Lymphocyte function-associated antigen 1

Lymphocyte function-associated antigen 1 (LFA-1) is a protein that in humans is encoded by the ITGAL gene. LFA-1 is a type of integrin, a large family of proteins that facilitate cell adhesion. It plays a crucial role in the immune system, particularly in the function of lymphocytes, a type of white blood cell.

Structure

LFA-1 is a heterodimeric protein, meaning it is composed of two different subunits. These subunits are known as the alpha (α) and beta (β) chains. The alpha chain is encoded by the ITGAL gene, while the beta chain is encoded by the ITGB2 gene. Each chain has a large extracellular domain, a single transmembrane domain, and a short cytoplasmic tail.

Function

LFA-1 plays a key role in the immune response by facilitating the interaction between T cells and antigen-presenting cells (APCs). This interaction is crucial for the activation of T cells, which are responsible for recognizing and responding to foreign substances in the body. LFA-1 also plays a role in the migration of lymphocytes to sites of infection or inflammation.

Clinical significance

Mutations in the ITGAL gene can lead to a rare genetic disorder known as Leukocyte adhesion deficiency (LAD). LAD is characterized by recurrent bacterial and fungal infections, impaired wound healing, and delayed separation of the umbilical cord. There is currently no cure for LAD, but treatments can help manage symptoms and prevent complications.

Research

Research into LFA-1 has potential implications for the treatment of various diseases, including autoimmune diseases, cancer, and infectious diseases. For example, drugs that inhibit LFA-1, known as LFA-1 antagonists, are being investigated for their potential to suppress the immune response in autoimmune diseases.

See also

• Integrin
• Leukocyte adhesion deficiency
• T cell
• Antigen-presenting cell