Overview of Immunity Flashcards
Multiple levels of protection
Layering
Redundancy
A single pathogen can be fought by the immune system multiple ways
What components of the immune system does blood contain?
Leukocytes, Lymphocytes, Clotting factors, Complement, and Antibodies
Two steps of the immune response.
First, recognition. Second, recruitment of effector mechanisms
Circulatory component of the immune system.
Lymphatic System
Functions of lymph nodes
- Filter interstitial fluids
- Removing antigens and make them available to B and T cells
- Provide a location where antigens can initiate an immune response
- Place for B cells to make antibodies
Functions of the lymph nodes
- Filter lymph
- Place for B & T cells to meet up
- Provide location where antigens can initiate immune response.
- Place for B cells to make antibodies.
Branches of the immune system
Innate and adapative
Non-specific immunity
Innate Immunity
Examples of Innate Immunity
Skin, mucus, eyelids
Acquired by antigen exposure and specific to a given antigen
Adaptive immunity
Clonal expansion (Clonal proliferation)
Activated B & T cells increase in number
Myeloid lineage
Granulocytes, monocytes, and macrophages
Categories of adaptive immunity
Humoral and cell-mediated
Humoral Response
B cell response, antibodies
T-cell response
Cell-mediated response
Components of Innate Immunity
- Leukocytes (macrophages)
- Biochemical constituents (enzymes)
- Anatomical/physical barriers
- Proteins (complement, cytokines, chemokines)
- Inflammation
What is the key function of the immune system?
To prevent and control infections, eliminate the pathogens and their harmful products, and distinguish between self and non self.
A coordinated effort between cells, cytokines, and circulating proteins to remove or limit the spread of infectious agent.
Inflammation
Lymphocytes that have yet to encounter their antigen
Naive cells
Effector cells
Carry out the immune function
Memory cells
Circulate and await next encounter with the antigen.
Four granulocytes
- Basophils
- Eosinophils
- Mast cells
- Neutrophils
Antigen presenting cells
- Dendritic cells
- Macrophages
- B cells
Produced by activated B cells
Antibodies
Proteins produced by activated immune cells
Cytokines
Proteins circulating in the blood stream aiding to the immune response
Complement
Production of antibodies and protection against extracellular pathogens by B cells
Humoral Immunity
2 types of adaptive immunity…
- Humoral
2. Cell mediated
Opsonization is related to which form of immunity
Innate
Antibodies are related to which form of immunity
Adaptive
What 3 mechanisms of action does innate immunity use?
- Complement lysis
- Opsonization
- PAMP recognition
What mechanisms of action does adaptive immunity use?
- Antibody neutralization
- Antibody-mediated ADCC
- Antibody and complement-mediated opsonization
- Complement lysis
Cellular and non cellular components of innate immunity
- Cellular components (PMNs)
- Soluble components (antibodies, complements)
- Intracellular (oxidative burst)
- Extracellular (clotting, lysis)
2 parts of the immune response
- Recognition
2. Effector mechanisms
Steps of recognition
- Recognize pathogen as non-self
2. Recognize the specific pathogens
Steps of effector mechanisms
- Kill or remove pathogen and products
2. Repair damage
Network of vessels and nodes that circulate and filter plasma-derived fluid
Lymph nodes
Three characteristics of innate immunity…
- Non-specific
- Present and birth
- Always “on” at basal levels
5 characteristics of adaptive immunity
- Specific
- Activated only when a specific pathogen is encountered
- Get better with each encounter
- Provide memory for next encounter
- Must be up regulated - slower to develop
How is innate immunity activated?
Activated by motifs or patterns common to pathogens
What is the first line of defense?
Innate immunity
What are the cellular and non-cellular mechanisms of innate immunity
- Anatomical barriers (Skin)
- Clearance mechanisms (phagocytosis)
- Physiological variables (pH)
- Chemical barriers (superoxide)
- Enzymatic proteins (lysozyme)
- Antimicrobial peptides (defensins)
Cellular components of adaptive immunity
- Lymphocytes (B and T Cells)
- Leukocytes (granulocytes)
- APC’s
Cells before activation
Naive cells
Cells which have been activated and carry out immune function
Effector cells
Cells which have been activated but are resting until next encounter
Memory Cells
Non-cellular components of adaptive immunity
- Antibodies (B cells)
- Cytokines (T cells)
- Complement (bloodstream)
Humoral immunity protects against extracellular or intracellular pathogens and products?
Extracellular
Which type of T cell is involved in humoral immunity?
CD4+ T helper 2 (Th2)
Does cell mediated immunity protect against intracellular or extracellular pathogens?
Intracellular
Which T cells are involved in cell-mediated immunity?
CD4+ T helper 1 (Th1)
How does innate immunity regulate adaptive immunity?
APCs phagocytose antigens and present them to T cells
Phagocytes and infected cells produce cytokines which affect activation and differentiation of B and T cells
Cytokines then guide the adaptive response
How does adaptive immunity regulate innate immunity
T cells produce cytokines that increase phagocytic activity and intracellular killing
What are primary lymphoid organs?
Thymus and bone marrow
What are secondary lymphoid organs?
Lymph nodes, spleen, gut, and other mucosal tissues
