Simultaneous Host and Parasite Expression Profiling Identifies Transcriptional Programs Associated with Cerebral Malaria

The development and outcome of cerebral malaria (CM) reflects a complex interplay between parasite-expressed virulence factors and host response to infection. To simultaneously analyze transcriptional programs in both parasite and host over the course of infection, we created microarrays to concurrently detect transcripts in the genomes of both Plasmodium berghei and mouse. Analysis of RNA from brain, lung, liver, and spleen of mice infected with P. berghei ANKA showed that parasite gene expression is readily detected in whole organ RNA. Comparison of CM-susceptible (C57BL/6) and CM-resistant (BALB/c) mice showed that both host and parasite display distinct organ-specific transcriptional signatures in susceptible versus resistant animals. Host genes whose expression differs between CM-resistant and CM-susceptible mice, at either baseline or induced by infection, tend to relate to humoral and immune response, complement activation, or cell-cell interactions, suggesting differences in immune function that may directly underlie protection from or susceptibility to CM. P. berghei, in contrast, displayed differential expression of genes related to apparent biosynthestic activities, with the majority of transcriptional activity observed in the lung. These data show that analysis of host and parasite gene expression profiles by hybridizing infected host samples to a single microarray is feasible, and can facilitate dissection of complex host-pathogen interactions. Keywords: Time course, Disease state analysis 5 mice per group per timepoint; Compare Brain, Liver, Lung and Spleen of infected (Day 3 and Day 6 post infection) to uninfected resistant (BALB/c) and susceptible (C57BL/6).