Cryptococcus neoformans is a human pathogenic fungus that mainly afflicts immunocompromised patie... more Cryptococcus neoformans is a human pathogenic fungus that mainly afflicts immunocompromised patients. One of its virulence strategies is the production of extracellular vesicles (EVs), containing cargo with immunomodulatory properties. We evaluated EV’s characteristics produced by capsular and acapsular strains of C. neoformans (B3501 and ΔCap67, respectively) growing in nutritionally poor or rich media and co-cultures with bone marrow-derived macrophages or dendritic cells from C57BL/6 mice. EVs produced under a poor nutritional condition displayed a larger hydrodynamic size, contained more virulence compounds, and induced a more robust inflammatory pattern than those produced in a rich nutritional medium, independently of strain. We treated infected mice with EVs produced in the rich medium, and the EVs inhibited more genes related to the inflammasome than untreated infected mice. These findings suggest that the EVs participate in the pathogenic processes that result in the dissem...
Most people infected with the fungus Paracoccidioides spp. do not get sick, but approximately 5% ... more Most people infected with the fungus Paracoccidioides spp. do not get sick, but approximately 5% develop paracoccidioidomycosis. Understanding how host immunity determinants influence disease development could lead to novel preventative or therapeutic strategies; hence, we used two mouse strains that are resistant (A/J) or susceptible (B10.A) to P. brasiliensis to study how dendritic cells (DCs) respond to the infection. RNA sequencing analysis showed that the susceptible strain DCs remodeled their transcriptomes much more intensely than those from the resistant strain, agreeing with a previous model of more intense innate immunity response in the susceptible strain. Contrastingly, these cells also repress genes/processes involved in antigen processing and presentation, such as lysosomal activity and autophagy. After the interaction with P. brasiliensis, both DCs and macrophages from the susceptible mouse reduced the autophagy marker LC3-II recruitment to the fungal phagosome compar...
Cryptococcus neoformansis an encapsulated yeast that causes disease mainly in immunosuppressed ho... more Cryptococcus neoformansis an encapsulated yeast that causes disease mainly in immunosuppressed hosts. It is considered a facultative intracellular pathogen because of its capacity to survive and replicate inside phagocytes, especially macrophages. This capacity is heavily dependent on various virulence factors, particularly the glucuronoxylomannan (GXM) component of the polysaccharide capsule, that render the non- or poorly-activated macrophage ineffective against phagocytosed yeast. Strategies utilized by macrophages to prevent this scenario include pyroptosis (a rapid highly inflammatory cell death) and vomocytosis (the expulsion of the pathogen from the intracellular environment without lysis). Inflammasome activation in phagocytes is usually protective against fungal infections, including cryptococcosis. Nevertheless, recognition ofC. neoformansby inflammasome receptors requires specific changes in morphology or the opsonization of the yeast, impairing a proper inflammasome func...
Fonsecaea pedrosoi is the main etiologic agent of chromoblastomycosis (CBM), one of the most prev... more Fonsecaea pedrosoi is the main etiologic agent of chromoblastomycosis (CBM), one of the most prevalent subcutaneous mycosis in tropical and subtropical countries. CBM is a poorly characterized chronic infection that commonly starts after transcutaneous inoculation of conidia and saprophytic hyphae of F. pedrosoi. Recently, we have shown that unlike conidia, hyphae and muriform cells (the parasitic morphotype) of F. pedrosoi promotes an intense inflammatory response pattern in vivo, which comprises the production of an inflammasome-derived cytokine, IL-1β. Nonetheless, the mechanisms underlying IL-1β production and maturation upon F. pedrosoi infection and its functional output in the course of CBM remains unknown. We show here that F. pedrosoi hyphae, differently from conidia, induce IL-1β secretion in both bone marrow-derived dendritic cells and macrophages. Using inhibitors and knockout cells, we demonstrated that the mechanisms underlying IL-1β production by hyphae-infected macro...
