RE: Quoting20 Jan 2019 21:12
Well now to quote scancell :)... I'll capitalise the bit to go wow at:
'post-translational changes are
the result of the stresses to which cancer cells are
often subjected. A case in point is stress-induced
autophagy leading to the post-translational conversion of arginine to citrulline by peptidylarginine deiminase (PAD) enzymes. These modified
epitopes are presented on MHC-II and stimulate
CD4 T-cell responses.20 To this end, we have
demonstrated that stress-induced citrullinated
peptide epitopes induce potent, cytotoxic CD4
T-cell-mediated, antitumour responses that could
constitute a completely new class of cancer
treatment.
Nutrient and oxygen deprivation, endoplasmic
reticulum (ER) stress, as well as accumulated
deoxyribonucleic acid (DNA) damage by rapidly
dividing cancer cells creates a ‘stressed’ environment. The ability of established tumours to grow
and survive depends largely on autophagic flux.
However, the majority of tumours do not express
MHC-II, as the immunosuppressive tumour
environment inhibits inflammation. Vaccinating
with citrullinated peptides induces pro-inflammatory, CD4 Th1 cells that are initially reactivated
within the tumour environment by APCs, constitutively expressing MHC-II and autophagy.
These reactivated CD4 T cells release IFN?,
which upregulates class MHC-II on the tumours,
allowing direct recognition by the cytotoxic CD4
T cells. We have shown that citrullinated peptides
stimulate CD4 T cells, which do not require CD8
responses for antitumour immunity,21,22 and leave
a memory response to prevent recurrence.
Although our first vaccine targets are vimentin
and enolase which are expressed by many cancers, other commonly expressed cytoskeletal, glycolytic, regulatory and chaperone proteins are
also citrullinated under conditions of cellular
stress.23–25 In theory, combinations of a select few
citrullinated peptides could be used to target ALL
MAJOR SOLID CANCERS resulting in a step change in
the approach to treating tumours. In addition to
citrullination, other stress-induced post-translational modifications (siPTM) have been observed
within MHC-bound peptides.26,27 Our overarching hypothesis is that these vaccines based upon
siPTM of proteins will elicit new or boost preexisting immunity that will eliminate tumours
with a low T-cell infiltrate.'