Lecture 13 - Immunology Flashcards
What is immunity?
Active Ability to Resist Disease ·∙ Identify Pathogens ·∙ Kill or Neutralize Pathogens
What is innate and adaptive immunity?
innate = nospecific adaptive = specific and needs activation
What is specificity?
Recognize + React With Particular Targets
What is memory?
Retain targets for Future Infections
What is tolerance?
Not Reacting with Self Targets
What are antigens?
Molecules Specific to Pathogenic Cells
·∙
Used By Immune System to Identify Pathogens
What are phagocytes?
Cells that engulf foreign particles and ingest and kill bacterial pathogens
What are stem cells?
Pluripotent Cells in Bone Marrow
·∙
Develop into Different Blood Cells
What are cytokines?
Proteins that Influence Cell Differentiation
What are the types of blood cells?
Erythrocytes (red blood cells, RBCs)
- ‐ Nonnucleated
- ‐ Carry oxygen from lungs to tissues
Leukocytes (white blood cells)
- ‐ Nucleated
- ‐ Active in immune system
What are the two circulatory systems?
Blood System
- RBCs, WBCs, and Plasma
- Gas Exchange, Blood Clotting
Lymph System
- Fluid Similar to Blood, No RBCs
- Immune Function
What are the cells of the immune system called? What are the types?
Leukocytes
Types
- Myeloid Cells (Innate Immunity)
- Lymphocytes (Adaptive Immunity)
What are the types of Myeloid cells?
Monocytes -Phagocytotic, Antigen-‐Presenting Cells -Example:Macrophages ·∙ Granulocytes -Phagocytotic, Contain Inclusions (“granules”) -Release Enzymes and toxins -example - MAST cells
What are the Types of Lymphocytes?
B Cells -Mature in Bone Marrow -Interact with Antigens via Antibodies ·∙ T Cells -Mature in Thymus -Interact with Antigens via T Cells Receptors (TCRs)
What is innate immunity?
- “In-‐Built” Immunity ·∙
- Noninducible ·∙
- Nonspecific
- No Previous Exposure Required
What is adaptive immunity?
- Aquired immunity
- inducible
- specific
- previous exposure required
What are the signal and receptor of innate immunity?
Signal = PAMPs
- Pathogen-‐Associated Molecular Patterns
- Surface Molecules on Pathogen Cells
- Examples: LPS, Flagella
Receptor = PRRs
- Pattern Recognition Receptors
- Recognize and Interact with PAMPs
- Present in Phagocytes
What are the signal and receptor of adaptive immunity?
Signal = Antigens
- Pathogen-‐Associated Molecules
- Surface Molecules on Pathogen Cells
- Examples: Surface Proteins, Endotoxins
Receptor = Antibodies (or TCRs)
- Soluble Proteins
- Recognize and Bind to Antigens
- Each Antibody Binds a Single Antigen
What is the primary and secondary response?
Adaptive immune responses
Primary Response
- Initial, Weak, Slow
- Production of antigen reactive cells
Secondary Response
- Secondary, Strong, Fast
- Activation of Antigen-‐Reactive Cells
How are antigens processed in adaptive immunity?
Macrophages Engulf and Digest Pathogens
-MHC Proteins Bind and Move Antigen to Cell Surface
(Major Histocompatibility Complex)
MHC I
– Present in All Cells
MHC II
– Present Only in APCs
What happens when the antigen is presented to T or B cells with MHC I or II?
T Cell = Cell-‐Mediated Immunity
-Target and Kill Intracellular Pathogens (Infected Host Cells)
B Cell = Antibody-‐Mediated Immunity
-Target and Kill Extracellular Pathogens or Toxins
What kinds of T cells confer cell-,mediated immunity?
T-‐Cytotoxic (TC) Cells
- Bind MHC I
- Recognize + Kill Infected Cells
T-‐Helper (TH) Cells
- Bind MHC II
- Produce Cytokines that Activate Other Cells
What kind of cell confers antibody-mediated immunity?
TH2 Cells Activate B Cells to Form Plasma Cells
Plasma Cells Produce/Release Antibodies
What do antibodies do?
Bind Specifically to a Single Antigen, Resulting in:
- Opsonization – Pathogen Cell Marked for Destruction
- Complement Proteins – Pathogen Cell Lysed
- Neutralization – Pathogen Interactions Blocked
