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How Your Immune System Functions | Dr. Max Krummel & Dr. Andrew Huberman

Huberman Lab Clips09:05Added Aug 31, 2026

Dr. Matthew (Max) Krummel and Dr. Andrew Huberman discuss how the immune system functions beyond simple defense, highlighting how aging, cellular turnover, a...

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Contributed by 刘嘉琪

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  1. How the Immune System Identifies Threats

  2. 00:00Sometimes I tend to then think the
  3. 00:01immune system you want to defend it like
  4. 00:02you want to defend a nation and you want
  5. 00:04to defend it from outsiders. And I've
  6. 00:06just told you a story that's if you want
  7. 00:08to take a political statement from it's
  8. 00:09pro- immigration because all these
  9. 00:11bacteria that live on us are actually
  10. 00:12bringing us goods and they they do a lot
  11. 00:15half the audience. No, I'm just kidding.
  12. 00:17I'm totally joking. We we're a
  13. 00:19bipartisan audience. I'm joking. Take it
  14. 00:21how you want to by analogy. It's the
  15. 00:24argument for you know why why certain um
  16. 00:27you know influx of of of u in this case
  17. 00:29organisms onto us you know create a more
  18. 00:32robust you know person than we were
  19. 00:34before. But I want to give you this
  20. 00:36story that one a famous um marinologist
  21. 00:38in the 1970s drew this parallel in
  22. 00:41wartime and said in you know World War
  23. 00:43II submarines would be underneath the
  24. 00:46ocean and they'd be traveling around and
  25. 00:48they would if they could if they heard
  26. 00:50another submarine they would scuttle the
  27. 00:53missiles you know torpedoes because that
  28. 00:55could be the enemy and the enemy could
  29. 00:56fire at them. And so they had two sets
  30. 00:59of books that they used. Uh, one of them
  31. 01:03was a book that gave them the sound
  32. 01:05profile of all, let's say it's a US, of
  33. 01:08all the US submarines. And so they could
  34. 01:10listen to the were of the engines. And
  35. 01:11if they heard a were of the engine that
  36. 01:12had the certain cycle of a general mo,
  37. 01:15you know, motors engine, they wouldn't
  38. 01:17fire. So that's the sort of like self I
  39. 01:19know what self is. And then they had
  40. 01:22another book that was the engine sounds
  41. 01:24of the known diesel engines of whatever
  42. 01:26engines of the German uh, you know,
  43. 01:28submarines. And if they heard that then
  44. 01:30they absolutely would fire. And that's a
  45. 01:32self versus non-self-discrimination
  46. 01:34problem just like the immune system has
  47. 01:35to do. But what I bring you with it
  48. 01:37aging is this concept that as you get
  49. 01:39weirder and different your body is
  50. 01:41getting like more complex then that
  51. 01:43those books you know start to have every
  52. 01:46possible possibly every possible
  53. 01:47permutation of every biomolelecule could
  54. 01:49could could be made by your body at that
  55. 01:51point. And then a virus doesn't
  56. 01:52necessarily have anything unique about
  57. 01:54it. A virus is also going to make
  58. 01:55proteins and that's your immune system
  59. 01:57can see the viral proteins and say oh a
  60. 01:59new thing has come in and that's you
  61. 02:01know that's out of range and now I need
  62. 02:03to mount that a T- cell response against
  63. 02:05this I need to make the you know bring
  64. 02:06in the troops but with aging we have
  65. 02:09this this kind of you know us diverging
  66. 02:11problem so that this you know this
  67. 02:14system that's supposed to sense us
  68. 02:16is just you know has a lot of cosmic
  69. 02:18background has a lot of noise in it and
  70. 02:20so I think it I think that's one of the
  71. 02:21reasons why we also have issue when
  72. 02:23we're aging and it's I I think it's also
  73. 02:24one of the issu reasons why cancer is
  74. 02:26more prevalent in later life for I mean
  75. 02:28there's two parts of that one is of
  76. 02:30course you've accumulated mutations in
  77. 02:31your cells that could be cancerous but
  78. 02:34also the immune system has been seeing
  79. 02:35those and all the various different
  80. 02:37accumulations of them and ones like them
  81. 02:39you know over these years to the point
  82. 02:41where the weird doesn't look that weird
  83. 02:43anymore you know something like a cancer
  84. 02:44that is different than you it's not that
  85. 02:47much different than like another cell
  86. 02:48over here that's gone you know like and
  87. 02:50it's just happily making skin and isn't
  88. 02:52cancerous but you is it's got some
  89. 02:55differences.
  90. 02:55What about the argument that there's so
  91. 02:58much cellular turnover that um the cells
  92. 03:02that accumulate these mutations are
  93. 03:04being eliminated? You're saying because
  94. 03:05they're clonal, they're producing
  95. 03:08different they become different, they
  96. 03:10produce cells that are also different,
  97. 03:12then they die. Is this is that the way
  98. 03:13it works?

