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Frontiers in Immunology 2024Immune checkpoint pathways, i.e., coinhibitory pathways expressed as feedback following immune activation, are crucial for controlling an excessive immune response....
Immune checkpoint pathways, i.e., coinhibitory pathways expressed as feedback following immune activation, are crucial for controlling an excessive immune response. Cytotoxic T lymphocyte antigen-4 (CTLA-4) and programmed cell death protein-1 (PD-1) are the central classical checkpoint inhibitory (CPI) molecules used for the control of neoplasms and some infectious diseases, including some fungal infections. As the immunosuppression of severe paracoccidioidomycosis (PCM), a chronic granulomatous fungal disease, was shown to be associated with the expression of coinhibitory molecules, we hypothesized that the inhibition of CTLA-4 and PD-1 could have a beneficial effect on pulmonary PCM. To this end, C57BL/6 mice were infected with yeasts and treated with monoclonal antibodies (mAbs) α-CTLA-4, α-PD-1, control IgG, or PBS. We verified that blockade of CTLA-4 and PD-1 reduced the fungal load in the lungs and fungal dissemination to the liver and spleen and decreased the size of pulmonary lesions, resulting in increased survival of mice. Compared with PBS-treated infected mice, significantly increased levels of many pro- and anti-inflammatory cytokines were observed in the lungs of α-CTLA-4-treated mice, but a drastic reduction in the liver was observed following PD-1 blockade. In the lungs of α-CPI and IgG-treated mice, there were no changes in the frequency of inflammatory leukocytes, but a significant reduction in the total number of these cells was observed. Compared with PBS-treated controls, α-CPI- and IgG-treated mice exhibited reduced pulmonary infiltration of several myeloid cell subpopulations and decreased expression of costimulatory molecules. In addition, a decreased number of CD4+ and CD8+ T cells but sustained numbers of Th1, Th2, and Th17 T cells were detected. An expressive reduction in several Treg subpopulations and their maturation and suppressive molecules, in addition to reduced numbers of Treg, TCD4+, and TCD8+ cells expressing costimulatory and coinhibitory molecules of immunity, were also detected. The novel cellular and humoral profiles established in the lungs of α-CTLA-4 and α-PD-1-treated mice but not in control IgG-treated mice were more efficient at controlling fungal growth and dissemination without causing increased tissue pathology due to excessive inflammation. This is the first study demonstrating the efficacy of CPI blockade in the treatment of pulmonary PCM, and further studies combining the use of immunotherapy with antifungal drugs are encouraged.
Topics: Mice; Animals; Paracoccidioidomycosis; CTLA-4 Antigen; Programmed Cell Death 1 Receptor; Mice, Inbred C57BL; Patient Acuity; Immunoglobulin G
PubMed: 38500881
DOI: 10.3389/fimmu.2024.1347318 -
Frontiers in Fungal Biology 2023In fungal pathogens the cell wall plays an important role in host-pathogen interactions because its molecular components (e.g., polysaccharides and proteins) may trigger...
In fungal pathogens the cell wall plays an important role in host-pathogen interactions because its molecular components (e.g., polysaccharides and proteins) may trigger immune responses during infection. GPI-anchored proteins represent the main protein class in the fungal cell wall where they can perform several functions, such as cell wall remodeling and adhesion to host tissues. Genomic analysis has identified the complement of GPI-anchored proteins in many fungal pathogens, but the function has remained unknown for most of them. Here, we conducted an RNA expression analysis of GPI-anchored proteins of which causes paracoccidioidomycosis (PCM), an important human systemic mycosis endemic in Latin America. The expression of the GPI-anchored proteins was analyzed by quantitative PCR in both the mycelium and yeast forms. qPCR analysis revealed that the transcript levels of 22 of them were increased in hyphae and 10 in yeasts, respectively, while 14 did not show any significant difference in either form. Furthermore, we cloned 46 open reading frames and purified their corresponding GPI-anchored proteins in the budding yeast. Immunoblot and ELISA analysis of four purified GPI-anchored proteins revealed immune reactivity of these proteins against sera obtained from PCM patients. The information obtained in this study provides valuable information about the expression of many GPI-anchored proteins of unknown function. In addition, based on our immune analysis, some GPI-anchored proteins are expressed during infection and therefore, they might serve as good candidates for the development of new diagnostic methods.
