Schistosoma mansoni: in vivoandin vitrostudies of immunity using the guinea-pig model

Parasitology ◽  
1983 ◽  
Vol 87 (3) ◽  
pp. 465-479 ◽  
Author(s):  
E. J. Pearce ◽  
Diane J. McLaren

SummaryIn vivoandin vitroparameters of immunity have been assessed in guinea-pigs sensitized with 500 normal or 500 radiation-attenuated cercariae ofSchistosoma mansoni. High levels of resistance to a challenge infection developed in both the chronic and irradiated vaccine model, but immunity was expressed earlier (week 4) and reached higher levels (90%) in the latter case. Vaccinated guinea-pigs have thus been shown to achieve greater resistance than the more commonly used rodent hosts.In vitrocytotoxicity assays have demonstrated that antibodies capable of participating in complement-dependent (lethal antibody) or eosinophil-mediated schistosomular killing, develop in the serum of guinea-pigs immunized with either normal or irradiated cercariae. The time course of development of the eosinophil adherence promoting antibody approximated in both models, the development of immunityin vivo, but the lethal antibody response paralleled the immune status of the animal only in the irradiated vaccine model

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.


2009 ◽  
Vol 58 (5) ◽  
pp. 648-655 ◽  
Author(s):  
Kristel Lourdault ◽  
Florence Aviat ◽  
Mathieu Picardeau

The dynamics of leptospirosis infection have been poorly studied. The purpose of this study was to determine the LD50, rate of bacterial dissemination, histopathology and antibody responses against leptospira following inoculation with the highly virulent Leptospira interrogans Fiocruz L1-130 strain in a guinea pig model of leptospirosis. Three routes of infection (intraperitoneal, conjunctival and subcutaneous inoculation) were used to establish disease in guinea pigs. The size and kinetics of leptospiral burdens in the blood and tissues of infected animals were determined over a 1 week course of infection using quantitative real-time PCR (qPCR). Bacteraemia peaked at day 5 post-infection reaching more than 5×104 leptospires ml−1. The highest spirochaetal load was found in the liver and kidneys, and was associated with alterations in organ tissues and a decline in liver and kidney functions. In contrast, lesions and bacteria were not detected in guinea pigs infected with an avirulent strain derived from a high-passage-number in vitro-passaged variant of the Fiocruz L1-130 strain. The use of qPCR supports the findings of earlier studies and provides an easy and reliable method for the quantification of L. interrogans in the tissues of infected animals. qPCR will be used in future studies to evaluate the efficacy of vaccine candidates against leptospirosis and the virulence of selected L. interrogans mutants relative to the parental strain.


Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 690-694 ◽  
Author(s):  
BH Becker ◽  
JL Miller

Abstract Previous studies in the guinea pig model system have established a close structural homology between human and guinea pig glycoproteins Ib (GPIb) and IIb/IIIa (GPIIb/IIIa). Moreover, the murine monoclonal antibody (MoAb) PG-1, which recognizes GPIb in guinea pig platelets and megakaryocytes, exerted full inhibition on von Willebrand factor (vWF)- dependent platelet agglutination without inhibiting aggregation induced by ADP, collagen, or thrombin. The present research extends this animal model system to study of the effects on hemostatic function following the in vivo injection of MoAb PG-1 or its F(ab')2 fragments. A hind limb template bleeding time methodology was developed for use in guinea pigs. Normal bleeding time was determined to be 2.7 +/- 0.5 minutes (mean +/- SD), with an observed range of two to four minutes. Platelet counts in these same animals were 501 +/- 82 x 10(3)/microL. After intraperitoneal (IP) injection of busulfan, guinea pigs became increasingly thrombocytopenic. As long as the platelet count remained above approximately 150 x 10(3)/microL, the bleeding time was not more than five minutes; however, further decrease in the platelet count was accompanied by more marked prolongations of the bleeding time. For 14 to 72 hours after IP injection of 1.3 mg/kg intact PG-1 MoAb, a hemorrhagic state was produced with a bleeding time greater than 20 minutes. The platelet count concurrently decreased to approximately 50% of its baseline value but could not be further decreased either by raising the initial PG-1 dosage tenfold or by administering a second, equal dose 24 hours after the initial injection. This finding may reflect a heterogeneity of circulating platelets with respect to GPIb, to Fc receptors, or to an interaction between them. After IP injection of 0.63 to 2.5 mg/kg PG-1 F(ab')2 fragment, platelet counts did not decrease more than 21% below baseline levels in a 72-hour period, and bleeding times never increased by more than one minute over baseline values. Nevertheless, platelets obtained from animals 24 hours after injection of 2.5 mg/kg PG-1 F(ab')2 showed full inhibition of agglutination induced by ristocetin. The response of these platelets to aggregation by asialo-vWF was also severely inhibited as compared with control platelets. PG-1 F(ab')2 produced no effect on aggregation induced by ADP. These studies show that virtually complete functional block of the vWF receptor by F(ab')2 fragments of the anti-GPIb MoAb PG- 1 is not sufficient to produce a hemorrhagic state in the guinea pig animal model system.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 719
Author(s):  
Marijana Stojanovic ◽  
Ivana Lukic ◽  
Emilija Marinkovic ◽  
Ana Kovacevic ◽  
Radmila Miljkovic ◽  
...  

