Intracellular immunization against HIV infection with an intracellular antibody that mimics HIV integrase binding to the cellular LEDGF protein

Jennifer Chambers,Leyuan Bao,Ami Miller,Mariliza Derveni,Simon E V Phillips,Camilo E Quevedo,Clare Hannon,Alison Simmons,Wilawan Bunjobpol,Abimael Cruz-Mignoni,Mei-Yi Sun,Denis Ptchelkine,Terence H Rabbitts

doi:10.1038/s41598-017-16742-2

Abstract

Preventing the protein-protein interaction of the cellular chromatin binding protein Lens Epithelium-Derived Growth Factor (LEDGF) and human immunodeficiency virus (HIV) integrase is an important possible strategy for anti-viral treatment for AIDS. We have used Intracellular Antibody Capture technology to isolate a single VH antibody domain that binds to LEDGF. The crystal structure of the LEDGF-VH complex reveals that the single domain antibody mimics the effect of binding of HIV integrase to LEDGF which is crucial for HIV propagation. CD4-expressing T cell lines were constructed to constitutively express the LEDGF-binding VH and these cells showed interference with HIV viral replication, assayed by virus capsid protein p24 production. Therefore, pre-conditioning cells to express antibody fragments confers effective intracellular immunization for preventing chronic viral replication and can be a way to prevent HIV spread in infected patients. This raises the prospect that intracellular immunization strategies that focus on cellular components of viral integrase protein interactions can be used to combat the problems associated with latent HIV virus re-emergence in patients. New genome editing development, such as using CRISPR/cas9, offer the prospect intracellularly immunized T cells in HIV+ patients.

Highlights

Protein-protein interactions (PPIs) are important inside cells for transcription, signaling and formation of complex organelles and a range of normal cellular activities such as maintenance, control of cell division, and quiescence
We show that a T cell line, constitutively expressing an anti-LEDGF/PSIP1 intracellular single domain antibody, has a marked reduction in HIV p24 production in Human Immunodeficiency Virus type 1 (HIV-1) infected cells, reflecting interference with infected virus replication
Isolation of a heavy chain variable region single domain antibody binding to LEDGF Integrase Binding Domain (IBD)

Summary

Introduction

Protein-protein interactions (PPIs) are important inside cells for transcription, signaling and formation of complex organelles and a range of normal cellular activities such as maintenance, control of cell division, and quiescence. The use of biological reagents against infections has been proposed and in particular intracellular antibody fragments[5] This concept developed into the idea of intracellular immunization[6,7] where intracellular antibody fragments delivered into cells could interfere with specific disease protein functions[7]. In this respect, the LEDGF-HIV IN interaction represents an attractive therapeutic target[8] since this mediates viral integration into transcriptional active regions[9] thereby allowing maintenance of latent HIV for subsequent rounds of viral production[8,9,10]. We show that a T cell line, constitutively expressing an anti-LEDGF/PSIP1 intracellular single domain antibody (iDAb), has a marked reduction in HIV p24 production in HIV-1 infected cells, reflecting interference with infected virus replication

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Discussion

Conclusion