A common theme across multiple fungal pathogens is their ability to impair the establishment of a... more A common theme across multiple fungal pathogens is their ability to impair the establishment of a protective immune response. Although early inflammation is beneficial in containing the infection, an uncontrolled inflammatory response is detrimental and may eventually oppose disease eradication. Chromoblastomycosis (CBM), a cutaneous and subcutaneous mycosis, caused by dematiaceous fungi, is capable of inducing a chronic inflammatory response. Muriform cells, the parasitic form of Fonsecaea pedrosoi, are highly prevalent in infected tissues, especially in long-standing lesions. In this study we show that hyphae and muriform cells are able to establish a murine CBM with skin lesions and histopathological aspects similar to that found in humans, with muriform cells being the most persistent fungal form, whereas mice infected with conidia do not reach the chronic phase of the disease. Moreover, in injured tissue the presence of hyphae and especially muriform cells, but not conidia, is ...
International journal of antimicrobial agents, Jan 9, 2017
Mastoparans, a class of peptides found in wasp venom, have significant effects following a sting ... more Mastoparans, a class of peptides found in wasp venom, have significant effects following a sting as well as useful applications in clinical practice. Among these is their potential use in the control of micro-organisms that cause infectious diseases with a significant impact on society. Thus, the present study describes the isolation and identification of a mastoparan peptide from the venom of the social wasp Pseudopolybia vespiceps and evaluated its antimicrobial profile against bacteria (Staphylococcus aureus and Mycobacterium abscessus subsp. massiliense), fungi (Candida albicans and Cryptococcus neoformans) and in vivo S. aureus infection. The membrane pore-forming ability was also assessed. The mastoparan reduced in vitro and ex vivo mycobacterial growth by 80% at 12.5 µM in infected peritoneal macrophages but did not affect the shape of bacterial cells at the dose tested (6.25 µM). The peptide also showed potent action against S. aureus in vitro (EC50 and EC90 values of 1.83 µ...
The black yeast Fonsecaea monophora is one of the main etiologic agents of chromoblastomycosis in... more The black yeast Fonsecaea monophora is one of the main etiologic agents of chromoblastomycosis in humans. Its pathogenicity profile is more invasive than that of related Fonsecaea species, causing brain infection in addition to (sub)cutaneous infections.
Considering the importance of macrophages as the first line of defense against fungal infection a... more Considering the importance of macrophages as the first line of defense against fungal infection and the different roles played by the two M1- and M2-like polarized macrophages, we decided to evaluate the effects ofParacoccidioides brasiliensisinfection on GM-CSF- and M-CSF-induced bone marrow-derived macrophages (BMM) from the A/J and B10.A mouse strains, an established model of resistance/susceptibility to PCM, respectively. Upon differentiation, the generated GM- or M-BMMs were characterized by morphological analyses, gene expression profiles, and cytokines production. Our main results demonstrate that GM-BMMs derived from A/J and B.10 produced high levels of pro- and anti-inflammatory cytokines that may contribute to generate an unbalanced early immune response. In accordance with the literature, the B10.A susceptible mice lineage has an innate tendency to polarize into M1-like phenotype, whereas the opposite phenotype occurs in A/J resistance mice. In this context, our data supp...
Journal of immunology (Baltimore, Md. : 1950), Jan 15, 1998
The activation of the nitric oxide (NO) production system and its involvement in the control of t... more The activation of the nitric oxide (NO) production system and its involvement in the control of the lung fungal burden and in immunosuppression mechanisms were studied during the course of Paracoccidioides brasiliensis-infected mice. Mice that had been infected with the fungus were treated daily with a specific inhibitor of NO synthesis, N omega-nitro-L-arginine, or with buffered saline (control); NO production was assessed on the basis of spontaneous NO2- production by bronchoalveolar and peritoneal macrophages (Mphi) and of serum NO3- levels. The infection coursed with an elevation of NO3- levels. The Mphi produced NO2- and released TNF-alpha only after stimulation with LPS. In addition, the immunoproliferative responses of spleen cells that had been stimulated with the fungus Ag or with Con A were depressed. An examination of the lungs of infected animals showed a progressive increase in the size of the lesions. Treatment of the animals, which resulted in an inhibition of NO2- pr...