Vaccines can have heterologous effects on the immune system, i.e., effects other than triggering an immune response against the disease targeted by the vaccine. We investigated whether monoclonal antibodies (mAbs) specific for tetanus could cross-react with Chlamydia and confer heterologous protection against chlamydial infection. The capability of two tetanus-specific mAbs, namely mAb26 and mAb51, to prevent chlamydial infection has been assessed: (i) in vitro, by performing a neutralization assay using human conjunctival epithelial (HCjE) cells infected with Chlamydia trachomatis serovar B, and (ii) in vivo, by using a guinea pig model of Chlamydiacaviae-induced inclusion conjunctivitis. The mAb26 has been superior in comparison with mAb51 in the prevention of chlamydial infection in HCjE cells. The mAb26 has conferred ≈40% inhibition of the infection, compared to less than 5% inhibition in the presence of the mAb51. In vivo, mAb26 significantly diminished ocular pathology intensity in guinea pigs infected with C. caviae compared to either the mAb51-treated or sham-treated guinea pigs. Our data provide insights that tetanus immunization generates antibodies which induce heterologous chlamydial immunity and promote protection beyond the intended target pathogen.


1977 ◽  
Vol 6 (4) ◽  
pp. 355-371 ◽  
Author(s):  
Zvi H. Marcus ◽  
Yael Shtal ◽  
Gerald Dominique ◽  
Laslo Nebel
Keyword(s):  

1994 ◽  
Vol 179 (3) ◽  
pp. 881-887 ◽  
Author(s):  
P J Jose ◽  
D A Griffiths-Johnson ◽  
P D Collins ◽  
D T Walsh ◽  
R Moqbel ◽  
...  

Eosinophil accumulation is a prominent feature of allergic inflammatory reactions, such as those occurring in the lung of the allergic asthmatic, but the endogenous chemoattractants involved have not been identified. We have investigated this in an established model of allergic inflammation, using in vivo systems both to generate and assay relevant activity. Bronchoalveolar lavage (BAL) fluid was taken from sensitized guinea pigs at intervals after aerosol challenge with ovalbumin. BAL fluid was injected intradermally in unsensitized assay guinea pigs and the accumulation of intravenously injected 111In-eosinophils was measured. Activity was detected at 30 min after allergen challenge, peaking from 3 to 6 h and declining to low levels by 24 h. 3-h BAL fluid was purified using high performance liquid chromatography techniques in conjunction with the skin assay. Microsequencing revealed a novel protein from the C-C branch of the platelet factor 4 superfamily of chemotactic cytokines. The protein, "eotaxin," exhibits homology of 53% with human MCP-1, 44% with guinea pig MCP-1, 31% with human MIP-1 alpha, and 26% with human RANTES. Laser desorption time of flight mass analysis gave four different signals (8.15, 8.38, 8.81, and 9.03 kD), probably reflecting differential O-glycosylation. Eotaxin was highly potent, inducing substantial 111In-eosinophil accumulation at a 1-2 pmol dose in the skin, but did not induce significant 111In-neutrophil accumulation. Eotaxin was a potent stimulator of both guinea pig and human eosinophils in vitro. Human recombinant RANTES, MIP-1 alpha, and MCP-1 were all inactive in inducing 111In-eosinophil accumulation in guinea pig skin; however, evidence was obtained that eotaxin shares a binding site with RANTES on guinea pig eosinophils. This is the first description of a potent eosinophil chemoattractant cytokine generated in vivo and suggests the possibility that similar molecules may be important in the human asthmatic lung.


