Final answer:
M1 macrophages are associated with TH1 immune responses, involved in host defense against pathogens and tumor cells, and produce pro-inflammatory cytokines. M2 macrophages, in contrast, are linked to TH2 responses, wound healing, produce anti-inflammatory factors, and promote tissue repair. Both have different cytokines inducing their activation and distinct roles in the immune system.
Step-by-step explanation:
The differences between M1 and M2 macrophages relate to their roles in the immune system. M1 macrophages, also known as classically activated macrophages, play a critical role in host defense against intracellular pathogens and tumor cells. They are typically associated with the TH1-mediated immune response, which involves inflammation and the destruction of pathogens or tumor cells. M1 macrophages are activated by interferon-gamma (IFN-γ) and produce pro-inflammatory cytokines like IL-12 and IL-23.
In contrast, M2 macrophages, or alternatively activated macrophages, are often involved in wound healing, tissue repair, and the resolution of inflammation. They are associated with the TH2 immune response and are induced by cytokines like IL-4 and IL-13. M2 macrophages produce anti-inflammatory factors such as IL-10 and TGF-β and help in remodeling and repairing tissues. Furthermore, M1 macrophages present antigens to T cells through MHC II molecules, stimulating an adaptive immune response, while M2 macrophages focus more on modulating inflammatory reactions and promoting tissue homeostasis.