In vitro type 1 fimbriae expression and antibiotic resistance by uro-pathogenic bacterial isolates from Human Immunodeficiency Virus infected patients

ABSTRACT The Gag-derived protein p6 of human immunodeficiency virus type 1 (HIV-1) plays a crucial role in the release of virions from the membranes of infected cells. It is presumed that p6 and functionally related proteins from other viruses act as adapters, recruiting cellular factors to the budding site. This interaction is mediated by so-called late domains within the viral proteins. Previous studies had suggested that virus release from the plasma membrane shares elements with the cellular endocytosis machinery. Since protein phosphorylation is known to be a regulatory mechanism in these processes, we have investigated the phosphorylation of HIV-1 structural proteins. Here we show that p6 is the major phosphoprotein of HIV-1 particles. After metabolic labeling of infected cells with [ortho- 32P]phosphate, we found that phosphorylated p6 from infected cells and from virus particles consisted of several forms, suggesting differential phosphorylation at multiple sites. Apparently, phosphorylation occurred shortly before or after the release of p6 from Gag and involved only a minor fraction of the total virion-associated p6 molecules. Phosphoamino acid analysis indicated phosphorylation at Ser and Thr, as well as a trace of Tyr phosphorylation, supporting the conclusion that multiple phosphorylation events do occur. In vitro experiments using purified virus revealed that endogenous or exogenously added p6 was efficiently phosphorylated by virion-associated cellular kinase(s). Inhibition experiments suggested that a cyclin-dependent kinase or a related kinase, most likely ERK2, was involved in p6 phosphorylation by virion-associated enzymes.

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A virus–envelope paired competitive assay to study entry efficiency of human immunodeficiency virus type 1 in vitro

Journal of Virological Methods ◽

10.1016/j.jviromet.2014.05.009 ◽

2014 ◽

Vol 205 ◽

pp. 91-98 ◽

Cited By ~ 2

Author(s):

Birco Schwalbe ◽

Heiko Hauser ◽

Michael Schreiber

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Study Entry ◽

Virus Envelope ◽

Competitive Assay ◽

Immunodeficiency Virus ◽

Entry Efficiency

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Ontogeny and Specificities of Mucosal and Blood Human Immunodeficiency Virus Type 1-Specific CD8+ Cytotoxic T Lymphocytes

Journal of Virology ◽

10.1128/jvi.77.1.291-300.2003 ◽

2003 ◽

Vol 77 (1) ◽

pp. 291-300 ◽

Cited By ~ 46

Author(s):

L. Musey ◽

Y. Ding ◽

J. Cao ◽

J. Lee ◽

C. Galloway ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

T Cell ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Cytotoxic T Lymphocyte ◽

Infected Individual ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT Induction of adaptive immunity to human immunodeficiency virus type 1 (HIV-1) at the mucosal site of transmission is poorly understood but crucial in devising strategies to control and prevent infection. To gain further understanding of HIV-1-specific T-cell mucosal immunity, we established HIV-1-specific CD8+ cytotoxic T-lymphocyte (CTL) cell lines and clones from the blood, cervix, rectum, and semen of 12 HIV-1-infected individuals and compared their specificities, cytolytic function, and T-cell receptor (TCR) clonotypes. Blood and mucosal CD8+ CTL had common HIV-1 epitope specificities and major histocompatibility complex restriction patterns. Moreover, both systemic and mucosal CTL lysed targets with similar efficiency, primarily through the perforin-dependent pathway in in vitro studies. Sequence analysis of the TCRβ VDJ region revealed in some cases identical HIV-1-specific CTL clones in different compartments in the same HIV-1-infected individual. These results clearly establish that a subset of blood and mucosal HIV-1-specific CTL can have a common origin and can traffic between anatomically distinct compartments. Thus, these effectors can provide immune surveillance at the mucosa, where rapid responses are needed to contain HIV-1 infection.

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Gag sequence variation in a human immunodeficiency virus type 1 transmission cluster influences viral replication fitness

Journal of General Virology ◽

10.1099/vir.0.048371-0 ◽

2013 ◽

Vol 94 (2) ◽

pp. 354-359 ◽

Cited By ~ 1

Author(s):

Esther F. Gijsbers ◽

Ad C. van Nuenen ◽

Hanneke Schuitemaker ◽

Neeltje A. Kootstra

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Sequence Variation ◽

Clinical Course ◽

Immunodeficiency Virus ◽

Compensatory Mutations ◽

Replication Fitness ◽

Hiv 1

Three men from a proven homosexual human immunodeficiency virus type 1 (HIV-1) transmission cluster showed large variation in their clinical course of infection. To evaluate the effect of evolution of the same viral variant in these three patients, we analysed sequence variation in the capsid protein and determined the impact of the observed variation on viral replication fitness in vitro. Viral gag sequences from all three patients contained a mutation at position 242, T242N or T242S, which have been associated with lower virus replication in vitro. Interestingly, HIV-1 variants from patients with a progressive clinical course of infection developed compensatory mutations within the capsid that restored viral fitness, instead of reversion of the T242S mutation. In HIV-1 variants from patient 1, an HLA-B57+ elite controller, no compensatory mutations emerged during follow-up.

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Direct In Vitro Binding of Full-Length Human Immunodeficiency Virus Type 1 Nef Protein to CD4 Cytoplasmic Domain

Journal of Virology ◽

10.1128/jvi.75.8.3960-3964.2001 ◽

2001 ◽

Vol 75 (8) ◽

pp. 3960-3964 ◽

Cited By ~ 40

Author(s):

Andrea Preusser ◽

Lars Briese ◽

Andreas S. Baur ◽

Dieter Willbold

Keyword(s):

Nuclear Magnetic Resonance ◽

Human Immunodeficiency Virus ◽

In Vitro Binding ◽

Vitro Binding ◽

Immunodeficiency Virus ◽

N Terminus ◽

Human Immunodeficiency Viruses ◽

Direct Binding

ABSTRACT The Nef protein of the simian and human immunodeficiency viruses is known to directly bind and downregulate the CD4 receptor. Although the molecular mechanism is well understood, direct binding of Nef and CD4 is difficult to demonstrate and is believed to be of low affinity. Applying nuclear magnetic resonance and fluorescence spectroscopy, we biophysically reevaluated the CD4-Nef complex and found the dissociation constant to be in the submicromolar range. We conclude that additional, so far disregarded residues in the N terminus of Nef are important for interaction with CD4.

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