Congenital Transmission of Toxoplasmosis from Mother Animals with Acute and Chronic Infections

Remington, Jack S.; Jacobs, Leon; Melton, Marjorie L.

doi:10.1093/infdis/108.2.163

Cited by 69 publications

(32 citation statements)

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“…This finding contrasts with numerous other studies on congenital toxoplasmosis using rats (Wildfuhr, 1954), mice (Beverly, 1959), rats and mice (Remington, Jacobs & Melton, 1961) and mice and hamsters (De Roever Bonnet, 1969), where vertical transmission has been demonstrated in chronically infected animals from generation to generation. These early studies used outbred animals, or in the case of Remington et al (1961) NIH mice. Our observations are based primarily on the BALB/c inbred strain and its H-2 congenic, BALB/K, derivative.…”

Section: Discussioncontrasting

confidence: 77%

Studies on a murine model of congenital toxoplasmosis: vertical disease transmission only occurs in BALB/c mice infected for the first time during pregnancy

Roberts

Alexander

1992

Parasitology

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This version is available at https://strathprints.strath.ac.uk/47342/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the SUMMARYThe incidence of congenital toxoplasmosis was determined by an ELISA in the litters of BALB/c mice which had been infected 8 weeks before mating, on day 12 of pregnancy, or on both these occasions. Of those mice given the infection for the first time on day 12 of pregnancy, 5 out of 6 gave birth to infected litters with approximately 50 % of the individuals in each litter being infected. BALB/c mice which had been infected 8 weeks before mating did not give birth to infected litters, even if they were reinfected on day 12 of pregnancy. Following infection BALB/c mice were found to harbour significantly fewer tissue cysts than the congenic H-2 derivative BALB/K strain. However, chronically infected BALB/K mice also failed to produce infected litters, indicating that tissue cyst burden in the dam did not influence congenital infection at least on the BALB background. This study demonstrates that BALB/c dams chronically infected with Toxoplasma gondii, have immunity capable of protecting their embryos from congenital infection, even if the dams are reinfected during pregnancy. Our results demonstrate that the BALB/c mouse can be used as a model of human or ovine congenital T. gondii infection suitable for testing putative vaccines.

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Section: Discussioncontrasting

confidence: 77%

Studies on a murine model of congenital toxoplasmosis: vertical disease transmission only occurs in BALB/c mice infected for the first time during pregnancy

Roberts

Alexander

1992

Parasitology

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“…Similarly as occurs in humans, chronically infected pregnant rats protect their fetuses from congenital infection (23,26,33,37), even though it was found that the occurrence of a low percentage of congenital transmission of T. gondii occurs during the chronic phase of maternal infection (11). Our results showed that all females in the chronic phase of infection, which were monitored by the presence of PAS-positive cerebral cysts and highavidity antibodies to T. gondii, did not transmit the infection to their fetuses.…”

Section: Discussionmentioning

confidence: 96%

“…Experimental models of congenital toxoplasmosis have been described in the literature since the early 1950s (2,8,17,19,23,26,27). However, there is no information concerning the kinetics of events leading to the understanding of how T. gondii tachyzoites reach the fetal tissues.…”

Section: Discussionmentioning

confidence: 99%

Effect ofToxoplasma gondiiInfection Kinetics on Trophoblast Cell Population inCalomys callosus, a Model of Congenital Toxoplasmosis