PubMed: 37746134
DOI: 10.3389/ffunb.2023.1243475 -
Scientific Reports Jul 2023Paracoccidioidomycosis (PCM) is a systemic mycosis with a high incidence in Latin America. Prior studies have demonstrated the significance of the enzyme Indoleamine...
The immunosuppressive activity of myeloid-derived suppressor cells in murine Paracoccidioidomycosis relies on Indoleamine 2,3-dioxygenase activity and Dectin-1 and TLRs signaling.
Paracoccidioidomycosis (PCM) is a systemic mycosis with a high incidence in Latin America. Prior studies have demonstrated the significance of the enzyme Indoleamine 2,3-dioxygenase (IDO-1) in the immune regulation of PCM as well as the vital role of myeloid-derived suppressor cells (MDSCs) in moderating PCM severity. Additionally, Dectin-1 and Toll-Like Receptors (TLRs) signaling in cancer, infection, and autoimmune diseases have been shown to impact MDSC-IDO-1 activity. To expand our understanding of MDSCs and the role of IDO-1 and pattern recognition receptors (PRRs) signaling in PCM, we generated MDSCs in vitro and administered an IDO-1 inhibitor before challenging the cells with Paracoccidioides brasiliensis yeasts. By co-culturing MDSCs with lymphocytes, we assessed T-cell proliferation to examine the influence of IDO-1 on MDSC activity. Moreover, we utilized specific antibodies and MDSCs from Dectin-1, TLR4, and TLR2 knockout mice to evaluate the effect of these PRRs on IDO-1 production by MDSCs. We confirmed the importance of these in vitro findings by assessing MDSC-IDO-1 in the lungs of mice following the fungal infection. Taken together, our data show that IDO-1 expression by MDSCs is crucial for the control of T-cell proliferation, and the production of this enzyme is partially dependent on Dectin-1, TLR2, and TLR4 signaling during murine PCM.
Topics: Animals; Mice; Myeloid-Derived Suppressor Cells; Paracoccidioidomycosis; Indoleamine-Pyrrole 2,3,-Dioxygenase; Toll-Like Receptor 2; Toll-Like Receptor 4; Mice, Knockout
PubMed: 37524886
DOI: 10.1038/s41598-023-39262-8 -
Journal of Fungi (Basel, Switzerland) Nov 2023The fungal pathogen causes systemic mycosis Paracoccidioidomycosis (PCM), which presents a broad distribution in Latin America. Upon infection, the fungus undergoes a...
The fungal pathogen causes systemic mycosis Paracoccidioidomycosis (PCM), which presents a broad distribution in Latin America. Upon infection, the fungus undergoes a morphological transition to yeast cells and provokes an inflammatory granulomatous reaction with a high number of neutrophils in the lungs. In this work, we employed proteomic analysis to investigate the in vitro response of the fungus to the interaction with human neutrophils. Proteomic profiling of yeast cells harvested at 2 and 4 h post interaction with human polymorphonuclear cells allowed the identification of 505 proteins differentially accumulated. The data indicated that yeast cells underwent a shift in metabolism from glycolysis to Beta oxidation, increasing enzymes of the glyoxylate cycle and upregulating enzymes related to the detoxification of oxidative and heat shock stress. To our knowledge, this is the first study employing proteomic analysis in the investigation of the response of a member of the genus to the interaction with neutrophils.
PubMed: 37998893
DOI: 10.3390/jof9111088 -
PLoS Neglected Tropical Diseases Sep 2023The occurrence of acute paracoccidioidomycosis (PCM) in urban areas of the Rio de Janeiro state, Brazil, has emerged in recent years. Therefore, young populations,...