ABSTRACTThe rapid increase in the incidence of multidrug-resistant infections today has led to en... more ABSTRACTThe rapid increase in the incidence of multidrug-resistant infections today has led to enormous interest in antimicrobial peptides (AMPs) as suitable compounds for developing unusual antibiotics. In this study, clavanin A, an antimicrobial peptide previously isolated from the marine tunicateStyela clava, was selected as a purposeful molecule that could be used in controlling infection and further synthesized. Clavanin A wasin vitroevaluated againstStaphylococcus aureusandEscherichia colias well as toward L929 mouse fibroblasts and skin primary cells (SPCs). Moreover, this peptide was challenged here in anin vivowound and sepsis model, and the immune response was also analyzed. Despite displaying clearin vitroantimicrobial activity toward Gram-positive and -negative bacteria, clavanin A showed no cytotoxic activities against mammalian cells, and in acute toxicity tests, no adverse reaction was observed at any of the concentrations. Moreover, clavanin A significantly reduced t...
Virulence factors represent crucial molecular features for understanding pathogenic mechanisms. H... more Virulence factors represent crucial molecular features for understanding pathogenic mechanisms. Here we describe a pipeline for in silico prediction of virulence factor genes in Mycobacterium massiliense genome that could be easily used in many other bacterial systems. Some few methods for this characterization are described in the literature, however these approaches are usually time-consuming and require information not always readily available. Using the proposed pipeline, the number and the accuracy of predicted ORF annotation were increased, and a broad identification of virulence factors could be achieved. Based on these results, we were able to construct a general pathogenic profile of M. massiliense. Furthermore, two important metabolic pathways, production of siderophores and bacterial secretion systems, both related to M. massiliense's pathogenicity, were investigated.
O presente trabalho objetivou avaliar, em vacas e em búfalas submetidas à mastite induzida por in... more O presente trabalho objetivou avaliar, em vacas e em búfalas submetidas à mastite induzida por inoculação de Staphylococcus aureus, a concentração da citocina pró-inflamatória interleucina-1β (IL-1β), a contagem de células somáticas (CCS) e a correlação destas com alguns parâmetros da resposta local e sistêmica à inflamação. Os animais tiveram uma glândula mamária inoculada e o processo inflamatório foi monitorado pela cultura bacteriológica do leite, CCS, quantificação da IL-1β na secreção láctea, avaliação da aparência/consistência da glândula, aparência da secreção láctea (resposta localizada à inflamação) e aferição da temperatura retal (resposta sistêmica à inflamação). Houve elevação nos níveis de IL-1β, na CCS e resposta localizada e sistêmica à inflamação, tanto na espécie bovina como na bubalina. A cinética da produção da citocina foi diferente nas duas espécies (P<0,05), sendo que as búfalas apresentaram elevação mais rápida, porém com níveis menos elevados, quando comp...
Due to a lack of molecular tools that enable gain- and loss-of-function studies, much research wi... more Due to a lack of molecular tools that enable gain- and loss-of-function studies, much research with the fungi of the Paracoccidioides genus has consisted of gene expression studies. These have addressed the direct interaction of these fungi with the mammalian host or their response to environmental stimuli of interest to the study of their adaptability to said host, such as the temperature shift that triggers dimorphic transition. In this chapter, we present a review of findings of host–pathogen interaction studies and what evidence they found of mechanisms whereby Paracoccidioides is able to overcome differences in environment and establish disease, and of how the host responds to the pathogen. In the first part, which deals with the pathogen response, expression studies have identified metabolic pathways genes thereof are upregulated when the fungi are exposed to different organs, as well as blood and derivatives, of mice and humans. Of note, these studies have suggested an important role, in the adaptation to host tissues, of a metabolic shift away from glycolysis and aerobic respiration and towards fermentative and non-aerobic ways of obtaining energy. With regard to the remarkable preference of the genus for male hosts, studies of the response of Paracoccidioides to oestradiol have suggested a role of Rho GTPases in the process. As for the second part, dealing with the host response to the fungus, despite the paucity of data, the few large-scale studies available offer evidence to support the model whereby Th1-driven immune responses are protective and disease is associated with Th2 and Th17 responses, in keeping with small-scale studies. Overall, gene expression studies have supplied a large amount of data that lack direct experimental confirmation but which keep revealing new research avenues.
