ABSTRACT Immune exhaustion and senescence are scarcely studied in HIV-pediatric patients. We studied the circulatory CD8 T cells activation/exhaustion and senescent phenotype of children and adolescents vertically infected with HIV or uninfected controls based on the expression of human leukocyte antigen (HLA-DR), CD38, T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT), programmed death 1 (PD-1) and CD57 by flow cytometry, during approximately one year. Eleven HIV-infected (HI) and nine HIV-uninfected (HU) children/adolescents who received two doses or one dose of meningococcal C conjugate vaccine (MenC), respectively, were involved in this study. Blood samples were collected before the immunization (T0), 1–2 months after the first dose (T1), and 1–2 months after the second dose (T2), which was administered approximately one year after the first one. HI patients not receiving combined antiretroviral therapy (cART) showed a higher frequency of CD8 T cells TIGIT+, PD-1+ or CD57+, as well as a higher frequency of CD8 T cells co-expressing CD38/HLA-DR/TIGIT or CD38/HLA-DR/PD-1 when compared to HI treated or HU individuals, at all times that they were assessed. CD8 T cells co-expressing CD38/DR/TIGIT were inversely correlated with the CD4/CD8 ratio but positively associated with viral load. The co-expression of CD38/DR/TIGIT or CD38/DR/PD-1 on CD8 T cells was also inversely associated with the CD4 T cells expressing co-stimulatory molecules CD127/CD28. The results showed a higher expression of exhaustion/senescence markers on CD8 T cells of untreated HI children/adolescents and its correlations with viral load.

OBJECTIVE: To investigate the associations between psychosocial factors and peripheral blood CD4 and CD8 T lymphocyte numbers in Brazilian peacekeepers. METHODS: Venous blood was collected from 759 peacekeepers who had just returned from a peace mission in Haiti. Among the 759 soldiers, 642 individuals completed the psychosocial measures. CD4 and CD8 T lymphocyte counts were measured by flow cytometry using a commercially available kit. Psychosocial factors, including military peace force stressors, clinical stress, anxiety and depression, were recorded. As a reference for T lymphocyte numbers, we measured T lymphocyte counts in 75 blood donors from the Instituto de Biologia do Exército, Rio de Janeiro. RESULTS: The median numbers of CD4 and CD8 T lymphocytes in the blood donors were 819 cells/µl and 496 cells/µl, respectively, with a CD4:CD8 ratio of 1.6. Significantly (p<0.05) lower CD4 T cell counts (759 cells/µl) were recorded for peacekeepers, with similar CD8 levels (548 cells/µl) and smaller CD4:CD8 ratios (1.3, p<0.001) compared to blood donors. These differences were due to a group of 14 military personnel with CD4 and CD8 medians of 308 and 266 cells/µl, respectively. Only one (7.1%) of these 14 individuals was diagnosed with clinical stress compared with 13.5% of the individuals with normal levels of CD4 T lymphocytes. One individual out of 628 (0.16%) had a Lipp's Stress Symptom Inventory score of 3, indicating near exhaustion. CONCLUSION: The prevalence of psychological disorders was low and there were no associations with CD4 or CD8 T cell numbers.

In Brazil, until 2004, the immunization policy against diphtheria involved childhood vaccination with no official routine booster dose administered after 15 years of age. This study assessed functional antibody levels against diphtheria among blood donors. A total of 140 blood samples were collected, and diphtheria antitoxin levels were evaluated by Vero cell neutralization test. The mean age of the population was 34 years old (range: 18-61 years); 37.8% females and 62.2% males. Overall, 30.7% (95%, CI: 23.4-38.7) individuals presented neutralizing antitoxin antibody titers < 0.01 IU/ml; 42.1% (95%, CI: 34.1-50.4) showed values between 0.01-0.09 IU/ml and, 27.1% (95%, CI: 20.2-34.9) had ³ 0.1 IU/ml. In the subgroup of individuals with history of diphtheria immunization during childhood (85%), a number of 28.5% showed unprotective levels of circulating neutralizing antibody (< 0.01 IU/ml). Despite the continuous progress of immunization programs directed to Brazilian population, currently healthy adults remain susceptible to diphtheria.

A expressão das proteínas reguladas pelo ferro (IRPs), in vitro, tem sido obtida pela adição de quelantes de ferro ao meio de cultura, após o crescimento bacteriano, na presença de fonte de ferro orgânico. Neste estudo foram investigados aspectos da máxima expressão das IRPs de meningococo durante o crescimento normal, em condições de cultura definidas, utilizando-se o meio de Catlin e os caldos Mueller-Hinton e Tryptic Soja (TSB). Foram avaliadas as melhores condições para se obter vesículas de membrana externa (OMVs) contendo IRPs para uso em vacina de meningococo B. A expressão das IRPs variou entre as diferentes cepas com relação as diferentes concentrações de Etilenediamine Di-orto-Hidroxifenil-ácido acético (EDDA), de acordo com o meio de cultura e também entre os diferentes lotes de TSB. Para cada cepa, um específico padrão de ERPs foi expresso e altas concentrações de EDDA, adição de glicose ou o uso de diferentes meios de cultura não resultou em expressão diferencial das IRPs. Não foi possível cultivar meningococo em condições normais de crescimento utilizando-se Desferral. Foi investigado condições de crescimento para se obter bom rendimento de OMVs com expressão de IRPs em meio de Catlin deficiente em ferro, contendo EDDA e hemina. Cultura de 32 h a 30ºC, após incubação por 16 h a 37ºC, manteve bom crescimento, porém, lise da bactéria foi observada após 46 h a 30ºC. Aproximadamente 4 vezes mais OMVs foram recuperadas do sobrenadante de cultura após 24 h a 30ºC do que das células após 16 h a 37ºC. As IRPs foram bem expressas nas OMVs obtidas do sobrenadante de cultura após 24 h a 30ºC como também nas OMVs obtidas das células crescidas por 16 h a 37ºC.

