IL4 and Lassa fever: Because LF patients display a spectrum of T cell activation states that can influence the activation and metabolic status of Mφ via differential cytokine production [54–56], we artificially polarised THP-1 Mφ toward a classical (M1) or alternative (M2) phenotype with pre-exposure of recombinant IFNγ or IL-4/IL-13 [23].