Unique transcriptional profile of liver-resident memory CD8⁺ T cells induced by immunization with malaria sporozoites

Sterile immunity against live Plasmodium infection can be achieved by immunization with radiation-attenuated sporozoites. This protection is known to be mediated in part by antigen-specific memory CD8⁺ T cells, presumably those residing in the liver. We characterized and compared the transcriptional profile of parasite-specific memory CD8⁺ T cells residing in the liver and spleen after immunization of mice with irradiated sporozoites. Microarray-based expression analysis of these memory CD8 ⁺ T cells indicated that liver-resident memory cells display a distinct gene expression profile. We found major differences in the expression of immune function genes as well as genes involved in the cell cycle, cell trafficking, transcription and intracellular signaling. Importantly, the malaria parasite-induced liver-resident CD8⁺ T cells display a transcriptional profile different to that described for CD8⁺ T cells following other microbial challenges.