Some T cells break the rules—and that can have serious consequences. Dr. Jim Heath explains a rare immune system dysfunction typically seen in older men that leads to worse COVID-19 outcomes. Learn more in the full talk on how AI is revealing the secrets of our immune system.
(ISB intro) – What are the T cells
that violate those rules and what does that mean
for those patients? And so here I’ve plotted
the patients with COVID-19. And what you can see here is that here’s the cytotoxic T cells, here’s the helper T cells. The helper T cells mostly
stay in their lane. They’re mostly over here. The cytotoxic T cells actually stretch out quite a bit into the helper T cell area. And what that means is that
you’ve got CD4-like CD8 T cells are helper-like cytotoxic T cells. And it turns out most
people don’t have those. But you see them in older men
more often than older women. Something like 20 individuals
out of 300 adults that we had. And those older men do much
worse when faced with COVID-19, they had much more severe disease. I mean, you can look at this, this is on a scale of of one to seven. Seven means you’re probably
not going to survive, and one means you don’t even
know you’ve been infected. And so if you have really strongly biased CD8-like CD8 T cells, you really never get beyond a
mild or or moderate infection. And you do definitely head
into serious infection land if you don’t have those. And if you look in the
blood of those patients, you saw that inflammation
got out of control. And if you actually look
at the T cell themselves, we have all the single
cell data on these T cells. They simply do not act like CD8 T cells. They have no capacity to kill. And so these patients that
had these rules violations, what what we’re finding
is that they simply did not have the capacity, that initial frontline
of defense of CD8 T cells that identify and kill the infected cells. And that had health consequences for them. (ISB outro)
