Paulo Eduardo Alencar Souza

Recruitment of CD8+ T cells expressing granzyme A is associated with lesion progression in human cutaneous leishmaniasis

Human infection with Leishmania braziliensis leads to the establishment of cutaneous leishmaniasis (CL), characterized by the appearance of skin lesions that progress from nonulcerated to ulcerated forms. Our goal was to characterize the immunological kinetics associated with this progression, comparing the cellular composition, cytokines and granzyme expression between lesions of patients with early (E‐CL) and late stages (L‐CL) of CL. Histopathological analysis showed that lesions from L‐CL had more exuberant inflammatory infiltrate as compared to E‐CL. Although E‐CL and L‐CL lesions were predominantly mononuclear, lesions from E‐CL patients presented higher neutrophil and eosinophil counts than L‐CL. While percentages of CD4+ and of CD68+ cells were slightly higher in L‐CL, a fivefold increase of CD8+ cells was observed in L‐CL, as compared to E‐CL. Moreover, CD8+ T‐cells from L‐CL expressed significantly higher levels of granzyme A than E‐CL. Interestingly, granzyme A expression was positively correlated with intensity of the inflammatory infiltrate in L‐CL but not E‐CL. Lastly, percentages of IFN‐γ+ and IL‐10+ cells were higher in L‐CL as compared to E‐CL, with CD4+ T‐cells and CD68+ monocytes as the main sources of these cytokines, respectively. These results suggest that recruitment of CD8+ granzyme A+ T cells is involved in lesion progression in human CL.

Anatomic variations and lesions of the maxillary sinus detected in cone beam computed tomography for dental implants

OBJECTIVE To evaluate the presence of anatomic variations and lesions of the maxillary sinus in cone beam computed tomography (CBCT) of the maxilla required for dental implant planning. MATERIAL AND METHODS This transversal prevalence study evaluated a sample of 500 consecutive CBCT exams. The inclusion criteria were CBCT exams of the maxilla required for dental implant planning. The CBCT exams were independently evaluated by two oral and maxillofacial radiologists who assessed the presence of anatomic variations and lesions of the maxillary sinus. As most of the CBCT exams did not allow the evaluation of the area close to the maxillary sinus roof, anatomic variations that take place at this site were not assessed. RESULTS The anatomic variations detected were pneumatization (83.2%), antral septa (44.4%), hypoplasia (4.8%), and exostosis (2.6%). The identified lesions were mucosal thickening (≤3 mm in 54.8% and >3 mm in 62.6%), polypoid lesions (21.4%), discontinuity of the sinus floor (17.4%), air-fluid level (4.4%), bone thickening of the maxillary sinus wall (3.8%), antroliths (3.2%), discontinuity of the sinus lateral wall (2.6%), sinus opacification (1.8%), and foreign body (1.6%). CONCLUSION Anatomic variations and lesions of the maxillary sinus were common findings in CBCT exams of the maxilla required for dental implant planning. As some of these conditions can modify dental implant planning and must require specialized treatment, its recognition is noteworthy in dental practice, and especially in implantology. The amount and significance of the anatomic variations and lesions detected in this study reinforces the importance of computed tomography in preoperative dental implant planning.

Phenotypic and functional characteristics of CD28+ and CD28− cells from chagasic patients: distinct repertoire and cytokine expression

Chronic human Chagas’ disease ranges from an asymptomatic to a severe cardiac clinical form. The involvement of the hosts immune response in the development and maintenance of chagasic pathology has been demonstrated by several groups. We have shown that activated T‐cells lacking CD28 expression are increased in the peripheral blood of chagasic patients (CP), suggesting a relationship between these cells and disease. In order to better characterize this cell population, determining their possible role in immunoregulation of human Chagas’ disease, we evaluated the expression of TCR‐Vbeta regions 2, 3·1, 5, 8 and 17, as well as the expression of IFN‐γ, TNF‐α, IL‐4 and IL‐10 by CD28+ and CD28− cells from polarized indeterminate and cardiac CP. Flow cytometric analysis demonstrated equivalent TCR‐Vbeta usage between CD4+CD28+ and CD4+CD28− cells from all groups (chagasic and healthy controls). However, there was a predominance of Vbeta5 expression in the CD28+ and CD28− populations in the CP groups (indeterminate and cardiac). Interestingly, CD8+CD28− cells from CP, but not from nonchagasic individuals, displayed a reduced frequency of most analysed Vbetas when compared with the CD8+CD28+ subpopulation. Comparison of V‐beta expression in CD28+ or CD28− cell populations among individuals from different groups also showed several interesting differences. Functionally, cardiac CP displayed a higher frequency of IFN‐γ, TNF‐α and IL‐4 producing lymphocytes than indeterminate CP. Correlation analysis between the frequency of cytokine expressing cells, and the frequency of CD4+ T‐cells with differential expression of CD28 demonstrated that CD4+CD28− T‐cells were positively correlated with TNF‐α in cardiac and with IL‐10 in indeterminate CP, suggesting that these cells might have an important regulatory role in human Chagas’ disease.

