|Johnson, W carl - Carl|
|Knowles, Donald - Don|
Submitted to: Parasite Immunology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/6/2010
Publication Date: 7/13/2010
Publication URL: http://handle.nal.usda.gov/10113/56576
Citation: Schneider, D.A., Yan, H., Bastos, R.G., Johnson, W.C., Gavin, P.R., Allen, A.J., Barrington, G.M., Hoesing, L.M., Knowles Jr, D.P., Goff, W.L. 2010. Dynamics of bovine spleen cell populations during the response to acute Babesia bovis infection: an immunohistological study. Parasite Immunology. Available: onlinelibrary.wiley.com/doi/10.1111/j.1365-3024.2010.01249.x/pdf. Interpretive Summary: Babesiosis is one of the most important tick-transmitted diseases affecting cattle in the world especially in tropical and sub-tropical regions. The immune response directed toward blood-associated parasitic infections such as malaria in humans and babesiosis in cattle is complex. The spleen is designed to filter blood removing aged red blood cells and responding to foreign pathogens associated with red blood cells. Therefore, cells within the spleen have different roles in the complex response. Many of these cells have been identified and studied to determine how they work. However, most of the studies have used spleen cells after having been removed from the spleen itself. In this study we designed methods that identified several of these different cells in the spleen during a Babesia infection thus determining their place within the overall spleen architecture. It was discovered that most of the different cell populations increased in number and one particular population moved into an region of the spleen where it would first encounter blood flowing into the spleen. These cells are the ones that first capture and then process foreign pathogens. Thus the study confirmed that these cells are in fact in a position to direct the immune response.
Technical Abstract: The spleen is the critical organ in defense against hemoparasitic diseases like babesiosis, responding to the pathogen in blood as it passes through the organ. As a lymphoid organ, the spleen is composed of cells whose role it is to orchestrate the engagement of infected erythrocytes and free parasites, and process the pathogens for presentation to lymphocytes. This innate immunity is critical as a first response to the infection and in directing aspects of the acquired immune response. Several cells working in concert activate the mechanisms required for the successful resolution of infection, and many in vitro and ex vivo studies have been done identifying these various cellular pathways. However, an immunohistological approach to the events in the spleen of cattle during response to a primary and acute infection with Babesia bovis has been limited. In this study cells were identified with monoclonal antibodies to phenotypic-specific markers and tracked throughout the first 2 weeks following B. bovis infection. The response was characterized as a profound hyperplasia with the loss of distinct architecture around splenic follicles, an increase in numbers of the majority of cell phenotype populations and the unambiguous redirection of immature dendritic cells to the interface between the splenic sinuses and follicles where pathogen first enters the organ.