[Show abstract][Hide abstract] ABSTRACT: In our previous study, we have found that 5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]-pyrimidin-4-ylamine (BAY 41-2272), a guanylate cyclase agonist, activates human monocytes and the THP-1 cell line to produce the superoxide anion, increasing in vitro microbicidal activity, suggesting that this drug can be used to modulate immune functioning in primary immunodeficiency patients. In the present work, we investigated the potential of the in vivo administration of BAY 41-2272 for the treatment of Candida albicans and Staphylococcus aureus infections introduced via intraperitoneal and subcutaneous inoculation. We found that intraperitoneal treatment with BAY 41-2272 markedly increased macrophage-dependent cell influx to the peritoneum in addition to macrophage functions, such as spreading, zymosan particle phagocytosis and nitric oxide and phorbol myristate acetate-stimulated hydrogen peroxide production. Treatment with BAY 41-2272 was highly effective in reducing the death rate due to intraperitoneal inoculation of C. albicans, but not S. aureus. However, we found that in vitro stimulation of peritoneal macrophages with BAY 41-2272 markedly increased microbicidal activities against both pathogens. Our results show that the prevention of death by the treatment of C. albicans-infected mice with BAY 41-2272 might occur primarily by the modulation of the host immune response through macrophage activation.
Full-text · Article · Jan 2015 · Memórias do Instituto Oswaldo Cruz
[Show abstract][Hide abstract] ABSTRACT: Hyper-IgM (HIGM) syndrome is a heterogeneous group of disorders characterized by normal or elevated serum IgM levels associated with absent or decreased IgG, IgA and IgE. Here we summarize data from the HIGM syndrome Registry of the Latin American Society for Immunodeficiencies (LASID). Of the 58 patients from 51 families reported to the registry with the clinical phenotype of HIGM syndrome, molecular defects were identified in 37 patients thus far. We retrospectively analyzed the clinical, immunological and molecular data from these 37 patients. CD40 ligand (CD40L) deficiency was found in 35 patients from 25 families and activation-induced cytidine deaminase (AID) deficiency in 2 unrelated patients. Five previously unreported mutations were identified in the CD40L gene (CD40LG). Respiratory tract infections, mainly pneumonia, were the most frequent clinical manifestation. Previously undescribed fungal and opportunistic infections were observed in CD40L-deficient patients but not in the two patients with AID deficiency. These include the first cases of pneumonia caused by Mycoplasma pneumoniae, Serratia marcescens or Aspergillus sp. and diarrhea caused by Microsporidium sp. or Isospora belli. Except for four CD40L-deficient patients who died from complications of presumptive central nervous system infections or sepsis, all patients reported in this study are alive. Four CD40L-deficient patients underwent successful bone marrow transplantation. This report characterizes the clinical and genetic spectrum of HIGM syndrome in Latin America and expands the understanding of the genotype and phenotype of this syndrome in tropical areas.
Full-text · Article · Jan 2014 · Journal of Clinical Immunology
[Show abstract][Hide abstract] ABSTRACT: Introduction: At least 20% of children up to 2 years old show recurrent wheezing (RW) that has been generally associated with asthma diagnosis. Aim: Evaluate surface markers, transcription factors and cytokine production in cells from RW children. Methods: We evaluated 25 RW and 9 non-RW children (around 30 months of age). Surface markers and transcriptional factors were analyzed by flow cytometry on peripheral blood mononuclear cells (PMBC). Cytokine production was also assessedin response to in vitro stimulation with TLR2, 3, 4, 5, 7 and NOD agonists; f-MLP; Der p, Blo t and Bla g allergens; IFN-?; and IL-12. Results: We observed no differences in cell surface receptors (p>0.05). However, lymphocytes from RW children expressed higher levels of STAT3 and T-bet compared with non-RW (p
[Show abstract][Hide abstract] ABSTRACT: Since neutrophil extracellular traps (NETs) is an important strategy, and in some cases decisive in resolution of infections, we analyzed NETs generation in patients presenting severe fungal infection. We conducted a study of 6 patients with severe chronic candidiasis and one with APECED (AIRE-1 deficiency). The NET generation assay was based on specific labeling of histone, elastase and DNA to be analyzed by fluorescence microscopy. We also evaluated the oxidative burst by flow cytometry (DHR oxidation) and myeloperoxidase (MPO) function by chemiluminescence. We performed in vitro assays with neutrophil treated or not with PMA (100 nM), C. albicans (2:1), Curdlan and depleted Zymosan (both 100 μg/mL). From the 7 patients analyzed, 4 have failed to generate NETs (< 5% of total area compared to NETs area from control). This failure was more evident when neutrophils from patients were stimulated specifically with C. albicans (p < 0.01, ANOVA). The APECED patient also showed failure in NETs generation when stimulated with dectin-1 (AIRE-1 signalling pathway) agonists. All patients had NADPH oxidase and MPO normal function. Our results starts a study of a new standard of primary immunodeficiency involving the specific failure on NETs production associated with susceptibility to C. albicans. Furthermore, we confirmed that AIRE-1 is important in the neutrophils response to candida.