Expression of epithelial-mesenchymal transition markers at the invasive front of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common malignances. In epithelial-mesenchymal transition (EMT), epithelial cells switch to mesenchymal-like cells exhibiting high mobility. This migratory phenotype is significant during tumor invasion and metastasis. Objective : The aim of this study is to evaluate the expression of the EMT markers E-cadherin, N-cadherin and vimentin in OSCC. Material and Methods : Immunohistochemical detection of E-cadherin, N-cadherin and vimentin was performed on 20 OSCC samples. Differences in the expression of each protein at the invasive front (IF) and in the central/superficial areas (CSA) of the tumor were assessed. Differences in the expression of each protein at the IF of both histologically high- and low-invasive OSCCs were evaluated. Associations among expression of proteins at the IF were assessed. Correlations between the expression levels of each protein at the IF and the tumor stage and clinical nodal status were also evaluated. Results : Reduced expression of E-cadherin was detected in 15 samples (75%). E-cadherin expression was reduced at the IF when compared to the CSA and in high-invasive tumors when compared to low-invasive tumors. All samples were negative for N-cadherin, even though one sample showed an inconspicuous expression. Positive expression of vimentin was observed in 6 samples (30%). Nevertheless, there was no difference in vimentin expression between the IF and the CSA regions or between the low- and high-invasive tumors. Furthermore, no association was observed among protein expression levels at the IF. Finally, no correlations were observed between each protein’s expression levels and tumor stage or clinical nodal status. Conclusions : Reduced E-cadherin expression at the IF and its association with histological invasiveness suggest that this protein is a noteworthy EMT marker in OSCC. Although vimentin was also detected as an EMT marker, its expression was neither limited to the IF nor was it related to histological invasiveness.

Aggressive and Chronic Periodontitis Correlate With Distinct Cellular Sources of Key Immunoregulatory Cytokines

BACKGROUND Chronic periodontitis (CP) and aggressive periodontitis (AP) are inflammatory diseases and the main cause of dental loss in adults. We aimed to investigate the expression of adhesion molecules and the source of proinflammatory and anti-inflammatory cytokines in circulating mononuclear cells from patients with CP and AP. METHODS Peripheral blood mononuclear cells from healthy controls and CP or AP patients were collected. The expression of the cell adhesion molecules CD11a and CD11b, and the cellular sources of interleukin (IL)-4, IL-10, IL-12, interferon-γ, and tumor necrosis factor-α by distinct subpopulations of circulating leukocytes were determined using flow cytometry. RESULTS The expression of CD11a, but not CD11b, was significantly higher within the CD4(+) and CD8(+) T cells in CP and AP than in healthy controls. The frequencies of tumor necrosis factor-α-expressing CD4(+) T cells and CD14(+) cells were higher in AP and CP, compared to healthy controls, respectively. Moreover, the frequency of IL-10 expressing CD14(+) cells was higher in CP, but not AP, compared to healthy controls CD4(+) T cells committed to IL-4 production was higher in CP than in healthy controls. CONCLUSION These results suggest the participation of CD11a in the pathogenesis of periodontal lesions and show distinct cellular sources of immunoregulatory cytokines in AP versus CP.

Implications of cytokine gene polymorphisms on the orchestration of the immune response: Lessons learned from oral diseases

Over the past 10 years, a plethora of information concerning the influence of gene polymorphisms on cytokine expression has been made available in the literature. Significant contribution to this field has come from studies of oral diseases, one of the widest spread health problems in the world, affecting hundreds of millions worldwide. Here we will discuss the importance of studies of gene polymorphism towards the identification of susceptible groups or prognostic indicators of oral disease. Additionally, we will highlight the differences in data obtained from genetically diverse populations and review the application of cytokine gene polymorphisms studies in oral diseases in autoimmune processes and parasitic infections.

Laminin-5 gamma 2 chain expression is associated with intensity of tumor budding and density of stromal myofibroblasts in oral squamous cell carcinoma.

BACKGROUND Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers worldwide. Laminin-5 gamma 2 chain (laminin-5 γ2) is a protein associated to a migratory phenotype in epithelial neoplastic cells. Stromal myofibroblasts also play a significant role in tumor invasion, due to its ability to modify the extracellular matrix. Tumor budding is a morphologic marker of tumor invasion. The aim of this study was to evaluate the expression of laminin-5 γ2 in OSCC and its association with intensity of tumor budding and density of stromal myofibroblasts. METHODS Paraffin-embedded archival samples of 57 OSCC patients were evaluated. Immunohistochemistry was employed to detect laminin-5 γ2, alpha smooth muscle actin (marker of stromal myofibroblasts), and multicytokeratin (to identify OSCC cells in tumor budding evaluation). Laminin-5 γ2 expression and its association with intensity of tumor budding and density of stromal myofibroblasts were analyzed. Association among intensity of tumor budding and density of stromal myofibroblasts was also evaluated. RESULTS Higher laminin-5 γ2 expression was associated with high-intensity tumor budding (P < 0.05) and with higher density of stromal myofibroblasts (P < 0.05). Moreover, high-intensity tumor budding was associated with higher density of stromal myofibroblasts (P < 0.05). CONCLUSIONS In OSCC, higher laminin-5 γ2 expression is associated with high-intensity tumor budding and with higher density of stromal myofibroblasts, suggesting that this expression is related to the establishment of an invasive phenotype of neoplastic cells and a permissive environment for tumor invasion in this neoplasia.

