RESUMO
Exploring and exploiting the microenvironmental similarities between pulmonary tuberculosis (TB) granulomas and malignant tumors has revealed new strategies for more efficacious host-directed therapies (HDTs). This opinion article discusses a paradigm shift in TB therapeutic development, drawing on critical insights from oncology. We summarize recent efforts to characterize and overcome key shared features between tumors and granulomas, including excessive fibrosis, abnormal angiogenesis, hypoxia and necrosis, and immunosuppression. We provide specific examples of cancer therapy application to TB to overcome these microenvironmental abnormalities, including matrix-targeting therapies, antiangiogenic agents, and immune-stimulatory drugs. Finally, we propose a new framework for combining HDTs with anti-TB agents to maximize therapeutic delivery and efficacy while reducing treatment dosages, duration, and harmful side effects to benefit TB patients.
RESUMO
The spectinamides are novel, narrow-spectrum semisynthetic analogs of spectinomycin, modified to avoid intrinsic efflux by Mycobacterium tuberculosis . Spectinamides, including lead MBX-4888A (Lee-1810), exhibit promising therapeutic profiles in mice, as single drugs and as partner agents with other anti-tuberculosis antibiotics including rifampin and/or pyrazinamide. To demonstrate that this translates to more effective cure, we first confirmed the role of rifampin, with or without pyrazinamide, as essential to achieve effective bactericidal responses and sterilizing cure in the current standard of care regimen in chronically infected C3HeB/FeJ mice compared to BALB/c mice. Thus, demonstrating added value in testing clinically relevant regimens in murine models of increasing pathologic complexity. Next we show that MBX-4888A, given by injection with the front-line standard of care regimen, is treatment shortening in multiple murine tuberculosis infection models. The positive treatment responses to MBX-4888A combination therapy in multiple mouse models including mice exhibiting advanced pulmonary disease can be attributed to favorable distribution in tissues and lesions, retention in caseum, along with favorable effects with rifampin and pyrazinamide under conditions achieved in necrotic lesions. This study also provides an additional data point regarding the safety and tolerability of spectinamide MBX-4888A in long-term murine efficacy studies.
RESUMO
Mycobacterium abscessus, a rapidly growing nontuberculous mycobacterium, is increasingly recognized as an important pathogen of the human lung, disproportionally affecting people with cystic fibrosis (CF) and other susceptible individuals with non-CF bronchiectasis and compromised immune functions. M. abscessus infections are extremely difficult to treat due to intrinsic resistance to many antibiotics, including most anti-tuberculous drugs. Current standard-of-care chemotherapy is long, includes multiple oral and parenteral repurposed drugs, and is associated with significant toxicity. The development of more effective oral antibiotics to treat M. abscessus infections has thus emerged as a high priority. While murine models have proven instrumental in predicting the efficacy of therapeutic treatments for M. tuberculosis infections, the preclinical evaluation of drugs against M. abscessus infections has proven more challenging due to the difficulty of establishing a progressive, sustained, pulmonary infection with this pathogen in mice. To address this issue, a series of three workshops were hosted in 2023 by the Cystic Fibrosis Foundation (CFF) and the National Institute of Allergy and Infectious Diseases (NIAID) to review the current murine models of M. abscessus infections, discuss current challenges and identify priorities toward establishing validated and globally harmonized preclinical models. This paper summarizes the key points from these workshops. The hope is that the recommendations that emerged from this exercise will facilitate the implementation of informative murine models of therapeutic efficacy testing across laboratories, improve reproducibility from lab-to-lab and accelerate preclinical-to-clinical translation.
Assuntos
Modelos Animais de Doenças , Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Animais , Mycobacterium abscessus/efeitos dos fármacos , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Camundongos , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Humanos , Avaliação Pré-Clínica de Medicamentos/métodos , Pulmão/microbiologia , Pulmão/efeitos dos fármacos , Pulmão/imunologiaRESUMO
The dual ß-lactam approach has been successfully applied to overcome target redundancy in nontuberculous mycobacteria. Surprisingly, this approach has not been leveraged for Mycobacterium tuberculosis, despite the high conservation of peptidoglycan synthesis. Through a comprehensive screen of oral ß-lactam pairs, we have discovered that cefuroxime strongly potentiates the bactericidal activity of tebipenem and sulopenem-advanced clinical candidates-and amoxicillin, at concentrations achieved clinically. ß-lactam pairs thus have the potential to reduce TB treatment duration.