[Show abstract][Hide abstract] ABSTRACT: CD40 ligand (CD40L) deficiency or X-linked hyper-IgM syndrome (X-HIGM) is a well-described primary immunodeficiency in which Pneumocystis jiroveci pneumonia is a common clinical feature. We have identified an unusual high incidence of fungal infections and other not yet described infections in a cohort of 11 X-HIGM patients from nine unrelated Brazilian families. Among these, we describe the first case of paracoccidioidomycosis (PCM) in X-HIGM. The molecular genetic analysis of CD40L was performed by gene sequencing and evaluation of CD40L protein expression. Nine of these 11 patients (82%) had fungal infections. These included fungal species common to CD40L deficiency (P. jiroveci and Candida albicans) as well as Paracoccidioides brasiliensis. One patient presented with PCM at age 11 years and is now doing well at 18 years of age. Additionally, one patient presented with a simultaneous infection with Klebsiella and Acinetobacter, and one with condyloma caused by human papilloma virus. Molecular analysis revealed four previously described CD40L mutations, two novel missense mutations (c.433 T > G and c.476 G > C) resulting in the absence of CD40L protein expression by activated CD4(+) cells and one novel insertion (c.484_485insAA) within the TNFH domain leading to a frame shift and premature stop codon. These observations demonstrated that the susceptibility to fungal infections in X-HIGM extends beyond those typically associated with X-HIGM (P. jiroveci and C. albicans) and that these patients need to be monitored for those pathogens.
Full-text · Article · Dec 2011 · Journal of Clinical Immunology
[Show abstract][Hide abstract] ABSTRACT: Phagocyte function is critical for host defense against infections. Defects in phagocytic function lead to several primary immunodeficiencies characterized by early onset of recurrent and severe infections. In this work, we further investigated the effects of BAY 41-2272, a soluble guanylate cyclase (sGC) agonist, on the activation of human peripheral blood monocytes (PBM) and THP-1 cells.
THP-1 cells and PBM viability was evaluated by methylthiazoletetrazolium assay; reactive oxygen species production by lucigenin chemiluminescence; gene and protein expression of NAPDH oxidase components by qRT-PCR and Western blot analysis, respectively; phagocytosis and microbicidal activity by co-incubation, respectively, with zymosan and Escherichia coli; and cytokine release by elisa.
BAY 41-2272, compared with the untreated group, increased spreading of monocytes by at least 35%, superoxide production by at least 50%, and gp91(PHOX) and p67(PHOX) gene expression 20 to 40 times, in both PBM and THP-1 cells. BAY 41-2272 also augmented phagocytosis of zymosan particles threefold compared with control, doubled microbicidal activity against E. coli and enhanced the release of TNF-α and IL-12p70 by both PBM and THP-1 cells. Finally, by inhibiting sGC with ODQ, we showed that BAY 41-2272-induced superoxide production and phagocytosis is not dependent exclusively on sGC activation.
In addition to its ability to induce vasorelaxation and its potential application for therapy of vascular diseases, BAY 41-2272 was shown to activate human mononuclear phagocytes. Hence, it is a novel pro-inflammatory drug that may be useful for controlling infections in the immunocompromised host.
Full-text · Article · Nov 2011 · British Journal of Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Infection with Toxoplasma gondii results in retinochoroiditis in 6% to 20% of immunocompetent individuals. The outcome of infection is the result of a set of interactions involving host genetic background, environmental, and social factors, and the genetic background of the parasite, all of which can be further modified by additional infections or even reinfection. Genes that encode several components of the immune system exhibit polymorphisms in their regulatory and coding regions that affect level and type of expression in response to stimuli, directing the immune response into different pathways. These variant alleles have been associated with susceptibility to immune-mediated diseases and with severity of pathology. We have investigated polymorphisms in several of these genes, identified as candidates for progression to retinochoroiditis caused by toxoplasmosis, namely chemokine (C-C motif) receptor 5 (CCR5), toll-like receptor-2 (TLR2), and TLR4. Furthermore, because interleukin-12 (IL-12) has been shown to be fundamental both in mice and in man to control a protective response against T. gondii, molecules that have a key function in IL-12 production will be emphasized in this review, in addition to discussing the importance of the genetic background of the parasite in the establishment of ocular disease.