186,194 research outputs found
Fusion complexes as immunogens for the induction of broad spectrum neutralizing antibodies against HIV-1
No full textBroad spectrum neutralizing monoclonal antibodies against HIV-1 elicited by immunizing with fusion complexes
No full textabstract 14
HLA class I increases the efficiency of fusion between the HIV-1 envelope and the target cell membrane and is parte of the fusion complex between the gp120/gp41 and the cellular receptors.
No full textHLA-C increases HIV-1 infectivity and is associated with gp120
No full textAbstract Background A recently identified genetic polymorphism located in the 5' region of the HLA-C gene is associated with individual variations in HIV-1 viral load and with differences in HLA-C expression levels. HLA-C has the potential to restrict HIV-1 by presenting epitopes to cytotoxic T cells but it is also a potent inhibitor of NK cells. In addition, HLA-C molecules incorporated within the HIV-1 envelope have been shown to bind to the envelope glycoprotein gp120 and enhance viral infectivity. We investigated this last property in cell fusion assays where the expression of HLA-C was silenced by small interfering RNA sequences. Syncytia formation was analyzed by co-cultivating cell lines expressing HIV-1 gp120/gp41 from different laboratory and primary isolates with target cells expressing different HIV-1 co-receptors. Virus infectivity was analyzed using pseudoviruses. Molecular complexes generated during cell fusion (fusion complexes) were purified and analyzed for their HLA-C content. Results HLA-C positive cells co-expressing HIV-1 gp120/gp41 fused more rapidly and produced larger syncytia than HLA-C negative cells. Transient transfection of gp120/gp41 from different primary isolates in HLA-C positive cells resulted in a significant cell fusion increase. Fusion efficiency was reduced in HLA-C silenced cells compared to non-silenced cells when co-cultivated with different target cell lines expressing HIV-1 co-receptors. Similarly, pseudoviruses produced from HLA-C silenced cells were significantly less infectious. HLA-C was co-purified with gp120 from cells before and after fusion and was associated with the fusion complex. Conclusion Virionic HLA-C molecules associate to Env and increase the infectivity of both R5 and X4 viruses. Genetic polymorphisms associated to variations in HLA-C expression levels may therefore influence the individual viral set point not only by means of a regulation of the virus-specific immune response but also via a direct effect on the virus replicative capacity. These findings have implications for the understanding of the HIV-1 entry mechanism and of the role of Env conformational modifications induced by virion-associated host proteins.</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
HLA-C increase fusion efficiency between the HIV-1 envelope and the cell membrane and is part of the fusion complex
No full textThe HIV-1 viral envelope originates from the cell membrane and contains different cellular proteins such as MHC class I molecules, which play a role in modulating viral infectivity. HLA-C is known to enhance viral infectiv- ity and reduce sensitivity to neutralizing antibodies by inducing gp120/41 conformational changes that may increase fusion efficiency and viral infectivity [1]. In this work we studied the effect of HLA-C on syncytia forma- tion and of its association with the HIV-1 gp120/41 and with the CD4/CCR5 receptors in purified fusion com- plexes
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Use of gp120-CD4-coreceptor fusion complexes and CD4-independent gp120s for the induction of HIV-1 neutralizing antibodies
No full textAbstract n. 6.1
Induction of HIV neutralizing antibodies using fusion complexes and a CD4-independent env
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