The aims of this work were (a) to evaluate the prevalence of coeliac disease (CD) in a large samp... more The aims of this work were (a) to evaluate the prevalence of coeliac disease (CD) in a large sample of the Brazilian general population and (b) to compare CD prevalence between children and adults. The study group comprised 4405 subjects (2629 F and 1776 M). Age distributions were 2034 (1-14 years), 848 (15-29), 584 (30-44), 667 (45-59) and 272 above 60. The immunoglobulin A antiendomysial antibody (IgA-EMA) test was used as the serological screening tool. All sera were submitted to turbidimetric measurement of IgA levels and those with IgA deficiency to the IgG antigliadin (IgG-AGA) test. The small intestinal biopsy was recommended for subjects showing either (a) IgA-EMA positivity or (b) selective IgA deficiency (SigAD) and IgG-AGA positivity. There were 16 EMA positive out of 4405 sera tested. SigAD was found in five cases (one adult and four children). Two of these children tested positive for IgG-AGA and underwent jejunal biopsy that, in both cases, disclosed a normal mucosa. Overall, 17 out of 18 eligible subjects performed the small intestinal biopsy. The prevalence of biopsy-proven CD in this study group was 3.41 per 1000 individuals. If all 18 EMA-positive patients were included, the overall prevalence would become 3.63 per 1000. The prevalence in adults and children was 2.11 per 1000 and 5.44 per 1000, respectively. This work supports previous findings showing that CD is not a rare disorder in Brazil and that there is an unexplained difference in the prevalence of CD between adults and children.
Cryptococcus neoformans is a human pathogenic fungus that mainly afflicts immunocompromised patie... more Cryptococcus neoformans is a human pathogenic fungus that mainly afflicts immunocompromised patients. One of its virulence strategies is the production of extracellular vesicles (EVs), containing cargo with immunomodulatory properties. We evaluated EV’s characteristics produced by capsular and acapsular strains of C. neoformans (B3501 and ΔCap67, respectively) growing in nutritionally poor or rich media and co-cultures with bone marrow-derived macrophages or dendritic cells from C57BL/6 mice. EVs produced under a poor nutritional condition displayed a larger hydrodynamic size, contained more virulence compounds, and induced a more robust inflammatory pattern than those produced in a rich nutritional medium, independently of strain. We treated infected mice with EVs produced in the rich medium, and the EVs inhibited more genes related to the inflammasome than untreated infected mice. These findings suggest that the EVs participate in the pathogenic processes that result in the dissem...
Most people infected with the fungus Paracoccidioides spp. do not get sick, but approximately 5% ... more Most people infected with the fungus Paracoccidioides spp. do not get sick, but approximately 5% develop paracoccidioidomycosis. Understanding how host immunity determinants influence disease development could lead to novel preventative or therapeutic strategies; hence, we used two mouse strains that are resistant (A/J) or susceptible (B10.A) to P. brasiliensis to study how dendritic cells (DCs) respond to the infection. RNA sequencing analysis showed that the susceptible strain DCs remodeled their transcriptomes much more intensely than those from the resistant strain, agreeing with a previous model of more intense innate immunity response in the susceptible strain. Contrastingly, these cells also repress genes/processes involved in antigen processing and presentation, such as lysosomal activity and autophagy. After the interaction with P. brasiliensis, both DCs and macrophages from the susceptible mouse reduced the autophagy marker LC3-II recruitment to the fungal phagosome compar...
