Cryptococcosis remains a significant cause of morbidity and mortality world-wide, particularly among AIDS patients. Yet, to date, there are no licensed vaccines clinically available to treat or ...prevent cryptococcosis. In this review, we provide a rationale to support continued investment in Cryptococcus vaccine research, potential challenges that must be overcome along the way, and a literature review of the current progress underway towards developing a vaccine to prevent cryptococcosis.
Expansion of Cryptococcus in unique patient populations and environmental niches highlights the need for a prophylactic vaccine to prevent cryptococcosis caused by virulent C. neoformans and C. gattii.
Vaccination with heat-killed Cryptococcus mutants containing cell-wall modifications appears to induce protective immune responses against cryptococcosis in mice.
Experimental studies show potential for eliciting long-lasting protective immunity against cryptococcosis in CD4+ T cell-deficient hosts.
Administration of fungal glycolipids, such as glucosylceramide, demonstrates significant protection against subsequent Cryptococcus infection in mice.
Mice vaccinated with an innovative β-glucan antigen-delivery platform containing immune stimulatory Cryptococcus fractions have protective anticryptococcal immune responses against virulent strains of C. neoformans and C. gattii.
Dimorphic fungal pathogens are a significant cause of human disease worldwide. Notably, the dimorphic fungal pathogens within the order Onygenales are considered primary pathogens, causing disease in ...healthy hosts. Current changes in taxonomy are underway due to advances in molecular phylogenetics, population genetics, and new emerging dimorphic fungal pathogens causing human disease. In this review, we highlight evolutionary relationships of dimorphic fungal pathogens that cause human disease within the order Onygenales and provide rationale to support increased investment in studies understanding the evolutionary relationships of these pathogens to improve rapid diagnostics, help identify mechanisms of antifungal resistance, understand adaptation to human host, and factors associated with virulence.
Development of vaccines against opportunistic infections is difficult as patients most at risk of developing disease are deficient in aspects of the adaptive immune system. Here, we utilized an ...experimental immunization strategy to induce innate memory in macrophages in vivo. Unlike current trained immunity models, we present an innate memory-like phenotype in macrophages that is maintained for at least 70 days post-immunization and results in complete protection against secondary challenge in the absence of adaptive immune cells. RNA-seq analysis of in vivo IFN-γ primed macrophages revealed a rapid up-regulation of IFN-γ and STAT1 signaling pathways following secondary challenge. The enhanced cytokine recall responses appeared to be pathogen-specific, dependent on changes in histone methylation and acetylation, and correlated with increased STAT1 binding to promoter regions of genes associated with protective anti-fungal immunity. Thus, we demonstrate an alternative mechanism to induce macrophage innate memory in vivo that facilitates pathogen-specific vaccine-mediated immune responses.
A repeat expansion mutation in the C9orf72 gene is the leading known genetic cause of FTD and ALS. The C9orf72-ALS/FTD field has been plagued by a lack of reliable tools to monitor this genomic locus ...and its RNA and protein products. We have validated assays that quantify C9orf72 pathobiology at the DNA, RNA and protein levels using knock-out human iPSC lines as controls. Here we show that single-molecule sequencing can accurately measure the repeat expansion and faithfully report on changes to the C9orf72 locus in what has been a traditionally hard to sequence genomic region. This is of particular value to sizing and phasing the repeat expansion and determining changes to the gene locus after gene editing. We developed ddPCR assays to quantify two major C9orf72 transcript variants, which we validated by selective excision of their distinct transcriptional start sites. Using validated knock-out human iPSC lines, we validated 4 commercially available antibodies (of 9 tested) that were specific for C9orf72 protein quantification by Western blot, but none were specific for immunocytochemistry. We tested 15 combinations of antibodies against dipeptide repeat proteins (DPRs) across 66 concentrations using MSD immunoassay, and found two (against poly-GA and poly-GP) that yielded a 1.5-fold or greater signal increase in patient iPSC-motor neurons compared to knock-out control, and validated them in human postmortem and transgenic mouse brain tissue. Our validated DNA, RNA and protein assays are applicable to discovery research as well as clinical trials.
Coccidioidomycosis (Valley fever) is a fungal disease caused by the inhalation of
or
. This neglected disease occurs in the desert areas of the western United States, most notably in California and ...Arizona, where infections continue to rise. Clinically, coccidioidomycosis ranges from asymptomatic to severe pulmonary disease and can disseminate to the brain, skin, bones, and elsewhere. New estimates suggest as many as 350,000 new cases of coccidioidomycosis occur in the United States each year. Thus, there is an urgent need for the development of a vaccine and new therapeutic drugs against
infection. In this review, we discuss the battle against
including the development of potential vaccines, the quest for new therapeutic drugs, and our current understanding of the protective host immune response to
infection.
The rapid evolution of SARS-CoV-2 variants highlights the need for new therapies to prevent disease spread. SARS-CoV-2, like SARS-CoV-1, uses the human cell surface protein angiotensin-converting ...enzyme 2 (ACE2) as its native receptor. Here, we design and characterize a mutant ACE2 that enables rapid affinity purification of a dimeric protein by altering the active site to prevent autoproteolytic digestion of a C-terminal His
epitope tag. In cultured cells, mutant ACE2 competitively inhibits lentiviral vectors pseudotyped with spikes from multiple SARS-CoV-2 variants and infectious SARS-CoV-2. Moreover, the protein can be nebulized and retains virus-binding properties. We developed a system for the delivery of aerosolized ACE2 to K18-hACE2 mice and demonstrated protection by our modified ACE2 when delivered as a prophylactic agent. These results show proof-of-concept for an aerosolized delivery method to evaluate anti-SARS-CoV-2 agents
and suggest a new tool in the ongoing fight against SARS-CoV-2 and other ACE2-dependent viruses.
