ThemKate fluorescent protein expressed byLeishmania mexicanamodifies the parasite immunopathogenicity inBALB/c mice

Summary Parasites have been engineered to express fluorescent reporter proteins, yet the impact of red fluorescent proteins on Leishmania infections remains largely unknown. We analysed the infection outcome of Leishmania mexicana parasites engineered for the constitutive expression of mK ate protein and evaluated their immunogenicity in BALB /c mice. Infection of BALB /c mice with mK ate transfected L. mexicana (Lmex mKate ) parasites caused enlarged lesion sizes, leading to ulceration, and containing more parasites, as compared to Lmex WT . The mK ate protein showed immunogenic properties inducing antibody production against the mK ate protein, as well as enhancing antibody production against the parasite. The augmented lesion sizes and ulcers, together with the more elevated antibody production, were related to an enhanced number of TNF ‐α and IL ‐1β producing cells in the infected tissues. We conclude that mK ate red fluorescent protein is an immunogenic protein, capable of modifying disease evolution of L. mexicana .