TZM-gfp cells: a tractable fluorescent tool for analysis of rare and early HIV-1 infection

David W Gludish,Elizabeth T Chimbayo,David G Russell,Dumizulu L Tembo,Kondwani C Jambo,Henry C Mwandumba,Saikat Boliar,Shannon Caldwell

doi:10.1038/s41598-020-76422-6

Abstract

Here we describe TZM-gfp, a novel HIV-1 reporter cell derived from the same parental clone JC.53, used previously to generate the widely-utilized indicator cell line TZM-bl. We re-engineered JC.53 cells to express GFP under regulation of HIV Tat and Rev. We characterize the new reporter cell line to show that TZM-gfp cells are equally susceptible to HIV infection, exhibit minimal background signal, and can report HIV infection in rare cells from a bulk population of experimentally-infected human monocyte-derived macrophages. We demonstrate the utility and sensitivity of the cells in detection of even a single HIV-positive macrophage by fluorescence-assisted correlative electron microscopy, using the GFP signal to guide imaging of HIV virions in primary co-culture. Finally, we used TZM-gfp cells for viral capture during co-culture with human peripheral blood mononuclear cells, showing that TZM-gfp can support outgrowth and analyses of patient-derived primary HIV-1 isolates.

Highlights

We describe TZM-gfp, a novel HIV-1 reporter cell derived from the same parental clone JC.[53], used previously to generate the widely-utilized indicator cell line TZM-bl
We demonstrate that these cells can be used in conjunction with correlative electron microscopy to detect and visualize virion production at the cellular level
TZM-gfp cell offers a highly-specific, sensitive, readout for viral infection with single cell resolution. We believe that such an adherent fluorescent reporter cell platform offers certain advantages for studying single or early infection events from primary tissue, blood samples, or reservoir populations where the frequency of viral infection is known to be low

Summary

Introduction

We describe TZM-gfp, a novel HIV-1 reporter cell derived from the same parental clone JC.[53], used previously to generate the widely-utilized indicator cell line TZM-bl. The global effort to study and therapeutically target HIV replication has been greatly advanced by the wide adoption of defined cell lines for in vitro study and quantitation of viral isolates While many of these reagents are human lymphoblastic leukemia cell lines that grow in suspension culture, a notable exception is the HeLa-derived HIV-1 indicator cell platform TZM-bl, which are adherent, non-immunological cells engineered to overexpress the HIV-1 co-receptors CD4, CCR5, and CXCR41. Though TZM-bl and other cell lines are available to quantify outgrowth from human patient samples using robust enzymatic readout, investigators face a shortage of tools to probe HIV biology at the level of the individual cell Given their wide adoption, we reasoned that TZM platform-based cells would be ideally suited to such studies, if re-engineered to generate a fluorescent signal upon HIV infection. We envision TZM-gfp cells as an additional reagent that builds on the utility of the TZM-bl platform to study HIV infection at the population, cellular and ultrastructural levels

Methods

Results

Conclusion