Assuntos
Complexo Mycobacterium avium , Infecção por Mycobacterium avium-intracellulare , Rifampina , Humanos , Infecção por Mycobacterium avium-intracellulare/tratamento farmacológico , Rifampina/uso terapêutico , Complexo Mycobacterium avium/efeitos dos fármacos , Antibacterianos/uso terapêutico , Pneumopatias/tratamento farmacológico , Pneumopatias/microbiologia , Resultado do TratamentoRESUMO
DNA-encoded chemical library (DEL) technology provides a time- and cost-efficient method to simultaneously screen billions of compounds for their affinity to a protein target of interest. Here we report its use to identify a novel chemical series of inhibitors of the thioesterase activity of polyketide synthase 13 (Pks13) from Mycobacterium tuberculosis (Mtb). We present three chemically distinct series of inhibitors along with their enzymatic and Mtb whole cell potency, the measure of on-target activity in cells, and the crystal structures of inhibitor-enzyme complexes illuminating their interactions with the active site of the enzyme. One of these inhibitors showed a favorable pharmacokinetic profile and demonstrated efficacy in an acute mouse model of tuberculosis (TB) infection. These findings and assay developments will aid in the advancement of TB drug discovery.
Assuntos
Antituberculosos , Inibidores Enzimáticos , Mycobacterium tuberculosis , Policetídeo Sintases , Bibliotecas de Moléculas Pequenas , Tioléster Hidrolases , Animais , Humanos , Camundongos , Antituberculosos/química , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Cristalografia por Raios X , Modelos Animais de Doenças , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/efeitos dos fármacos , Policetídeo Sintases/metabolismo , Policetídeo Sintases/química , Policetídeo Sintases/genética , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Tioléster Hidrolases/antagonistas & inibidores , Tioléster Hidrolases/metabolismo , Tioléster Hidrolases/química , Tioléster Hidrolases/genética , Tuberculose/tratamento farmacológico , Tuberculose/microbiologiaRESUMO
Linezolid is a drug with proven human antitubercular activity whose use is limited to highly drug-resistant patients because of its toxicity. This toxicity is related to its mechanism of actionâlinezolid inhibits protein synthesis in both bacteria and eukaryotic mitochondria. A highly selective and potent series of oxazolidinones, bearing a 5-aminomethyl moiety (in place of the typical 5-acetamidomethyl moiety of linezolid), was identified. Linezolid-resistant mutants were cross-resistant to these molecules but not vice versa. Resistance to the 5-aminomethyl molecules mapped to an N-acetyl transferase (Rv0133) and these mutants remained fully linezolid susceptible. Purified Rv0133 was shown to catalyze the transformation of the 5-aminomethyl oxazolidinones to their corresponding N-acetylated metabolites, and this transformation was also observed in live cells of Mycobacterium tuberculosis. Mammalian mitochondria, which lack an appropriate N-acetyltransferase to activate these prodrugs, were not susceptible to inhibition with the 5-aminomethyl analogues. Several compounds that were more potent than linezolid were taken into C3HeB/FeJ mice and were shown to be highly efficacious, and one of these (9) was additionally taken into marmosets and found to be highly active. Penetration of these 5-aminomethyl oxazolidinone prodrugs into caseum was excellent. Unfortunately, these compounds were rapidly converted into the corresponding 5-alcohols by mammalian metabolism which retained antimycobacterial activity but resulted in substantial mitotoxicity.
