The Week India - July 29, 2018

THE WEEK · JULY 29, 2018 33

HEALTH

second reagent in our combi-
national therapy is an agonistic
antibody targeting OX40. This
antibody binds its target, and
causes activation of a subset
of T-cells known as T effector
cells and reduces the activity
of a different subset of T-cells
known as T regulatory cells (T
regs). T regs are suppressors of
T effector cell. So, by combining
both reagents we are activating
the activators and suppressing
the suppressors, and this way
we switch the balance from an
immune-suppressive to an im-
mune-promoting environment.”
One of the most interesting as-
pects of the study was that some
of the tumour-specifi c, activated
T-cells left the original tumour
to fi nd and destroy other iden-
tical tumours throughout the
body, thereby displaying an
overall body response.
“The biggest risk of cancer is

not necessarily the primary tu-

mour, but the metastasis. For

this reason, in our experiments,

we implanted tumours at two

different sites of the mouse's ab-

domen. We treated only one of

those tumours with our combi-

nation (CpG and an antibody)

and monitored the tumour de-

velopment in both the treated

and the non-treated tumour.

We found that the combina-

tion of CpG and an antibody

against OX40 was suffi cient

to regress the treated tumour

and then, a few days later, the

non-treated tumour also com-

pletely regressed. We waited

three months after the mice

DR RONALD LEVY

CpG

OX40 40

_OX40 _OX40

Activates antigen

presenting cells

OX40 upregulation

on T-cells

Specific anti-tumour

T-cell proliferation and migration

Treated tumour Systemic anti-

tumour response

PICTURE COURTESY: STEVE FISCH