免疫グロブリンFc受容体（FcR）は、いくつかの造血細胞に発現する膜分子であり、抗体を介した病原体の認識と細胞応答を結びつけます。FcRは抗体のFc領域（定常部位）を認識し、感染症やその他の脅威に対する免疫応答を促進します。

Immune checkpoint blockade antibody therapy is an approach in cancer treatment that uses the body's immune system to target and destroy cancer cells. Immune checkpoints are regulatory pathways in immune cells that cancer cells exploit to evade detection. Key immune checkpoints include PD-1, PD-L1, and CTLA-4. By blocking these pathways, antibodies like pembrolizumab, nivolumab, and ipilimumab allow T-cells to recognize and attack cancer cells more effectively.

Fc-mediated antibody effector functions play an important role in the humoral immune response and form a necessary link between innate and adaptive immunity. The constant (Fc) region is the tail portion of an antibody that interacts with other components of the immune system, such as immune cells and complement proteins. Well-known functions include opsonization, antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and complement activation.

今回のエピソードでは、抗体フォーマット、特にFab、F(ab')2、およびFcフラグメントについて引き続き解説します。