Dendritic cells (DCs) efficiently bind and transmit human immunodeficiency virus (HIV) to cocultured T cells and so may play an important role in HIV transmission. DC-SIGN, a novel C-type lectin that is expressed in DCs, has recently been shown to bind R5 HIV type 1 (HIV-1) strains and a laboratory-adapted X4 strain. To characterize the interaction of DC-SIGN with primate lentiviruses, we investigated the structural determinants of DC-SIGN required for virus binding and transmission to permissive cells. We constructed a panel of DC-SIGN mutants and established conditions which allowed comparable cell surface expression of all mutants. We found that R5, X4, and R5X4 HIV-1 isolates as well as simian immunodeficiency and HIV-2 strains bound to DC-SIGN and could be transmitted to CD4/coreceptor-positive cell types. DC-SIGN contains a single N-linked carbohydrate chain that is important for efficient cell surface expression but is not required for DC-SIGN-mediated virus binding and transmission. In contrast, C-terminal deletions removing either the lectin binding domain or the repeat region abrogated DC-SIGN function. Trypsin-EDTA treatment inhibited DC-SIGN mediated infection, indicating that virus was maintained at the surface of the DC-SIGN-expressing cells used in this study. Finally, quantitative fluorescence-activated cell sorting analysis of AU1-tagged DC-SIGN revealed that the efficiency of virus transmission was strongly affected by variations in DC-SIGN expression levels. Thus, variations in DC-SIGN expression levels on DCs could greatly affect the susceptibility of human individuals to HIV infection.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC114220PMC
http://dx.doi.org/10.1128/JVI.75.10.4664-4672.2001DOI Listing

Publication Analysis

Top Keywords

dc-sign
12
immunodeficiency virus
12
human immunodeficiency
8
simian immunodeficiency
8
virus binding
8
binding transmission
8
cell surface
8
surface expression
8
variations dc-sign
8
dc-sign expression
8

Similar Publications

The naturally occurring mutation E484D in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can render viral entry ACE2 independent and imdevimab resistant. Here, we investigated whether the cellular proteins ASGR1, DC-SIGN, and TMEM106B, which interact with the viral S protein, can contribute to these processes. Employing S protein-pseudotyped particles, we found that expression of ASGR1 or DC-SIGN jointly with TMEM106B allowed for robust entry of mutant E484D into otherwise non-susceptible cells, while this effect was not observed upon separate expression of the single proteins and upon infection with SARS-CoV-2 wild type (WT).

View Article and Find Full Text PDF

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tick-borne virus with a human mortality rate of up to 30%, posing a significant threat to public health. However, the lack of suitable research models has impeded the development of effective human vaccines. In this study, we engineered transgenic mice (3xTg) using a novel construct that simultaneously expresses three C-type Lectin receptors, identified as critical SFTSV entry receptors.

View Article and Find Full Text PDF

Lactobacillus crispatus S-layer proteins modulate innate immune response and inflammation in the lower female reproductive tract.

Nat Commun

December 2024

Imperial College Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism Digestion and Reproduction, Imperial College London, London, UK.

Lactobacillus species dominance of the vaginal microbiome is a hallmark of vaginal health. Pathogen displacement of vaginal lactobacilli drives innate immune activation and mucosal barrier disruption, increasing the risks of STI acquisition and, in pregnancy, of preterm birth. We describe differential TLR mediated activation of the proinflammatory transcription factor NF-κB by vaginal pathogens and commensals.

View Article and Find Full Text PDF

Dengue infection changes the expressions of CD154 and CD148 in human platelets.

Virus Res

January 2025

Department of Translational Virology, Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth (Deemed to be University), Katraj-Dhankawadi, Pune 411043, India. Electronic address:

Platelets are essential for hemostasis and vascular integrity. Platelets recognize dengue virus through the DC-SIGN receptor. Upon pathogen recognition, platelets rapidly modulate the expression of adhesion molecules to trigger immune cell interactions and regulate the immune response.

View Article and Find Full Text PDF

Carbohydrate-mediated interactions between chloroviruses and the immune system.

Commun Biol

December 2024

Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.

Understanding the molecular mechanisms which drive and modulate host-pathogen interactions are essential when designing effective therapeutic and diagnostic approaches aimed at controlling infectious diseases. Certain large and giant viruses have recently been discovered as components of the human virome, yet little is known about their interactions with the host immune system. We have dissected the role of viral N-linked glycans during the interaction between the glycoproteins from six chloroviruses (belonging to three chlorovirus classes: NC64A, SAG, and Osy viruses) and the representative carbohydrate-binding receptors of the innate immune system.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!