2004 ◽  
Vol 72 (1) ◽  
pp. 489-497 ◽  
Author(s):  
Anna I. Bakardjiev ◽  
Brian A. Stacy ◽  
Susan J. Fisher ◽  
Daniel A. Portnoy

ABSTRACT Feto-placental infections represent a major cause of pregnancy complications, and yet the underlying molecular and cellular mechanisms of vertical transmission are poorly understood. Listeria monocytogenes, a facultative intracellular pathogen, is one of a group of pathogens that are known to cause feto-placental infections in humans and other mammals. The purpose of this study was to evaluate possible mechanisms of vertical transmission of L. monocytogenes. Humans and guinea pigs have a hemochorial placenta, where a single layer of fetally derived trophoblasts separates maternal from fetal circulation. We characterized L. monocytogenes infection of the feto-placental unit in a pregnant guinea pig model and in primary human trophoblasts and trophoblast-derived cell lines. The clinical manifestations of listeriosis in the pregnant guinea pigs and the tropism of L. monocytogenes to the guinea pig placenta resembled those in humans. Trophoblast cell culture systems were permissive for listerial growth and cell-to-cell spread and revealed that L. monocytogenes deficient in internalin A, a virulence factor that mediates invasion of nonphagocytic cells, was 100-fold defective in invasion. However, crossing of the feto-placental barrier in the guinea pig model was independent of internalin A, suggesting a negligible role for internalin-mediated direct invasion of trophoblasts in vivo. Further understanding of vertical transmission of L. monocytogenes will help in designing more effective means of treatment and disease prevention.


2017 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Vijayalakshmi Maruthamuthu ◽  
Ruckmani Kandasamy

<p class="Abstract">The plant <em>Myxopyrum </em>serratulum is traditionally claimed to relieve asthma and cough. The present study was undertaken to evaluate the bronchodilatory effect of the methanolic extract of <em>M. </em>serratulum on histamine-induced bronchospasm by <em>in vivo</em> and the inhibitory effect of the extract on histamine-contracted tracheal chain and ileum by <em>in vitro</em> guinea pig model. Additionally, the relaxant effect of four cumulative concentrations of the extract (0.25, 0.5, 0.7 and 1.0 g%) was assessed using precontracted tracheal chain under different conditions. The extract (400 mg/kg) prolonged the preconvulsive time to 102.3 ± 3.8 sec when compared to saline and standard chlorpheniramine maleate as 121.3 ± 4.5 sec (p&lt;0.05). The extract also possessed significant inhibitory effect on histamine-contracted guinea pig ileum and tracheal chain and also exhibited significant relaxation effect on precontracted tracheal chain of guinea pig models contracted by 60 mM KCl (p&lt;0.001) and 10 µM methacholine (p&lt;0.001) when compared with standard theophylline.</p>


1962 ◽  
Vol 24 (4) ◽  
pp. 491-NP ◽  
Author(s):  
JANET EVERETT

SUMMARY The direct influence of oestriol and progesterone, and a combination of these hormones, on endometrium of guinea-pigs has been studied in organ culture. Progesterone stimulated the size and number of stromal cells, and provoked slight dilation of uterine glands. The glands were more numerous and widely dilated in the presence of oestriol, and the number and size of stromal cells were even greater than with progesterone alone. A combination of the two hormones led to the simultaneous appearance of synergism—well-preserved epithelium and glands of a secretory nature, and antagonism—there being fewer stromal cells of a smaller size than with either hormone alone. The significance of these results is discussed in relation to the effects of the hormones in vivo. The inhibitory action of progesterone on the appearance of the cystic hyperplasia of the uterine glands provoked by oestriol was noted.


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