The 236A/E7 antibody reacts with the human FoxP3 (Forkhead box protein P3) transcription factor, a member of the forkhead or winged helix family of transcription factors. The expression of FoxP3, also known as Scurfin, IPEX and JM2, has been found to be associated with CD4+ CD25+ regulatory T cells and represents a specific marker for these cells. Flow cytometric analysis has shown that FoxP3 is expressed by the majority of CD4+ CD25+ (high) T cells in peripheral blood while less than half of CD4+ CD25+ (intermediate) cell population are FoxP3 positive. Approximately 5-10% of peripheral CD4+ cells are CD4+ CD25+ T regulatory cells. T regulatory cells are thought to play a critical role in the control of T cell mediated autoimmunity by suppressing the proliferation and cytokine production of other T cells. To support this hypothesis, it has been found that Foxp3 is mutated in scurfy (sf) mice. Cumulative evidence suggests that the 236A/E7 antibody recognizes epitopes from both isoforms of Exon 2 alternatively-spliced variants and is located in the region between Exon 2 and the Zn/LZ domains (aa 105-235).
The antibody was conjugated to BD Horizon BB700, which is part of the BD Horizon Brilliant™ Blue family of dyes. It is a polymer-based tandem dye developed exclusively by BD Biosciences. With an excitation max of 485 nm and an emission max of 693 nm, BD Horizon BB700 can be excited by the 488 nm laser and detected in a standard PerCP-Cy™5.5 set (eg, 695/40-nm filter). This dye provides a much brighter alternative to PerCP-Cy5.5 with less cross laser excitation off the 405 nm and 355 nm lasers.