Cancer Treatment with NK Cells
Natural Killer Cells (NK Cells) are lymphocytes in the same family as
T and B cells, coming from a common progenitor. However, as cells of
the innate immune system, NK cells are classified as group I Innate
Lymphocytes (ILCs) and respond quickly to a wide variety of pathological
challenges. NK cells are best known for killing virally infected cells,
and detecting and controlling early signs of cancer. As well as
protecting against disease, specialized NK cells are also found in the
placenta and may play an important role in pregnancy.
NK cells were first noticed for their ability to kill tumour cells without any priming or prior activation (in contrast to cytotoxic T cells, which need priming by antigen presenting cells). They are named for this ‘natural’ killing. Additionally, NK cells secrete cytokines such as IFNγ and TNFα, which act on other immune cells like Macrophage and Dendritic cells to enhance the immune response.
NK cells were first noticed for their ability to kill tumour cells without any priming or prior activation (in contrast to cytotoxic T cells, which need priming by antigen presenting cells). They are named for this ‘natural’ killing. Additionally, NK cells secrete cytokines such as IFNγ and TNFα, which act on other immune cells like Macrophage and Dendritic cells to enhance the immune response.
How Do NK Cells Target Cancer Cells
While on patrol NK cells constantly contact
other cells. Whether or not the NK cell kills these cells depends on a
balance of signals from activating receptors and inhibitory receptors on
the NK cell surface. Activating receptors recognise molecules that are
expressed on the surface of cancer cells and infected cells, and ‘switch
on’ the NK cell. Inhibitory receptors act as a check on NK cell
killing.
Most normal healthy cells express MHC I receptors which mark
these cells as ‘self’. Inhibitory receptors on the surface of the NK
cell recognise cognate MHC I, and this ‘switches off’ the NK cell,
preventing it from killing.
Cancer cells and infected cells often lose
their MHC I, leaving them vulnerable to NK cell killing. Once the
decision is made to kill, the NK cell releases cytotoxic granules
containing perforin and granzymes, which leads to lysis of the target
cell.
NK21 – NK Cells for Cancer
At ImmuneCells21 we produce the NK21 –
Natural Killer Cells for Cancer. The protocol we have developed produces
2 infusions of cytotoxic killer cells per blood collection (100ml). The
NK cells are culture and released for therapeutic use on day 18 &
day 21. In a full cancer treatment program we will perform 3 blood
collections (weekly) & NK cultures, giving a total of 6 cytotoxic
killer cell infusions on days: