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Micro Exam 3
Immunology
56
Microbiology
Professional
11/28/2009

Additional Microbiology Flashcards

 


 

Cards

Term
4 characteristic signs of inflammation
Definition
  1. erythema - due to increased blood flow
  2. heat - due to increase in blood and more rapid metabolic processes
  3. edema - increased permeability, fluid moves from blood to tissue spaces
  4. pain - injury to nerve fibers or bacterial toxins
Term
Histamine
Definition

Increase Vasodilation

Increase Permeability

Released by mast cells in connective tissue - basophils in the blood

Term
Prostaglandins
Definition

Intensify the effects of histamine

Released by injured tissue

Term
Leukotrienes
Definition

Increase Permeability

Released by mast cells and basophils

Function in adherence of phagocytes to pathogens

Term
Cytokines
Definition
  • Released by monocytes, macrophages, lymphocytes
  • Regulators of inflammatory response
  • Attract leukocytes, initiate fever
Term
Complement
Definition
  • Increase Vasodilation
  • Increase Permeability
  • Stimulates histamine release
  • Attract neutrophils
  • Promotes phagocytosis
Term
Examples and Function of Polymorphonuclear Cells
Definition

Basophils, neutrophils, eosinophils, mast cells

Destroy intracellular pathogens (phagocytosis), release chemicals

Term
Examples and Function of Antigen Presenting Cells
Definition

Macrophages, monocytes, dendritic cells

Present antigens to lymphocytes

Term
Neutrophils
Definition

Short lived
Ingest, kill, and digest microbial pathogens
First to inflammatory sites
Granules contain antimicrobial agents, such as:

  1. lysozymes
  2. lactoferrin
Term
Eosinophils
Definition
Mediate allergic reactions and defense against helminths
Term
Basophils
Definition

Mast cells are tissue counterpart

Produce cytokines in defense against parasites

Responsible for allergic reaction

Secrete primary mediators (histamines) and secondary mediators (leukotrienes)

Term
Monocytes
Definition

Macrophages are tissue counterpart

Phagocytosis and intracellular killing

Antigen presentation to T-cells

Recruit other immune cells through cytokine and production

Specialized Macrophages:

  1. Kupfer cells (liver)
  2. Glial cells (brain)
  3. Langerhans cells (skin)
  4. Osteoclasts
  5. Alveolar macrophages
Term
Dendritic cells
Definition

these are differentiated macrophages that act as APCs to active T-helper cells, Cytotoxic T cells, B-cells

Found in most organs

Term
B lymphocytes
Definition

Differentiate into plasma cells to secrete immunoglobulin glycoproteins that bind antigens with high degree of specificity

 

Term
T Lymphocytes
Definition

immature thymocytes differentiate in the thymus

cell mediated immunity

help B-cells produces immunoglobulins

CD4 expressing T helper cells

CD8 expressing Cytotoxic T cells

Term
CD4 Expressing Cells
Definition
  • T-Helper Cells
  • Regulators of delayed-type hypersensitivity responses
  • Assist in the stimulation of B cells

 

Term
CD8 Expressing Cells
Definition

Cytotoxic T cells

Cytotoxic against tumor cells and host cells with intracellular pathogens

Term
Natural Killer Cells
Definition

Large, granular lymphocytes

Kill tumor cells and pathogen-infected cells

Enhanced by IFN and IL

Lack the major B and T-cell markers

Kill by direct and antibody-dependent cytotoxicity

Term
Primary or Secondary Lymphoid Organ? Fetal Liver
Definition
Primary
Term
Primary or Secondary Lymphoid Organ? Adult bone marrow
Definition
Primary
Term
Primary or Secondary Lymphoid Organ? Thymus
Definition
Primary
Term
Primary or Secondary Lymphoid Organ? Lymph Nodes
Definition
Secondary
Term
Primary or Secondary Lymphoid Organ? Spleen
Definition
Secondary
Term
Spleen: Red Pulp
Definition
  • Has vascular sinuses with macrophages
  • Macrophages break down old RBCs and recycles hemoglobin - retrieval of iron
  • Macrophages also break down platelets

 

Term
Spleen: white pulp
Definition
  • T and B cell area
  • Germinal centers w/ macrophages and dendritic cells --> present antigens to lymphocytes
  • B-cells become plasma cells so they can make immunoglobulins
  • Macrophages break down antigens

 

Term
Lymph Nodes: Function
Definition

Filters antigen and debri from lymph

Macrophages and dendritic cells (primarily in medulla area) cleanse lymph

T cell and B cell maturation occurs here

 

Term
Primary or Secondary Lymphoid Organ? Mucosa Associated Lymphoid Tissue
Definition
Secondary
Term
Musoca Associated Lymphoid Tissue (MALT): Examples
Definition

Tonsils

Peyer's Patches (located in ileum)

