Immune development in HIV-exposed uninfected children born to HIV-infected women

Immunological and clinical findings suggestive of some immune dysfunction have been reported among HIV-exposed uninfected (HEU) children and adolescents. Whether these defects are persistent or transitory is still unknown. HEU pediatric population at birth, 12 months, 6-12 years were evaluated in comparison to healthy age-matched HIV-unexposed controls. Plasma levels of LPS, sCD14, cytokines, lymphocyte immunophenotyping and T-cell receptor excision circles (TREC) were assessed. HEU and controls had similar LPS levels, which remained low from birth to 6-12 years; for plasma sCD14, IL-2, IL-6, IL-7, IL-10, IL-12p70, IL-13, IL-17, IFN-γ, TNF-α, G-CSF, GM-CSF and MCP-1, which increased from birth to 12 months and then decreased at 6-12 years; and for TREC/106 PBMC at birth in HEU and controls. By contrast, plasma MIP-1β levels were lower in HEU than in controls (p=0.009) at 12 months, and IL-4 levels were higher in HEU than controls (p=0.04) at 6-12 years. Immune activation was higher in HEU at 12 months and at 6-12 years than controls based on frequencies of CD38+HLA-DR+CD8+T cells (p=0.05) and of CD38+HLA-DR+CD4+T cells (p=0.006). Resting memory and activated mature B cells increased from birth to 6-12 years in both groups. The development of the immune system in vertically HEU individuals is comparable to the general population in most parameters, but subtle or transient differences exist. Their role in influencing clinical incidences in HEU is unknown

New application of dynamic magnetic resonance imaging for the assessment of deglutitive tongue movement

Background: Deglutitive motion of the tongue may function to maintain tooth position. However, the causation between abnormal patterns of orofacial muscle function and dental malocclusion remains unclear. To clarify the pathogenic mechanism of malocclusion, it is important to determine the relative positional relationship between the tongue tip and incisor edge or the dorsal tongue and palate during deglutition. Here, we assessed the utility of 3-T segmented cine-magnetic resonance (MR) imaging, combined with static MR images for hard tissue visualization, in assessing the relationship between the tongue and the surrounding tissues during deglutitive tongue movement. Methods: Cine-MR images were acquired from three healthy female volunteers during deglutition who had no history of swallowing disorder or other chronic illness, normal alignment and occlusion, and a skeletal class I relationship. Three cine-MR images were taken during deglutition in accordance with an auditory cue for each volunteer. During static imaging, custom-made, contrast-medium-filled clear retainers were positioned in the mouth to allow visualization of the upper and lower incisors and hard palate boundaries. Static images were superimposed onto images of the three stages in deglutitive tongue movement, which were selected from a series of cine-MR images. These superimpositions were assessed five times by tracing cephalometric parameters to examine the reproducibility of the method. Results: Traces varied little across repeated measurements, and all subjects had a similar pattern of dorsal tongue movement. Tongue-to-palate contact increased slightly during the first to second stage of swallowing and abruptly increased during the second to third stage, while the tongue tip position remained constant. Conclusions: Segmented cine-MR imaging combined with static MR images is useful for assessing soft tissue motion during deglutition. This method is particularly useful in dentistry to evaluate the relationship between tongue function and maxillofacial morphology in terms of orthodontic treatment and orofacial myofunctional therapy, and for improving tongue movement during speech therapy

