Different Transcriptomic Responses After Moderate and Severe Heat Shock in Trypanosoma cruzi Epimastigotes

Trypanosoma cruzi undergoes heat stress during its life cycle. In this study, we performed a transcriptomic analysis of the heat shock response in epimastigotes from different T. cruzi strains. In both clone CL Brener and the Y strain, very few to no statistically significant variations were observed in the transcriptome at 37°C, whereas differentially expressed genes were observed at 40°C, with 1018 upregulated and 734 downregulated transcripts in CL Brener and 1426 upregulated and 1223 downregulated transcripts in the Y strain. Upregulated transcripts were enriched in catabolic pathways, whereas downregulated transcripts were enriched in catabolic and anabolic pathways. In addition, the expression pattern of different members of several heat shock protein gene families varied. The expression patterns of members of surface protein gene families, such as trans-sialidases, GP63, mucins, and mucin-associated proteins, also varied, although the physiological significance of these patterns remains unclear. We conclude that, in T. cruzi epimastigotes, transcriptome modulation at 37°C was less pronounced than expected for an 8°C increase in temperature, whereas at 40°C, there was functional enrichment in both induced and repressed transcripts, characterizing a classical response to severe heat shock.