antiB7

antiB7 is a term used to refer to antibodies directed against B7 family molecules, primarily B7-1 (CD80) and B7-2 (CD86), which are costimulatory ligands expressed on antigen-presenting cells. In immunology, B7–CD28/CTLA-4 interactions provide the second signal required for full T cell activation; blocking these ligands can dampen T cell responses.

Most antiB7 antibodies bind either CD80 or CD86, blocking interaction with CD28 as well as CTLA-4, depending on their binding site. This can suppress T cell activation and cytokine production, potentially promoting tolerance. Some antibodies may also deplete B7-expressing cells via effector functions, though this depends on antibody isotype and design.

Clinical and research use: AntiB7 antibodies are used to study T cell costimulation, autoimmunity, transplantation, and cancer immunology. Examples include anti-CD80 antibodies such as galiximab, which have been evaluated in clinical trials for non-Hodgkin lymphoma and other indications. Anti-B7 strategies are conceptually related to, but distinct from, CTLA-4–Ig fusion proteins like abatacept, which inhibit B7–CD28 signaling by sequestering B7 ligands rather than targeting them with a monoclonal antibody.

Limitations: B7 blockade can increase infection risk, affect vaccine responses, and the outcome can vary depending on whether CD80 or CD86 is targeted. B7 expression on antigen-presenting cells is dynamic and influenced by activation status and cytokines.