CD4+ T Cell Profile and Activation Response in Sickle Cell Disease Patients with Osteonecrosis.

Recent evidence suggests that abnormalities involving CD4+T lymphocytes are associated with the pathophysiology of osteonecrosis (ON); however, few studies have addressed the CD4+T cells in ON related to sickle cell disease (SCD/ON). In addition, T cells producing multiple cytokines simultaneously are often present in the inflammatory milieu and may be implicated in the immune response observed in SCD/ON. In the present study, we aimed to characterize the functional status of CD4+T cells in SCD by simultaneously determining the frequency of IFN-γ +, IL-4+, and IL-17+ CD4+T in cell cultures under exogenous stimuli. Peripheral blood mononuclear cells (PB-MNCs) from 9 steady-state SCD patients, 15 SCD/ON patients, and 19 healthy controls had functional status of CD4+T cells analyzed. Bone marrow mononuclear cells (BM-MNCs) from 24 SCD/ON patients (SCD BM) and 18 patients with ON not related to SCD (non-SCD BM) were also analyzed. We found that PB-MNC of SCD patients with or without ON presented significantly reduced TCD4+, TCD8+, and TCD4+ naïve cell frequencies and increased frequency of circulating CD4+T cells able to simultaneously produce IFN-γ +/IL4+ and IL-17+/IL4+ compared to healthy controls. Conversely, the polyclonal stimulation of BM-MNC induced an increased frequency of CD4+IFN-γ + and CD4+IL-17+ in SCD BM compared to non-SCD BM. The increased proportion of CD4+ T cells able to produce a broad spectrum of proinflammatory cytokines after a strong stimulus indicates that the immune system in SCD/ON patients presents an expressive pool of partially differentiated cells ready to take on effector function. It is possible that this increased subpopulation may extend to inflammatory sites of target organs and may contribute to the maintenance of inflammation and the pathophysiology of osteonecrosis in sickle cell disease.

Prevotella intermedia and periodontitis are associated with severe asthma.

BACKGROUND: Periodontitis, an inflammatory disease of multibacterial etiology that affects the protective and supporting tissues surrounding teeth, can influence the course of respiratory diseases, such as asthma, due to epithelial alterations arising from inflammatory and immunological processes, bronchial remodeling, or by the aspiration of pathogenic colonizers found in periodontal pockets. This study evaluated the levels of periodontal pathogens Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans in the subgingival biofilm of individuals with and without severe asthma. METHODS: A case-control study enrolling 457 individuals (220 with asthma and 237 without asthma) was conducted at the Program for Control of Asthma in Bahia (ProAR) Clinic located in Salvador, Bahia, Brazil. A structured questionnaire was used to obtain data on sociodemographic, health status, and lifestyle habits. A clinical periodontal assessment was performed, including bleeding on probing, probing depth, and clinical attachment level. Subgingival biofilm was collected at the deepest site of each sextant, and bacterial DNA was extracted. Quantitative real-time PCR analysis was performed to detect and relatively quantify periodontopathogens in the biofilm. RESULTS: Statistically significant positive associations were found between periodontitis and severe asthma, (odds ratio [OR]adjusted] : 4.00; 95% confidence interval [CI]: 2.26 to 7.10). High levels of P. intermedia were found in association with the presence of severe asthma (ORadjusted : 2.64; 95% CI: 1.62 to 4.39; P < 0.01). CONCLUSIONS: The present results suggest that periodontitis and P. intermedia are associated with severe asthma. However, the functional consequences of this dysbiosis upon asthma susceptibility and its phenotypes remain unclear.

Production of interferon-gamma, interleukin-6, and interleukin-1ß by human peripheral blood mononuclear cells stimulated with novel lys-gingipain synthetic peptides.

BACKGROUND: Periodontitis is a progressive inflammatory process, and its pathogenesis is related to the presence of a dysbiotic subgingival biofilm that elicits the immune response. Porphyromonas gingivalis is a keystone pathogen, and its Lys-gingipain (Kgp) virulence factor is involved in the pathogen-host interaction through the production of cytokines by host cells, but the specific mechanisms of this interaction have not been elucidated. The present study evaluated the in vitro production of interferon-gamma (IFN-γ), interleukin (IL)-6, and IL-1ß cytokines in response to antigenic stimulation of peripheral blood mononuclear cells (PBMCs) with novel Kgp synthetic peptides. METHODS: Our previous in silico study predicted 16 immunogenic peptides from Kgp protein. Nine peptides derived from different regions of the protein were chemically synthesized. The synthetic peptides Kgp12, 17, and 18 were selected based on the immunoglobulin G immunoreactivity in the serum of patients with periodontitis (P) and individuals without periodontitis (WP), and they were used in in vitro stimulation of PBMC derived from groups P and WP. Enzyme-linked immunosorbent assay and microsphere-based flow cytometric assay were used to verify the levels of the cytokines produced in PBMC cultures after 48 hours. RESULTS: Kgp12, 17, and 18 peptides induced lower production of IFN-γ. Kgp12 induced higher levels of IFN-γ in WP than in P individuals. Kgp12 induced higher production of IL-6 and IL-1ß compared with the other stimuli. CONCLUSION: The novel Kgp synthetic peptides tested herein are immunogenic peptides (epitopes) since they induced the production of cytokines by PBMC and therefore may be useful tools in evaluating the pathogen-host interaction.

Serum antibody levels against Porphyromonas gingivalis extract and its chromatographic fraction in chronic and aggressive periodontitis.

