1
|
Vargas-Villavicencio JA, Besné-Mérida A, Correa D. Vertical transmission and fetal damage in animal models of congenital toxoplasmosis: A systematic review. Vet Parasitol 2016; 223:195-204. [PMID: 27198800 DOI: 10.1016/j.vetpar.2016.04.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/04/2016] [Accepted: 04/18/2016] [Indexed: 11/17/2022]
Abstract
In humans, the probability of congenital infection and fetal damage due to Toxoplasma gondii is dependent on the gestation period at which primary infection occurs. Many animal models have been used for vaccine, drug testing, or studies on host or parasite factors that affect transmission or fetal pathology, but few works have directly tested fetal infection and damage rates along gestation. So, the purpose of this work was to perform a systematic review of the literature to determine if there is a model which reflects these changes as they occur in humans. We looked for papers appearing between 1970 and 2014 in major databases like Medline and Scopus, as well as gray literature. From almost 11,000 citations obtained, only 49 papers fulfilled the criteria of having data of all independent variables and at least one dependent datum for control (untreated) groups. Some interesting findings could be extracted. For example, pigs seem resistant and sheep susceptible to congenital infection. Also, oocysts cause more congenitally infected offspring than tissue cysts, bradyzoites or tachyzoites. In spite of these interesting findings, very few results on vertical transmission or fetal damage rates were similar to those described for humans and only for one of the gestation thirds, not all. Moreover, in most designs tissue cysts - with unknown number of bradyzoites - were used, so actual dose could not be established. The meta-analysis could not be performed, mainly because of great heterogeneity in experimental conditions. Nevertheless, results gathered suggest that a model could be designed to represent the increase in vertical transmission and decrease in fetal damage found in humans under natural conditions.
Collapse
Affiliation(s)
- José Antonio Vargas-Villavicencio
- Lab. de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Ciudad de México 04530, Mexico
| | - Alejandro Besné-Mérida
- Lab. de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Ciudad de México 04530, Mexico
| | - Dolores Correa
- Lab. de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Ciudad de México 04530, Mexico.
| |
Collapse
|
2
|
Vargas-Villavicencio JA, Cedillo-Peláez C, Rico-Torres CP, Besné-Mérida A, García-Vázquez F, Saldaña JI, Correa D. Mouse model of congenital infection with a non-virulent Toxoplasma gondii strain: Vertical transmission, "sterile" fetal damage, or both? Exp Parasitol 2016; 166:116-23. [PMID: 27068784 DOI: 10.1016/j.exppara.2016.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 03/23/2016] [Accepted: 04/05/2016] [Indexed: 12/21/2022]
Abstract
Congenital transmission of Toxoplasma gondii may occur if the mother gets infected for the first time while pregnant. The risk of mother-to-child transmission depends on the gestation trimester at infection, being lowest in the first and highest in the last. Conversely, fetal damage is frequent and more severe at the beginning of pregnancy. The objective of this study was to evaluate congenital transmission and pathological aspects in the placenta and the fetus using a mouse model of congenital infection of the second gestation third. Forty-five female BALB/c mice were infected intravenously with 2.5-10.0 × 10(6) tachyzoites of the ME49 strain at middle gestation. Samples of maternal spleen and fetal/placental units were taken 72 h later. We determined parasite load and vertical transmission by qPCR, as well as damage macroscopically and by histopathology. With the lowest dose, 18% of the fetuses were infected. Also, 40% of fetuses/litter were altered, while this value was 10% in the control group (P < 0.05). These results are similar to those described in humans in terms of vertical transmission and fetal damage during the second third of gestation. The maternal spleen had 10-1000 times more tachyzoites than the placenta, and the later retained 90-99% of the parasites that could reach the fetus. Nevertheless, we found resorptions, abortions or fetal tissue damage in the presence but also in the absence of parasites. Our data indicate a strong protective effect of maternal organs and the placenta against fetal infection, but extensive damage of the later may led to resorption or abortion without vertical transmission.
Collapse
Affiliation(s)
- J A Vargas-Villavicencio
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico
| | - C Cedillo-Peláez
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico
| | - C P Rico-Torres
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico
| | - A Besné-Mérida
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico; Doctorado en Ciencias de la Salud y Reproducción Animal, FMVZ, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - F García-Vázquez
- Departamento de Anatomía Patológica, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico
| | - J I Saldaña
- Investigador Cátedra CONACyT en el Instituto Nacional de pediatría, Laboratorio de Inmunología Experimental, Mexico City, Mexico
| | - D Correa
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, SSa. Torre de Investigación, Av. Insurgentes Sur 3700-C, Col. Insurgentes Cuicuilco, Mexico City 04530, Mexico.
| |
Collapse
|
3
|
Shin EH, Chun YS, Kim WH, Kim JL, Pyo KH, Chai JY. Immune responses of mice intraduodenally infected with Toxoplasma gondii KI-1 tachyzoites. THE KOREAN JOURNAL OF PARASITOLOGY 2011; 49:115-23. [PMID: 21738266 PMCID: PMC3121067 DOI: 10.3347/kjp.2011.49.2.115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/01/2011] [Accepted: 06/02/2011] [Indexed: 11/23/2022]
Abstract
Toxoplasma gondii Korean isolate (KI-1) tachyzoites were inoculated intraduodenally to BALB/c mice using a silicon tube, and the course of infection and immune responses of mice were studied. Whereas control mice, that were infected intraperitoneally, died within day 7 post-infection (PI), the intraduodenally infected mice survived until day 9 PI (infection with 1×105 tachyzoites) or day 11 PI (with 1×106 tachyzoites). Based on histopathologic (Giemsa stain) and PCR (B1 gene) studies, it was suggested that tachyzoites, after entering the small intestine, invaded into endothelial cells, divided there, and propagated to other organs. PCR appeared to be more sensitive than histopathology to detect infected organs and tissues. The organisms spread over multiple organs by day 6 PI. However, proliferative responses of splenocytes and mesenteric lymph node (MLN) cells in response to con A or Toxoplasma lysate antigen decreased significantly, suggesting immunosuppression. Splenic CD4+ and CD8+ T-lymphocytes showed decreases in number until day 9 PI, whereas IFN-γ and IL-10 decreased slightly at day 6 PI and returned to normal levels by day 9 PI. No TNF-α was detected throughout the experimental period. The results showed that intraduodenal infection with KI-1 tachyzoites was successful but did not elicit significant mucosal immunity in mice and allowed dissemination of T. gondii organisms to systemic organs. The immunosuppression of mice included reduced lymphoproliferative responses to splenocytes and MLN cells to mitogen and low production of cytokines, such as IFN-γ, TNF-α, and IL-10, in response to T. gondii infection.
Collapse
Affiliation(s)
- Eun-Hee Shin
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University Medical Research Center, Seoul 110-799, Korea
| | | | | | | | | | | |
Collapse
|