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Barroso-Gonzalez J.,Laboratorio Of Inmunologia Celular Y Viral | Barroso-Gonzalez J.,University of La Laguna | Garcia-Exposito L.,Laboratorio Of Inmunologia Celular Y Viral | Puigdomenech I.,Institute Of Recerca En Ciencies Of La Salut Germans Trias I Pujol Igtp | And 4 more authors.
Communicative and Integrative Biology | Year: 2011

Viruses have developed different survival strategies in host cells by crossing cell-membrane compartments, during different steps of their viral life cycle. In fact, the non-regenerative viral membrane of enveloped viruses needs to encounter the dynamic cell-host membrane, during early steps of the infection process, in which both membranes fuse, either at cell-surface or in an endocytic compartment, to promote viral entry and infection. Once inside the cell, many viruses accomplish their replication process through exploiting or modulating membrane traffic, and generating specialized compartments to assure viral replication, viral budding and spreading, which also serve to evade the immune responses against the pathogen. In this review, we have attempted to present some data that highlight the importance of membrane dynamics during viral entry and replicative processes, in order to understand how viruses use and move through different complex and dynamic cell-membrane structures and how they use them to persist. © 2011 Landes Bioscience. Source

Carrillo J.,Institute Of Recerca Of La Sida Irsicaixa Hivacat | Molinos-Albert L.M.,Institute Of Recerca Of La Sida Irsicaixa Hivacat | Molinos-Albert L.M.,Institute Of Recerca En Ciencies Of La Salut Germans Trias I Pujol Igtp | De La Concepcion M.L.R.,Institute Of Recerca Of La Sida Irsicaixa Hivacat | And 12 more authors.
PLoS ONE | Year: 2015

Antibodies with the ability to block the interaction of HIV-1 envelope glycoprotein (Env) gp120 with CD4, including those overlapping the CD4 binding site (CD4bs antibodies), can protect from infection by HIV-1, and their elicitation may be an interesting goal for any vaccination strategy. To identify gp120/CD4 blocking antibodies in plasma samples from HIV-1 infected individuals we have developed a competitive flow cytometry-based functional assay. In a cohort of treatment-naïve chronically infected patients, we showed that gp120/ CD4 blocking antibodies were frequently elicited (detected in 97% plasma samples) and correlated with binding to trimeric HIV-1 envelope glycoproteins. However, no correlation was observed between functional CD4 binding blockade data and titer of CD4bs antibodies determined by ELISA using resurfaced gp120 proteins. Consistently, plasma samples lacking CD4bs antibodies were able to block the interaction between gp120 and its receptor, indicating that antibodies recognizing other epitopes, such as PGT126 and PG16, can also play the same role. Antibodies blocking CD4 binding increased over time and correlated positively with the capacity of plasma samples to neutralize the laboratory-adapted NL4.3 and BaL virus isolates, suggesting their potential contribution to the neutralizing workforce of plasma in vivo. Determining whether this response can be boosted to achieve broadly neutralizing antibodies may provide valuable information for the design of new strategies aimed to improve the anti-HIV-1 humoral response and to develop a successful HIV-1 vaccine. © 2015 Carrillo et al. Source

Molinos-Albert L.M.,Institute Of Recerca En Ciencies Of La Salut Germans Trias I Pujol Igtp | Carrillo J.,Institute Of Recerca En Ciencies Of La Salut Germans Trias I Pujol Igtp | Curriu M.,Institute Of Recerca En Ciencies Of La Salut Germans Trias I Pujol Igtp | Rodriguez de la Concepcion M.L.,Institute Of Recerca En Ciencies Of La Salut Germans Trias I Pujol Igtp | And 4 more authors.
Retrovirology | Year: 2014

Background: The MPER region of the HIV-1 envelope glycoprotein gp41 is targeted by broadly neutralizing antibodies. However, the localization of this epitope in a hydrophobic environment seems to hamper the elicitation of these antibodies in HIV infected individuals.We have quantified and characterized anti-MPER antibodies by ELISA and by flow cytometry using a collection of mini gp41-derived proteins expressed on the surface of 293T cells. Longitudinal plasma samples from 35 HIV-1 infected individuals were assayed for MPER recognition and MPER-dependent neutralizing capacity using HIV-2 viruses engrafted with HIV-1 MPER sequences.Results: Miniproteins devoid of the cysteine loop of gp41 exposed the MPER on 293T cell membrane. Anti-MPER antibodies were identified in most individuals and were stable when analyzed in longitudinal samples. The magnitude of the responses was strongly correlated with the global response to the HIV-1 envelope glycoprotein, suggesting no specific limitation for anti-MPER antibodies. Peptide mapping showed poor recognition of the C-terminal MPER moiety and a wide presence of antibodies against the 2F5 epitope. However, antibody titers failed to correlate with 2F5-blocking activity and, more importantly, with the specific neutralization of HIV-2 chimeric viruses bearing the HIV-1 MPER sequence; suggesting a strong functional heterogeneity in anti-MPER humoral responses.Conclusions: Anti-MPER antibodies can be detected in the vast majority of HIV-1 infected individuals and are generated in the context of the global anti-Env response. However, the neutralizing capacity is heterogeneous suggesting that eliciting neutralizing anti-MPER antibodies by immunization might require refinement of immunogens to skip nonneutralizing responses. © 2014 Molinos-Albert et al.; licensee BioMed Central Ltd. Source

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