Background: Due to the persistence of latent HIV-infected cellular reservoirs, HIV virus
can not be eradicated completely.
Objective: To identify proteins related to HIV latency, we performed a subcellular proteomic study
in HIV latent cell lines.
Methods: An established HIV-1 latent cell model (J-Lat Tat-GFP Clone A7 cells, A7 cells) and its
parental cell line (Jurkat cells) were used. The plasma membrane (PM) fraction from cultured cells
was enriched through aqueous two-phase partition. PM proteins were extracted and then separated
using two-dimensional electrophoresis (2DE). Differentially expressed proteins were identified by
mass spectrometry, and verified by western blotting.
Results: Thirteen non-redundant proteins were identified to be differentially expressed in the A7
PM fraction compared to those in the Jurkat PM. Eight had a PM location through Gene Ontology
(GO) analysis. A differential protein network of CAPG-ACTR3-CD3D was detected to have interactions
with HIV Vpr, Tat, gp160, etc. through STRING software analysis. One of the differential
proteins (Macrophage-capping protein (CAPG)) was verified by western blotting to be down- regulated
in two cell lines and HIV resting CD4+ T cells negatively selected from patients.
Conclusion: We identified 13 proteins in A7 compared to Jurkat cells. CAPG may be a potential
biomarker related to HIV latency.