Learn to distinguish M1, M2, Th0, Th1, Th2, Th17, Treg, inflammatory factors in one video and what diseases their abnormalities cause

📖Library Reading Notes
1

https://www.bilibili.com/video/BV1AR4y1f7yQ

Preface

When I was studying immunology, I was quite confused. Recently, I had to prepare a report on arthritis literature, and all the various cells and factors involved gave me a headache. Going back to review the textbook was out of the question—it would only make me more overwhelmed.

Then I found this video. Although it’s a promotional video from a reagent company, it explains things simply and clearly, and it provides many clinical and research examples to illustrate the functions of these cells and factors.

Notes

Macrophage Differentiation Process

Monocytes first differentiate into naive macrophages. If they encounter pro-inflammatory factors, they differentiate into M1 macrophages to amplify inflammation; if anti-inflammatory factors are present, they polarize into M2 macrophages. Excessive M1 leads to inflammatory damage to the body, while excessive M2 causes fibrosis and promotes cancer progression.

M1 M2
Overview Pro-inflammatory Repair
Function Phagocytose pathogens Clear neutrophil extracellular traps
Secreted factors Recruit more inflammatory cells Signal inflammatory cells to stop
Promote fibroblast differentiation into myofibroblasts (secrete collagen to repair wounds
Induce angiogenesis
IL-6, TNFα IL-4, IL-10

Inflammation Initiation and Resolution Process

Antigen-presenting cells encounter pathogens and pass the information to naive T cells (T0).

  • For intracellular pathogens, T0 differentiates into Th1, secreting IFN-γ (pro-inflammatory factor); subsequently, naive macrophages differentiate into M1 macrophages to amplify inflammation.
  • For extracellular pathogens (such as fungi), T0 differentiates into Th17, secreting IL-17, recruiting and activating neutrophils to phagocytose pathogens and release extracellular traps.
  • For large pathogens (such as worms), T0 differentiates into helper Th2
    • Secreting IL-4 and IL-5, activating B cells and eosinophils
    • Additionally, IL-4 promotes differentiation of M0 into M2

When antigen-presenting cells detect there are no more pathogens, they receive factors from M2 and pass the information to naive T cells (T0) to differentiate into regulatory T cells (Treg), which release IL-10 and halt the immune response.

2

Cytokines are a large class of proteins that play roles in cell signaling and immune responses. In contrast, chemokines are a specific subset of cytokines that guide immune cells to sites of infection. Different cell types can produce cytokines and chemokines, but chemokines mainly regulate the movement and localization of white blood cells during immune responses. Cytokines exhibit a variety of functions, including regulating inflammation and cell growth, whereas chemokines primarily focus on directing immune cells to areas of inflammation or injury.