules endothéliales de cerveau bovin (BBEC) a été infectée in vitro par C. ruminantium. Les cellules infectées ont été récoltées tous les jours et ce jusqu’au sixième jour où toutes les cellules sont lysées. La même expérience a été effectuée sur des BBEC qui ont été simultanément infectées et traitées avec de l’INFγ. De l’ARN a été purifié à partir de ces cellules et après électrophorèse sur gel d’agarose transféré sur un filtre de nylon. Ce filtre a été sondé avec un ADNc radiomarqué codant pour l’IL6 bovine. Des signaux à 1 kb ont été détectés seulement sur les ARN de cellules après le quatrième jour de l’infection, que celles-ci aient été traitées ou non par l’INFγ. Tous les autres échantillons, incluant l’ARN de cellules qui n’ont pas été infectées mais traitées à l’INFγ, se sont révélés négatifs pour l’expression d’IL6. Ainsi, après infection par C. ruminantium, l’expression d’IL6 est induite peu avant que l’effet cytopathogène n’apparaisse. A l’heure actuelle, des surnageants de milieu de culture de ces cellules sont testés pour leur capacité à induire des réponses prolifératives des cellules T.

scholarly journals Une étude in vitro du cycle de vie de Cowdria ruminantium

1993 ◽  
Vol 46 (1-2) ◽  
pp. 247-247
Author(s):  
L. Prozesky ◽  
A. Hart ◽  
M.S. Brett
Keyword(s):  
Post Inoculation ◽  
Cowdria Ruminantium ◽  
Cycle De Vie

Le cycle de vie de Cowdria ruminantium a été étudié dans des cellules SBE 189 par microscopie classique et électronique. Des cultures ont été infectées avec un inoculum synchronisé et fixées et préparées entre 15 min et 111 h post-inoculation (PI). Après 12 h, de grands corps réticulaires seuls ou en petits groupes ont été identifiés dans des vacuoles intracytoplasmatiques entourées de membranes. Ils se développaient graduellement dans des corps réticulaires plus petits avec une structure interne plus granuleuse. De 66 à 75 h PI, il y avait une augmentation importante de la taille des colonies. La plupart des colonies contenaient des corps réticulaires, bien que quelques corps intermédiaires et opaques aux électrons aient été visibles. Des corps réticulaires solitaires extracellulaires avec une couche ressemblant au peptidoglycan ont été observés 84 h PI. Après 90 h, des corps intermédiaires et opaques aux électrons fussent présents en abondance et cela coïncidait avec la lyse des cellules de culture. Le cycle de développement de Cowdria ruminantium durait donc environ 4 jours, dans cette étude.

scholarly journals Le développement d’anticorps contre Cowdria ruminantium chez la souris et leur rôle dans la cowdriose

1993 ◽  
Vol 46 (1-2) ◽  
pp. 197-201
Author(s):  
B. Byrom ◽  
Suman M. Mahan ◽  
Anthony F. Barbet
Keyword(s):  
Cowdria Ruminantium

Les réponses immunitaires contre Cowdria ruminantium ont été étudiées en utilisant des souris DBA/2 et Balb/c comme modèle. Les deux souches de souris ont été inoculées avec 1, 10 ou 100 DL50 de C. ruminantium (stock Crystal Springs). Des anticorps contre C. ruminantium ont commencé à se développer dans la deuxième semaine après l'inoculation et le titre d'anticorps dépendait de la dose de C. ruminantium inoculée. Le rôle possible des anticorps sur la maladie a été recherché au moyen des tests de neutralisation in vitro, utilisant des sérums de souris et de bovins. Les résultats ont montré que les sérums hyperimmuns des souris DBA/2 et Balb/c étaient capables de neutraliser l'infection in vitro, celui des souris DBA/2 montrant l'effet neutralisant le plus fort. Deux sérums de bovins, l'un d'un animal infecté au laboratoire et l'autre provenant d'un mélange de sérums de deux animaux infectés naturellement, ont également montré un effet neutralisant.