Assuntos
Antituberculosos , Mycobacterium tuberculosis , Oxazolidinonas , Pró-Fármacos , Pró-Fármacos/farmacologia , Pró-Fármacos/química , Antituberculosos/farmacologia , Antituberculosos/química , Mycobacterium tuberculosis/efeitos dos fármacos , Oxazolidinonas/farmacologia , Oxazolidinonas/química , Animais , Testes de Sensibilidade Microbiana , Camundongos , Humanos , Linezolida/farmacologia , Linezolida/química , Farmacorresistência Bacteriana , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismoRESUMO
Host-directed therapies (HDTs) represent an emerging approach for bacterial clearance during tuberculosis (TB) infection. While most HDTs are designed and implemented for immuno-modulation, other host targets-such as nonimmune stromal components found in pulmonary granulomas-may prove equally viable. Building on our previous work characterizing and normalizing the aberrant granuloma-associated vasculature, here we demonstrate that FDA-approved therapies (bevacizumab and losartan, respectively) can be repurposed as HDTs to normalize blood vessels and extracellular matrix (ECM), improve drug delivery, and reduce bacterial loads in TB granulomas. Granulomas feature an overabundance of ECM and compressed blood vessels, both of which are effectively reduced by losartan treatment in the rabbit model of TB. Combining both HDTs promotes secretion of proinflammatory cytokines and improves anti-TB drug delivery. Finally, alone and in combination with second-line antitubercular agents (moxifloxacin or bedaquiline), these HDTs significantly reduce bacterial burden. RNA sequencing analysis of HDT-treated lung and granuloma tissues implicates up-regulated antimicrobial peptide and proinflammatory gene expression by ciliated epithelial airway cells as a putative mechanism of the observed antitubercular benefits in the absence of chemotherapy. These findings demonstrate that bevacizumab and losartan are well-tolerated stroma-targeting HDTs, normalize the granuloma microenvironment, and improve TB outcomes, providing the rationale to clinically test this combination in TB patients.
Assuntos
Tuberculose Latente , Mycobacterium tuberculosis , Tuberculose , Humanos , Animais , Coelhos , Bevacizumab/farmacologia , Losartan/farmacologia , Tuberculose/microbiologia , Antituberculosos/farmacologia , Granuloma , Tuberculose Latente/microbiologiaRESUMO
Tuberculosis (TB) drug discovery and development has undergone nothing short of a revolution over the past 20 years. Successful public-private partnerships and sustained funding have delivered a much-improved understanding of mycobacterial disease biology and pharmacology and a healthy pipeline that can tolerate inevitable attrition. Preclinical and clinical development has evolved from decade-old concepts to adaptive designs that permit rapid evaluation of regimens that might greatly shorten treatment duration over the next decade. But the past 20 years also saw the rise of a fatal and difficult-to-cure lung disease caused by nontuberculous mycobacteria (NTM), for which the drug development pipeline is nearly empty. Here, we discuss the similarities and differences between TB and NTM lung diseases, compare the preclinical and clinical advances, and identify major knowledge gaps and areas of cross-fertilization. We argue that applying paradigms and networks that have proved successful for TB, from basic research to clinical trials, will help to populate the pipeline and accelerate curative regimen development for NTM disease.
Assuntos
Antituberculosos , Infecções por Mycobacterium não Tuberculosas , Humanos , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Antituberculosos/uso terapêutico , Antituberculosos/farmacologia , Animais , Desenvolvimento de Medicamentos/métodos , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia , Micobactérias não Tuberculosas/efeitos dos fármacos , Descoberta de Drogas , Pneumopatias/tratamento farmacológico , Pneumopatias/microbiologiaRESUMO
Physiological abnormalities in pulmonary granulomas-pathological hallmarks of tuberculosis (TB)-compromise the transport of oxygen, nutrients, and drugs. In prior studies, we demonstrated mathematically and experimentally that hypoxia and necrosis emerge in the granuloma microenvironment (GME) as a direct result of limited oxygen availability. Building on our initial model of avascular oxygen diffusion, here we explore additional aspects of oxygen transport, including the roles of granuloma vasculature, transcapillary transport, plasma dilution, and interstitial convection, followed by cellular metabolism. Approximate analytical solutions are provided for oxygen and glucose concentration, interstitial fluid velocity, interstitial fluid pressure, and the thickness of the convective zone. These predictions are in agreement with prior experimental results from rabbit TB granulomas and from rat carcinoma models, which share similar transport limitations. Additional drug delivery predictions for anti-TB-agents (rifampicin and clofazimine) strikingly match recent spatially-resolved experimental results from a mouse model of TB. Finally, an approach to improve molecular transport in granulomas by modulating interstitial hydraulic conductivity is tested in silico.
