Leishmania chagasi and Leishmania amazonensis are the etiologic agents of different clinical forms of human leishmaniasis in South America. In an attempt to select candidate antigens for a vaccine protecting against different Leishmania species, the efficacy of vaccination using Leishmania ribosomal proteins and saponin as adjuvant was examined in BALB/c mice against challenge infection with both parasite species. Mice vaccinated with parasite ribosomal proteins purified from Leishmania infantum plus saponin showed a specific production of IFN-γ, IL-12 and GM-CSF after in vitro stimulation with L. infantum ribosomal proteins. Vaccinated mice showed a reduction in the liver and spleen parasite burdens after L. chagasi infection. After L. amazonensis challenge, vaccinated mice showed a decrease of the dermal pathology and a reduction in the parasite loads in the footpad and spleen. In both models, protection was correlated to an IL-12-dependent production of IFN-γ by CD4(+) and CD8(+) T cells that activate macrophages for the synthesis of NO. In the protected mice a decrease in the parasite-mediated IL-4 and IL-10 responses was also observed. In mice challenged with L. amazonensis, lower levels of anti-parasite-specific antibodies were detected. Thus, Leishmania ribosomal proteins plus saponin fits the requirements to compose a pan-Leishmania vaccine.

There is a critical need for careful and independent validation of reported symptomatic efficacy and dopaminergic biomarker changes induced by nilotinib in Parkinson disease (PD).OBJECTIVES To assess safety and tolerability of nilotinib in participants with moderately advanced PD. Secondary and exploratory objectives were to assess its affect on PD disability, pharmacokinetics, cerebrospinal fluid (CSF) penetration, and biomarkers. DESIGN, SETTING, AND PARTICIPANTSThis was a 6-month, multicenter, randomized parallel-group, double-blind, placebo-controlled trial. Recruitment was from November 20, 2017, to December 28, 2018, and follow-up ended on September 9, 2019. The study was conducted at 25 US sites. The study approached 173 patients, of whom 48 declined, 125 were screened, and 76 who received a stable regimen of PD medications were enrolled (39% screen failure).INTERVENTIONS Participants were randomized 1:1:1 to placebo, 150-mg nilotinib, or 300-mg nilotinib once daily orally for 6 months, followed by 2-month off-drug evaluation. MAIN OUTCOMES AND MEASURESThe primary outcomes were safety and tolerability. The tolerability end point was defined as the ability to complete the study while receiving the assigned dose. An active arm was considered tolerable if the percentage of participants meeting the tolerability end point for that group was not significantly lower than the percentage observed in the placebo group. Secondary outcomes included change in PD disability (Movement Disorder Society Unified Parkinson's Disease Rating Scale [MDS-UPDRS], Part II OFF/ON). Exploratory outcomes included serum and CSF pharmacokinetic profile, and CSF dopaminergic biomarkers.RESULTS At baseline, mean (SD) participants' age was 64.6 (7.5) years, 52 were male (68%), mean (SD) disease duration was 9.9 years (4.7), MDS-UPDRS Part 1-3 OFF score was 66.4 (19.3), ON score was 48.4 (16.2), and Montreal Cognitive Assessment score was 27.1 (2.2). The number of participants who completed the study receiving the assigned dose were 21 (84%), 19 (76%), and 20 (77%) in the placebo, 150-mg, and 300-mg arms, respectively. Both active doses had acceptable safety profile. The most common reasons for drug suspension were asymptomatic, dose-dependent elevations of amylase, and/or lipase. Nilotinib, 150 mg and 300 mg, exhibited worse MDS-UPDRS-3 ON scores compared with placebo, achieving significance for nilotinib, 300 mg, at month 1 (P < .01). There was no difference in the change of MDS-UPDRS-3 OFF from baseline to 6 months between groups (P = .17). Cerebrospinal fluid/serum ratio of nilotinib concentration was 0.2% to 0.3%. There was no evidence of treatment-related alteration of dopamine metabolites in the CSF.CONCLUSIONS AND RELEVANCE While we demonstrated acceptable safety and tolerability of nilotinib in our cohort, the low CSF exposure and lack of biomarkers effect combined with the efficacy data trending in the negative direction indicate that nilotinib should not be further tested in PD.

Four new antigenic proteins located in Leishmania ribosomes have been characterized: S4, S6, L3 and L5. Recombinant versions of the four ribosomal proteins from Leishmania major were recognized by sera from human and canine patients suffering different clinical forms of leishmaniasis. The prophylactic properties of these proteins were first studied in the experimental model of cutaneous leishmaniasis caused by L. major inoculation into BALB/c mice. The administration of two of them, LmL3 or LmL5 combined with CpG-oligodeoxynucleotides (CpG-ODN) was able to protect BALB/c mice against L. major infection. Vaccinated mice showed smaller lesions and parasite burden compared to mice inoculated with vaccine diluent or vaccine adjuvant. Protection was correlated with an antigen-specific increased production of IFN-γ paralleled by a decrease of the antigen-specific IL-10 mediated response in protected mice relative to non-protected controls. Further, it was demonstrated that BALB/c mice vaccinated with recombinant LmL3 or LmL5 plus CpG-ODN were also protected against the development of cutaneous lesions following inoculation of L. braziliensis. Together, data presented here indicate that LmL3 or LmL5 ribosomal proteins combined with Th1 inducing adjuvants, may be relevant components of a vaccine against cutaneous leishmaniasis caused by distinct species.