Macrophages helper T-cells and some nerve cells possess T-4, OV CD-4 antigen receptor sites over their surface. HIV gets attached to these site and passes into cells. It multiplies in cells. Virus particles bud out of the cells which die afterward.
The newly released – virus particles attack new cells especially the helper T-cells. Soon the number of helper T- cells decreases. Since helper T-cells are essential for functioning of immune system their reduced number results in deficient functioning of immune system of the infected person.
