Immunology 1: Principles and Applications

Immunology 1

• Module: Biomedical Sciences
• Lecturer: Ms Panayiota Lazarou
• Assessment:
  • Formative: Consolidation session
  • Summative: Eassessment (Biomedical sciences)
• Aim:
  • Apply dental therapy and dental hygiene principles derived from biomedical, behavioural and materials sciences
  • Develop knowledge in immunology (GDC 1.1)
  • Complete preparatory work (Introduction to immunology) beforehand
• Intended Learning Outcomes:
  • Consolidate learning from the asynchronous session (Introduction to immunology)
  • Identify organs and tissues of the immune system
  • Discuss origins and functions of immune system cells
  • Detail the processes and functions of non-specific and adaptive immune systems
• Consolidation of Learning:
  • Understand immunology
  • Discuss and elaborate on innate and adaptive immunity characteristics
  • Understand immune cell origins, types and functions
  • Understand non-specific barriers
• Primary Components of Immune System:
  • Tonsils
  • Thymus
  • Bowel
  • Lymph nodes
  • Spleen
  • Bone marrow
  • Skin -Mucous membranes (nose, throat, bladder, genitals)

Organs and Tissues of the Immune System (Primary Components)

• Bone Marrow: Forms all immune cells
  • B lymphocytes mature in bone marrow
  • T lymphocytes travel to the thymus
• Thymus: Processes lymphocyte precursors to become T cells
• Lymphocyte Progenitors: Arise in bone marrow, Pre-B cells mature in bone marrow, Pre-T cells mature in the thymus

Cells of the Immune System

• Blood Cells:
  • Monocyte
  • Lymphocyte
  • Neutrophil
  • Eosinophil
  • Basophil
  • Macrophage
  • Erythrocyte
  • Platelets
• Blood Stem Cell: Myeloid and lymphoid stem cells, which differentiated into granulocytes (e.g., neutrophils, eosinophils, basophils), erythrocytes, and platelets.

Cells of the Immune System

• Macrophage/Neutrophil/B Cell/Basophil/T Lymphocyte/Natural Killer Cell: Detailed images of each cell type.

Innate Immune System

• Non-specific immune system (innate barriers):
  • Skin fatty acids affect pH preventing certain pathogens
  • Mucous membranes and cilia lining of tracts - lysozyme
  • Temperature
  • pH
  • Chemical mediators
  • Inflammation (body's response to tissue damage/microbial invasion)
• Humoral factors of the innate immune system:
  • Complement system: A complex group of proteins in the blood (factors 1-9)
    • Classical pathway triggered by immune complexes
    • Alternative pathway triggered by bacterial cell wall structures
    • Lectin pathway activated by bacterial cell wall structures
  • Cytokines: Glycoproteins that impact the immune system (e.g., ramping up or slowing it down). Produced by helper T cells (Th cells) and macrophages.

Inflammation

• Inflammation brings phagocytes to the injured area to:
  • Isolate, destroy, and inactivate the pathogen
  • Remove debris
  • Prevent spread of infection
  • Prepare healing
  • Recruit effector cells if innate immune cells cannot control the infection or repair tissue damage
  • Mobilize effector cells (T and B lymphocytes)

Adaptive Immunity

• Activated when innate immunity is ineffective in eliminating infectious agents
• Specific to pathogen presented
• Generates pathogen-specific immunologic pathways, eliminating pathogens/infected cells
• Develops immunologic memory, eliminating specific pathogens in subsequent infections
• T Cell and Antigen presenting cells (APCs): Attacks non-self pathogens. Mistakes can happen (e.g., rheumatoid arthritis, lupus)
• T cells activated through antigen presenting cells (e.g., macrophages): Cells involved in the primary immune response.
• T Cells differentiation and function:
  • Class I and Class II MHC molecules
  • Cytotoxic T cells (Tc)
  • Helper T cells (TH)
• B cells: Involved in antibody-mediated immunity
  • Antibody production
• Overview of processes involved in the primary immune response: Phagocytosis, antigen presentation, activation of T and B cells, antibody production, and memory cell formation.