Most T lymphocytes have a dual specificity for which one of the following pairs of molecules?
A)A particular allelic form of a major histocompatibility complex (MHC)molecule and a peptide bound to the MHC molecule
B)Both MHC class I and class II molecules
C)Both peptide and glycolipid antigens
D)Both soluble peptides and peptide-MHC complexes
E)MHC molecules and CD4 or CD8

Question

Quizplus · Accepted Answer

Most T cells are specific for polymorphic residues of a self major histocompatibility complex (MHC)molecule,which accounts for their MHC restriction,and for residues of a peptide antigen displayed by the MHC molecule,which accounts for antigen specificity.The receptor that recognizes peptide-MHC complexes is called the T cell receptor (TCR).Mature F1F1F1S1F1F1F10 T cells (the predominant type)express either CD4 or CD8,but not both.As such,each F1F1F1S1F1F1F10 T cell is restricted to bind either MHC class II or class I molecules,but not both.Although a small subset of T cells may recognize glycolipid antigens bound to class I MHC-like molecules called CD1,these T cells do not also recognize peptide antigens.Unlike the B cell receptor (immunoglobulins),the TCR can recognize only peptides displayed on MHC molecules,not soluble peptides alone.T cells express CD4 or CD8 and do not recognize CD4 or CD8 on other cells.

Most T Lymphocytes Have a Dual Specificity for Which One