Human immunodeficiency virus type I (HIV-1) causes AIDS by infecting immune cells.It is known that there are two ways in which a virus can spread in the body.One is cell-free, which is a method in which a virus is released from an infected cell and the virus attaches to other cells.The other is cell-to-cell, which is a method in which cells come into direct contact with each other and pass the virus to spread the infection.It was thought that the former contributed mainly to the progress of AIDS, but in 2 it was reported that cell-to-cell infection may not be the cause of the cure of AIDS. It is attracting attention.

　The research group aimed to quantify the contribution of cell-free and cell-to-cell to the spread of HIV-1 infection.A notable technique is to create an environment where cell-to-cell infection does not occur by culturing cells while shaking the flask.By mathematically analyzing the data obtained in this way and the data obtained from normal culture, we succeeded in quantifying the contribution of cell-free and cell-to-cell.According to this, cell-to-cell infection accounts for 60% of cell-to-cell infections, accelerating the rate of spread of infection in the body by 3.9 times.It shows the importance of cell-to-cell infection in future AIDS research.

　Previous drug treatments may not have been able to control cell-to-cell infections, which may force a shift in treatment strategy.The research group will continue to aim to elucidate the whole picture of cell-to-cell infection.It can be expected to lead to the development of new drugs aimed at eradicating AIDS.