Semen by definition is the fluid ejaculated from a male, which includes the sperm cells as well as a number of other components. The Elements (ingredients) Of Semen. Very simply put, seminal fluid is a thick white secretion rich in sugars, mostly fructose to fuel the sperm cells on their journey to the egg. This secretion is what composes the bulk of semen by volume (50-80%). Although mostly comprised of water, proteins, and sugars.
The T-cell receptor, or TCR, is a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules.
There are four types of T cells, each with a special purpose. Helper T cells detect infection and get the other cells of the immune system ready for battle. Helper T cells also tell B cells to produce antibodies, highly specialized proteins that help defend the body against infection. Cytotoxic, or killer, T cells destroy infected cells. Regulatory T cells tell the immune system when the battle with the pathogens is over and to stop fighting. Memory T cells remember how to defeat an infection and can respond rapidly if the same infection reoccurs.