Stromal myofibroblasts in focal reactive overgrowths of the gingiva

Focal reactive overgrowths are among the most common oral mucosal lesions. The gingiva is a significant site affected by these lesions, when triggered by chronic inflammation in response to microorganisms in dental plaque. Myofibroblasts are differentiated fibroblasts that actively participate in diseases characterized by tissue fibrosis. The objective of this study was to evaluate the presence of stromal myofibroblasts in the main focal reactive overgrowths of the gingiva: focal fibrous hyperplasia (FFH), peripheral ossifying fibroma (POF), pyogenic granuloma (PG), and peripheral giant cell granuloma (PGCG). A total of 10 FFHs, 10 POFs, 10 PGs, and 10 PGCGs from archival specimens were evaluated. Samples of gingival mucosa were used as negative controls for stromal myofibroblasts. Oral squamous cell carcinoma samples, in which stromal myofibroblasts have been previously detected, were used as positive controls. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin (α-sma). Myofibroblast immunostaining was qualitatively classified as negative, scanty, or dense. Differences in the presence of myofibroblasts among FFH, POF, PG, and PGCG were analyzed using the Kruskal-Wallis test. Stromal myofibroblasts were not detected in FFH, POF, PG, or PGCG. Consequently, no differences were observed in the presence of myofibroblasts among FFH, POF, PG, or PGCG (p > 0.05). In conclusion, stromal myofibroblasts were not detected in the focal reactive overgrowths of the gingiva that were evaluated, suggesting that these cells do not play a significant role in their pathogenesis.

Facial soft tissues of mouth-breathing children: Do expectations meet reality?

OBJECTIVE To quantify the differences between the facial soft tissue morphology of severely obstructed mouth breathing (MB) and that of predominantly nasal breathing (NB) children. METHODS Soft tissue measurements were performed in the lateral cephalograms of 64 severely obstructed MB children (mean age 6.7 ± 1.6) compared with 64 NB children (mean age 6.5 ± 1.3). Groups were paired by age, gender, skeletal maturation status and sagittal skeletal pattern. Based on the assumption of normality and homoscedasticity, comparison of the means and medians of soft tissue measurements between the two groups was performed. RESULTS The facial convexity and anterior facial height ratio of MB were similar to NB children. The upper lip of MB children was protruded, and its base was thinner compared with NB; however, the length was not affected. The lower lip was shorter and more protruded in MB children. The nasolabial angle, nasal prominence, and chin thickness were smaller in MB children. CONCLUSIONS The facial soft tissue of severely obstructed MB children is different than in NB children. Changes in lips, nasolabial angle, nasal prominence, and chin thickness are associated with severe airway obstruction in children.

NFATc1 and TNFα expression in giant cell lesions of the jaws

BACKGROUND Activation mutations of SH3BP2 gene have been demonstrated in cherubism and central giant cell lesion (CGCL). In the present study we first attempted to investigate the SH3BP2 gene in peripheral giant cell lesion (PGCL). The effect of SH3BP2 gene mutations on the transcription of the downstream genes nuclear factor of activated T cells (NFATc1) and the cytokine tumor necrosis factor-alpha (TNF-alpha) was also investigated together with the immunolocalization of NFATc1 protein in a set of cases of PGCL, CGCL and cherubism with and without SH3BP2 mutation. METHOD Fresh samples of five PGCL, five CGCL and one cherubism cases were included in this study. One of the samples of CGCL presented a somatic heterozygous mutation c.1442A>T in exon 11. The cherubism case showed a heterozygotic substitution c.320C>T in both blood and lesion. These mutations were previously published. All coding and flanking regions of the SH3BP2 gene were sequenced in the cases of PGCL. The real-time polymerase chain reaction (RT-PCR) was performed to analyze the transcription of NFATc1 and TNF-alpha genes. The immunohistochemical analysis of the NFATc1 protein was also performed. RESULTS No SH3BP2 gene mutation was found in PGCL. The RT-PCR showed increased expression of NFATc1 and decreased transcription of TNF-alpha in all the samples. The immunohistochemical analysis of the NFATc1 protein showed a predominant nuclear staining in the multinucleated giant cells. CONCLUSION The development of giant cells lesions of the jaws and cherubism are possibly mediated by overexpression of NFAT in the nucleus of the multinucleated cells.