Malaria Immunosuppression (VIDEO) University of Iowa Health Care This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption Malaria prevents the host body (human or mouse) from developing lasting immunity. A new University of Iowa study, led by microbiology professor John Harty, has homed in on a potential culprit of this immunosuppression. The molecule, CTLA-4, is produced by a type of immune cell called a Treg cell. Blocking CTLA-4 at the right time during blood-stage infection allows mice to quickly clear malaria. Importantly the treated mice also develop lasting immunity to malaria. The video, captured with intravital confocal immunofluorescence microscopy, shows Treg cells (green) delivering CTLA-4 to B cell (blue/ magenta)-Helper T cell (red) clusters in the spleen of a mouse. The CTLA-4 molecule inhibits efficient production of antibodies against malaria. If this pathway works in humans as it does in mice, blocking CTLA-4 might be a way to improve malaria treatment and boost immunity to reinfection. The study was published Sept. 11 online in Nature Medicine. Credit Samarchith Kurup/ Scott Anthony, dept. of Microbiology and Immunology, University of Iowa. Usage Restrictions The video may be used with appropriate credit for informational and educational purposes only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.