Influence of HLA-DRB-1 alleles on the production of antibody against CSP, MSP-1, AMA-1, and DBP in Brazilian individuals naturally infected with Plasmodium vivax

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo imuno-histoquímico da co-expressão de citoqueratinas, vimentina e actina em neoplasias de glândula salivar

Human salivary gland tumors originated from intercalated ducts present a broad range of histologic and cytologic patterns, mainly due to the presence of myoepithelial cells. The aim of this study is to verify the differentiation grade of neoplastic cells and a possible relation between myoepithelial cell differentiation and the presence of luminal secretory contents. The expression of vimentin and cytokeratin (CK) intermediate filaments, actin myofilament and epithelial membrane antigen (EMA) was investigated by double labeling immunocytochemical technique, in thirty salivary gland neoplasms: 5 pleomorphic adenomas, 5 myoepitheliomas, 3 basal cell adenomas, 7 adenoid cystic carcinomas (ACC) and 10 polimorphous low grade adenocarcinomas (PLGA). Tumors with intercalated duct differentiation (pleomorphic adenomas, basal cell adenomas and ACC) express CKs 7, 8, 18 and 19 in the luminal cells and coexpress eventually CK14 with these CKs. Some luminal cells stained with anti-EMA antibody, mainly where a secretory content in the lumen was observed. Outer ductal cells and other myoepithelial-like cells express vimentin, sometimes coexpressing actin and/or CK14 with vimentin. Plasmacytoid cells in myoepitheliomas and pleomorphic adenomas express vimentin and rarely CKs 7, 8, 18 and 19, sometimes coexpressing these CKs with CK14 but they are negative for the remaining antigens. Tumors without intercalated duct differentiation (solid basal cell adenoma and PLGA) express vimentin and CKs 7, 8, 14 and 18, sometimes coexpressing CKs 8 and 18 with CK14. In conclusion, in tumors with intercalated duct differentiation, myoepithelial cells express vimentin and sometimes coexpress actin and/or CK14 with vimentin, never coexpressing other CKs with vimentin. CK14 and actin are independently expressed by myoepithelial cells, so their expression is probably induced by different stimulus. However, the secretory function of luminal cells, visualized by EMA staining, ....

Calvarial ectopic meningothelial meningioma

Meningiomas are the most common benign neoplasm of the brain whereas ectopic presentation, although reported, is rare. Among these ectopic tumors, there are a group of purely intraosseous meningiomas, which usually are diagnosed differentially from common primary osseous tumor such as fibrous dysplasia and osteoid osteoma. We report a 62-year-old female with a history of headaches and 6 months of progressive right parietal bulging, with no neurological signs. Parietal craniotomy was performed with immediate titanium cranioplasty of the parietal convexity. Histopathology exams revealed an ectopic intradiploic meningioma without invasion of cortical layers, with positive staining for progesterone receptors and epithelial membrane antigen. Ectopic intraosseous meningiomas remain a rare neoplasm with only a few cases reported. The main theories to justify the unusual topography appear to be embryological remains of neuroectodermal tissue or cellular dedifferentiation. Surgical treatment seems the best curative option.

Upregulation of soluble and membrane-bound human leukocyte antigen G expression is primarily observed in the milder histopathological stages of chronic hepatitis C virus infection

Chronic hepatitis C virus (HCV) infection is a worldwide health problem that may evolve to cirrhosis and hepatocellular carcinoma. Incompletely understood immune system mechanisms have been associated with impaired viral clearance. The nonclassical class I human leukocyte antigen G (HLA-G) molecule may downregulate immune system cell functions exhibiting well-recognized tolerogenic properties. HCV genotype was analyzed in chronic HCV-infected patients. Because HLA-G expression may be induced by certain viruses, we evaluated the presence of HLA-G in the liver microenvironment obtained from 89 biopsies of patients harboring chronic HCV infection and stratified according to clinical and histopathological features. Overall, data indicated that HCV genotype 1 was predominant, especially subgenotype 1a, with a prevalence of 87%. HLA-G expression was observed in 45(51%) liver specimens, and it was more frequent in milder stages of chronic hepatitis (67.4%) than in moderate (27.8%; p = 0.009) and severe (36.0%; p = 0.021) stages of the disease. Altogether, these results suggest that the expression of HLA-G in the context of HCV is a complex process modulated by many factors, which may contribute to an immunologic environment favoring viral persistence. However, because the milder forms predominantly expressed HLA-G, a protective role of this molecule may not be excluded. (C) 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier B.V. All rights reserved.

