ZAP-70 promotes microenvironment interactions and increases protein-translation in chronic lymphocytic leukemia

ABSTRACT: The expression of ZAP-70 in a subset of CLL patients strongly correlates with a more aggressive clinical course, though the exact underlying mechanisms remain elusive. The ability of ZAP-70 to enhance B cell receptor (BCR) signaling, independently of its kinase function, likely contributes. Here we employed RNA-sequencing and proteomic analyses of primary cells and cell lines, differing only in their expression of ZAP-70, to further define how ZAP-70 increases aggressiveness of CLL. We identified that ZAP-70 is required for the constitutive expression of T cell chemokines and the MHC class I molecule CD1c in the absence of an overt BCR signal, both promoting interactions with T cells. In addition, quantitative mass spectrometry of double-cross linked ZAP-70 complexes demonstrated that direct protein-protein interactions between ZAP-70 and cytoskeletal proteins positively regulate cell migration, irrespectively of CCR7 expression. Importantly, these functions of ZAP-70 did not require antigen-stimulation of the BCR. In contrast, we observed that ZAP-70 rapidly forms complexes with ribosomal proteins in BCR-activated cells, while decreasing the expression of ZAP-70 significantly reduced protein biosynthesis, providing evidences that ZAP-70 contributes to translational dysregulation in CLL. In conclusion, ZAP-70 promotes microenvironment-interactions and protein-translation in CLL cells, both likely to improve cellular fitness and to further drive disease progression.

INSTRUMENT(S): Orbitrap Fusion Lumos, LTQ Orbitrap Velos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): B Cell, Primary Cell

DISEASE(S): Chronic Lymphocytic Leukemia

SUBMITTER: Valar Nila Roamio Franklin  

LAB HEAD: Clive D'Santos

PROVIDER: PXD019465 | Pride | 2022-08-26

REPOSITORIES: Pride