HIV’s spread between immune cells is apparently aided by nano-sized spheres known as extracellular vesicles, or EVs.

EVs bud out of cells and are believed to ferry molecules from cell to cell as a form of communication.

Publishing their findings in Scientific Reports, researchers worked with cell cultures infected with HIV, out of which they isolated the virus as well as EVs that budded out of HIV-infected cells. Then they divided the the virus copies from these EVs and tested HIV’s ability to infect in new cell cultures both in the presence of the EVs and without.

When exposed to HIV but not EVs, blocks of human lymphatic tissue were infected at a rate 55 percent below the rate seen when they were exposed to both HIV and EVs.

The researchers discovered that when HIV-infected cells produce EVs, the EVs have a key HIV protein on their surfaces, known as gp120. The virus uses this protein to aid in its infection of new cells. The scientists believe that without the EV-provided gp120 protein, HIV had a harder time infecting cells in their experiment.

To read a press release about the study, click here.

To read the study abstract, click here.