Cryptococcus neoformansis an encapsulated yeast that causes disease mainly in immunosuppressed ho... more Cryptococcus neoformansis an encapsulated yeast that causes disease mainly in immunosuppressed hosts. It is considered a facultative intracellular pathogen because of its capacity to survive and replicate inside phagocytes, especially macrophages. This capacity is heavily dependent on various virulence factors, particularly the glucuronoxylomannan (GXM) component of the polysaccharide capsule, that render the non- or poorly-activated macrophage ineffective against phagocytosed yeast. Strategies utilized by macrophages to prevent this scenario include pyroptosis (a rapid highly inflammatory cell death) and vomocytosis (the expulsion of the pathogen from the intracellular environment without lysis). Inflammasome activation in phagocytes is usually protective against fungal infections, including cryptococcosis. Nevertheless, recognition ofC. neoformansby inflammasome receptors requires specific changes in morphology or the opsonization of the yeast, impairing a proper inflammasome func...
Fonsecaea pedrosoi is the main etiologic agent of chromoblastomycosis (CBM), one of the most prev... more Fonsecaea pedrosoi is the main etiologic agent of chromoblastomycosis (CBM), one of the most prevalent subcutaneous mycosis in tropical and subtropical countries. CBM is a poorly characterized chronic infection that commonly starts after transcutaneous inoculation of conidia and saprophytic hyphae of F. pedrosoi. Recently, we have shown that unlike conidia, hyphae and muriform cells (the parasitic morphotype) of F. pedrosoi promotes an intense inflammatory response pattern in vivo, which comprises the production of an inflammasome-derived cytokine, IL-1β. Nonetheless, the mechanisms underlying IL-1β production and maturation upon F. pedrosoi infection and its functional output in the course of CBM remains unknown. We show here that F. pedrosoi hyphae, differently from conidia, induce IL-1β secretion in both bone marrow-derived dendritic cells and macrophages. Using inhibitors and knockout cells, we demonstrated that the mechanisms underlying IL-1β production by hyphae-infected macro...
A common theme across multiple fungal pathogens is their ability to impair the establishment of a... more A common theme across multiple fungal pathogens is their ability to impair the establishment of a protective immune response. Although early inflammation is beneficial in containing the infection, an uncontrolled inflammatory response is detrimental and may eventually oppose disease eradication. Chromoblastomycosis (CBM), a cutaneous and subcutaneous mycosis, caused by dematiaceous fungi, is capable of inducing a chronic inflammatory response. Muriform cells, the parasitic form of Fonsecaea pedrosoi, are highly prevalent in infected tissues, especially in long-standing lesions. In this study we show that hyphae and muriform cells are able to establish a murine CBM with skin lesions and histopathological aspects similar to that found in humans, with muriform cells being the most persistent fungal form, whereas mice infected with conidia do not reach the chronic phase of the disease. Moreover, in injured tissue the presence of hyphae and especially muriform cells, but not conidia, is ...
International journal of antimicrobial agents, Jan 9, 2017
Mastoparans, a class of peptides found in wasp venom, have significant effects following a sting ... more Mastoparans, a class of peptides found in wasp venom, have significant effects following a sting as well as useful applications in clinical practice. Among these is their potential use in the control of micro-organisms that cause infectious diseases with a significant impact on society. Thus, the present study describes the isolation and identification of a mastoparan peptide from the venom of the social wasp Pseudopolybia vespiceps and evaluated its antimicrobial profile against bacteria (Staphylococcus aureus and Mycobacterium abscessus subsp. massiliense), fungi (Candida albicans and Cryptococcus neoformans) and in vivo S. aureus infection. The membrane pore-forming ability was also assessed. The mastoparan reduced in vitro and ex vivo mycobacterial growth by 80% at 12.5 µM in infected peritoneal macrophages but did not affect the shape of bacterial cells at the dose tested (6.25 µM). The peptide also showed potent action against S. aureus in vitro (EC50 and EC90 values of 1.83 µ...
