CCL2 and tuberculosis: The most important mechanism through which TB enhances HIV-1 replication and the progression to AIDS in dually infected patients is the augmentation in expression of TNF-alpha and the HIV-1 noninhibitory beta-chemokine (MCP-1), low presence of HIV-1 inhibitory beta-chemokines (MIP-1 alpha, MIP-1 beta, and RANTES).