This book is a comprehensive compilation of research on HIV and AIDS. The prevalence of AIDS pandemic reminds us that in spite of the ceaseless quest for knowledge and information since the early 1980s, we have a lot to learn and comprehend about AIDS and HIV. This syndrome represents one of the biggest challenges for humanity, science and medicine. The aim of this book is to provide a source of encouragement for researchers and serve as an efficient guide for graduate students in their ongoing search for a cure of HIV, and aid clinicians. Therefore, this book includes two broad sections which describe the relationship and interaction of HIV with cellular cells and the immune system.