Replies to post #599415 on NorthWest Biotherapeutics Inc (NWBO)

[ADVFN_doclee]

[If] a DC samples a single tumorous cell, now presumably non-self, certainly only a small part of the cell undergoes mutation while the large majority of the cell remains unchanged and is no different than in the non tumorous cell. so how does the DC recognize that the unchanged portions of the cell are not non-self and refrain from attacking them as non-self?

Cancerous cells are the result of damaged DNA. Cells can repair their own damaged DNA to an extent but if that is not possible it usually self-initiates apoptosis (cell death). However, if apoptosis cannot be initiated (presumably because the DNA damage has destroyed the mechanisms to initiate apoptosis) the damaged DNA is likely to be unstable. This will result in increasing damage to the DNA which is expressed on the cell surface as increasing numbers of abnormal epitopes / peptides. The increasing damage to the DNA will lead to uncontrolled growth of abnormal cells (ie malignant change). Once this process has started, even if there is only 1 abnormal epitope on each cell, the individual cells are beyond repair and the only way the body can control the situation is to destroy any and all abnormal cells, be there just 1 malignant epitope or hundreds displayed on each cell.

Thus, if a cell is displaying even 1 abnormal epitope the dendrocytes recognize that single epitope as being foreign and they will then programme Killer T-cells to destroy in its entirety any cell displaying that epitope. There is no part-way between normal and abnormal (just as somebody is either pregnant or not pregnant - there is no such thing as being "only very slightly pregnant").