To understand the normal life cycle of HIV in human cells, researchers have to be able to visualize the virus and immune cells that respond to it. As a substitute for directly looking at HIV in human tissue, laboratory scientists often use the related Simian Immunodeficiency Virus, SIV, which infects monkeys. Directly visualizing CD8+ T cells, a type of immune cell that kills infected cells to control infectious agents such as SIV or HIV, in tissue from infected animals is an invaluable step in understanding the monkey’s immune reaction to SIV (and by extension, the human’s reaction to HIV).
VIDI postdoctoral fellow Dr. Annelie Tjernlund and colleagues, including VIDI co-director Dr. Larry Corey, have devised a new method to directly identify CD8+ T cells specific for SIV in frozen tissue from SIV-infected monkeys. This method improves on past methods that require fresh tissue, and thus limited the scope of possible experiments that could be performed. Using this new technique, the scientists looked at various tissue types from SIV-infected macaques, and found SIV-specific CD8+ T cells in certain parts of lymphoid tissue near the gut, a known hotspot of HIV or SIV replication. This finding suggests these T cells might play a role in this tissue in controlling HIV or SIV replication.
In situ detection of Gag-specific CD8+ cells in the GI tract of SIV infected Rhesus macaques. Tjernlund A, Zhu J, Laing K, Diem K, McDonald D, Vazquez J, Cao J, Ohlen C, McElrath MJ, Picker LJ, Corey L. Retrovirology. 2010 Feb 16;7:1-14.