Page 16 - Science Focus (Issue 018)

Enter the Chimera Background Information – Immune Cells at
Work!
Cancer is undoubtedly one of the most dreaded
maladies known to humans. It is defined as a condition CAR-T cells are constructed based on our current
where cells proliferate uncontrollably [1]. Besides surgery, understanding of immune cells, which is a part of our
conventional cancer treatments include radiotherapy natural defense mechanism for dealing with infections
or chemotherapy that aims at selectively killing cancer and diseases in our body. Here’s some background
cells. However, this is often accompanied by unwanted information about our immune cells related to the
side effects, as these therapies tend to kill off healthy therapy.
cells as well [2]. Fortunately, recent developments of
immunotherapies allow us to fight cancer in a more
precise manner, with our own immune system. Enter the Fact Number 1:
Chimera – the renowned chimeric antigen receptor T The T Cell Involved Is Known as Cytotoxic T Cell
cell (CAR-T cell) therapy, a man-made hybrid created Also known as killer T cells, one can infer from
for the sole purpose of eradicating cancer. The idea of its name that this cell type kills other cells (“cyto-”
this therapy is to extract a type of immune cell known meaning cell and “toxic” implying lethality). Cytotoxic
as T cells from the patient, genetically engineer them T cells usually kill cells that are damaged, as their
into CAR-T cells in vitro, and infuse the transformed cells continued existence is undesirable for the body, such
back into the patient’s body. With the newly gained as virus-infected cells which are hijacked to shelter
ability to recognize and attack cancer cells, CAR-T cells and replicate the pathogen. The major task of the T
are almost like a “living drug” against cancer, fighting cell is to distinguish damaged cells from healthy cells,
them off cell by cell!
CAR-T Cells: 1 編按：「Chimera」在英文有多重意思，原指希臘神話一隻會噴火、

由獅子、山羊和蛇合成的怪獸，引伸義為「幻想、空想」，後來被借
用至生物學上。作者在英文原文中用了語帶雙關的手法。
2 編按：CAR-T細胞在英文普遍被形容為「living drug」。
3 T細胞可以透過釋放一些會戳破細胞膜的蛋白質，使目標細胞爆裂
而死，這稱為細胞溶解。

1 T cells can effectively kill the target cell by releasing
proteins that poke holes on its plasma membrane,
causing a cell to burst, known as cell lysis.