Cross-inhibition of pathogenic agents and the host proteins they exploit.

The major limitations of pathogen-directed therapies are the emergence of drug-resistance and their narrow spectrum of coverage. A recently applied approach directs therapies against host proteins exploited by pathogens in order to circumvent these limitations. However, host-oriented drugs leave the pathogens unaffected and may result in continued pathogen dissemination. In this study we aimed to discover drugs that could simultaneously cross-inhibit pathogenic agents, as well as the host proteins that mediate their lethality. We observed that many pathogenic and host-assisting proteins belong to the same functional class. In doing so we targeted a protease component of anthrax toxin as well as host proteases exploited by this toxin. We identified two approved drugs, ascorbic acid 6-palmitate and salmon sperm protamine, that effectively inhibited anthrax cytotoxic protease and demonstrated that they also block proteolytic activities of host furin, cathepsin B, and caspases that mediate toxin's lethality in cells. We demonstrated that these drugs are broad-spectrum and reduce cellular sensitivity to other bacterial toxins that require the same host proteases. This approach should be generally applicable to the discovery of simultaneous pathogen and host-targeting inhibitors of many additional pathogenic agents.

Bithionol blocks pathogenicity of bacterial toxins, ricin, and Zika virus.

Diverse pathogenic agents often utilize overlapping host networks, and hub proteins within these networks represent attractive targets for broad-spectrum drugs. Using bacterial toxins, we describe a new approach for discovering broad-spectrum therapies capable of inhibiting host proteins that mediate multiple pathogenic pathways. This approach can be widely used, as it combines genetic-based target identification with cell survival-based and protein function-based multiplex drug screens, and concurrently discovers therapeutic compounds and their protein targets. Using B-lymphoblastoid cells derived from the HapMap Project cohort of persons of African, European, and Asian ancestry we identified host caspases as hub proteins that mediate the lethality of multiple pathogenic agents. We discovered that an approved drug, Bithionol, inhibits host caspases and also reduces the detrimental effects of anthrax lethal toxin, diphtheria toxin, cholera toxin, Pseudomonas aeruginosa exotoxin A, Botulinum neurotoxin, ricin, and Zika virus. Our study reveals the practicality of identifying host proteins that mediate multiple disease pathways and discovering broad-spectrum therapies that target these hub proteins.

Identification of agents effective against multiple toxins and viruses by host-oriented cell targeting.

A longstanding and still-increasing threat to the effective treatment of infectious diseases is resistance to antimicrobial countermeasures. Potentially, the targeting of host proteins and pathways essential for the detrimental effects of pathogens offers an approach that may discover broad-spectrum anti-pathogen countermeasures and circumvent the effects of pathogen mutations leading to resistance. Here we report implementation of a strategy for discovering broad-spectrum host-oriented therapies against multiple pathogenic agents by multiplex screening of drugs for protection against the detrimental effects of multiple pathogens, identification of host cell pathways inhibited by the drug, and screening for effects of the agent on other pathogens exploiting the same pathway. We show that a clinically used antimalarial drug, Amodiaquine, discovered by this strategy, protects host cells against infection by multiple toxins and viruses by inhibiting host cathepsin B. Our results reveal the practicality of discovering broadly acting anti-pathogen countermeasures that target host proteins exploited by pathogens.

Intended use for a neoadjuvant chemoradiation response prediction test for locally advanced esophageal adenocarcinoma: a survey analysis of thoracic surgeons in the US.

OBJECTIVE: A multi-analyte immunohistochemistry (IHC) based test (DecisionDx-EC * *DecisionDx-EC, Castle Biosciences, Incorporated, Friendswood, TX. Hereafter referred to as the "IHC-based test". ) was developed and proved able to accurately predict response to neoadjuvant chemoradiotherapy (neoCTRT) in esophageal adenocarcinoma (EC) patients with locoregional disease. A survey was conducted with surgeons attending the 2013 Society of Thoracic Surgeons Annual Conference to assess their intention to change standard of care patient treatment based on predictive results obtained from this test. RESEARCH DESIGN AND METHODS: Fifty-seven thoracic surgeons were provided a questionnaire regarding the current clinical management of locoregional EC patients, and their intention to change management strategy if a patient is predicted by the multi-analyte IHC-based test to experience pathological complete response (pathCR) or extremely resistant to neoCTRT (exCTRT). RESULTS: Forty-four out of 46 enrolled respondents indicated that they administer neoCTRT followed by surgery to treat locally advanced EC. Fifteen (32%) respondents presently prescribing neoCTRT to EC patients acknowledged that a pathCR prediction provided by the multi-analyte IHC-based test would change their current regimens. Conversely, 28 surgeons (61%) would be willing to adjust their current strategy for patients predicted to be resistant to neoCTRT, significantly more than the case where patients are predicted to be pathCR (p = 0.01). Twenty-five percent (25%) of surgeons willing to adjust treatment in response to a patient being a potential exCTRT chose to remove CTRT from the strategy, and instead would choose surgery alone for these patients. CONCLUSIONS: Results from the current survey show that patients' response to neoCTRT predicted by the multi-analyte IHC-based test has a significant influence on the decision-making process in the clinic. Nearly twice as many surgeons stated an intention to change strategy with the knowledge that the patient is likely to have extreme resistance to planned treatments than when one is a potential responder. The current survey study is limited by its 'intended use' nature, therefore does not reflect physicians' real action in the clinic upon implementation of this test. However, survey results strongly suggest that use of the IHC-based predictive test is of great interest to physicians, and would likely contribute to more individualized treatment for patients with distinct sensitivity to neoCTRT.