Assuntos
Mycobacterium tuberculosis , Tuberculose , Animais , Camundongos , Coelhos , Oxigênio/metabolismo , Tuberculose/tratamento farmacológico , Tuberculose/patologia , Granuloma/patologia , Modelos Animais de Doenças , Nutrientes , Mycobacterium tuberculosis/metabolismoRESUMO
Cure rates for pulmonary disease caused by the Mycobacterium avium complex (MAC) are poor. While ß-lactam are front line antibiotics against Mycobacterium abscessus pulmonary disease, they have not been used or recommended to treat MAC lung infections. Through a comprehensive screen of oral ß-lactams, we have discovered that selected pairs combining either a penem/carbapenem or penicillin with a cephalosporin are strongly bactericidal at clinically achieved concentrations. These dual ß-lactam combinations include tebipenem and sulopenem, both in phase 3, and Food and Drug Administration-approved amoxicillin and cefuroxime. They could therefore immediately enter clinical trials or clinical practice.
Assuntos
Antibacterianos , Complexo Mycobacterium avium , Infecção por Mycobacterium avium-intracellulare , beta-Lactamas , Humanos , Complexo Mycobacterium avium/efeitos dos fármacos , beta-Lactamas/uso terapêutico , beta-Lactamas/administração & dosagem , Infecção por Mycobacterium avium-intracellulare/tratamento farmacológico , Infecção por Mycobacterium avium-intracellulare/microbiologia , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Administração Oral , Pneumopatias/tratamento farmacológico , Pneumopatias/microbiologia , Testes de Sensibilidade MicrobianaRESUMO
Introduction: Understanding drug exposure at disease target sites is pivotal to profiling new drug candidates in terms of tolerability and efficacy. Such quantification is particularly tedious for anti-tuberculosis (TB) compounds as the heterogeneous pulmonary microenvironment due to the infection may alter lung permeability and affect drug disposition. Murine models have been a longstanding support in TB research so far and are here used as human surrogates to unveil the distribution of several anti-TB compounds at the site-of-action via a novel and centralized PBPK design framework. Methods: As an intermediate approach between data-driven pharmacokinetic (PK) models and whole-body physiologically based (PB) PK models, we propose a parsimonious framework for PK investigation (minimal PBPK approach) that retains key physiological processes involved in TB disease, while reducing computational costs and prior knowledge requirements. By lumping together pulmonary TB-unessential organs, our minimal PBPK model counts 9 equations compared to the 36 of published full models, accelerating the simulation more than 3-folds in Matlab 2022b. Results: The model has been successfully tested and validated against 11 anti-TB compounds-rifampicin, rifapentine, pyrazinamide, ethambutol, isoniazid, moxifloxacin, delamanid, pretomanid, bedaquiline, OPC-167832, GSK2556286 - showing robust predictability power in recapitulating PK dynamics in mice. Structural inspections on the proposed design have ensured global identifiability and listed free fraction in plasma and blood-to-plasma ratio as top sensitive parameters for PK metrics. The platform-oriented implementation allows fast comparison of the compounds in terms of exposure and target attainment. Discrepancies in plasma and lung levels for the latest BPaMZ and HPMZ regimens have been analyzed in terms of their impact on preclinical experiment design and on PK/PD indices. Conclusion: The framework we developed requires limited drug- and species-specific information to reconstruct accurate PK dynamics, delivering a unified viewpoint on anti-TB drug distribution at the site-of-action and a flexible fit-for-purpose tool to accelerate model-informed drug design pipelines and facilitate translation into the clinic.