The monoclonal antibody 3C3 reacts with human Toll-like receptor 4 (TLR4, CD284). TLRs belong to a family of proteins that specifically recognize and sense microbial products. They are highly conserved throughout evolution. In Drosophila, toll is required for the anti-fungal response, while the related 18-wheeler is involved in antibacterial defences. TLRs identified as type I transmembrane signalling receptors act as innate immune recognition receptors against many pathogens. TLR4 is a functional receptor for gram-negative bacterial lipopolysaccharides (LPS). TLR4 associates with MD-2 which is absolutely required for LPS-induced activation of TLR4. TLR4 has been identified next to MD-2 and CD14 as a receptor that is central to the innate immune response to LPS of Gram-negative bacteria. The monoclonal antibody 3C3 is a TLR4 function-blocking antibody that is useful for studies on the role of TLR4 as a receptor for LPS induced cytokine production by TLR4 bearing cells.
Flow cytometry, Functional studies
For flow cytometry, dilutions to be used depend on detection system applied. It is recommended that users test the reagent and determine their own optimal dilutions. The typical starting working dilution is 1:50. For functional studies, in vitro dilutions have to be optimized in user's experimental setting.