MHC restriction AP Viral antiger elease of eceptor cell T cell expansion of on 1L-2 Am ified elosg79nCoontggg Cell will be dest ad th have the viral antigen APC or virus-infected cells,present viral antigen in association with self class I molecules,recognized by cytotoxic cells,and class II molecules,recognized by helper cells.Binding of the Class I molecule/viral antigen complex to T cytotoxic cell receptors stimulates expansion of cytotoxic cells,Binding of the classI eiracextothelper receptors stilateexpasion of helper ce The response may be amplified by the release of interleukin 1 from APC and interleukin 2 from both T cell subsets.T cytotoxic cells will recognize and destroy only target cells expressing both self class I molecules and viral antigen. Class III genes control the level of at least tw major proteins known as C4,the fourth component of complement,and Slp (sex-linked protein.C4 is a three-chair glycoprotein containing an alpha,beta,gamma chain with molecular weights of 93, 77,and 32 kD,respectively.The Slp locus encodes a sex-linked protein expressed only in males of certain strains of mice. Major Histocompatibility Complex in Humans (HLA) Nearly forty years ago human leukocyte -associated(HA)Antigens were discovered that were similar to the H-2 complex in mice.The HLA system in humans were of critical APC or virus-infected cells, present viral antigen in association with self class I molecules, recognized by cytotoxic cells, and class II molecules, recognized by helper cells. Binding of the Class I molecule/viral antigen complex to T cytotoxic cell receptors stimulates expansion of cytotoxic cells, Binding of the class I molecule/viral complex to t helper receptors stimulates expansion of helper cells. The response may be amplified by the release of interleukin 1 from APC and interleukin 2 from both T cell subsets. T cytotoxic cells will recognize and destroy only target cells expressing both self class I molecules and viral antigen. Class III genes control the level of at least two major proteins known as C4, the fourth component of complement, and Slp (sex-linked protein. C4 is a three-chain glycoprotein containing an alpha, beta, gamma chain with molecular weights of 93, 77, and 32 kD, respectively. The Slp locus encodes a sex-linked protein expressed only in males of certain strains of mice. Major Histocompatibility Complex in Humans (HLA) Nearly forty years ago human leukocyte-associated (HLA) Antigens were discovered that were similar to the H-2 complex in mice. The HLA system in humans were of critical