A potential treatment for HIV

The human immunodeficiency virus (HIV) was recorded to affect 38.4 million people globally at the end of 2021. This virus attacks the immune system, incapacitating CD4 cells: white blood cells (WBCs) which play a vital role in activating the innate immune system and fighting infection. The normal range of CD4 cells in our body is from 500 to 1500 cells/mm3 of blood; HIV can rapidly deplete the CD4 count to dangerous levels, damaging the immune system and leaving the body highly susceptible to infections. Whilst antiretroviral therapy (ART) can help manage the virus by interfering with viral replication and helping the body manage the viral load, it fails to eliminate the virus altogether. The reason for this is due to the presence of latent viral reservoirs where HIV can lay dormant and reignite infection if ART is stopped. 

Whilst a cure has not yet been discovered, a promising avenue being explored in the hopes of eradicating HIV has been CRISPR/Cas9 technology. This highly precise gene-editing tool has been shown to have the ability to induce mutations at specific points in the HIV proviral DNA. Guide RNAs pinpoint the desired genome location and Cas9 nuclease enzymes act as molecular scissors that remove selected segments of DNA.  Therefore, CRISPR/Cas9 technology provides access to the viral genetic material integrated into the genome of infected cells, allowing researchers to cleave HIV genes from infected cells, clearing latent viral reservoirs. Furthermore, the CRISPR/Cas9 gene-editing tool can also prevent HIV from attacking the CD4 cells in the first place. HIV binds to the chemokine receptor, CCR5, expressed on CD4 cells, in order to enter the WBC. CRISPR/Cas9 can cleave the genes for the CCR5 receptor and therefore preventing the virus from entering and replicating inside CD4 cells. 

CRISPR/Cas9 technology provides a solution that current antiretroviral therapies cannot solve. Through gene-editing, researchers can dispel the lasting reservoirs unreachable by ART that HIV is able to establish in our bodies. However, further research and clinical trials are still required to fully understand the safety and efficacy of this approach to treating HIV before it can be implemented as a standard treatment. 

Written by Bisma Butt

Related article: Antiretroviral therapy