Role of immune modulation in primary HIV infection

Hydroxyurea inhibits HIV without attacking the virus directly. By inhibiting a cellular enzyme (ribonucleotide reductase) the drug decreases the intracellular concentration of deoxynucleotide triphosphates, thus favoring the incorporation of other drugs, such as the reverse transcriptase inhibitors, into the nascent viral DNA. A large body of data has shown that hydroxyurea can be successfully used during chronic infection. In this manuscript we review the use of hydroxyurea during primary HIV infection. In several independent studies hydroxyurea has been shown to: 1) inhibit HIV in combination with a reverse transcriptase inhibitor and a protease inhibitor as efficiently as with standard highly active antiretroviral therapies; 2) stimulate the immune system by increasing the percentage of naive cells and the percentage of cells capable of responding to antigens; 3) "cool down" the immune system hyper-activation. The role of hydroxyurea in inducing control of HIV during structured treatment interruptions remains to be clarified.