scholarly journals In vitro mycobacterial growth inhibition assays: A tool for the assessment of protective immunity and evaluation of tuberculosis vaccine efficacy

Vaccine ◽  
2016 ◽  
Vol 34 (39) ◽  
pp. 4656-4665 ◽  
Author(s):  
Rachel Tanner ◽  
Matthew K. O’Shea ◽  
Helen A. Fletcher ◽  
Helen McShane
Keyword(s):  
Growth Inhibition ◽  
Vaccine Efficacy ◽  
Protective Immunity ◽  
Mycobacterial Growth

The carboxy-terminus of merozoite surface protein 1: structure, specific antibodies and immunity to malaria

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1445-1456 ◽  
Author(s):  
A. A. HOLDER
Keyword(s):  
Protective Immunity ◽  
First Generation ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Carboxy Terminus ◽  
Vaccine Candidates ◽  
Merozoite Surface Protein 1 ◽  
Early Results ◽  
Experimental Approaches

SUMMARYOver the last 30 years, evidence has been gathered suggesting that merozoite surface protein 1 (MSP1) is a target of protective immunity against malaria. In a variety of experimental approaches usingin vitromethodology, animal models and sero-epidemiological techniques, the importance of antibody against MSP1 has been established but we are still finding out what are the mechanisms involved. Now that clinical trials of MSP1 vaccines are underway and the early results have been disappointing, it is increasingly clear that we need to know more about the mechanisms of immunity, because a better understanding will highlight the limitations of our current assays and identify the improvements required. Understanding the structure of MSP1 will help us design and engineer better antigens that are more effective than the first generation of vaccine candidates. This review is focused on the carboxy-terminus of MSP1.

scholarly journals A Universal Dengue Vaccine Elicits Neutralizing Antibodies Against Strains from All Four Dengue Serotypes

2020 ◽  
Author(s):  
Naoko Uno ◽  
Ted M. Ross
Keyword(s):  
Dengue Virus ◽  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Rhesus Macaques ◽  
Effective Vaccine ◽  
Wild Type ◽  
Monovalent Vaccine ◽  
Viral Particles ◽  
Tropical Areas

Any potential dengue virus (DENV) vaccine needs to elicit protective immunity against strains from all four serotypes to avoid potential antibody dependent enhancement (ADE). In this study, four independent DENV envelope (E) glycoproteins were generated using wild-type E sequences from viruses isolated between 1943 to 2006 using computationally-optimized broadly reactive antigen (COBRA) methodology. COBRA and wild-type E antigens were expressed on the surface of subvirion viral particles (SVPs). Four separate wild-type E antigens were used for each serotype. Mice vaccinated with wild-type DENV SVPs had anti-E IgG antibodies that neutralized serotype specific viruses. COBRA DENV SVPs elicited a broader breadth of antibodies that neutralized strains across all four serotypes. Two COBRA DENV vaccine candidates that elicited the broadest breadth of neutralizing antibodies in mice were used to vaccinate rhesus macaques (Macca mulata) that were either immunologically naïve to any DENV serotype or were had pre-existing antibodies to DENV. Antibodies elicited by COBRA DENV E immunogens neutralized all 12 strains of DENV in vitro, which was comparable to antibodies elicited by a tetravalent wild-type E SVP vaccination mixture. Therefore, using a single DENV COBRA E protein can elicit neutralizing antibodies against strains representing all four serotypes of DENV in both naïve and dengue pre-immune populations. Importance Dengue virus infects millions of people living in the tropical areas of the world. Dengue induced diseases can range from mild to severe with death. An effective vaccine will need to neutralize viruses from all four serotypes of dengue without induced enhanced disease. A dengue E vaccine candidate generated by computationally optimized broadly reactive antigen algorithms elicits broadly neutralizing protection for current circulating strains from all four serotypes regardless of immune status. Most Dengue vaccines in development formulate four separate components based on prM-E from a wild type strain representing each serotype. Designing a monovalent vaccine that elicits protective immunity against all four serotypes is an effective and economical strategy

scholarly journals Influences of Glycosylation on Antigenicity, Immunogenicity, and Protective Efficacy of Ebola Virus GP DNA Vaccines

