Submitted to: Proceedings of the International Congress of Parasitology X
Publication Type: Proceedings
Publication Acceptance Date: 12/31/2002
Publication Date: 4/16/2003
Citation: Almeria, S., Demarez, T., Dawson, H.D., Araujo, R., Padilhia, T., Dubey, J.P., Gasbarre, L.C. 2003. Immune responses in dam and fetus after experimental infection of pregnant cows with neospota caninum. Parasitology International Congress. pp. 413-18. Interpretive Summary:
Technical Abstract: The present study was performed to define the immune responses in the dam and fetus after infection of pregnant cows with N. caninum. Four cows were infected early in the second trimester of pregnancy (110 days of gestation) intravenously with 107 culture derived tachyzoites and three pregnant cows were kept as uninfected controls. Animals were euthanized at 3-4 weeks after infection (131-138 days of pregnancy). Tissues (brain, spinal chord. muscle, heart, liver, spleen) were collected from both, dam and fetus, and were examined for presence of parasites. Immune responses in lymphocyte populations from lymph nodes and spleen ofboth dam and fetus were ascertained by flow cytometry and by real time PCR for cytokine message expression. Quantification of bovine cytokines was performed by real time PCR using bovine- specific TaqMan@ probes for IL-10, IL-4, IFN-gamma, and IL-12. No abortion was observed in any infected dam at the time of the killing, however, transplacental infection had already taken place and parasites were detected in tissues from at least 3 of 4 infected fetuses. Infected dams showed significantly higher CD3+ populations in mesenteric lymph nodes (MLN) compared to uninfected dams. Percentages of CD4+ and CD8+ subpopulations were higher, while B-cell populations were lower in the infected dams, although differences were not statistically significant In the fetus few immunocompetent lymphocytes were present, however, similarly to the dams, higher CD3+, CD4+, CD8+ and IL-2 R+ cells and lower B-cells+ were present in the spleen of infected fetus compared to uninfected fetus, although differences were not statistically significant, due to the high variability among animals. Preliminary results showed a high increase in bIL10 in spleen populations of infected fetuses versus uninfected fetuses.