Increased Frequency of CD4 and CD8 Regulatory T Cells in Individuals under 15 Years with Multibacillary Leprosy

Background: Leprosy is a chronic disease, caused by Mycobacterium leprae, which poses a serious public health problem worldwide. Its high incidence in people under 15 years old in Ceara state, Brazil, reflects the difficulty of its control. the spectrum of clinical manifestations is associated with the immune response developed, with the Th1 and Th2 responses being related to the paucibacillary and multibacillary forms, respectively. Regulatory T cells (Treg), which can suppress Th1 and Th2 response, have received special attention in the literature and have been associated with development of chronic infections. However, their role in leprosy in individuals under 15 years old has not yet been elucidated. We evaluated the frequency of CD4(+)/CD8(+)CD25(high)FOXP3(+) and CD4(+)/CD8(+)CD25(high)FOXP3(high) cells in leprosy patients and household contacts, in both cases under 15 years old.Methodology/Principal Findings: PBMC from 12 patients and 17 contacts were cultured for 72 hours with anti-CD3 and anti-CD28 (activators) or with activators associated with total sonicated fraction of M. leprae. After culture, the frequency of CD4(+)/CD8(+) Treg was identified by flow cytometry. Cells stimulated by activators and antigen from multibacillary patients showed Treg frequencies almost two times that of the contacts: CD4(+)FOXP3(+) (21.93 +/- 8.43 vs. 13.79 +/- 8.19%, p = 0.0500), CD4(+)FOXP3(high) (10.33 +/- 5.69 vs. 5.57 +/- 4.03%, p = 0.0362), CD8(+)FOXP3(+) (13.88 +/- 9.19 vs. 6.18 +/- 5.56%, p = 0.0230) and CD8(+)FOXP3(high) (5.36 +/- 4.17 vs. 2.23 +/- 2.68%, p = 0.0461). Furthermore, the mean fluorescence intensity of FOXP3 in Treg was higher in multibacillary patients than in the contacts. Interestingly, there was a positive correlation of the bacillary index and number of lesions with the frequency of all Treg evaluated in patients.Conclusions/Significance: We have demonstrated for the first time that multibacillary leprosy patients under 15 years old have greater CD4(+) and CD8(+) Treg frequencies and these correlate with clinical and laboratorial aspects of disease. These findings suggest the involvement of these cells in the perpetuation of M. leprae infection.Fundacao Cearense de Apoio ao Desenvolvimento Cientifico e TecnologicoPost-Graduation Program in Medical MicrobiologyUniv Fed Ceara, Dept Pathol & Legal Med, Med Lab Immunol, Fortaleza, Ceara, BrazilDermatol Ctr Dona Libania, Fortaleza, Ceara, BrazilWalter Cantidio Univ Hosp, Fortaleza, Ceara, BrazilUniv Fortaleza, Fortaleza, Ceara, BrazilUniversidade Federal de São Paulo, Dept Pediat, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pediat, São Paulo, BrazilWeb of Scienc

Anti-PGL1 salivary IgA/IgM, serum IgG/IgM, and nasal Mycobacterium leprae DNA in individuals with household contact with leprosy

Objectives: Leprosy household contacts represent a group at high risk of developing the disease. the aim of this study was to detect Mycobacterium leprae subclinical infection in this group through serological and molecular parameters.Methods: Serum anti-PGL1 IgG/IgM and salivary anti-PGL1 IgA/IgM was investigated using an ELISA, and nasal carriage of M. leprae DNA was detected by PCR, in leprosy household contacts of paucibacillary (PB) and multibacillary (MB) household leprosy patients (n = 135), their index cases (n = 30), and in persons living in a low endemic city (n = 17).Results: Salivary anti-PGL1 IgA and IgM and serum anti-PGL1 IgG showed good correlation comparing contacts and index cases (p 0.05). A high frequency of anti-PGL1 IgM positivity was found in IgG-negative samples (p < 0.0001). for IgG-positive samples, IgM antibodies were also positive in most of the samples. None of the 17 volunteers living in a low endemic city presented seropositivity for IgG; however, two of them showed positivity for anti-PGL1 IgM. M. leprae DNA was found in the nasal swabs of nine out of the 85 MB household leprosy contacts (10.6%) and in three out of the 50 PB household leprosy contacts (6.0%).Conclusion: We strongly suggest that serum IgG/IgM and salivary anti-PGL1 IgA/IgM measurements are used to follow leprosy household contacts. (C) 2013 International Society for Infectious Diseases. Published by Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Ceara, Fac Pharm, Dept Clin Anal & Toxicol, BR-60430370 Fortaleza, Ceara, BrazilUniv Fed Ceara, Fac Pharm, Dept Pharm, BR-60430370 Fortaleza, Ceara, BrazilUniversidade Federal de São Paulo, Div Pediat Infect Dis, São Paulo, BrazilUniv Fed Ceara, Fac Med, Dept Pathol, BR-60430370 Fortaleza, Ceara, BrazilUniversidade Federal de São Paulo, Div Pediat Infect Dis, São Paulo, BrazilCNPq: 472.471/2007-4Web of Scienc

Efficacy of Plectranthus amboinicus (Lour.) Spreng in a Murine Model of Methicillin-Resistant Staphylococcus aureus Skin Abscesses

The present work aimed to evaluate the effectiveness of Plectranthus amboinicus (Lour.) Spreng against MRSA clinical isolates. The in vitro antimicrobial activity of the hydroalcoholic extract (HE), the ethyl acetate (EA) fraction and its subfractions were determined by broth microdilution and bioautography against MRSA clinical isolates. The microdilution checkerboard method was used to assess in vitro drug combination studies. To induce abscess formation, bacterial suspensions were added to Citodex and inoculated subcutaneously into male Swiss mice. The treatment protocol consisted of 2 doses of HE, the EA fraction or vancomycin introduced intraperitoneally into mice 3 and 12 h after infection. The EA fraction and its subfractions presented the lowest minimal inhibitory concentrations (MIC, 0.25 to 0.5 mg/mL). The plant samples were bacteriostatic at 2x and 4x MIC and bactericidal at 100 mg/mL. The EA fraction presented synergism with vancomycin and an additive effect with ciprofloxacin. A significant reduction of abscess volume, bacterial cell counts in abscess slurries, and inflammatory scores was observed in the HE and EA fraction-treated groups. The samples were effective in treating the animals in a dose-dependent fashion. The present study proved the effectiveness of P. amboinicus fractions against MRSA using in vitro and in vivo assays