Antigen - Kougen (English spelling) antigen

Japanese: 抗原 - こうげん（英語表記）antigen

When a living organism is administered a "non-self" substance, it has the property of producing corresponding antibodies and sensitized lymphocytes. The substance that causes such a reaction is called an antigen. In addition, this antigen specifically binds to antibodies, binds to complement, and causes reactions such as forming immune complexes, and also specifically binds to sensitized lymphocytes and causes a cell-mediated immune response. An antigen that has both the immunogenicity to produce antibodies and the reactogenicity to react specifically with the antibodies is called a complete antigen, while an antigen that only has reactogenicity is called an incomplete antigen (hapten). A substance that is less antigenic than an incomplete antigen, does not produce antibodies by itself, and does not show an antigen-antibody reaction, but has affinity with antibodies and suppresses the specific reaction between a complete antigen and its antibody is called a semi-hapten. There are artificial antigens, nonspecific antigens, and Forssman antigens.

Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information

Japanese:

生物体には，「非自己的」 (ノン・セルフ) な物質を投与されたとき，それに対応する抗体や，感作リンパ球をつくりだす性質がある。こうした反応を引起す物質を抗原という。また，この抗原は，抗体と特異的に結合し，さらに補体と結合し，免疫複合体をつくるなどの反応を起すほか，感作リンパ球と特異的に結合し，細胞性免疫反応を起す作用もある。抗体をつくりだす免疫原性と，その抗体と特異的に反応する反応原性の両方の性質をもっている抗原を完全抗原，反応原性だけをもつものを不完全抗原 (ハプテン) という。不完全抗原よりも抗原性を欠き，単独では抗体を産生しないし，抗原抗体反応を呈さないが，抗体との親和性をもち，完全抗原とその抗体との間の特異的反応を抑制する物質をセミハプテンと呼ぶ。人工抗原，非特異性抗原，フォルスマン Forssman抗原などがある。

出典　ブリタニカ国際大百科事典小項目事典ブリタニカ国際大百科事典小項目事典について　情報

<<: Desert - Kougen

>>: Light source