A Novel Mechanism for TNFR-Associated Factor 6-Dependent CD40 Signaling

A novel mechanism for TNFR-associated factor 6-dependent CD40 signaling.

Members of the TNFR family play critical roles in the regulation of the immune system. One member of the family critical for efficient activation of T-dependent humoral immune responses is CD40, a cell surface protein expressed by B cells and other APC. The cytoplasmic domain of CD40 interacts with several members of the TNFR-associated factor (TRAF) family, which link CD40 to intracellular sig...

Modification of LAT Adapter Signaling via Interaction with and TNFR-Associated Factor 6 Regulates TCR

TNFR-associated factor 6 regulates TCR signaling via interaction with and modification of LAT adapter.

TNFR-associated factor (TRAF)6 is an essential ubiquitin E3 ligase in immune responses, but its function in adaptive immunity is not well understood. In this study, we show that TRAF6 is recruited to the peripheral ring of the T cell immunological synapse in Jurkat T cells or human primary CD4(+) T cells conjugated with staphylococcal enterotoxin E-pulsed B cells. This recruitment depends on TR...

TNF receptor-associated factor 6-dependent CD40 signaling primes macrophages to acquire antimicrobial activity in response to TNF-alpha.

IFN-gamma is considered an essential stimulus that allows macrophages to acquire activity against intracellular pathogens in response to a second signal such as TNF-alpha. However, protection against important pathogens can take place in the absence of IFN-gamma through mechanisms that are still dependent on TNF-alpha. Engagement of CD40 modulates antimicrobial activity in macrophages. However,...

CD40 ligand-induced carcinoma cell death: a balance between activation of TNFR-associated factor (TRAF) 3-dependent death signals and suppression of TRAF6-dependent survival signals.

The effects of CD40 ligation in an epithelial context are complex, with the level of CD40 engagement influencing the physiological outcome. Low levels of CD40 ligation promote cell survival/proliferation, whereas high levels induce growth arrest/apoptosis. The precise form of the CD40 stimulus affects these responses with the most profound effects in carcinoma cells being induced by membrane-bo...