The black yeast Fonsecaea monophora is one of the main etiologic agents of chromoblastomycosis in... more The black yeast Fonsecaea monophora is one of the main etiologic agents of chromoblastomycosis in humans. Its pathogenicity profile is more invasive than that of related Fonsecaea species, causing brain infection in addition to (sub)cutaneous infections.
Considering the importance of macrophages as the first line of defense against fungal infection a... more Considering the importance of macrophages as the first line of defense against fungal infection and the different roles played by the two M1- and M2-like polarized macrophages, we decided to evaluate the effects ofParacoccidioides brasiliensisinfection on GM-CSF- and M-CSF-induced bone marrow-derived macrophages (BMM) from the A/J and B10.A mouse strains, an established model of resistance/susceptibility to PCM, respectively. Upon differentiation, the generated GM- or M-BMMs were characterized by morphological analyses, gene expression profiles, and cytokines production. Our main results demonstrate that GM-BMMs derived from A/J and B.10 produced high levels of pro- and anti-inflammatory cytokines that may contribute to generate an unbalanced early immune response. In accordance with the literature, the B10.A susceptible mice lineage has an innate tendency to polarize into M1-like phenotype, whereas the opposite phenotype occurs in A/J resistance mice. In this context, our data supp...
Journal of immunology (Baltimore, Md. : 1950), Jan 15, 1998
The activation of the nitric oxide (NO) production system and its involvement in the control of t... more The activation of the nitric oxide (NO) production system and its involvement in the control of the lung fungal burden and in immunosuppression mechanisms were studied during the course of Paracoccidioides brasiliensis-infected mice. Mice that had been infected with the fungus were treated daily with a specific inhibitor of NO synthesis, N omega-nitro-L-arginine, or with buffered saline (control); NO production was assessed on the basis of spontaneous NO2- production by bronchoalveolar and peritoneal macrophages (Mphi) and of serum NO3- levels. The infection coursed with an elevation of NO3- levels. The Mphi produced NO2- and released TNF-alpha only after stimulation with LPS. In addition, the immunoproliferative responses of spleen cells that had been stimulated with the fungus Ag or with Con A were depressed. An examination of the lungs of infected animals showed a progressive increase in the size of the lesions. Treatment of the animals, which resulted in an inhibition of NO2- pr...
ABSTRACTThe rapid increase in the incidence of multidrug-resistant infections today has led to en... more ABSTRACTThe rapid increase in the incidence of multidrug-resistant infections today has led to enormous interest in antimicrobial peptides (AMPs) as suitable compounds for developing unusual antibiotics. In this study, clavanin A, an antimicrobial peptide previously isolated from the marine tunicateStyela clava, was selected as a purposeful molecule that could be used in controlling infection and further synthesized. Clavanin A wasin vitroevaluated againstStaphylococcus aureusandEscherichia colias well as toward L929 mouse fibroblasts and skin primary cells (SPCs). Moreover, this peptide was challenged here in anin vivowound and sepsis model, and the immune response was also analyzed. Despite displaying clearin vitroantimicrobial activity toward Gram-positive and -negative bacteria, clavanin A showed no cytotoxic activities against mammalian cells, and in acute toxicity tests, no adverse reaction was observed at any of the concentrations. Moreover, clavanin A significantly reduced t...
Virulence factors represent crucial molecular features for understanding pathogenic mechanisms. H... more Virulence factors represent crucial molecular features for understanding pathogenic mechanisms. Here we describe a pipeline for in silico prediction of virulence factor genes in Mycobacterium massiliense genome that could be easily used in many other bacterial systems. Some few methods for this characterization are described in the literature, however these approaches are usually time-consuming and require information not always readily available. Using the proposed pipeline, the number and the accuracy of predicted ORF annotation were increased, and a broad identification of virulence factors could be achieved. Based on these results, we were able to construct a general pathogenic profile of M. massiliense. Furthermore, two important metabolic pathways, production of siderophores and bacterial secretion systems, both related to M. massiliense's pathogenicity, were investigated.
