Anti-Mouse FR4 Alexa Fluor® 647 (Discontinued. Refer to Alternative Format: APC, cat. 17-5445)

Description: The monoclonal antibody eBio12A5 recognizes FR4, also known as Folate receptor 4, FR δ and FBP3 (folate binding protein3). FR4 is a heavily glycosylated 35 kD receptor for folic acid and the physiologic circulating form of the vitamin, N5-methyltetrahydrofolate. Natural T regs have high levels of FR4 and together with CD25 can be used to distinguish natural Tregs, effector T cells, memory-like T cells and naïve T cells. FR4^hi CD25^hi cells are natural Tregs with high levels of Foxp3. FR4^hi CD25^lo cells are identified as central memory T cells which upon stimulation can proliferate and produce large amounts of IL-2. In contrast FR4^lo CD25^hi secrete proinflammatory cytokines such as IFNγ and IL-17 and have been characterized as effector memory T cells.

Based on co-staining studies, the epitopes recognized by eBioTH6 (cat 51-5446) and eBio12A5 are different thereby allowing functional studies with eBioTH6 to be evaluated with eBio12A5.

References: Elnakat H, Ratnam M. Distribution, functionality and gene regulation of folate receptor isoforms: implications in targeted therapy.Adv Drug Deliv Rev. 2004 Apr 29;56(8):1067-84.

Spiegelstein O, Eudy JD, Finnell RH. Identification of two putative novel folate receptor genes in humans and mouse.Gene. 2000 Nov 27;258(1-2):117-25.

Sugimoto N, Oida T, Hirota K, Nakamura K, Nomura T, Uchiyama T, Sakaguchi S. Foxp3-dependent and -independent molecules specific for CD25+CD4+ natural regulatory T cells revealed by DNA microarray analysis.Int Immunol. 2006 Aug;18(8):1197-209.

Yamaguchi T, Hirota K, Nagahama K, Ohkawa K, Takahashi T, Nomura T, Sakaguchi S. Control of immune response by antigen-specific regulatory T cells expressing the folate receptor. Immunity July 2007 ePub (eBio12A5 FC, IP)