  99. How Immune Pruning Prevents Cancer

  100. 03:15Yeah. And I think I think you you are
  101. 03:16bringing something up that's also true,
  102. 03:18which is that all the time I think the
  103. 03:19immune system is defending us against,
  104. 03:22you know, mutations. So, one example
  105. 03:24that everybody sees when they get to be
  106. 03:25about 40 or 50 is is little these white
  107. 03:28spots in your skin. And we we think that
  108. 03:31those are places where the immune system
  109. 03:32has sensed a collection of cells that
  110. 03:35were precancerous, maybe they were even
  111. 03:37beginning of cancer, and has wiped them
  112. 03:38out. And and so the you know, a lot of
  113. 03:41the origin of cancers in skin is is
  114. 03:43melanin producing cells like melan you
  115. 03:45know melanoma is what we call skin
  116. 03:47cancer. um those melanocytes that that
  117. 03:50white area they've been wiped of a whole
  118. 03:52collection of melanocytes and that's why
  119. 03:54it's you know like it's white instead of
  120. 03:57as dark as your as the rest of your
  121. 03:58skin. So you know to that extent the
  122. 04:00idea that the immune system is is
  123. 04:02pruning you all the time is you know
  124. 04:04there's it looks like there's pretty
  125. 04:05good evidence for that.
  126. 04:06Um and the question is when does
  127. 04:08something become dangerous?
  128. 04:10That's that's that's that you know
  129. 04:12that's fundamentally question with
  130. 04:13cancer and these sort of things. If you
  131. 04:14said, "I want to actually have the
  132. 04:16fittest cells in my skin to uh fill in a
  133. 04:20gap if I scratch myself. I would like to
  134. 04:21have cells that quickly replicate just
  135. 04:22like maybe in kids. Kids heal so
  136. 04:24ridiculously quickly, right? Because
  137. 04:26they have an abundance of these cells
  138. 04:27that
  139. 04:28I think I think they're they're their
  140. 04:29wound healing. I mean, there's a group
  141. 04:30out of Stanford that studies this, but
  142. 04:32essentially, you know, wound healing in
  143. 04:33in in young is quite quite a bit faster
  144. 04:36and more efficient and and there's many
  145. 04:38that there's many levels of that. Yeah.
  146. 04:41But um yeah, remarkably faster. If
  147. 04:42you're a parent, you've seen this. You
  148. 04:43know, you cut yourself on the same day
  149. 04:45as a kid your kid cut yourself and
  150. 04:47they're they're three days later they
  151. 04:48can't even find it on them and you know
  152. 04:50like four weeks later you're still like
  153. 04:52got you know scap or something. But I
  154. 04:54was just coming to the point that if you
  155. 04:55do that and you you want this do you
  156. 04:57want you maybe want that to fill back in
  157. 04:58because you know certainly out in the
  158. 05:00wild having an open wound is a bad
  159. 05:02thing. So you like to heal quickly.
  160. 05:05Well, if a mutation has happened that
  161. 05:07fills that cell in quick, more quickly,
  162. 05:09that is almost by definition a mutation
  163. 05:11that's let that cell divide faster.
  164. 05:14Well, what is cancer? It's cells that
  165. 05:16divide faster. So, in some sense, all
  166. 05:18these events in your life where winners
  167. 05:20win by filling in the space left by
  168. 05:22cells that die is selecting for cells
  169. 05:24that get a little out of range with
  170. 05:26growth. They may be a little bit better
  171. 05:28at growing. And then again, the question
  172. 05:30is like, well, how much better do you
  173. 05:32want that? You want it to like help you,
  174. 05:34but at some point you don't want it to
  175. 05:35basically form a lesion and will grow
  176. 05:37grow grow and go other places and grow,
  177. 05:39which is called metastasis in cancer,
  178. 05:41which is how most people die. To me,

