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.
During thymic development T cells are present in a CD4 + CD8 + double positive interim state. Moreover, in several species such as rat, macaque, chicken, man and especially the swine even in peripheral blood mature T cells expressing CD4 as well as CD8 have been characterised (reviewed in (Zuckermann, 1999)).s depicted in Fig. 2 B, CD4 + CD8 + T cells in canine peripheral blood do not express the CD1a marker in contrast to monocytes used as internal positive control (data not shown). Two distinct T cell receptors can be found on canine T cells.