UNLABELLED: Periodontitis is an inflammatory oral disease caused by multifactorial intrinsic and extrinsic agents, including Gram-negative bacteria such as Porphyromonas gingivalis. OBJECTIVE: To evaluate if there is difference in the serum levels of IgA, IgG and IgG subclasses reactive to Porphyromonas gingivalis in subjects with different periodontal conditions. METHODS: The study included 89 patients divided into four groups: 29 subjects with moderate or severe chronic periodontitis (CP), 12 with aggressive periodontitis (AP), 22 with gingivitis or mild periodontitis (GP), and 26 healthy controls (HC). Humoral response was assayed by enzyme-linked immunosorbent assay (ELISA) to verify serum levels of IgG, IgG1, IgG2, IgG3, IgG4 and IgA serum levels reacting to crude P. gingivalis ATCC 33277 sonicate extract and fraction IV, an enrichment of the immunoreactive bands of the crude extract obtained by chromatography. RESULTS: IgA, IgG (p < 0.01), IgG2, IgG3 and IgG4 serum level reactions to fraction IV were higher in the CP group compared with the healthy control. The CP group had higher levels of IgG and IgG4 to both antigens than the GP group, and higher levels of IgG and IgG4 to sonicate extract than the AP group. There were statistically significant differences in serum levels of IgG to both antigens (p < 0.01), IgG2 to fraction IV (p < 0.01), IgG3 to fraction IV (p < 0.05) and IgG4 to both antigens (p < 0.05) between AP and HC groups. IgG1 titers to sonicate extract were significantly higher (p < 0.05) in the GP group in comparison to the AP group. CONCLUSIONS: The findings of this study suggest that there are differences in the serum levels of IgA, IgG and IgG subclasses in patients with different periodontal conditions.

Humoral immune response to antigens of Porphyromonas gingivalis ATCC 33277 in chronic periodontitis

Introduction: Periodontitis is a chronic disease that results from an interaction of a mixed bacterial challenge and the host response. Objective: The purposes of this study were to evaluate the IgG serum levels to Porphyromonas gingivalis antigens by ELISA in individuals with different periodontal conditions correlated with clinical parameters, and to analyze the immunoreactivity profiles by Western blotting. Methods: Serum IgG levels against the cell sonicate antigen from P. gingivalis ATCC 33277 of 28 patients with chronic periodontitis (CP), 10 patients with gingivitis (G) and 21 periodontally healthy individuals (H) were measured by ELISA and Western immunoblotting. Results: In the CP group, sera reactivity by ELISA was significantly higher than in the G and H groups (Kruskal-Wallis p<0.001; Dunnet t3 p= 0.001 and Dunnet t3 p= 0.0001). There was no statistically significant difference between G and HP reactivity (Dunnett t3 p=0.617). Among individuals with chronic periodontitis, the IgG-anti-P. gingivalis serum levels were positively correlated with percentage of clinical attachment level =5mm (r s = + 0.375, p<0.05) and a negative correlation was found between IgG-anti-P. gingivalis levels and percentage of probing pocket depth 0-3mm (r s = - 0. 411, p< 0.05). The analysis of sera immunoreactivity profiles to sonicate antigen by Western blotting showed differences between the sera of CP, G and H group individuals. The serum from CP frequently reacted with high molecular weight (103 kDa, 86 kDa, 72 kDa, 60 kDa, 58 kDa, 52 kDa) protein fractions. Conclusions: Serum levels of IgG anti-P. gingivalis distinguished individuals with chronic periodontitis, gingivitis and healthy periodontium. There was a correlation between clinical parameters and serum IgG levels against P. gingivalis. There was a difference in the recognition profile of protein fractions among the studied groups and some bands were more specific.

Humoral immune response to antigens of Porphyromonas gingivalis ATCC 33277 in chronic periodontitis.

INTRODUCTION: Periodontitis is a chronic disease that results from an interaction of a mixed bacterial challenge and the host response. OBJECTIVE: The purposes of this study were to evaluate the IgG serum levels to Porphyromonas gingivalis antigens by ELISA in individuals with different periodontal conditions correlated with clinical parameters, and to analyze the immunoreactivity profiles by Western blotting. METHODS: Serum IgG levels against the cell sonicate antigen from P. gingivalis ATCC 33277 of 28 patients with chronic periodontitis (CP), 10 patients with gingivitis (G) and 21 periodontally healthy individuals (H) were measured by ELISA and Western immunoblotting. RESULTS: In the CP group, sera reactivity by ELISA was significantly higher than in the G and H groups (Kruskal-Wallis p<0.001; Dunnet t3 p= 0.001 and Dunnet t3 p= 0.0001). There was no statistically significant difference between G and HP reactivity (Dunnett t3 p=0.617). Among individuals with chronic periodontitis, the IgG-anti-P. gingivalis serum levels were positively correlated with percentage of clinical attachment level =5mm (r s = + 0.375, p<0.05) and a negative correlation was found between IgG-anti-P. gingivalis levels and percentage of probing pocket depth 0-3mm (r s = - 0. 411, p< 0.05). The analysis of sera immunoreactivity profiles to sonicate antigen by Western blotting showed differences between the sera of CP, G and H group individuals. The serum from CP frequently reacted with high molecular weight (103 kDa, 86 kDa, 72 kDa, 60 kDa, 58 kDa, 52 kDa) protein fractions. CONCLUSIONS: Serum levels of IgG anti-P. gingivalis distinguished individuals with chronic periodontitis, gingivitis and healthy periodontium. There was a correlation between clinical parameters and serum IgG levels against P. gingivalis. There was a difference in the recognition profile of protein fractions among the studied groups and some bands were more specific.