S‐Fms signalobody enhances myeloid cell growth and migration

Abstract

Since receptor tyrosine kinases (RTKs) control various cell fates in many types of cells, mimicry of RTK functions is promising for artificial control of cell fates. We have previously developed single-chain Fv (scFv)/receptor chimeras named signalobodies that can mimic receptor signaling in response to a specific antigen. While the RTK-based signalobodies enabled us to control cell growth and migration, further extension of applicability in another cell type would underlie the impact of the RTK-based signalobodies. In this study, we applied the scFv-c-Fms (S-Fms) signalobody in a murine myeloid progenitor cell line, FDC-P1. S-Fms transduced a fluorescein-conjugated BSA (BSA-FL)-dependent growth signal and activated downstream signaling molecules including MEK, ERK, Akt, and STAT3, which are major constituents of Ras/MAPK, PI3K/Akt, and JAK/STAT signaling pathways. In addition, S-Fms transduced a migration signal as demonstrated by the transwell-based migration assay. Direct real-time observation of the cells further confirmed that FDC/S-Fms cells underwent directional cell migration toward a positive gradient of BSA-FL. These results demonstrated the utility of the S-Fms signalobody for controlling growth and migration of myeloid cells. Further extension of our approach includes economical large-scale production of practically relevant blood cells as well as artificial control of cell migration for tissue regeneration and immune response.

Sequential control of myeloid cell proliferation and differentiation by cytokine receptor-based chimeric antigen receptors

“…The 4M5.3 scFv was affinity-matured by yeast display from an antibody clone 4-4-20 derived from a murine hybridoma [ 26 ]. The EpoR D2 domain was included in the CARs because our previous studies had already demonstrated that CARs with the EpoR D2 domain and diverse cytoplasmic signaling domains are functional [ 18 – 22 , 24 , 28 ]. The transmembrane and intracellular domains derived from IL-3Rα and βc chain were utilized to create a pair of piCAR chains, named S(M)-IL3Rα and S(M)-IL3Rβc, respectively ( Fig 1B ).…”

“…The ligand-binding domain of cytokine receptors was replaced with single-chain Fv (scFv), which could alter ligand specificity from cytokines to specific antigens. In our previous studies, we have successfully attained antigen-induced proliferation [ 18 , 19 ], differentiation [ 20 ], migration [ 21 , 22 ], and death [ 23 , 24 ] using appropriate signaling domains derived from cytokine receptors. However, sequential regulation from proliferation to differentiation, which would be the most fundamental and important in cell and gene therapies for curing blood disorders, has yet to be demonstrated.…”

STAT3 for Cardiac Regenerative Medicine: Involvement in Stem Cell Biology, Pathophysiology, and Bioengineering

“…For STAT3 activation, Kawahara and colleagues have developed several artificial cytokine receptors, named signalobodies, to control cellular functions. The scFv-c-Fms (S-Fms) signalobody activates downstream signaling molecules, including MEK, ERK, AKT, and STAT3 [125][126][127]. A heterodimeric signalobody of V H /EpoR and V L /gp130 could also induce the activation of JAK/STAT signaling [128].…”

Cell fate‐inducing CARs orthogonally control multiple signaling pathways

“…To this end, we constructed a series of chimeric receptors in which the extracellular domains of these cytokine receptors were replaced with scFv. As a result, we succeeded in developing CARs that control the four fundamental cell fates, namely proliferation-, differentiation-, migration-, and apoptosis-inducing CARs (piCAR, [18,19] diCAR, [12,20] miCAR, [21,22] and aiCAR, [23,24] respectively).…”