et al. 2002

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This work evaluated the kinetics of events that occur in the placenta of Calomys callosus after Toxoplasma gondii infection. Animals on the first day of pregnancy (dop) and virgin nonpregnant females were perorally infected with 20 cysts of T. gondii strain ME49. After 100 days of infection, the virgin animals were mated and received an additional 20 cysts on the first dop. The placentas and the embryos from both acutely and chronically infected animals were analyzed up to day 20 of pregnancy by morphological and immunocytochemical assays. Noninfected and infected animals exhibited placenta with normal morphology. From the seventh dop and infection onwards, liver and spleen cells of the infected animals contained several parasitophorous vacuoles. On the 13th day, the maternal blood present at the placental blood spaces contained T. gondii-infected leukocytes. Infected placental cells were only seen on the 15th dop, being the trophoblast giant cells, the first cell type to contain signs of the parasite internalization, followed by labyrinth zone cells 24 h later and spongiotrophoblast cells only after the 19th dop. Fetal liver and brain were infected by T. gondii concomitantly to the labyrinth cell infection. No signals of infection were observed on placentas and embryos from chronically infected animals. Therefore, considering the sequence of events leading to the infection of the various organs, it could be hypothesized that the placenta is infected later on during pregnancy, which may be related to the defense roles played by this structure. However, trophoblast giant cells are unable to completely stop the progression of T. gondii infection towards the fetal tissues. C. callosus was demonstrated to be a suitable experimental model to study the dynamics of congenital toxoplasmosis.

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“…The ISOBG mice still transmitted N. caninum despite previous exposure, demonstrating that the mouse appears to develop little long term immunity to N. caninum after initial infection. This organism is unique compared with T. gondii (50,51), and more similar to other protozoal agents, such as Plasmodium and Trypanosoma sp., in which long term infection is associated with recurrent problems for both mother and offspring during gestation (10,23,52). Because murine models have been unrewarding in terms of studying gestational effects in these diseases (53), murine neosporosis may serve as a model for investigating congenital disease where the organism induces little long term protection.…”

Section: Discussionmentioning

confidence: 99%

Neutralization of Maternal IL-4 Modulates Congenital Protozoal Transmission: Comparison of Innate Versus Acquired Immune Responses

Long

Baszler

2000

The Journal of Immunology

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IL-4 levels were modulated in mice to test the hypothesis that induction of a maternal type 1 response would decrease the frequency of congenital Neospora caninum transmission. This hypothesis tested the relationship between IL-4 and both innate and adaptive immunity utilizing two basic experimental designs. In the first, maternal IL-4 was neutralized with mAb during pregnancy in naive mice concomitant with initial, virulent infection. In the second, maternal IL-4 was neutralized before pregnancy concomitant with a priming inoculation consisting of live, avirulent N. caninum tachyzoites followed by virulent challenge during subsequent gestation. In mice that were naive before pregnancy, neutralization of IL-4 during gestational challenge did not result in decreased congenital transmission as measured by PCR performed on 1-day-old neonatal mice. In mice that were primed and modulated before pregnancy, congenital transmission from gestational challenge was significantly decreased compared with control mice. Reduction in transmission constituted a decrease in the numbers of mice transmitting N. caninum and a lower frequency of transmission by individual dams (p < 0.05). Decreased congenital transmission was associated with significantly lower levels of maternal splenocyte IL-4 secretion, lower IL-4 mRNA levels, and higher levels of IFN-γ secretion. Protected mice had significantly decreased Neospora-specific IgG1 compared with nonmodulated mice. These studies define a relationship between maternal Ag-specific immunity and the frequency of congenital transmission and demonstrate that modulation of type 2 cytokine responses can change the frequency of congenital protozoal transmission.

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Congenital Transmission of Toxoplasmosis from Mother Animals with Acute and Chronic Infections

Cited by 69 publications

References 0 publications

Studies on a murine model of congenital toxoplasmosis: vertical disease transmission only occurs in BALB/c mice infected for the first time during pregnancy

Studies on a murine model of congenital toxoplasmosis: vertical disease transmission only occurs in BALB/c mice infected for the first time during pregnancy

Effect ofToxoplasma gondiiInfection Kinetics on Trophoblast Cell Population inCalomys callosus, a Model of Congenital Toxoplasmosis

Neutralization of Maternal IL-4 Modulates Congenital Protozoal Transmission: Comparison of Innate Versus Acquired Immune Responses

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