The occurrence of acute paracoccidioidomycosis (PCM) in urban areas of the Rio de Janeiro state, Brazil, has emerged in recent years. Therefore, young populations, including pregnant women, are at a higher risk of infection. Furthermore, young women undergoing itraconazole treatment for PCM have increased chances to get pregnant because this medication may reduce the effectiveness of contraceptives. Acute PCM is invasive, reaching abdominal organs, posing a maternal-fetal risk. PCM treatment in pregnant women is also challenging due to the teratogenicity associated with the currently available oral drugs. There are scarce studies on PCM and pregnancy, mainly consisting of case reports and experimental murine models that highlight the severity of this association. We conducted a database research at a PCM reference center in Rio de Janeiro state from 1980 to 2020. We included patients diagnosed with PCM who were pregnant shortly before, at admission, or at any moment of their PCM follow-up care. Data related to pregnancy, childbirth, and the newborn were obtained from the Brazilian official public databases. We also reviewed the epidemiological and clinical features of these patients. During the study period, we identified 18 pregnant patients, with a median age of 26 years (range: 16-38). Among these cases, six (33.3%) were detected in the last 5 years, and 14 (77.8%) presented acute PCM, supporting the recent shift in the epidemiological profile towards acute PCM. Most pregnancies occurred during PCM treatment (n = 11, 61.1%), which led to challenges in the therapeutic management. Maternal-fetal complications occurred in some of these cases, including vaginal bleeding (n = 1), preeclampsia (n = 1), prematurity (n = 2), low birth weight (n = 4), and fetal deaths (n = 2). PCM during pregnancy presents a significant public health concern in the context of the emergence of acute PCM in urban areas.
Topics: Humans; Female; Animals; Mice; Pregnancy; Adolescent; Young Adult; Adult; Paracoccidioidomycosis; Brazil; Cohort Studies; Itraconazole; Databases, Factual
PubMed: 37708219
DOI: 10.1371/journal.pntd.0011645 -
Microorganisms Sep 2023Paracoccidioidomycosis ceti (PCM-C) is a chronic granulomatous keloidal dermatitis in cetaceans that has been reported worldwide and is caused by . Serological...
Paracoccidioidomycosis ceti (PCM-C) is a chronic granulomatous keloidal dermatitis in cetaceans that has been reported worldwide and is caused by . Serological cross-reactions among highly pathogenic fungal infections and related diseases have been reported. However, the true cross-reaction of antibodies against has remained unknown due to the use of positive control sera from infected dolphins. This study aimed to re-evaluate antibodies from mechanically dislodged fungal cells in the infected tissue of a PCM-C case and demonstrate the actual cross-reaction. The results revealed a limited cross-reaction between PCM-C and paracoccidioidomycosis, while the antibodies did not react with other pathogens such as , , and . Thus, the method for evaluation of the antibody against PCM-C is reliable, and there is potential for epidemiological study.
PubMed: 37894086
DOI: 10.3390/microorganisms11102428 -
Virulence Dec 2023Paracoccin (PCN), a glycoprotein, has been reported to play roles in fungal biology and paracoccidioidomycosis pathogenesis. Lectin and chitinase domains account for...
Paracoccin (PCN), a glycoprotein, has been reported to play roles in fungal biology and paracoccidioidomycosis pathogenesis. Lectin and chitinase domains account for the PCN's dual roles as an immunomodulatory agent and virulence factor. Soluble PCN injected in infected mice, by interacting with TLRs' N-glycans, drives the host immune response toward a protective Th1 axis. Otherwise, mice infection with yeasts overexpressing PCN (ov-PCN) revealed that PCN acts as a fungal virulence factor, thanks to its chitinase activity on the cell wall, resulting in resistance to phagocytes' fungicidal activity and development of severe paracoccidioidomycosis. Because antifungal drug administration follows the disease diagnosis, we studied the PCN effect on yeast resistance or susceptibility to antifungal agents. Using a paracoccidioidomycosis model developed in larvae, we confirmed the observation, in the murine host, that ov-PCN yeasts display maximum virulence compared to wild-type (wt-PCN) or PCN-silenced (kd-PCN) yeasts. PCN overexpression accounted for the highest susceptibility of to antifungal and reduced relative mRNA expression of genes encoding proteins related to cell wall remodeling. The lowest virulence, detected in infection with kd-PCN yeasts, correlated with the lowest susceptibility to antifungals and impact on genes for cell wall remodeling. So, we defined that the grade of endogenous PCN production influences the virulence and susceptibility to antifungal drugs, as well as the expression of genes related to cell wall remodeling. We postulate that this variable gene expression is mechanistically associated with virulence changes.