  179. New Framework for Immunity

  180. 05:44that the issue of self and non-self is
  181. 05:46one of the ones that's been with
  182. 05:47immunology for a very long time. And
  183. 05:49again, it's way richer than we thought
  184. 05:51about, I think, in the 1990s or 2000s,
  185. 05:54you know. And then at the same time, the
  186. 05:56idea of what you can do with that
  187. 05:58information is also I call this kind of
  188. 05:59a new immunity. Immunity used to be like
  189. 06:02a fuel gauge. You'd say it was low for
  190. 06:04itself. Then it was really high against
  191. 06:06viruses and it was like a fuel gauge.
  192. 06:07You know, now it's really hot. And what
  193. 06:09we originally thought we were doing with
  194. 06:10cancer imotherapy was making it just
  195. 06:12hotter in general. But now you realize
  196. 06:15that in between like the immune system
  197. 06:17not caring about something at all and
  198. 06:19and going and you know like releasing
  199. 06:21all its fury on something are all these
  200. 06:23other things it can do with the
  201. 06:24information it gathers in there. And
  202. 06:26that's where I was saying you know it
  203. 06:27can it can like quarantine bacteria.
  204. 06:28It's not going to kill them. It's it's
  205. 06:30in that zone. The bacteria as long as
  206. 06:32they're in the right zone, there's not
  207. 06:33too many of them, there's not too few of
  208. 06:34them, immune system can actually help
  209. 06:35them be there. It can produce things
  210. 06:37that like either tighters them out of
  211. 06:39circulation or keeps them there. You
  212. 06:41know, in all these other settings, like
  213. 06:42I say, in the heart and the can go to
  214. 06:44almost any organ and uh and the immune
  215. 06:47system is consistently present and it's
  216. 06:49consistently measuring you. And the U
  217. 06:52again is this complex you. It's not just
  218. 06:54what came from the egg, it's the you
  219. 06:56that's you right now, including all the
  220. 06:58mutations that that you might have
  221. 06:59accred and all the bacteria and and and
  222. 07:01the viruses. You know, we have a lot of
  223. 07:03viruses in our bodies that we tend to
  224. 07:05think that at the end of a of a illness
  225. 07:07that we've gone back to our pure state.
  226. 07:09This may came from religion. You know,
  227. 07:10we were born pure and if God made us
  228. 07:12correctly, then we would be pure at the
  229. 07:14end of things and you know that would be
  230. 07:16pure immunity would would purify us of
  231. 07:18things. But the more we look, the more

  232. Dormant Viruses & Immunopathology

  233. 07:21we find that every virus leaves a little
  234. 07:22evidence of a little bit of itself. And
  235. 07:25then there's a then there's the goal for
  236. 07:26the immune system to kind of quarantine
  237. 07:27that to say this, you know, maybe we
  238. 07:29don't want to kill every one of our
  239. 07:31cells to get rid of every virus that's
  240. 07:32infected one of our cells. We need to
  241. 07:35leave some of those alive. We don't like
  242. 07:37for example herpes virus infection
  243. 07:39infects the nerves and when people have
  244. 07:41uh you know emergence they they get
  245. 07:43nerve pain and worse. A lot of that is
  246. 07:45caused by the immune system reacting to
  247. 07:48the virus trying to get out and then
  248. 07:50killing off neurons. So the the the it's
  249. 07:52imopathology. The immune system is c
  250. 07:55causing as much of the damage and
  251. 07:56problem as the viruses. And it's the
  252. 07:58failure of that day taunt. And when
  253. 08:00certain viruses are just sitting in us,
  254. 08:02we're perfectly fine. You know, we have
  255. 08:04viruses sitting around and as long as
  256. 08:06they're laying dormant, our immune
  257. 08:08system can say, "Okay, I'm going to just
  258. 08:09hang out here and if anything bad
  259. 08:10happens, I'm going to squatchch that."
  260. 08:13But it's not like we've been purified.
  261. 08:14You know, that's a reality that's a
  262. 08:16little bit too bad. But, you know, it's
  263. 08:18also one where you say, again, if if the
  264. 08:20goal of us is to make it to 30, let's
  265. 08:22say you get a a an early liver infection
  266. 08:25of a HCV or HPV. If the immune system
  267. 08:28can just let that be, you're not going
  268. 08:30to destroy your own liver and you'll
  269. 08:32live to produce and your genes will get
  270. 08:34passed on. On the other hand, if you
  271. 08:36mounted a massive immune response, you
  272. 08:38know, you went all the way in the fuel
  273. 08:39gauge to the right, your immune system
  274. 08:41can kill you. It absolutely can. You
  275. 08:43know, it's can can kill any cell it
  276. 08:46wants. So, so that that that again that
  277. 08:47idea that the space in between is the
  278. 08:49one that we actually are starting to
  279. 08:50understand that it has all these
  280. 08:51specialized roles that are not always
  281. 08:54about getting rid of things at all cost.