Superantigens (SAgs) are proteins produced by pathogenic microbes to elicit potent, antigen-independent T cell responses that are believed to enhance the microbes' pathogenicity. Here we show that the human lymphotropic herpesvirus Epstein-Barr virus (EBV) transcriptionally activates the env gene of an endogenous retrovirus, HERV-K18, that possesses SAg activity. SAg activity was demonstrated by MHC class II dependent preferential activation of TCRVB13 T cells in response to murine B cells transfected with the HERV-K18 env gene. This is a unique demonstration of a pathogen inducing a host-encoded Sag and accounts for the previously described EBV associated Sag activity. The T cell activation elicited by the Sag could play a central role in EBV infection and associated diseases.

Download full-text PDF

Source
http://dx.doi.org/10.1016/s1074-7613(01)00210-2DOI Listing

Publication Analysis

Top Keywords

sag activity
12
epstein-barr virus
8
endogenous retrovirus
8
retrovirus herv-k18
8
env gene
8
sag
5
virus transactivates
4
transactivates human
4
human endogenous
4
herv-k18 encodes
4

Similar Publications

Previously, boost and sag effects seen in unfused tetanic contractions have been studied exclusively at constant stimulation frequency. However, intervals between successive discharges of motoneurons vary during voluntary movements. We therefore aimed to test whether the extra-efficient force production at the onset of contraction (boost) occurs during stimulation with variable intervals, and to what extent it depends on the level of interpulse interval (IPI) variability and history of stimulation.

View Article and Find Full Text PDF

Acetylcholine modulates the network physiology of the hippocampus, a crucial brain structure that supports cognition and memory formation in mammals . In this and adjacent regions, synchronized neuronal activity within theta-band oscillations (4-10Hz) is correlated with attentive processing that leads to successful memory encoding . Acetylcholine facilitates the hippocampus entering a theta oscillatory regime and modulates the temporal organization of activity within theta oscillations .

View Article and Find Full Text PDF

A new twist on superantigen-activated autoimmune disease.

J Clin Invest

January 2025

Division of Rheumatology, Center of Excellence for Intestinal and Immunology Research, University of Alberta, Edmonton, Alberta, Canada.

Superantigen-induced (Sag-induced) autoimmunity has been proposed as a mechanism for many human disorders, without a clear understanding of the potential triggers. In this issue of the JCI, McCarthy and colleagues used the SKG mouse model of rheumatoid arthritis to characterize the role of Sag activity in inflammatory arthritis by profiling arthritogenic naive CD4+ T cells. Within the diseased joints, they found a marked enrichment of T cell receptor-variable β (TCR-Vβ) subsets that were reactive to the endogenously encoded mouse mammary tumor virus (MMTV) Sag.

View Article and Find Full Text PDF

Type II CRISPR endonucleases are widely used programmable genome editing tools. Recently, CRISPR-Cas systems with highly compact nucleases have been discovered, including Cas9d (a type II-D nuclease). Here, we report the cryo-EM structures of a Cas9d nuclease (747 amino acids in length) in multiple functional states, revealing a stepwise process of DNA targeting involving a conformational switch in a REC2 domain insertion.

View Article and Find Full Text PDF

Small GTPase RHEB is a well-known mTORC1 activator, whereas neddylation modifies cullins and non-cullin substrates to regulate their activity, subcellular localization and stability. Whether and how RHEB is subjected to neddylation modification remains unknown. Here, we report that RHEB is a substrate of NEDD8-conjugating E2 enzyme UBE2F.

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!