Part 2 Immune System Crash course

Mar 4, 2025

Lecture Notes: The Adaptive Immune System

Introduction

  • Key Concept: Know your enemy to defeat it.
  • Immune System Overview: Innate vs. Adaptive Immunity.
    • Innate Immunity: Immediate response but lacks specificity.
    • Adaptive Immunity: Specific and systemic response, slower but more effective over time.

Adaptive Immune System

  • Activation: Requires introduction to specific pathogens.
  • Memory: Remembers past pathogens for quicker future responses.
  • Systemic: Can combat threats throughout the whole body.

Components of Adaptive Immunity

  • Humoral Immunity: Involves antibodies.
    • B Lymphocytes: Originate and mature in bone marrow.
    • Antibodies: Proteins that patrol body fluids.
    • Pathogen Recognition: Utilizes unique antibodies to bind specific antigens.

Antigen Recognition and Response

  • Antigens: Foreign molecules that trigger immune response.
  • B Lymphocyte Activation:
    • NaĂŻve B cells encounter antigens, bind, and activate.
    • Cloning: Creates effector (plasma) cells and memory cells.
    • Effector Cells: Produce antibodies at high rates.
    • Memory Cells: Ensure faster secondary responses.

Antibody Actions

  • Neutralization: Block pathogens from binding to host tissues.
  • Agglutination: Clump antigens together for easier destruction.
  • Signalling: Attract other immune cells to destroy complexes.

Immunity Types

  • Active Immunity:
    • Natural: Through infection.
    • Artificial: Through vaccination.
  • Passive Immunity:
    • Natural: Antibodies from mother to child.
    • Artificial: Antibodies through serum transfusion.

Vaccination

  • Function: Introduces weakened pathogens to stimulate immune memory.
  • Benefits: Provides immunity against severe diseases.
  • Challenges: Some viruses, like influenza, evolve quickly, requiring new vaccines.

Conclusion

  • Summary: Discussed humoral response and its significance.
  • Next Steps: Cellular immunity will be covered in the following episode.

Acknowledgments

  • Production Team: Listed contributors and roles in producing the content.

Note: Further details on cellular immunity will be discussed in the next lecture.