The rapid evolution of SARS-CoV-2 variants poses a challenge for immune recognition and antibody therapies. However, the virus is constrained by the requirement that it recognizes a human host receptor protein. A recombinant ACE2 could protect against SARS-CoV-2 infection by functioning as a soluble decoy receptor. We designed a mutant version of ACE2 with impaired catalytic activity to enable the purification of the protein using a single affinity purification step. This protein can be nebulized and retains the ability to bind the relevant domains from SARS-CoV-1 and SARS-CoV-2. Moreover, this protein inhibits viral infection against a panel of coronaviruses in cells. Finally, we developed an aerosolized delivery system for animal studies and show the modified ACE2 offers protection in an animal model of COVID-19. These results show proof-of-concept for an aerosolized delivery method to evaluate anti-SARS-CoV-2 agents
and suggest a new tool in the ongoing fight against SARS-CoV-2.
Coccidioides immitis and Coccidioides posadasii are soil-dwelling fungi of arid regions in North and South America that are responsible for Valley fever (coccidioidomycosis). Forty percent of ...patients with Valley fever exhibit symptoms ranging from mild, self-limiting respiratory infections to severe, life-threatening pneumonia that requires treatment. Misdiagnosis as bacterial pneumonia commonly occurs in symptomatic Valley fever cases, resulting in inappropriate treatment with antibiotics, increased medical costs, and delay in diagnosis. In this proof-of-concept study, we explored the feasibility of developing breath-based diagnostics for Valley fever using a murine lung infection model. To investigate potential volatile biomarkers of Valley fever that arise from host−pathogen interactions, we infected C57BL/6J mice with C. immitis RS (n = 6), C. posadasii Silveira (n = 6), or phosphate-buffered saline (n = 4) via intranasal inoculation. We measured fungal dissemination and collected bronchoalveolar lavage fluid (BALF) for cytokine profiling and for untargeted volatile metabolomics via solid-phase microextraction (SPME) and two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS). We identified 36 volatile organic compounds (VOCs) that were significantly correlated (p < 0.05) with cytokine abundance. These 36 VOCs clustered mice by their cytokine production and were also able to separate mice with moderate-to-high cytokine production by infection strain. The data presented here show that Coccidioides and/or the host produce volatile metabolites that may yield biomarkers for a Valley fever breath test that can detect coccidioidal infection and provide clinically relevant information on primary pulmonary disease severity.
The objective of the laboratory study is to examine the conditions under which transition metal ions (e.g., ferrous ion, Fe
2+) could activate the persulfate anion (S
2O
8
2−) to produce a powerful ...oxidant known as the sulfate free radical (SO
4
−
) with a standard redox potential of 2.6 V. The SO
4
−
is capable of destroying groundwater contaminants in situ such as trichloroethylene (TCE). Experiments using Fe
2+ as an activator under various molar ratios of S
2O
8
2−/Fe
2+/TCE in an aqueous system indicated that partial TCE degradation occurred almost instantaneously and then the reaction stalled. Either destruction of SO
4
−
in the presence of excess Fe
2+ or the rapid conversion of all Fe
2+ to Fe
3+ limited the ultimate oxidizing capability of the system. Sequential addition of Fe
2+ in small increments resulted in an increased TCE removal efficiency. Therefore, it appeared that Fe
2+ played an important role in generating SO
4
−
. An observation of oxidation–reduction potential (ORP) variations revealed that the addition of sodium thiosulfate (Na
2S
2O
3) to the ferrous ion activated persulfate system could significantly decrease the strong oxidizing conditions. It was hypothesized that the thiosulfate induced reducing conditions might convert Fe
3+ to a lower valence state of Fe
2+, making the Fe
2+ available to activate persulfate decomposition. The sequential addition of thiosulfate (S
2O
3
2−), after the initial stalling of ferrous ion activated persulfate oxidation of TCE, resulted in an improvement in TCE removal. The ferrous ion activated persulfate–thiosulfate redox couple resulted in fairly complete TCE degradation in aqueous systems in a short time frame. In soil slurry systems, TCE degradation was slower in comparison to aqueous systems.
Physiological changes that occur in the spring are preparatory for salmonid smolts to successfully enter seawater, but variation is likely to exist within species with a wide geographic distribution. ...Whether differences in development of seawater tolerance exist among populations that differ in distance to the ocean, temporally during the spring, or as fish migrate downstream is not known. Juvenile sockeye salmon Oncorhynchus nerka from four regions in the Fraser River catchment, British Columbia, were intercepted to assess physiological differences among populations and at different times during migration to characterize the parr–smolt transformation. Pre‐migratory fish had low levels of gill Na+–K+‐ATPase (NKA) activity. High gill NKA activities were observed at the start of migration for some populations, but smolts leaving the lake did not consistently have higher gill NKA activity than non‐migratory juvenile O. nerka sampled in their natal lakes. Gill NKA activity was highly variable at the start of migration with no relationship with distance from the ocean. Gill NKA activity changes with migration were also highly variable, but consistently smolts in the ocean had the highest enzyme activities. Internal and external factors may influence this variation, but the dynamic nature of smolting was not based on the region of origin, timing during migration or on the year of migration.
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