Decay Kinetics of HIV-1 Specific T Cell Responses in Vertically HIV-1 Exposed Seronegative Infants

Objective: The majority of infants born, in developed countries, to HIV-1 positive women are exposed to the HIV-1 virus in utero or peri/post-partum, but are born uninfected. We, and others, have previously shown HIV-1 specific T cell responses in HIV-1 exposed seronegative (HESN) neonates/infants. Our objective in this study was to examine the rate of decay in their HIV-1 specific T cell response over time from birth. Design: Cross-sectional and longitudinal studies of HIV-1 specific T cell responses in HESN infants were performed. Methods: Peripheral blood mononuclear cells (PBMC) were isolated from 18 HIV-1 DNA PCR negative infants born to HIV-1 infected mothers receiving care at the Jacobi Medical Center, Bronx, NY, USA. PBMC were examined for T cell responses to HIV-1 antigens by interferon-gamma (IFN-γ) ELISPOT. Results: PBMC from 15 HESN neonates/infants were analyzed. We observed a decay of HIV-1 specific T cell responses from birth at a rate of −0.599 spot forming unit/106 cells per day, with a median half-life decay rate of 21.38 weeks (13.39–115.8). Conclusion: Our results support the dynamic nature of T cell immunity in the context of a developing immune system. The disparate rate of decay with studies of adults placed on antiretroviral drugs suggests that antigen specific T cell responses are driven by the natural rate of decay of the T cell sub-populations themselves

Unexpected Diversity of Cellular Immune Responses against Nef and Vif in HIV-1-Infected Patients Who Spontaneously Control Viral Replication

Background: HIV-1-infected individuals who spontaneously control viral replication represent an example of successful containment of the AIDS virus. Understanding the anti-viral immune responses in these individuals may help in vaccine design. However, immune responses against HIV-1 are normally analyzed using HIV-1 consensus B 15-mers that overlap by 11 amino acids. Unfortunately, this method may underestimate the real breadth of the cellular immune responses against the autologous sequence of the infecting virus. Methodology and Principal Findings: Here we compared cellular immune responses against nef and vif-encoded consensus B 15-mer peptides to responses against HLA class I-predicted minimal optimal epitopes from consensus B and autologous sequences in six patients who have controlled HIV-1 replication. Interestingly, our analysis revealed that three of our patients had broader cellular immune responses against HLA class I-predicted minimal optimal epitopes from either autologous viruses or from the HIV-1 consensus B sequence, when compared to responses against the 15-mer HIV-1 type B consensus peptides. Conclusion and Significance: This suggests that the cellular immune responses against HIV-1 in controller patients may be broader than we had previously anticipated.National Institutes of Health (NIH)[R24 RR015371]Ministry of Health[914/BRA/3014-UNESCO]Sao Paulo City Health Department[2004-0.168.922-7]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[04/15856-9]Coordenacao de Aperfeicoamento de Pessoal de Ni-vel Superior (CAPES), Brazilian Ministry of Educatio

Exercícios de Ciências Físico-Químicas - 9º Ano

“A dúvida é o princípio da sabedoria!” - Aristóteles Actualmente, a ciência é um dos pilares fundamentais da Humanidade e uma boa preparação na área científica é deveras importante, sobretudo para aqueles que, no 10º ano de escolaridade, seguem a área científico-tecnológica. Este livro visa ser um auxiliar de estudo para os alunos do 9º ano, ajudando-os na preparação do seu estudo das ciências físicas e químicas, sendo este um ano importante na vida dos estudantes pois é também o ano que “fecha” o 3º ciclo do ensino básico. As três áreas sobre as quais este livro incide são “Em trânsito”, “Sistemas Eléctricos e Electrónicos” e ainda “Classificação dos materiais”, abrangendo três áreas da ciência actualmente em discussão, quer devido ao problema dos recursos e do seu custo, quer no que toca ao desenvolvimento da tecnologia, comunicação e electrónica. Estas três áreas inserem-se no tema “Viver melhor na Terra” e espera-se que, com este auxiliar de estudo, os alunos conheçam ainda melhor o mundo que os rodeia e o campo das ciências em particular. Conclui-se assim que só uma boa preparação científica e uma compreensão rigorosa dos fenómenos do quotidiano permitirá à Ciência avançar e servir o Homem

Sequence coverage and adjusted sequence coverage of three representative patient samples.

<p>The number of sequences representing each nucleotide position (coverage) from three patient samples sequenced in the same GS Junior run is shown after alignment to the NC_001802 HXB2 HIV reference sequence. Also shown is the number of sequences that align to each nucleotide position after eliminating sequences with low quality scores (adjusted coverage) at each nucleotide position for each patient sample. Pyrosequencing was performed on three overlapping amplicons with nucleotide positions for each amplicon represented at the top of the graph.</p

The statistics of the two GS Junior runs used to assess the patient samples in this study.

<p>The statistics of the two GS Junior runs used to assess the patient samples in this study.</p

Drug resistance mutations located within or adjacent to homopolymers in the HXB2 HIV subtype B reference sequence.

1<p>Codons representing the mutated amino acid are shown in boldface.</p

Drug resistance mutations identified in the patient samples sequenced using the Roche/454 GS Junior HIV drug resistance genotyping method.

<p>Drug resistance mutations identified in the patient samples sequenced using the Roche/454 GS Junior HIV drug resistance genotyping method.</p