Overview of Immunology

Overview of Immunology

• Definition: Immunology is the branch of biomedical science that deals with the study of the immune system.
• Immune System Function: Protects the body against pathogens (bacteria, viruses, fungi, parasites) and foreign substances.

Key Components of the Immune System

1. Innate Immunity

   • First line of defense.
   • Non-specific responses.
   • Components:
     • Physical barriers (skin, mucous membranes).
     • Cellular components (phagocytes, natural killer cells).
     • Chemical mediators (complement system, cytokines).

2. Adaptive Immunity

   • Specific responses to pathogens.
   • Component:
     • Lymphocytes (B cells and T cells).
     • B cells produce antibodies, provide humoral immunity.
     • T cells are involved in cell-mediated immunity (CD4+ helper T cells and CD8+ cytotoxic T cells).

Immune Response Process

1. Recognition: Detection of pathogens through pattern recognition receptors (PRRs).
2. Activation: Triggering of immune cells and initiation of immune responses.
3. Response: Elimination of pathogens via phagocytosis, destruction by lymphocytes, or antibody binding.
4. Memory: Formation of memory cells for quicker response during re-exposure to the same pathogen.

Types of Immunity

• Active Immunity: Immunity that develops after exposure to a pathogen or through vaccination.
• Passive Immunity: Immunity gained by receiving antibodies from another source (e.g., maternal antibodies).

Important Concepts

• Antigens: Molecules that trigger an immune response.
• Antibodies: Proteins produced by B cells that specifically target antigens.
• Vaccination: Introducing antigens to stimulate the adaptive immune response without causing disease.
• Autoimmunity: When the immune system mistakenly attacks the body’s own cells.
• Allergies: Exaggerated immune responses to non-pathogenic substances.

Immune System Disorders

• Immunodeficiencies: Conditions where the immune system is less active (e.g., HIV/AIDS).
• Autoimmune Diseases: Conditions where the immune system targets the body’s own tissues (e.g., rheumatoid arthritis, lupus).
• Hypersensitivity Reactions: Excessive immune responses to harmless substances (e.g., allergens).

Immune System Development

• Hematopoiesis: Formation of blood cells including immune cells from stem cells in bone marrow.
• Thymic Selection: Process where T cells mature and are tested for functionality and self-tolerance in the thymus.

Immune System Enhancements

• Intervention Techniques: Includes immunotherapy, monoclonal antibodies, and gene therapy to enhance or modulate the immune response.
• Probiotics and Microbiome: The role of gut health and its impact on the immune system's efficiency.

Immunology Overview

• The study of the immune system, its components, and functions.
• Protects the body from pathogens and foreign substances.

Key Components

• Innate immunity:
  • First line of defense, non-specific.
  • Physical barriers: Skin, mucous membranes.
  • Cellular components: Phagocytes (engulf pathogens), natural killer (NK) cells (kill infected cells).
  • Chemical mediators: Complement system (a group of proteins that helps destroy pathogens), cytokines (signaling molecules).
• Adaptive immunity:
  • Specific response to pathogens.
  • Lymphocytes: B cells (produce antibodies, humoral immunity), T cells (involved in cell-mediated immunity).
    • CD4+ helper T cells: help activate other immune cells.
    • CD8+ cytotoxic T cells: directly kill infected cells.

Immune Response Process

• Recognition: Identifies pathogens with pattern recognition receptors (PRRs).
• Activation: Triggers immune cells and starts the immune response.
• Response: Eliminates pathogens via:
  • Phagocytosis (engulfing and digesting).
  • Lymphocyte destruction (T cell killing).
  • Antibody binding (neutralizing or marking for destruction).
• Memory: Forms memory cells for faster response upon re-exposure.

Types of Immunity

• Active immunity:
  • Develops after exposure to a pathogen or vaccination.
  • Body generates its own antibodies.
• Passive immunity:
  • Received from another source (e.g., maternal antibodies).
  • Temporary protection.

Important Concepts

• Antigens: Molecules that trigger the immune response.
• Antibodies: Proteins produced by B cells that specifically bind to antigens.
• Vaccination: Introduces antigens to stimulate adaptive immunity without causing disease.
• Autoimmunity: Immune system attacks the body's own cells.
• Allergies: Exaggerated immune responses to non-pathogenic substances (allergens).

Immune System Disorders

• Immunodeficiencies: Weakened immune system (e.g., HIV/AIDS).
• Autoimmune diseases: Immune system attacks body tissues (e.g., rheumatoid arthritis, lupus).
• Hypersensitivity reactions: Excessive immune responses to harmless substances (e.g., allergies).

Immune System Development

• Hematopoiesis: Formation of blood cells (including immune cells) from stem cells in bone marrow.
• Thymic selection: T cells mature and are tested for functionality and self-tolerance in the thymus.

Immune System Enhancements

• Intervention techniques:
  • Immunotherapy: Modifies the immune response.
  • Monoclonal antibodies: Target specific antigens.
  • Gene therapy: Modifies genes to improve immune function.
• Probiotics and microbiome: Gut health influences immune system efficiency.