Dr. Ohainle is a Senior Staff Scientist that directs her own NIH-funded research in the Emerman Lab. Dr. Ohainle created a novel CRISPR screening method to identify genes important for inhibiting or enhancing HIV infection in cells, HIV-CRISPR screening (Ohainle et al eLife 2018). Current work in the Ohainle Group includes 1) additional screens to identify genes responsible for inhibiting the replication of HIV-1 and related primate lentivurses and 2) studies aimed at understanding the mechanism of restriction of lentiviral capsids by TRIM34, an HIV restriction factor identified through HIV-CRISPR screening. Dr. Ohainle’s work combines both high throughput functional genomics approaches and molecular virology aimed at uncovering basic mechanisms of viral replication, host antiviral effectors and the interplay between the two.
To infect human cells transmitted viruses must adapt to counteract the arsenal of human restriction factors encoded in the genome. HIV has evolved to escape or antagonize restriction factor barriers, thereby allowing for adaptation for replication in human cells. These host-encoded restriction factors play a key role in limiting infection of HIV and SIVs. By studying HIV strains and mutants that are not well-adapted to human cells we can better understand important human restriction barriers. Currently we are using HIV-CRISPR screening to identify key host cell restrictions blocking infection by a diverse array of HIV and SIV variants. Restriction factors that target the HIV capsid, key to delivery of HIV genomes into the host cell and to/through nuclear pores, are a major focus of the lab. The high-throughput nature, adaptability to different CRISPR sgRNA libraries, assay of the complete HIV lifecycle inside a cell and portability to other cell and viral systems make HIV-CRISPR screening a major step forward in the study of HIV restriction factor biology.
The HIV capsid gene (p24 or CA) forms the core of the HIV virion and is key to effective uncoating and delivery of the HIV genome into the nucleus where integration into the host chromosome can occur. Through HIV-CRISPR Screening we’ve recently found that a single amino acid CA mutation leads to enhanced susceptibility of HIV to a novel cellular restriction mediated by TRIM34. Our initial studies of TRIM34 show that it inhibits HIV at reverse transcription, requires its close paralog, TRIM5alpha, for its antiviral activity and inhibits a broad range of primate lentiviruses. Understanding the evolution and function of TRIM34 are a major focus of the lab.
November 2019: Our newest paper describing TRIM34 inhibition of HIV-1 and SIV capsids is up on bioRxiv.
August 2019: The Ohainle lab receives a Collaborative Development Award (CDA) from the CHEETAH (Center for the Structural Biology of Cellular Host Elements in Egress, Trafficking and Assembly of HIV)
June 2019: The Ohainle Lab is awarded an R01 to find and study CA-targeting HIV restriction factors.
May 2019: Molly is awarded the Andy Kaplan Prize at the Cold Spring Harbor Retroviruses meeting.
December 2018: The HIV-CRISPR screen is published in eLife.
Selected publications are listed below. For a complete list of publications, see Molly’s NCBI bibliography.
Ohainle, M.*, Kim, K., Keceli, S., Felton, A., Campbell, E.M., Luban, J., and Emerman, M.* (2019). TRIM34 acts with TRIM5 to restrict HIV and SIV capsids. bioRxiv, 820886. *co-corresponding authors
Sharma, A., McLaughlin, R.N., Jr., Basom, R.S., Kikawa, C., OhAinle, M., Yount, J.S., Emerman, M., and Overbaugh, J. (2019). Macaque interferon-induced transmembrane proteins limit replication of SHIV strains in an Envelope-dependent manner. PLoS Pathog 15, e1007925.
OhAinle, M.*, Helms, L., Vermeire, J., Roesch, F., Humes, D., Basom, R., Delrow, J.J., Overbaugh, J., and Emerman, M.* (2018). A virus-packageable CRISPR screen identifies host factors mediating interferon inhibition of HIV. Elife 7. *co-corresponding authors
Roesch, F., OhAinle, M., and Emerman, M. (2018). A CRISPR screen for factors regulating SAMHD1 degradation identifies IFITMs as potent inhibitors of lentiviral particle delivery. Retrovirology 15, 26.
lentiCRISPRv2 ISG library – coming soon
NIH AIDS Reference and Reagent Repository:
HIV-CRISPR – coming soon
PIKAHIV library – coming soon
HIV-CRISPR Screening - coming soon