Immunology Chapter 1

Long-term immunity conferred by an adaptation to a specific pathogenic infection.

Short-term immune response to a wide array of pathogens.

The functions of the immune system that restrict an infection and eliminate it, such as complement, Mfs, neutrophils, Abs, and effector T cells.

The immune system's ability to fight a specific pathogenic infection better the second time than the first.

• 1. Pluripotent hematopoietic stem cell
• 2. Common lymphoid progenitor
• 3. B cell
• 4. Plasma cell

• 1. Pluripotent hematopoietic stem cell
• 2. Common lymphoid progenitor
• 3. T cell
• 4. Effector T cell

• 1. Pluripotent hematopoietic stem cell
• 2. Common lymphoid progenitor
• 3. NK cell
• 4. Effector NK cell

• 1. Pluripotent hematopoietic stem cell
• 2. Common lymphoid/myeloid progenitor
• 3. Immature DC
• 4. Mature DC

• 1. Pluripotent hematopoietic stem cells
• 2. Common myeloid progenitor
• 3. Granulocyte progenitor
• 4. Granulocytes

• 1. Pluripotent hematopoietic stem cells
• 2. Common myeloid progenitor
• 3. Macrophage progenitor
• 4. Mast cell precursor
• 5. Mast cell

• 1. Pluripotent hematopoietic stem cells
• 2. Common myeloid progenitor
• 3. Macrophage progenitor
• 4. Monocyte
• 5. Macrophage

• 1. Pluripotent hematopoietic stem cells
• 2. Common myeloid progenitor
• 3. Megakaryocyte progenitor
• 4. Megakaryocyte
• 5. Platelets

• 1. Pluripotent hematopoietic stem cells
• 2. Common myeloid progenitor
• 3. Erythrocyte progenitor
• 4. Erythroblast
• 5. Erythrocyte

• 1. Phagocytosis
• 2. Activation of bactericidal mechanisms
• 3. Ag presentation

• 1. Ag uptake in peripheral lymph system
• 2. Ag presentation

• 1. Phagocytosis
• 2. Activation of bactericidal mechanisms

Killing of Ab coated parasites

• 1. Promotion of allergic response
• 2. Augmentation of anti-parasitic immunity

Release of granules containing histamine and active agents

To kill virus infected cells

• 1. Proliferate and differentiate into plasma cells
• 2. Secrete B-cell receptor aka Abs

• 1. Cytotoxic T cells - kill virus and other intracellular infected cells
• 2. Helper T cells - Signal other components of the immune system to activate
• 3. Regulartory T cells - Regulate immune response

• 1. Innate - Macrophages, DCs, Neutrophils, Eosinophils, Basophils
• 2. Adaptive - T cells, B cells, NK cells, DCs

• 1. Location of lymphocyte generation and maturation
• 2. Bone marrow makes B cells
• 3. Thymus gland makes T cells

• 1. Where mature naive lymphocytes are maintained and adaptive immune response is innitiated.
• 2. Organs include spleen, lymph nodes, and mucosal lymphoid tissue

Secreted proteins that affect the behavior of nearby cells

Secreted proteins that act as chemoattractants for other immune cells (e.g. neutrophils and monocytes)

Plasma proteins that coat pathogens thus targeting them for phagocytosis by Mfs

Local heat, pain, redness, and swelling due to the effect of complement, cytokines, and chemokines

• 1. Bacteria trigger macrophages to release cytokines and chemokines
• 2. Vasodilation and increased vascular permeability cause redness, heat, and swelling
• 3. Inflammatory cells migrate into tissue, releasing inflammatory mediators that cause pain

• 1. Pathogen-Recognition Receptors
• 2. Located on Mfs, neutrophils, and dendrites that help them recognize pathogens (PAMPs)

• 1. Pathogen-Associated Molecular Patterns
• 2. Present on microorganisms that allow innate immune cells to recognize them using PRRs

• 1. A single progenitor cell gives rise to a large number of lymphocytes, each with a different specificity
• 2. Removal of potentially self-reactive immature lymphocytes by clonal deletion
• 3. Remaining pool of mature naive lymphocytes, each with a single type of receptor with a unique specificity for Ag
• 4. Proliferation and differentiation of activated lymphocytes to form a clones (clonal expansion) of effector cells with identical receptors specific for the Ag that activated it

• 1. 2 identical H chains and 2 identical L chains
• 2. Each H and L chain has a C and V region
• 3. The V regions of the H and L chains form the Ag binding site
• 4. The stem is formed from the C region of the H chains

• 1. Alpha and Beta chains - similar in size
• 2. Each has C and V region
• 3. V regions form Ag binding site
• 4. The stem is formed from the C region of the chains

The small part of an antigenic molecule that is recognized by antigen receptor on Abs

Programmed cell death

• 1. Afferent lymphatic vessels - drain lymph into the node
• 2. Primary lymphoid follicle - mostly B cells
• 3. Germinal centers - areas in secondary lymphoid follicle with intense B cell proliferation
• 4. Paracortical area - mostly T cells
• 5. Medulla - medullary cords consisting of macrophages and plasma cells
• 5. Efferent lymphatic vessels - drains lymph away from node

• 1. M cell - entry point of Ag from gut into patch
• 2. Subepithelial dome - area just beneath intestinal epithelium rich in DCs, B cells, and T cells
• 3. Follicle - contains germinal center for B cell proliferation
• 4. T cell dependant area - area between follicles rich in T cells
• 5. Efferent lymphatics - drain lymph away from patch

• Primary response:
• 1. Ag exposure
• 2. Lag Phase - low [Ab]
• 3. [Ab] rises then declines
• Secondary response (booster)
• 1. Ag re-exposure
• 2. Rapid and intense increase in [Ab]

• 1. Extracellular bacteria, parasites, fungi (pneumonia)
• 2. Intracellular bacteria, parasites (leprosy)
• 3. Intracellular Viruses (flu)
• 4. Extracellular parasitic worms (ascariasis)

• 1. Neutralization - Ab neutralizes pathogen by preventing it from binding to cells
• 2. Opsinization - Ab coats pathogen thus targeting it for phagocytosis
• 3. Complement activation - Ab coat pathogen which activates complement components which coat pathogen and target it for phagocytosis

• 1. Virus infects cell
• 2. Viral proteins synthesized in cytosol
• 3. Peptide fragments of viral proteins are bound by MHC I molecules
• 4. Bound peptides are transported to the cell surface
• 5. Cytotoxic CD8 T cells recognize complex of viral peptide and MHC I and kills infected cell

• 1. Expressed by APC's (DCs, macrophages, B cells)
• 2. Bind peptides
• 3. Translocate them to cell surface
• 4. Recognized by helper T cells which activate the APC

• 1. Innate
• 2. Adaptive
• 3. Immunological Memory

Inflammation, complement activation, phagocytosis and destruction of pathogen (minutes, days)

• 1. Interaction between Ag-presenting DCs and Ag-specific T cells: recognition of Ag, adhesion, co-stimulation, T cell proliferation and differentiation (hrs, days)
• 2. Activation of Ag-specific B cells (hrs, days)
• 3. Formation of effector and memory T cells (days, wks)
• 4. Interation of T cells w/B cells, formation of germinal centers; formation of plasma cells and memory B cells; production of Ab (days, wks)
• 5. Emigration of effector lymphocytes form peripheral lymphoid organs (days, wks)
• 6. Effector cells and Abs eliminate pathogen (days, wks)

Maintenance of memory B cells and T cells and high serum Ab levels; protection against reinfection (wks, lifelong)