O presente trabalho objetivou avaliar, em vacas e em búfalas submetidas à mastite induzida por in... more O presente trabalho objetivou avaliar, em vacas e em búfalas submetidas à mastite induzida por inoculação de Staphylococcus aureus, a concentração da citocina pró-inflamatória interleucina-1β (IL-1β), a contagem de células somáticas (CCS) e a correlação destas com alguns parâmetros da resposta local e sistêmica à inflamação. Os animais tiveram uma glândula mamária inoculada e o processo inflamatório foi monitorado pela cultura bacteriológica do leite, CCS, quantificação da IL-1β na secreção láctea, avaliação da aparência/consistência da glândula, aparência da secreção láctea (resposta localizada à inflamação) e aferição da temperatura retal (resposta sistêmica à inflamação). Houve elevação nos níveis de IL-1β, na CCS e resposta localizada e sistêmica à inflamação, tanto na espécie bovina como na bubalina. A cinética da produção da citocina foi diferente nas duas espécies (P<0,05), sendo que as búfalas apresentaram elevação mais rápida, porém com níveis menos elevados, quando comp...
Due to a lack of molecular tools that enable gain- and loss-of-function studies, much research wi... more Due to a lack of molecular tools that enable gain- and loss-of-function studies, much research with the fungi of the Paracoccidioides genus has consisted of gene expression studies. These have addressed the direct interaction of these fungi with the mammalian host or their response to environmental stimuli of interest to the study of their adaptability to said host, such as the temperature shift that triggers dimorphic transition. In this chapter, we present a review of findings of host–pathogen interaction studies and what evidence they found of mechanisms whereby Paracoccidioides is able to overcome differences in environment and establish disease, and of how the host responds to the pathogen. In the first part, which deals with the pathogen response, expression studies have identified metabolic pathways genes thereof are upregulated when the fungi are exposed to different organs, as well as blood and derivatives, of mice and humans. Of note, these studies have suggested an important role, in the adaptation to host tissues, of a metabolic shift away from glycolysis and aerobic respiration and towards fermentative and non-aerobic ways of obtaining energy. With regard to the remarkable preference of the genus for male hosts, studies of the response of Paracoccidioides to oestradiol have suggested a role of Rho GTPases in the process. As for the second part, dealing with the host response to the fungus, despite the paucity of data, the few large-scale studies available offer evidence to support the model whereby Th1-driven immune responses are protective and disease is associated with Th2 and Th17 responses, in keeping with small-scale studies. Overall, gene expression studies have supplied a large amount of data that lack direct experimental confirmation but which keep revealing new research avenues.
The aims of this work were (a) to evaluate the prevalence of coeliac disease (CD) in a large samp... more The aims of this work were (a) to evaluate the prevalence of coeliac disease (CD) in a large sample of the Brazilian general population and (b) to compare CD prevalence between children and adults. The study group comprised 4405 subjects (2629 F and 1776 M). Age distributions were 2034 (1-14 years), 848 (15-29), 584 (30-44), 667 (45-59) and 272 above 60. The immunoglobulin A antiendomysial antibody (IgA-EMA) test was used as the serological screening tool. All sera were submitted to turbidimetric measurement of IgA levels and those with IgA deficiency to the IgG antigliadin (IgG-AGA) test. The small intestinal biopsy was recommended for subjects showing either (a) IgA-EMA positivity or (b) selective IgA deficiency (SigAD) and IgG-AGA positivity. There were 16 EMA positive out of 4405 sera tested. SigAD was found in five cases (one adult and four children). Two of these children tested positive for IgG-AGA and underwent jejunal biopsy that, in both cases, disclosed a normal mucosa. Overall, 17 out of 18 eligible subjects performed the small intestinal biopsy. The prevalence of biopsy-proven CD in this study group was 3.41 per 1000 individuals. If all 18 EMA-positive patients were included, the overall prevalence would become 3.63 per 1000. The prevalence in adults and children was 2.11 per 1000 and 5.44 per 1000, respectively. This work supports previous findings showing that CD is not a rare disorder in Brazil and that there is an unexplained difference in the prevalence of CD between adults and children.
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