Virus-host mucosal interactions during early SIV rectal transmission

Area of Science:

• Virology
• Immunology
• Gastroenterology

Background:

• Understanding early rectal transmission of Human Immunodeficiency Virus type 1 (HIV-1) is crucial for developing effective prevention strategies.
• The rectal mucosa's role in initial viral entry and host response requires detailed investigation.

Purpose of the Study:

• To elucidate virus-host interactions during early rectal transmission of HIV-1.
• To investigate the host's immune response in the rectal mucosa following simian immunodeficiency virus (SIV) inoculation.

Main Methods:

• Utilized the simian immunodeficiency virus (SIV)-Indian rhesus macaque model.
• Employed mRNA deep sequencing to analyze host gene expression in rectal mucosa.
• Examined responses at 3, 6, and 10 days post-rectal inoculation (dpi).

Main Results:

• The rectal mucosa demonstrated an active response to SIV infection starting as early as 3 dpi.
• More robust immune responses were observed at 6 and 10 dpi.
• High expression of genes for lymphocyte chemoattractants, inflammation, and immune activation was noted, alongside high expression of SIV accessory genes.

Conclusions:

• Host failure to contain SIV replication at the rectal portal of entry is due to a dual mechanism.
• This includes recruitment of susceptible cells via immune gene expression and viral evasion of host defenses by SIV accessory genes.
• Provides novel insights into the mechanisms underlying rectal HIV-1 transmission.