Deletion of N-acetylmuramyl-L-alanine amidases alters the host immune response to Mycobacterium tuberculosis infection

Identification of Potential Inhibitors of Mycobacterium tuberculosis Amidases: An Integrated In Silico and Experimental Study

Virtual screening is a crucial tool in early stage drug discovery for identifying potential hit candidates. Here, we present an integrated approach that combines theoretical and experimental techniques to identify, for the first time, inhibitors of amidases (Ami1-Ami4) from Mycobacterium tuberculosis. Through computational methods, we proposed a set of potential inhibitors, which were subsequently evaluated experimentally using differential scanning fluorimetry. This led to the identification of two promising hits: a carbohydrazide core (hit 1) and a tetrazole core (hit 5). We further developed a small collection of compounds derived from hit 1, which demonstrated improved affinity for Ami1. Additionally, we determined the crystallographic structure of the Ami1-hit 5 complex at a resolution of 1.45 Å, providing molecular-level insights into the interaction of this compound within the catalytic site. The findings of this study contribute to the advancement of drug discovery against tuberculosis and propose new targets for therapeutic development.

The progress of Mycobacterium tuberculosis drug targets

Tuberculosis (TB) has been troubling humans for hundreds of years, is a highly infectious disease caused by Mycobacterium tuberculosis (Mtb) infection, Mtb can infect almost all organs of the body and is one of the deadly infectious diseases in the world. At present, the first-line treatment regimen has a long treatment cycle and is prone to multiple drug resistance. Anti-tuberculosis drugs and latent tuberculosis infection (LTBI) resistance are increasing year by year, and new targets and new bioactive compounds are urgently needed to treat this disease. This review focuses on the latest reported anti-TB drug targets and related compounds in recent years, reviews the current TB drug regimen and major defects, outlines the key drug targets developed to date in Mtb, and the current situation of newly discovered anti-TB resistant forms of drugs. To provide a reference for the research and development of new anti-TB drugs and bring new treatment strategies for TB patients.

Polysaccharides and glycolipids of Mycobacterium tuberculosis and their induced immune responses

Tuberculosis (TB) is a chronic infectious disease mainly caused by Mycobacterium tuberculosis (M. tuberculosis). The structures of polysaccharides and glycolipids at M. tuberculosis cell wall vary among different strains, which affect the physiology and pathogenesis of mycobacteria by activating or inhibiting innate and acquired immunity. Among them, some components such as lipomannan (LM) and lipoarabinomannan (LAM) activate innate immunity by recognizing some kinds of pattern recognition receptors (PRRs) like Toll-like receptors, while other components like mannose-capped lipoarabinomannan (ManLAM) could prevent innate immune responses by inhibiting the secretion of pro-inflammatory cytokines and maturation of phagosomes. In addition, many glycolipids can activate natural killer T (NKT) cells and CD1-restricted T cells to produce interferon-γ (IFN-γ). Furthermore, humoral immunity against cell wall components, such as antibodies against LAM, plays a role in immunity against M. tuberculosis infection. Cell wall polysaccharides and glycolipids of M. tuberculosis have potential applications as antigens and adjuvants for novel TB subunit vaccines.

OUP accepted manuscript

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