Question

All T lymphocytes express a molecule known as lymphocyte function-associated antigen-1 (LFA-1). This is thought to be the most important adhesion molecule for lymphocyte activation because antibodies to it effectively inhibit the activation of both native and armed effector cells. LFA-1 is up-regulated by T cell activation and is a member of a family of cell-surface proteins known as what?

Streptolysins
Immunophilins
Interleukins
Selectins
Integrins

Answer 1

T lymphocytes express LFA-1, an important adhesion molecule that is up-regulated upon activation and is a member of the integrins family. T lymphocytes also rely on T cell receptors (TCRs) and the CD4 or CD8 co-receptors to bind to antigen-presenting cells (APCs) and become activated.The correct option is E.

Step-by-step explanation:

Lymphocyte function-associated antigen-1 (LFA-1) is a molecule expressed on all T lymphocytes and is crucial for lymphocyte activation. LFA-1 belongs to a family of cell-surface proteins called integrins.

These proteins play a significant role in cell adhesion and are important for the proper functioning of the immune system. Integrins assist in the immune response by mediating the adhesion between T cells and antigen-presenting cells (APCs), a necessary step for the T cell activation process.

During the activation process, T cells require the presence of their specific antigen receptors known as T cell receptors (TCRs). The two most common types of TCRs in T lymphocytes are the alpha-beta T cell receptors.

These receptors work alongside co-receptor molecules, CD4 or CD8, which determine the type of MHC molecule they will engage with on the APC.

CD4+ cells bind to MHC II molecules, while CD8+ cells bind to MHC I molecules. The engagement and activation of these cells prompt them to differentiate into either helper T lymphocytes (TH) or cytotoxic T lymphocytes (CTLs) accordingly.The correct option is E.