Topics: Animals; Mice; Antifungal Agents; Virulence; Larva; Paracoccidioidomycosis; Paracoccidioides; Fungal Proteins; Moths; Virulence Factors
PubMed: 36599817
DOI: 10.1080/21505594.2022.2150455 -
Journal of Fungi (Basel, Switzerland) Sep 2023Paracoccidioidomycosis (PCM) is a neglected endemic mycosis in Latin America. Most cases occur in Brazil. It is classified as PCM infection and PCM disease and is...
Paracoccidioidomycosis (PCM) is a neglected endemic mycosis in Latin America. Most cases occur in Brazil. It is classified as PCM infection and PCM disease and is subdivided into chronic (adult type) or acute (juvenile type) disease, with the latter being less frequent and more severe. In 2016, we reported an increase in the numbers of patients diagnosed with acute PCM after a highway's construction. We conducted a study at INI-Fiocruz, a reference center for infectious diseases, including endemic mycoses, in Rio de Janeiro, Brazil, aiming to deepen the analysis of this new clinical and epidemiological profile of PCM. The authors developed a retrospective study including 170 patients diagnosed with PCM between 2010 and 2019. There was an increase in the number of atypical and severe forms, starting in 2014. In subsequent years, we detected a higher incidence of adverse outcomes with patients requiring more hospitalizations and an increased mortality rate. We estimate that PCM has become more severe throughout the Rio de Janeiro state, affecting a greater number of young individuals and leading to a greater number of and longer hospitalizations. Surveillance measures and close monitoring of future notification data in the state, with emphasis on children, adolescents, and young adults are necessary for a better understanding of the perpetuation of this public health challenge.
PubMed: 37755054
DOI: 10.3390/jof9090946 -
Revista Da Sociedade Brasileira de... 2024Accurate diagnosis of paracoccidioidomycosis is crucial for improving patient outcomes. Paracoccidioides antibody detection by double immunodiffusion (DID) is a...
BACKGROUND
Accurate diagnosis of paracoccidioidomycosis is crucial for improving patient outcomes. Paracoccidioides antibody detection by double immunodiffusion (DID) is a convenient diagnostic tool, but testing performance can vary based on certain factors.
METHODS
We assessed DID performance using a commercially prepared Paracoccidioides reagents (IMMY, USA), involving 40 serum specimens, including 20 from patients with proven paracoccidioidomycosis and 20 from patients without the disease. The DID test demonstrated a sensitivity of 90% (95% CI=68%-99%) and a specificity of 100% (95% CI=83%-100%).
CONCLUSIONS
Our findings suggest that DID using commercial reagents may provide a feasible tool with satisfactory testing performance for anti-Paracoccidioides antibody detection.
Topics: Humans; Sensitivity and Specificity; Antibodies, Fungal; Immunodiffusion; Paracoccidioidomycosis; Paracoccidioides; Reagent Kits, Diagnostic; Female; Male
PubMed: 38808801
DOI: 10.1590/0037-8682-0094-2024 -
Medical Mycology May 2024The epidemiological dynamics of paracoccidioidomycosis (PCM) has been changing over the years. We analyzed secondary public data from the Hospital Information System of...
The epidemiological dynamics of paracoccidioidomycosis (PCM) has been changing over the years. We analyzed secondary public data from the Hospital Information System of the Brazilian Unified Health System (SIH/SUS), focusing on PCM-related hospitalizations and in-hospital deaths. In the period between 2010 and 2019, 396 hospitalizations and 30 deaths were related to PCM among 7 073 334 hospitalizations registered in Rio de Janeiro. We highlight the rising rates, reflecting the increase in the number of acute forms previously reported. Urgent public health policies are essential to prevent poor outcomes related to this neglected mycosis.
Topics: Brazil; Humans; Paracoccidioidomycosis; Hospitalization; Hospital Mortality; Male; Middle Aged; Female; Adult; Aged; Adolescent; Young Adult; Child; Child, Preschool; Aged, 80 and over
PubMed: 38684477
DOI: 10.1093/mmy/myae048