Host-pathogen interactions: lessons from phagocytic predation on fungi

Effectiveness of phytoproducts against pathogenic free-living amoebae - A scoping and critical review paving the way toward plant-based pharmaceuticals

Infections caused by free-living amoebae (FLA) have increased worldwide and are expected to worsen. The lack of drugs that are effective (especially against cysts), affordable, and safe to treat these infections exacerbates the concern. Plants present a promising source of bioactive compounds for developing effective drugs; however, the scientific literature on this topic has yet to be adequately synthesized. This work provides a critical scoping review summarizing the amoebicidal performance of plant-derived products and their potential for developing effective drugs to treat FLA infections. Out of 5889 articles retrieved from multiple databases, 119 articles were selected, from which data on 180 plant species belonging to 127 genera and 62 families were extracted. The extracts, essential oils, and compounds from these plants exhibited a diverse range of potency against cysts and trophozoites. Among the compounds studied, periglaucine A, kolavenic acid, and (+)-elatol are promising cysticidal drug candidates due to their high potency, as well as their known low toxicity to non-target cells. Tovophillin A, gartinin, 8-deoxygartinin, garcinone E, 9-hydroxycalabaxanthone, γ-mangostin, and borneol also exhibit high cysticidal potency, but their selectivity profile is unknown. Resveratrol, rosmarinic acid, β-amyrin, and vanillic acid stand out for their high potency against trophozoites and low toxicity to mammalian cells. Another group of compounds with similarly high trophocidal potency includes (-)-epicatechin, (-)-epigallocatechin, apigenin, costunolide, demethoxycurcumin, kaempferol, methyl-β-orcinolcarboxylate, sakuraetin, (+)-elatol, debromolaurinterol, luteolin, (-)-rogiolol, cystomexicone B, epigallocatechin gallate, quercetin, and α-bisabolol. These compounds are priority candidates for further studies on in vivo efficacy, safety, pharmacokinetics, and pharmacodynamics.

The microbial damage and host response framework: lesson learned from pathogenic survival trajectories and immunoinflammatory responses of Talaromyces marneffei infection

The adverse outcomes of fungal infection in mammalian hosts depend on the complex interactions between the host immune system and pathogen virulence-associated traits. The main clinical problems arise when the host response is either too weak to effectively eliminate the pathogen or overly aggressive, resulting in host tissue damage rather than protection. This article will highlight current knowledge regarding the virulence attributions and mechanisms involved in the dual-sided role of the host immune system in the immunopathogenesis of the thermally dimorphic fungus Talaromyces marneffei through the lens of the damage response framework (DRF) of microbial pathogenesis model.

"Under Pressure" - How fungi evade, exploit, and modulate cells of the innate immune system

The human immune system uses an arsenal of effector mechanisms to prevent and counteract infections. Yet, some fungal species are extremely successful as human pathogens, which can be attributed to a wide variety of strategies by which these fungi evade, exploit, and modulate the immune system. These fungal pathogens normally are either harmless commensals or environmental fungi. In this review we discuss how commensalism, but also life in an environmental niche without human contact, can drive the evolution of diverse and specialized immune evasion mechanisms. Correspondingly, we discuss the mechanisms contributing to the ability of these fungi to cause superficial to life-threatening infections.

Chain-Engineering-Based De Novo Drug Design against MPXVgp169 Virulent Protein of Monkeypox Virus: A Molecular Modification Approach

The unexpected appearance of the monkeypox virus and the extensive geographic dispersal of cases have prompted researchers to concentrate on potential therapeutic approaches. In addition to its vaccine build techniques, there should be some multiple integrated antiviral active compounds because of the MPV (monkeypox virus) outbreak in 2022. This study offers a computational engineering-based de novo drug discovery mediated by random antiviral active compounds that were screened against the virulent protein MPXVgp169, as one of the key players directing the pathogenesis of the virus. The screening of these candidates was supported by the use of 72 antiviral active compounds. The top candidate with the lowest binding affinity was selected for the engineering of chains or atoms. Literature assisted to identify toxic chains or atoms that were impeding the stability and effectiveness of antiviral compounds to modify them for enhanced efficacy. With a binding affinity of -9.4 Kcal/mol after chain, the lipophilicity of 0.41, the water solubility of 2.51 as soluble, and synthetic accessibility of 6.6, chain-engineered dolutegravir was one of the best active compounds, as proved by the computational engineering analysis. This study will revolutionize the era of drug engineering as a potential therapeutic strategy for monkeypox infection.

Immunity to Invasive Fungal Diseases

Invasive fungal diseases are rare in individuals with intact immunity. This, together with the fact that there are only a few species that account for most mycotic diseases, implies a remarkable natural resistance to pathogenic fungi. Mammalian immunity to fungi rests on two pillars, powerful immune mechanisms and elevated temperatures that create a thermal restriction zone for most fungal species. Conditions associated with increased susceptibility generally reflect major disturbances of immune function involving both the cellular and humoral innate and adaptive arms, which implies considerable redundancy in host defense mechanisms against fungi. In general, tissue fungal invasion is controlled through either neutrophil or granulomatous inflammation, depending on the fungal species. Neutrophils are critical against Candida spp. and Aspergillus spp. while macrophages are essential for controlling mycoses due to Cryptococcus spp., Histoplasma spp., and other fungi. The increasing number of immunocompromised patients together with climate change could significantly increase the prevalence of fungal diseases.