Molecular Basis of the Human Immunodeficiency Virus

Human Immunodeficiency Virus (HIV) is the causative agent of Acquired Immunodeficiency Syndrome (AIDS), a deadly disease that affects the human immune system. HIV is a retrovirus that infects T-cells, macrophages, and dendritic cells in the immune system, leading to their destruction and, ultimately, the onset of AIDS. The molecular basis of HIV infection involves the interaction of the viral envelope protein gp120 with the host cell receptor CD4 and a co-receptor such as CCR5 or CXCR4. This binding triggers a conformational change in gp120 that exposes a fusion peptide, allowing the viral envelope to fuse with the host cell membrane and release its contents into the cytoplasm. Once inside the host cell, the viral genome is reverse-transcribed into DNA, which is then integrated into the host cell genome by the viral integrase enzyme. This allows the virus to replicate with the host cell and evade the immune system's surveillance. Despite advances in antiretroviral therapy, HIV continues to pose a significant global health threat, with over 38 million people living with HIV/AIDS worldwide. Understanding the molecular mechanisms of HIV infection is critical for developing effective treatments and vaccines to combat this deadly disease.