Immune development in HIV-exposed uninfected children born to HIV-infected women

Immunological and clinical findings suggestive of some immune dysfunction have been reported among HIV-exposed uninfected(HEU) children and adolescents. Whether these defects are persistent or transitory is still unknown. HEU pediatric population at birth, 12 months, 6-12 years were evaluated in comparison to healthy age-matched HIV-unexposed controls. Plasma levels of LPS, sCD14, cytokines, lymphocyte immunophenotyping and T-cell receptor excision circles (TREC) were assessed. HEU and controls had similar LPS levels, which remained low from birth to 6-12 yearsfor plasma sCD14, IL-2, IL-6, IL-7, IL-10, IL-12p70, IL-13, IL-17, IFN-gamma, TNF-alpha, G-CSF, GM-CSF and MCP-1, which increased from birth to 12 months and then decreased at 6-12 yearsand for TREC/10(6) PBMC at birth in HEU and controls. By contrast, plasma MIP-1 beta levels were lower in HEU than in controls (p=0.009) at 12 months, and IL-4 levels were higher in HEU than controls (p=0.04) at 6-12 years. Immune activation was higher in HEU at 12 months and at 6-12 years than controls based on frequencies of CD38+HLA-DR+CD8+T cells (p=0.05) and of CD38+HLA-DR+CD4+T cells (p=0.006). Resting memory and activated mature B cells increased from birth to 6-12 years in both groups. The development of the immune system in vertically HEU individuals is comparable to the general population in most parameters, but subtle or transient differences exist. Their role in influencing clinical incidences in HEU is unknown.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Fed Sao Paulo, Dept Pediat, Sao Paulo, SP, BrazilUniv Miami, Dept Med, Miami, FL USAUniversidade Federal de São Paulo, Departamento de Pediatria, Divisão de Infectologia Pediátrica, Rua Pedro de Toledo, 781, 9º andar, CEP 04039-032, Vila Clementino, São Paulo, SP, Brazil.FAPESP: 10/09701-3FAPESP: 10/09738-4Web of Scienc

Strong HIV-1-Specific T Cell Responses in HIV-1-Exposed Uninfected Infants and Neonates Revealed after Regulatory T Cell Removal

BACKGROUND: In utero transmission of HIV-1 occurs on average in only 3%–15% of HIV-1-exposed neonates born to mothers not on antiretroviral drug therapy. Thus, despite potential exposure, the majority of infants remain uninfected. Weak HIV-1-specific T-cell responses have been detected in children exposed to HIV-1, and potentially contribute to protection against infection. We, and others, have recently shown that the removal of CD4(+)CD25(+) T-regulatory (Treg) cells can reveal strong HIV-1 specific T-cell responses in some HIV-1 infected adults. Here, we hypothesized that Treg cells could suppress HIV-1-specific immune responses in young children. METHODOLOGY/PRINCIPAL FINDINGS: We studied two cohorts of children. The first group included HIV-1-exposed-uninfected (EU) as well as unexposed (UNEX) neonates. The second group comprised HIV-1-infected and HIV-1-EU children. We quantified the frequency of Treg cells, T-cell activation, and cell-mediated immune responses. We detected high levels of CD4(+)CD25(+)CD127(−) Treg cells and low levels of CD4(+) and CD8(+) T cell activation in the cord blood of the EU neonates. We observed HIV-1-specific T cell immune responses in all of the children exposed to the virus. These T-cell responses were not seen in the cord blood of control HIV-1 unexposed neonates. Moreover, the depletion of CD4(+)CD25(+) Treg cells from the cord blood of EU newborns strikingly augmented both CD4(+) and CD8(+) HIV-1-specific immune responses. CONCLUSIONS/SIGNIFICANCE: This study provides new evidence that EU infants can mount strong HIV-1-specific T cell responses, and that in utero CD4(+)CD25(+) T-regulatory cells may be contributing to the lack of vertical transmission by reducing T cell activation

Organização cromatinica, fragmentação de DNA e morte celular em eritrocitos circulantes de algumas especies de serpentes

