Mycobacterium leprae fusion protein 1 (LEP-F1) (LEP-F1)

LEP-F1 is a recombinant fusion protein designed as a vaccine antigen to combat leprosy, caused by Mycobacterium leprae. It consists of three specific bacterial proteins—ML0405, ML0411, and ML2055—which were selected for their ability to trigger strong T-cell responses in humans (Duthie et al., 2011, PubMed: 21177304). When administered, typically alongside an adjuvant like GLA-SE, LEP-F1 stimulates the production of Th1 cytokines, particularly interferon-gamma (IFN-γ), which is essential for activating macrophages to eliminate intracellular mycobacteria (Duthie et al., 2014, PubMed: 24412114). This target is the primary component of the LepVax vaccine, which has undergone Phase 1 clinical testing (NCT03310346) to provide both prophylactic protection and potentially therapeutic benefits. Research indicates that LEP-F1 can also serve as a diagnostic tool to identify individuals exposed to M. leprae, helping to map and control the spread of the disease (Duthie et al., 2018, PubMed: 29337211). The development of LEP-F1 represents a significant advancement in leprosy control, moving beyond multi-drug therapy toward prevention and early detection.

Other names

LepVax antigenML0405-ML0411-ML2055 fusion proteinRecombinant M. leprae fusion proteinLeprosy fusion protein 1

Induction of a Th1-mediated immune response through the activation of antigen-specific T-cells and production of pro-inflammatory cytokines like IFN-gamma (Duthie et al., 2014, PubMed: 24412114).