Integrated Investigation of Inhibitors Active on Infectious Diseases: Insights into Molecular and Cellular Mechanisms of Function

Infectious diseases have shaped the course of human history and continue to pose significant challenges to global health. They are caused by pathogenic microorganisms such as bacteria, viruses, parasites, or fungi and can spread, directly or indirectly, from one person to another. They are responsible for a significant proportion of deaths worldwide, particularly in low- and middle-income countries. Diseases such as HIV/AIDS, malaria, tuberculosis, and more recently, COVID-19, have claimed millions of lives and caused immense socio-economic disruption.Malaria is a parasitic infection that is widespread in tropical and subtropical regions of the world. Due to its high mortality rates, it represents a significant global public health problem. In 2022, there were 249 million reported cases of malaria with an estimated 608,000 deaths. The emergence of resistance to artemisinin-based combination therapies (ACT), which has now spread to Africa, is a serious threat to malaria containment efforts and underscores the need to find efficient alternatives. Therefore, the search for new chemical series is critical to discovering and developing new drugs to combat malaria. Identifying and validating hits from both natural and synthetic sources that are active on both asexual and sexual stages of the malaria parasite will increase the chances of success.The rise of antimicrobial resistance (AMR), coupled with a decrease in the discovery of novel antibiotics, raises the specter of a post-antibiotic era, where even minor injuries could prove fatal. In 2019, an estimated 4.95 million patients died worldwide due to drug-resistant bacterial infections, which was greater than the number of deaths caused by HIV and tuberculosis combined. Six pathogens (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa) are the leading cause of death worldwide. One strategy to address this challenge is to prioritize research and development efforts towards discovering new molecules with antibacterial properties and unique modes of action. By investing in such endeavors, we can work to mitigate the potential consequences of bacterial resistance and safeguard against a future where common infections become life-threatening.Viral infections have had a profound impact on human history and continue to present significant global health challenges. Viruses can cause diseases ranging from the common cold to more severe illnesses such as HIV/AIDS, influenza, Ebola, and most recently, COVID-19. The burden of viral diseases on global health is immense. They are responsible for millions of deaths each year and can cause widespread epidemics or even pandemics, leading to significant socio-economic disruption. The recent COVID-19 pandemic is a stark reminder of the devastating potential of viral diseases.This proposal is based on the early drug discovery and development process and is focused on the elucidation of the mechanism of action of inhibitors active on infectious diseases. We will investigate previously identified molecular targets from key pathogenic agents including Plasmodium falciparum, Gram-positive and -negative bacteria (Escherichia coli, P. aeruginosa, K. pneumoniae, and A. baumannii), and viruses (SARS-CoV-2, ZIKV, YFV, and CHKV) to shed light on the molecular and cellular mechanisms of action. State-of-the-art methods in organic synthesis, cell biology, medicinal chemistry, and structural biology will be applied to unravel the mechanisms of action of known inhibitors and discover new ones.The Sao Carlos Institute of Physics at the University of São Paulo has a world-renowned structural biology and medicinal chemistry program, providing state-of-the-art facilities for discovering and developing inhibitors as lead candidates. Our facilities are well-equipped to support all steps of this proposal. Our laboratory is a center of excellence of the Medicine for Malaria Venture (MMV), which screens all MMV portfolio compounds for activity against the strains of malaria currently circulating in Brazil. Additionally, we have collaborated with Drugs for Neglected Diseases initiative (DNDi) to deliver new alternatives for the treatment of other endemic diseases, including viral infections.The Parasite Chemotherapy Unit (PCU) of the Swiss Tropical and Public Health Institute is a drug discovery center for protozoan parasites. The PCU has over 25 years of experience in assay development and drug efficacy testing for the causative agents of malaria (Plasmodium spp.), African sleeping sickness (Trypanosoma brucei), Chagas disease (T. cruzi), and leishmaniasis (Leishmania spp.). Primary and secondary in vitro assays are combined with mouse models of disease and molecular approaches to drug action and resistance. Also, the PCU serves as a reference center for MMV, and we have been key to developing several new drug candidates for malaria, including arterolane, artefenomel, cipargamine and ganaplacide.Therefore, the proposed research integrates diverse work packages, assays, and objectives to comprehensively investigate molecular targets across pathogens to form a cohesive framework, enabling a comprehensive exploration of molecular targets across diverse pathogens. This approach is pivotal for discovering new compounds and unraveling critical mechanisms of action, ultimately advancing the development of effective treatments and containment strategies for infectious diseases.