African trypanosomiasis is caused by to the infection of a protozoan parasite of the Trypanosoma genus. It is transmitted by the tsetse fly, and is largely affecting cattle in the sub-humid areas of Africa, causing a high economic impact. However, not all the bovine strains are equally susceptible to the infection (1). 

In order to dissect the mechanisms underlying susceptibility to African trypanosoma infection, Peylhard et al (2) performed blood transcriptional profiles of trypanotolerant, trypanosensitive and mixed cattle breeds, before and after experimental infection with T. congolense. 

First of all, the authors have characterized the basal transcriptional profiles in the blood of the different breeds under study, which could be classified in a wide array of functional pathways. Of note, after infection some pathways were consistently enriched in all the group tested. Among them, the immune system-related ones were again on the top functions reported. The search for specific canonical pathways pointed to a prominent role of lipid and cholesterol-related pathways, as well as mitochondrial function and B and T lymphocyte activation.

However, the analysis of infected animals demonstrated that trypanosusceptible animals showed a stronger transcriptomic reprogramming, highly enriched in specific metabolic and immunological pathways. It is worthy to highlight striking differences in genes involved in immune signal transduction, cytokines and markers of different leukocyte subpopulations.

This work represents undoubtedly a significant momentum in the field, since the authors explore in deep a wide panel of cattle breeds representing the majority of West-African taurine and zebu in a systematic way. Since the animals were studied at different timepoints after infection, future longitudinal analyses of these datasets will be providing a precious insight on the kinetics of immune and metabolic reprogramming associated with susceptibility and tolerance to African trypanosoma infection, widening the application of this interesting study into new therapeutic interventions.

References

1. Berthier D, Peylhard M, Dayo G-K, Flori L, Sylla S, Bolly S, Sakande H, Chantal I, Thevenon S (2015) A Comparison of Phenotypic Traits Related to Trypanotolerance in Five West African Cattle Breeds Highlights the Value of Shorthorn Taurine Breeds. PLOS ONE, 10, e0126498. https://doi.org/10.1371/journal.pone.0126498

2. Peylhard M, Berthier D, Dayo G-K, Chantal I, Sylla S, Nidelet S, Dubois E, Martin G, Sempéré G, Flori L, Thévenon S (2022) Whole blood transcriptome profiles of trypanotolerant and trypanosusceptible cattle highlight a differential modulation of metabolism and immune response during infection by Trypanosoma congolense. bioRxiv, 2022.06.10.495622, ver. 2 peer-reviewed and recommended by Peer Community Infections. https://doi.org/10.1101/2022.06.10.495622.