UCSD’s Rebecca and
is one step closer to finding a cure for chronic lymphocytic leukemia, the most
common form of leukemia found in adults.
Earlier this month, a research team led by Thomas J. Kipps,
a professor of medicine, published its study on the use of gene therapy to
activate the immune system against leukemia cells. During their research, Kipps
and his colleagues found that autoantibodies could be produced against leukemia
cancer cells and that certain antibodies react with a particular embryonic
protein, the exact function of which they were able to isolate.
The protein, ROR1, is active during an early stage of human
development known as embryo genesis, but is then turned off. Kipps and his team
found, however, that leukemia cells use this protein to advance their own
survival.
“We wanted to find out why — what is their function?” Kipps
said.
ROR1 is located on the surface of leukemia cells, and
analyzing its interactions with other cellular structures could lead to two
important breakthroughs, according to the research team.
First, antibodies that are able to react with ROR1 can mark
the cell for destruction. The immune system relies on antibodies to distinguish
malignant cells from normal ones — a process useless in cancer patients.
“Leukemia cells are like stealth bombers, they avoid
detection by the immune system,” Kipps said.
If antibodies could be produced to bind the ROR1 on leukemia
cells, the immune system can be activated against them. Using a gene therapy
procedure developed at UCSD, Kipps’ team inserted a gene into CLL patients that
produced the necessary antibodies, or what he referred to as “turning off the
stealth button.”
Secondly, because ROR1 is only found on leukemia cells, it
can be used to precisely and specifically detect its presence even after
treatment or in patients suffering from an early stage of the disease.
This use of ROR1 marks a departure from conventional
leukemia treatments, in which antibodies bind with antigens on normal cells as
well as cancerous ones, causing damaging side effects to already typically
immune-suppressed leukemia patients.
Kipps, a veteran in the field of CLL research and UCSD
professor since the early 1990s, said he is excited to see leukemia patients,
who normally are unable to make antibodies against anything, develop antibodies
against their own leukemia cells.
As deputy director of the Rebecca and
of studies on this particular form of leukemia, and treated patients from all
over the country as well as from
“This study establishes UCSD as the go-to place for leukemia
treatment,” he said.
Having published the study in the journal Proceedings of the
National Academy of Sciences, Kipps and his research team are looking forward
to the possible development of CLL vaccines.
