HIV Semen Biology
HIV BiologyHuman Immunodeficiency Virus (HIV) infects cells by first binding to specific receptors on the cell surface, then entering the cell. HIV uses two receptors to gain entry. One receptor is termed CD4 and is on the surface of cells belonging to the immune system.
Once inside the cell, HIV engineers a copy of its genetic information to become an integral part of the cell's genes. It does not kill the cell it has infected, but it takes advantage of the cell's machinery to make new virus particles that are released from the surface of the cell. The new virus then attaches to a new, uninfected (CD4) cell, to repeat the process.
Therefore, HIV infection has two forms in the body: free virus particles, and virus-infected cells.Not all virus-infected cells produce virus particles all the time. Some infected cells do not produce new virus particles unless they are stimulated to respond to another type of infection, such as the flu, or a bacterial infection. Once stimulated, they begin to produce new HIV particles, and then die. Because CD4-cells are a key player in immune responses to all types of infections, the relentless loss that results from HIV infection gradually erodes the immune system, which leads to AIDS.
Most of the HIV-infected cells are in lymph nodes, a few circulate in the blood stream, and others are scattered throughout the body. Importantly, even after 25 years of research, the organ source of semen HIV is unknown.
Semen is a complex and unusual body fluid. It does not exist anywhere within the body, it is created by ejaculation of cells and fluids from three tissues (epididymis, seminal vesicles and prostate) carried by two duct systems (vas deferens and urethra). Each semen specimen is unique.