I'm Siamon Gordon. I'm at the Sir William Dunn School of Pathology in Oxford.
I'm going to talk about macrophages in two parts today.
First, the mononuclear phagocyte system, which I'll explain later.
I'll discuss the tissue-resident macrophages,
their distribution throughout the body, and their functions.
Then, in Part 2, which is to follow, I'll be talking about
the same system but the tissue recruited macrophages, their activation, and regulation.
The context of macrophage physiology and pathology is very much based
on homeostasis which is maintaining a steady state.
First, the concept was introduced by Claude Bernard in the 19th century and
I can recommend a very good experimental introduction by him republished by Dover Publications.
But the term homeostasis was derived from Walter Cannon an American physiologist
and there's a book that he's written called
The Wisdom of the Body that I would also recommend to students.
The point I wanted to make is that it's an active process to maintain
the steady-state, the milieu intérieur as Claude Bernard initially described it.
It actually is on the physiological and pathological level when homeostasis breaks down.
The grandfather of the field of macrophages is Élie Metchnikoff shown on the left here,
and he is known for the discovery of phagocytosis,
macrophage properties and he and Paul Ehrlich
received the Nobel Prize in 1998 for their work on immunity,
Metchnikoff for cellular immunity and Paul Ehrlich for humoral immunity.
Now there was a conflict between these two but it
turned out that both were correct and each interacts
with the other system and the Nobel Prize award tried to reconcile
these two rather disparate views of
immunology current at the time and very controversial at the time.