Interviewer: Dr. Kennedy, thank you for taking the time today to discuss
natural killer cells during a SARS-CoV-2 infection.
Could you give a brief overview of the role
of natural killer cells during an infection in the human body,
and their role in a SARS-CoV-2 infection?
Dr. Kennedy: Yes. Natural killer cells are innate cells,
which means that they're a rapid and early line of defence,
and they work in concert with the adaptive immune system.
Natural killer cells are also cellular responders,
so while antibodies and other humoral proteins can protect, with a virus,
the spread of a virus within liquid systems,
the cellular responders can actually destroy the machines
that are producing virus (the infected cells).
You asked me particularly about SARS-CoV-2.
That's an area where we have
very limited information about how NK cells are involved.
There are a couple of different ways that they might be involved.
They could be directly lysing infected cells,
and preventing the spread of the virus that way.
They could be producing cytokines in order to activate the adaptive immune response,
and raise awareness among other immune cells that this infection is ongoing,
and that a coordinated response is needed.
But they might also have an immuno-regulatory role.
Natural killer cells have been known in some viral infections
to lyse antigen-presenting cells or CD4 T-cells,
and in that way dampen down the immune response.
Natural killer cells in general can have very complicated roles in viral infections.
They can control the virus,
in our classic overview of what a natural killer cell does,