The expression of iron regulated proteins (IRPs) in vitro has been obtained in the past by adding iron chelators to the culture after bacterial growth, in the presence of an organic iron source. We have investigated aspects concerning full expression of the meningococcal IRPs during normal growth, in defined conditions using Catlin medium, Mueller Hinton and Tryptic Soy Broth (TSB). The expression of IRPs varied between different strains with respect to Ethylenediamine Di-ortho-Hidroxy-phenyl-acetic acid (EDDA) concentrations, and according to culture medium, and also between different lots of TSB. For each strain, a specific set of IRPs were expressed and higher EDDA concentrations, or addition of glucose, or use of different culture media did not resulted in a differential expression of IRPs. We were not able to grow N. meningitidis under normal growth conditions using Desferal. We looked for a good yield of outer membrane vesicles (OMVs) expressing IRPs in iron-deficient Catlin medium containing EDDA and Hemin. Culture for 32 h at 30ºC after growing for 16 h at 37ºC supported good bacterial growth. Bacterial lysis was noted after additional 24 h at 30ºC. Approximately 4 times more OMVs was recoverable from a culture supernatant after 24 h at 30ºC than from the cells after 16 h at 37ºC. The IRP were as well expressed in OMVs from culture supernatant obtained after 24 h at 30ºC as from the cells after 16 h at 37ºC.

Em razão da recente epidemia de doença meningocócica causada por N. meningitidis B na Grande São Paulo, Brasil, foi feita revisão das epidemias dessa doença ocorridas no Brasil desde o início do século e uma análise das vacinas atuais contra N. meningitidis A, C, Y e W135. Também são discutidos os mais recentes avanços no desenvolvimento e aplicação de vacina contra M meningitidis B, um desafio constante para os maiores centros de pesquisa de todo o mundo.

In view of a recent epidemic of meningococcal disease caused by serogroup B N. meningitidis in the Greater S. Paulo area (Brazil), a review of the epidemics that occurred in Brazil during the period from 1900 to 1990 is presented. The current status of vaccines against N. meningitidis A.C.Y. and W135 is analysed. The recent advances in the development and effectiveness of B. meningococci vaccines are discussed.

Em razão da recente epidemia de doença meningocócica causada por N. meningitidis B na Grande São Paulo, Brasil, foi feita revisão das epidemias dessa doença ocorridas no Brasil desde o início do século e uma análise das vacinas atuais contra N. meningitidis A, C, Y e W135. Também são discutidos os mais recentes avanços no desenvolvimento e aplicação de vacina contra M meningitidis B, um desafio constante para os maiores centros de pesquisa de todo o mundo.

In view of a recent epidemic of meningococcal disease caused by serogroup B N. meningitidis in the Greater S. Paulo area (Brazil), a review of the epidemics that occurred in Brazil during the period from 1900 to 1990 is presented. The current status of vaccines against N. meningitidis A.C.Y. and W135 is analysed. The recent advances in the development and effectiveness of B. meningococci vaccines are discussed.

S. saprophyticus é freqüentemente isolado de infecções do trato urinário de mulheres jovens e sexualmente ativas. Ao contrário de S. aureus, esta espécie não possui fatores de virulência bem definidos. O objetivo deste estudo é analisar a aderência de S. saprophyticus a células HEp-2 e eritrócitos de carneiro. As amostras foram isoladas a partir da urina de pacientes com infecção urinária. Foram realizados testes de hemaglutinação, aderência a células HEp-2 e a capacidade de carboidratos específicos inibirem as interações entre estes tipos celulares e S. saprophyticus. A maioria das cepas se mostrou hemaglutinante e sensível a inibição da hemaglutinação pela manose (100mM). Foram verificados altos níveis de aderência às células HEp-2. As diferenças em especificidade e nível de aderência do microrganismo a células de HEp-2 e eritrócitos sugerem a participação de diferentes adesinas nos processos de interações celulares.

S. saprophyticus has been frequently isolated from urinary tract infections in young women. In contrast with S. aureus, no defined virulence factors have been recognized for the coagulase negative Staphylococcus species. The objective this study was to analyze the adherence of S. saprophyticus to HEp-2 cells and sheep erythrocytes. The sample were isolated from urine of patients with urinary infection. Hemagglutination, adherence to HEp-2 cells tests and inhibition by specific carbohydrates of the interactions between these cells were analyzed. Most of the strains were hemagglutinanting whose properties was inhibited by mannose (100mM). There was a high adherence level to HEp-2 cells. The differences in specificity and attachment level noted in this study suggest that multiple adhesins are involved in the mechanism of cellular interaction.