2006 ◽  
Vol 81 (4) ◽  
pp. 1821-1837 ◽  
Author(s):  
William Dowling ◽  
Elizabeth Thompson ◽  
Catherine Badger ◽  
Jenny L. Mellquist ◽  
Aura R. Garrison ◽  
...  
Keyword(s):  
T Cell ◽  
Protective Immunity ◽  
Ebola Virus ◽  
Dna Vaccines ◽  
Protective Efficacy ◽  
T Cell Epitopes ◽  
Glycosylation Sites ◽  
Membrane Bound ◽  
Antibody Epitopes

ABSTRACT The Ebola virus (EBOV) envelope glycoprotein (GP) is the primary target of protective immunity. Mature GP consists of two disulfide-linked subunits, GP1 and membrane-bound GP2. GP is highly glycosylated with both N- and O-linked carbohydrates. We measured the influences of GP glycosylation on antigenicity, immunogenicity, and protection by testing DNA vaccines comprised of GP genes with deleted N-linked glycosylation sites or with deletions in the central hypervariable mucin region. We showed that mutation of one of the two N-linked GP2 glycosylation sites was highly detrimental to the antigenicity and immunogenicity of GP. Our data indicate that this is likely due to the inability of GP2 and GP1 to dimerize at the cell surface and suggest that glycosylation at this site is required for achieving the conformational integrity of GP2 and GP1. In contrast, mutation of two N-linked sites on GP1, which flank previously defined protective antibody epitopes on GP, may enhance immunogenicity, possibly by unmasking epitopes. We further showed that although deleting the mucin region apparently had no effect on antigenicity in vitro, it negatively impacted the elicitation of protective immunity in mice. In addition, we confirmed the presence of previously identified B-cell and T-cell epitopes in GP but show that when analyzed individually none of them were neither absolutely required nor sufficient for protective immunity to EBOV. Finally, we identified other potential regions of GP that may contain relevant antibody or T-cell epitopes.

scholarly journals Human-human hybridomas secreting monoclonal antibodies to the Mr 195,000 Plasmodium falciparum blood stage antigen.

1986 ◽  
Vol 163 (1) ◽  
pp. 179-188 ◽  
Author(s):  
R Schmidt-Ullrich ◽  
J Brown ◽  
H Whittle ◽  
P S Lin
Keyword(s):  
Plasmodium Falciparum ◽  
Growth Inhibition ◽  
Protective Immunity ◽  
Lymphoblastoid Cell Line ◽  
In Vitro Growth ◽  
Human Lymphoblastoid Cell ◽  
Immune Precipitation ◽  
Human Lymphoblastoid Cell Line ◽  
Donor Lymphocytes

Using the human lymphoblastoid cell line, GM 4672, and PBL of Gambian adults immune to Plasmodium falciparum (Pf) malaria, we have produced human-human hybridomas and selected those that produce mAb against Pf antigens. The fusion frequency, using PWM-stimulated donor lymphocytes was between 6.8 X 10(-5) and 1.5 X 10(-6). Using immune fluorescence, immune precipitation, and Pf in vitro growth inhibition, we cloned four hybridomas that reacted with the Pf Mr 195,000 schizont/merozoite protein. The differences in proteins immune precipitated and in growth inhibition indicate that, during development of protective immunity against Pf malaria, a spectrum of antibodies is produced reacting with different epitopes on the same antigen. Only a portion of these antibodies exhibits biological activity, suggesting that the recognition of certain epitopes is required for the development of a protective immune response.

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