Expression of GEF1 in Xenopus laevis oocytes and HEK-293 cells gave rise to a Cl- channel that remained permanently open and was blocked by nitro-2-(3-phenyl-propylamino) benzoic acid and niflumic acid. NPPB induced petite-like colonies, resembling the GEF1 knock-out. The fluorescent halide indicator SPQ was quenched in a wild-type strain, in contrast to both a GEF1 knock-out strain and yeast grown in the presence of NPPB. Immunogold and electron microscopy located Gef1p in the plasma membrane, vacuole, endoplasmic reticulum and Golgi apparatus. Eleven substitutions in five residues forming the ion channel of GEF1 were introduced; some of them (S186A, I188N, Y459D, Y459F, Y459V, I467A, I467N and F468N) did not rescue the pet phenotype, whereas F468A, A558F and A558Y formed normal colonies. All the pet mutants showed reduced O2 consumption, small mitochondria and mostly disrupted organelles. Finally, electron microscopy revealed that the plasma membrane of the mutants develop multiple foldings and highly ordered cylindrical protein-membrane complexes. All the experiments above suggest that Gef1p transports Cl- through the plasma membrane and reveal the importance of critical amino acids for the proper function of the protein as suggested by structural models. However, the mechanism of activation of the channel has yet to be defined.

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Invasive Candidiasis (IC) presents a global mortality rate greater than 40%, occupying the fourth place worldwide as the most frequent opportunistic nosocomial disease. Although the genus Candida consists of around 200 species, only 20 are reported as etiological agents of IC, being Candida albicans the most frequent causal agent. Even when there is a broad range of antifungals drugs for Candida infections, azoles, polyenes, and echinocandins are considered among the most effective treatment. However, there is some incidence for antifungal resistance among some Candida strains, limiting treatment options. Several molecular mechanisms with antifungal agents have been reported for C. albicans where insertions, deletions, and point mutations in genes codifying target proteins are frequently related to the antifungal drug resistance. Furthermore, gene overexpression is also frequently associated to antifungal resistance as well as an increase in the activity of proteins that reduce oxidative damage. This chapter summarizes the main molecular mechanisms to C. albicans antifungal drug resistance, besides offering an overview of new antifungal agents and new antifungal targets to combat fungal infections.

ImportanceCOVID-19 pneumonia is often associated with hyperinflammation. The efficacy and safety of anakinra in treating patients with severe COVID-19 pneumonia and hyperinflammation are still unclear.ObjectiveTo assess the efficacy and safety of anakinra vs standard of care alone for patients with severe COVID-19 pneumonia and hyperinflammation.Design, Setting, and ParticipantsThe Clinical Trial of the Use of Anakinra in Cytokine Storm Syndrome Secondary to COVID-19 (ANA-COVID-GEAS) was a multicenter, randomized, open-label, 2-group, phase 2/3 clinical trial conducted at 12 hospitals in Spain between May 8, 2020, and March 1, 2021, with a follow-up of 1 month. Participants were adult patients with severe COVID-19 pneumonia and hyperinflammation. Hyperinflammation was defined as interleukin-6 greater than 40 pg/mL, ferritin greater than 500 ng/mL, C-reactive protein greater than 3 mg/dL (rationale, ≥5 upper normal limit), and/or lactate dehydrogenase greater than 300 U/L. Severe pneumonia was considered if at least 1 of the following conditions was met: ambient air oxygen saturation 94% or less measured with a pulse oximeter, ratio of partial pressure O2 to fraction of inspired O2 of 300 or less, and/or a ratio of O2 saturation measured with pulse oximeter to fraction of inspired O2 of 350 or less. Data analysis was performed from April to October 2021.InterventionsUsual standard of care plus anakinra (anakinra group) or usual standard of care alone (SoC group). Anakinra was given at a dose of 100 mg 4 times a day intravenously.Main Outcomes and MeasuresThe primary outcome was the proportion of patients not requiring mechanical ventilation up to 15 days after treatment initiation, assessed on an intention-to-treat basis.ResultsA total of 179 patients (123 men [69.9%]; mean [SD] age, 60.5 [11.5] years) were randomly assigned to the anakinra group (92 patients) or to the SoC group (87 patients). The proportion of patients not requiring mechanical ventilation up to day 15 was not significantly different between groups (64 of 83 patients [77.1%] in the anakinra group vs 67 of 78 patients [85.9%] in the SoC group; risk ratio [RR], 0.90; 95% CI, 0.77-1.04; P = .16). Anakinra did not result in any difference in time to mechanical ventilation (hazard ratio, 1.72; 95% CI, 0.82-3.62; P = .14). There was no significant difference between groups in the proportion of patients not requiring invasive mechanical ventilation up to day 15 (RR, 0.99; 95% CI, 0.88-1.11; P > .99).Conclusions and RelevanceIn this randomized clinical trial, anakinra did not prevent the need for mechanical ventilation or reduce mortality risk compared with standard of care alone among hospitalized patients with severe COVID-19 pneumonia.Trial RegistrationClinicalTrials.gov Identifier: NCT04443881