HIV-1 infection is characterized by progressive depletion of CD4+ T cells that eventually leads to clinically significant immunodeficiency. A chronic generalized immune activation is now being recognized to be the main driving force for T cell depletion, loss of anti-HIV-1 immunity and disease progression during chronic HIV-1 infection. However, it is still unknown whether reducing immune activation will restore CD4 T cell counts and leading to immune reconstitution in chronic HIV infection. Mesenchymal stem cells (MSC) have been demonstrated to decrease immune responses of the host, and can suppress inflammation in HIV-infected non-responders. Here, the investigators propose a hypothesis that MSC can reduce immune activation which subsequently lead to the restoration of CD4 T-cell counts dependent on dose of transfused MSCs in HIV-infected patients.