Related Experiment Video
Updated: May 22, 2026

Highly Efficient Transfection of Human THP-1 Macrophages by Nucleofection
Published on: September 2, 2014
Single-chain variable fragment intrabody impairs LPS-induced inflammatory responses by interfering with the
Chisato Sakuma1, Mitsuru Sato, Takato Takenouchi
1Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan.
Wiskott-Aldrich syndrome protein (WASP) plays important roles in both acquired and innate immune responses. We recently uncovered that the WASP N-terminal domain specifically binds the Src homology (SH) 3 domain of Bruton's tyrosine kinase (Btk) in macrophages. Over-expression of the WASP N-terminal domain impairs LPS-induced inflammatory responses. To evaluate the significance of this interaction in LPS signaling, we established bone marrow-derived macrophage (BMDM) cell lines from transgenic (Tg) mice expressing anti-WASP N-terminal domain single-chain variable fragment (scFv) intrabody. Anti-WASP scFv specifically bound endogenous WASP and inhibited its specific binding to the SH3 domain of Btk in the Tg BMDMs. Tyrosine phosphorylation in WASP was inhibited after LPS stimulation. As a result, TNF-α, IL-6, and IL-1β gene transcription and NF-κB phosphorylation were impaired. These observations strongly suggest that the phosphorylation of WASP by Btk plays a pivotal role in transducing the LPS signaling pathway in macrophages.
Wiskott-Aldrich syndrome protein (WASP) plays important roles in both acquired and innate immune responses. We recently uncovered that the WASP N-terminal domain specifically binds the Src homology (SH) 3 domain of Bruton's tyrosine kinase (Btk) in macrophages. Over-expression of the WASP N-terminal domain impairs LPS-induced inflammatory responses. To evaluate the significance of this interaction in LPS signaling, we established bone marrow-derived macrophage (BMDM) cell lines from transgenic (Tg) mice expressing anti-WASP N-terminal domain single-chain variable fragment (scFv) intrabody. Anti-WASP scFv specifically bound endogenous WASP and inhibited its specific binding to the SH3 domain of Btk in the Tg BMDMs. Tyrosine phosphorylation in WASP was inhibited after LPS stimulation. As a result, TNF-α, IL-6, and IL-1β gene transcription and NF-κB phosphorylation were impaired. These observations strongly suggest that the phosphorylation of WASP by Btk plays a pivotal role in transducing the LPS signaling pathway in macrophages.
Related Concept Videos
The JAK-STAT Signaling Pathway
NF-κB-dependent Signaling Pathway
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...