Orientador: Maria Luiza Silveira MelloDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: A freqüência e a intensidade de fragmentação do DNA, relacionadas à morte celular programada, variam nos eritrócitos nucleados dos vários vertebrados. Como os dados de fragmentação de DNA em répteis são escassos, no presente trabalho foram estudados eritrócitos de serpentes (Crotalus durissus terrificus, Bothrops jararaca, B. alternatus e B. neuwiedii) em termos de fragmentação de DNA relacionada à supraorganização da cromatina e morte celular. O estudo foi estendido a espécimes de C. d. terrificus infectados por Hepatozoon sp.. Foram realizados análise de imagem da cinética de hidrólise de Feulgen, ensaio de TUNEL, ensaio Cometa e observações em microscopia eletrônica de transmissão. Poucos eritrócitos foram encontrados em morte celular. O DNA das serpentes, especialmente de C. d. terrificus e B. neuwiedii, mostrou ser mais resistente à hidrólise ácida de Feulgen e à fragmentação do DNA pelo ensaio TONEL, quando comparados ao anfíbio Rana catesbeiana. Dados de ensaio Cometa mostraram que B. neuwiedii também teve menor fragmentação de DNA, enquanto C. d. terrificus apresentou maior freqüência de células com danos, talvez por abundância de sítios álcali-sensíveis em seu DNA e não por fragmentação de DNA ligada à morte celular. A ultraestrutura dessas células sugere alguma atividade metabólica devido à presença de mitocôndrias, Complexos de Golgi e nucléolo. B. jararaca e B. alternatus apresentaram diferenças na fragmentação de DNA/morte celular quando comparados com C. d. terrificus e B. neuwiedii, sugerindo-se relação com especiação selecionada por diferentes hábitats. Nos espécimes infectados foram encontrados eritrócitos infectados e não-infectados pelo protozoário. A presença de Hepatozoon sp. como parasita em serpentes, inclusive no interior dos eritrócitos circulantes, induz um aumento da fragmentação de DNA em C. d. terrificus induzindo células, inclusive não infectadas, à morte celularAbstract: The frequency and intensity of the DNA fragmentation, related to programmed cell death, varies in nucleated erythrocytes of various vertebrates. As data on DNA fragmentation in reptiles are scarce, in the present work erythrocytes of snakes (Crotalus durissus terrificus, Bothrops jararaca, B. alternatus and B. neuwiedii) were studied in terms of DNA fragmentation related to chromatin supraorganization and cell death. The study was extended to C. d. terrificus specimens infected by Hepatozoon sp. Image analysis of Feulgen hydrolysis kinetics, the TONEL assay, the single cell gel electrophoresis, and electron microscopy observations were undertaken. A few circulating erythrocytes were found committed to cell death. The snake's DNA, especially of C. d. terrificus and B. neuwiedii, showed to be more resistant to the Feulgen acid hydrolysis and to the DNA fragmentation revealed by the TONEL assay, when compared to the amphibian Rana catesbeiana. Data on the Comet assay showed that B. neuwiedii had less DNA fragmentation, although C. d. terrificus showed more frequency of damaged cells, perhaps of due to abundance of alkali-sensitive DNA sites and not to the DNA fragmentation related to the cell death. The ultrastructure of these cells suggested a certain cell metabolic activity due to the presence of mitochondria, Golgi complexes and nucleolus. B. jararaca and B. alternatus showed differences in DNA fragmentation/cell death as compared to C. d. terrificus and B. neuwiedii, possibly related to the selected speciation by the different habitas. In the infected specimens erythrocytes were found infected and non-infected by the protozoon. The presence of Hepatozoon sp. as a snake parasite, inclusive inside the circulating erythrocytes, induces increase in the DNA fragmentation of C. d. terrificus erythrocytes even of non-infected cells, to cell deathMestradoBiologia CelularMestre em Biologia Celular e Estrutura

New application of dynamic magnetic resonance imaging for the assessment of deglutitive tongue movement

Abstract Background Deglutitive motion of the tongue may function to maintain tooth position. However, the causation between abnormal patterns of orofacial muscle function and dental malocclusion remains unclear. To clarify the pathogenic mechanism of malocclusion, it is important to determine the relative positional relationship between the tongue tip and incisor edge or the dorsal tongue and palate during deglutition. Here, we assessed the utility of 3-T segmented cine-magnetic resonance (MR) imaging, combined with static MR images for hard tissue visualization, in assessing the relationship between the tongue and the surrounding tissues during deglutitive tongue movement. Methods Cine-MR images were acquired from three healthy female volunteers during deglutition who had no history of swallowing disorder or other chronic illness, normal alignment and occlusion, and a skeletal class I relationship. Three cine-MR images were taken during deglutition in accordance with an auditory cue for each volunteer. During static imaging, custom-made, contrast-medium-filled clear retainers were positioned in the mouth to allow visualization of the upper and lower incisors and hard palate boundaries. Static images were superimposed onto images of the three stages in deglutitive tongue movement, which were selected from a series of cine-MR images. These superimpositions were assessed five times by tracing cephalometric parameters to examine the reproducibility of the method. Results Traces varied little across repeated measurements, and all subjects had a similar pattern of dorsal tongue movement. Tongue-to-palate contact increased slightly during the first to second stage of swallowing and abruptly increased during the second to third stage, while the tongue tip position remained constant. Conclusions Segmented cine-MR imaging combined with static MR images is useful for assessing soft tissue motion during deglutition. This method is particularly useful in dentistry to evaluate the relationship between tongue function and maxillofacial morphology in terms of orthodontic treatment and orofacial myofunctional therapy, and for improving tongue movement during speech therapy