Video Experimental Relacionado
Updated: May 22, 2026
10:50
Assessment of Immunologically Relevant Dynamic Tertiary Structural Features of the HIV-1 V3 Loop Crown R2 Sequence by ab initio Folding
Published on: September 16, 2010
El VIH-1 evita la neutralización mediada por anticuerpos a través del enmascaramiento conformacional de los sitios de
Peter D Kwong1, Michael L Doyle, David J Casper
1Vaccine Research Center, National Institutes of Health, Bethesda, Maryland 20892, USA. pdkwong@nih.gov
Nature
|December 13, 2002
Resumen
El virus de la inmunodeficiencia humana (VIH-1) evita la neutralización de anticuerpos a través del enmascaramiento conformacional de su envolvente glicoproteína (gp120). Este mecanismo permite que el virus se una a los receptores mientras resiste los ataques de anticuerpos, lo que contribuye a la infección persistente y el SIDA.
Área de la Ciencia:
- Inmunología Inmunología.
- Virología Virología.
- Biología Estructural Biología estructural.
Sus antecedentes:
- El virus de la inmunodeficiencia humana (VIH-1) persiste al evadir la neutralización de anticuerpos, a pesar de los sitios de unión al receptor gp120 accesibles.
- Los abundantes anticuerpos dirigidos por el sobre contra el VIH-1 a menudo carecen de una capacidad de neutralización significativa, una paradoja dada los sitios de unión expuestos de gp120.
Objetivo del estudio:
- Investigar el mecanismo por el cual el VIH-1 evita la neutralización de anticuerpos.
- Explorar el papel de los cambios conformacionales en gp120 sobre la unión de anticuerpos y su impacto en la resistencia a la neutralización.
Principales métodos:
- Entropías de unión medidas para 20 anticuerpos reactivos a gp120.
- Se analizaron los ciclos termodinámicos receptor-anticuerpo.
- Probó una molécula de receptor dodecamérico soluble para la potencia de neutralización contra los aislados primarios del VIH-1.
Principales resultados:
- El reconocimiento de anticuerpos de los sitios de unión al receptor en gp120 induce cambios conformacionales.
- Se identificó un mecanismo de "enmascaramiento conformacional", que explica el escape de neutralización del VIH-1.
- Un receptor dodecamérico soluble neutralizó potentemente los aislados primarios del VIH-1, lo que demuestra el papel de la avidez en la superación del enmascaramiento.
Conclusiones:
- El VIH-1 utiliza el enmascaramiento conformacional de gp120 para resistir la neutralización de anticuerpos mientras mantiene la unión al receptor.
- La alta avidez por el compromiso del receptor multivalente puede superar este enmascaramiento, a diferencia de las interacciones típicas de anticuerpos.
- Esta estrategia es crucial para la persistencia y la patogénesis del VIH-1, destacando una diferencia clave entre la evasión viral de anticuerpos y los receptores del huésped.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:10Retrovirus Life Cycles
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to...
00:36Viral Mutations
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material for adaptive...
01:29Immune Response Against Viral Pathogens
The immune system's response to viral infections is a complex and coordinated process involving natural killer (NK) cells, T cell-mediated responses, and antibody-mediated responses.
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
01:26Size and Structure of Viral Genomes
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
01:29Viruses with RNA Genomes
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
01:30Inhibitors of Viral Protein Synthesis
Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...