Human Platelet Antigen Genotype Is Associated With Progression of Fibrosis in Chronic Hepatitis C

Although progression of fibrosis in the chronic hepatitis C depends on environmental, viral, and host factors, genetic polymorphisms have been associated recently with this progression, including the expression of integrins, adhesion proteins. Some integrins expressed on the platelet membrane show polymorphic antigenic determinants called human platelet antigens (HPA), where the major ones are HPA-1, -3, -5. The association between HCV infection and HPA-5b has been demonstrated. Similarly, the HPA profile could determine if HPA is related to progression of fibrosis. The goal of this study was to evaluate the association between the frequencies of HPA-1, -3, and -5 and degree of fibrosis in HCV-infected patients. Genomic DNA from 143 HCV-infected patients was used as the source for HPA genotyping by PCR-SSP or PCR-RFLP. Progression of fibrosis was evaluated using the METAVIR scoring system, and the patients were grouped according to degree of fibrosis into G1 (n = 81, with F1, portal fibrosis without septa or F2, few septa) and G2 (n = 62, with F3, numerous septa, or F4, cirrhosis). Statistical analysis was performed using the proportional odds model. The genotypic frequency of HPA-1a/1b was significantly higher in the patients in G2. To evaluate the influence of the time of infection to the development of fibrosis and its effect on the genetic factor HPA-1, 96 patients from 143 studied were evaluated considering the time of HCV infection, and these results suggest that the HPA-1a/1b genotype promotes the development of fibrosis in HCV infection with time. J. Med. Virol. 84: 56-60, 2012. (C) 2011 Wiley Periodicals, Inc.

Protection of calves against Haemonchus placei and Haemonchus contortus after immunization with gut membrane proteins from H. contortus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distinct localization of T cell Agrin during antigen presentation - evidence for the expression of Agrin receptor(s) in antigen-presenting cells

Agrin is over-expressed by activated and autoimmune T cells, and synergizes with the T cell receptor (TCR) to augment cell activation. In the present study, we show that Agrin accumulates to distinct areas of the plasma membrane and that cell activation causes its redistribution. During antigen presentation, Agrin primarily accumulates to the periphery of the mature immunological synapse, mostly in lamellipodia-like protrusions that wrap around the antigen-presenting cell and, conversely, anti-Agrin sera induced a significant redistribution of TCR at the plasma membrane. We also provide evidence for the expression of Agrin receptors in peripheral blood monocytes, dendritic cells and a fraction of B cells. Interestingly, interferon-a treatment, which induces the expression of Agrin in T cells, also augmented Agrin binding to monocytes. Stimulation of monocytes with recombinant Agrin induced the clustering of surface receptors, including major histocompatibility complex class II, activation of intracellular signalling cascades, as well as enhanced dsRNA-induced expression of pro-inflammatory cytokines interleukin-6 and tumour necrosis factor-a. Collectively, these results confirm the location of Agrin at the immunological synapse between T cells and antigen-presenting cells and justify further characterization of its receptors in the immune system.

Expression of human leucocyte antigen-G primarily targets affected skin of patients with psoriasis

P>BackgroundThe nonclassical human leucocyte antigen (HLA)-G molecule has been well recognized as a tolerogenic molecule and few studies have evaluated the role of the molecule in inflammatory cutaneous autoimmune diseases.ObjectivesTo evaluate the expression of HLA-G in skin specimens of patients with psoriasis and to analyse its correlation with epidemiological and clinical variables.MethodsThirty untreated patients with psoriasis and 32 healthy individuals were enrolled. Immunohistochemistry was applied to identify HLA-G expression in formalin-fixed paraffin-embedded cutaneous skin biopsies.ResultsSoluble and membrane-bound HLA-G expression was detected in 30 (90%) of the skin specimens from patients presenting clinical and histopathological features of psoriasis. Although infiltrating lymphomononuclear cells of the dermis exhibited HLA-G expression, the epidermis was primarily targeted. HLA-G expression was also observed in 27% (three of 11) of the specimens that exhibited no clinical and histopathological features of psoriasis (nonaffected areas). In contrast, skin specimens obtained from healthy individuals exhibited no HLA-G expression (P < 0 center dot 0001). The intensity of HLA-G expression was not associated with type I/II psoriasis, Psoriasis Area and Severity Index score or clinical forms.ConclusionsAs the HLA-G molecule was consistently expressed in affected and, to a lesser extent, in nonaffected areas of untreated patients with psoriasis, irrespective of the severity of the clinical variants, one may hypothesize that the presence of HLA-G may be responsible, at least in part, for the regulation of autoimmune effector cells.

Antigen distribution in mucocutaneous biopsies of human paracoccidiomycosis

The authors studied the distribution of Paracoccidioides brasiliensis antigen(s) in human skin and oral mucosa. In biopsies obtained from untreated patients showing the chronic form of the disease, the authors demonstrated the P. brasiliensis antigen using two polyclonal immune sera raised in rabbits, one against the exoantigens of P. brasiliensis and the other against a 43-kDa glycoprotein. Langerhans' cells were detected through double immunolabeling using an anti-S100 protein monoclonal antibody. Double labeling immunohistochemistry showed that both of the immune sera labeled the yeast cells in the center of the granuloma and those transmigrating through the epithelial layer equally well. Granulomas exhibited the P. brasiliensis antigen permeating cells, mainly at the periphery of the granulomatous inflammation. The P. brasiliensis antigen(s) accumulated in the macrophages but not in the Langerhans' cells. P. brasiliensis antigens, detected by antiserum against parasite exoantigens, were also deposited between basal keratinocytes, but not in the granular cells, in 47% of the biopsies. P. brasiliensis antigens, as assessed by immunoelectron microscopic techniques, are present in the cytoplasm of the yeast cells in the host tissues. Antigens are transported to the cell membrane and later excreted through the cell wall. Antigenic deposits are also seen at the fungus-host interface.

Efeito quimiopreventivo e modulador de HLA-G (Human Leukocyte Antigen - G) de Morelloflavona

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)