Appendix

Term
Musoca Associated Lymphoid Tissue (MALT): general locations and functions
Definition
  • These are cellular aggregates (non-encapsulated) in the lining of the respiratory and digestive tracts
  • They are strategically located to recognize antigens and respond with an appropriate immune response
  • Contain resident intraepithelial lymphocytes
Term
Omenn's Syndrome
Definition
  • This is a form of SCID (Severe Combined Immunodeficiency)
  • An autosomal recessive disorder
  • Absence of germinal centers in lymph nodes --> replaced with a diffuse infiltrate of large cells with abundant cytoplasm
  • There is abnormal intra-thymic T-cell development plus inefficient and/or abnormal generation of TCR's as well as a deficiency of B-cells and receptors (antibodies)

 

Term
Omenn's Syndrome: Symptoms
Definition

Chronic diarrhea

leukocytosis

Term
T-Helper Cells: Characteristics
Definition
  1. Express the CD4 co-receptor
  2. Recognize antigens complexed with MHC II on B cells, macrophages, or other APCs
  3. Activate memory T helper cells and cytokine-secreting cells
  4. Stimulated B-cells
Term
Cytotoxic T cells: Characteristics
Definition
  1. Express the CD8 co-receptor
  2. Dependent upon MHC I on APCs
  3. Are cytotoxic against tumor cells
  4. Are cytotoxic against host cells with intracellular pathogens --> causes them to undergo apoptosis
Term
What are the 3 groups of molecules that specifically recognize foreign antigens for the adaptive immune system?
Definition
  1. T-cell receptors
  2. B-cell receptors
  3. MHC
Term
T/F: Not all TCR's expressed by a single T-cell are specific for the same antigen
Definition

False

ALL TCR's expressed by a SINGLE T-CELL ARE SPECIFIC for the SAME ANTIGEN

Term
Endogenous (cytoplasmic) Antigen Processing: Characteristics
Definition

MHC I are associated with this type of antigen processing

MHC I are found in all nucleated cells (excluding immunological cells)

MHC I participates in anitgen presentation to CD8 Cytotoxic T cells

Endogenous because the virus has already infected the cell and has started to make viral proteins that are in the cytoplasm (endogenous pathogens)

The viral protein is degraded by proteosomes and the degradation products of the viral protein are combined with MHC I --> sent to cell surface for presentation

This marks the cell for destruction by Cytotoxic T cells

 

 

 

Term
Exogenous (endosomal) Antigen Processing: Characteristics
Definition
  • MHC II are associated with this type of antigen processing
  • MHC II molecules are found on APC's (macrophages, dendritic cells) and B-cells
  • MHC II participates in antigen presentation to CD4 T-Helper cells
  • Exogenous because the pathogen is outside the cells and is taken up by endosomes that break it down
  • The degradation products will be combined with MHC II and sent to the surface of the cell for presentation
Term
Cytokine-related disorder due to: Overproduction of IL-1, IL-6, TNF
Definition
  1. Drop in BP
  2. Shock
  3. Fever
  4. Blood clotting

endotoxin stimulation of macrophages after G- bacterial infection --> septic shock

Term
Cytokine-related disorder due to: Massive release of cytokines
Definition
superantigen stimulation of T-cells by bacterial toxins --> toxic shock
Term
Cytokine-related disorder due to: Decreased expression of IL-2 receptor
Definition

Immune suppression

Caused by Trypanosoma cruzi --> Chagas

Term
IgD
Definition

With IgM, it the major Ig expressed by mature B-cells

Functions in activation of B-cells by antigens

Term
IgG
Definition
  • Protects fetus
  • Neutralizes bacterial toxins and viruses
  • Complement activator
  • Plays a huge role in persistent viral, bacterial, and fungal infections
Term
IgE
Definition

Binds to allergens

Mediates hypersensitivity reactions (such as asthma, hives, hay fever) by inducing degranulation of basophils and mast cells

Protects against parasitic infections

Term
IgA
Definition
Main Ig in external secretions (tears, saliva, breast milk, mucus)
Term
IgM
Definition
  • Analagous to neutrophils in that they are the first to respond to an infection
  • Has 10 antigen binding sites
  • Activates complement pathway
Term
Phase of the Adaptive Immune Response
Definition
  1. Antigen recognition
  2. Lymphocyte activation
  3. Effector Phase
  4. Decline (homeostatis)
  5. Memory
Term
What is the immunological basis for multiple myeloma?
Definition
  • Cancer of the cells in the bone marrow --> results in an increase in plasma cells
  • There will be a decrease in polymorphonuclear cells

 

Term
In patients with multiple myeloma, why are patients considered more susceptible to bacterial infections?
Definition
  • They have a marked increase in plasma cells, which results in an increase in IgG and they are producing only that particular Ig
    Their body is not producing any other Ig (such as IgA, IgD, IgM, etc.)
  • This leaves the patient susceptible to other pathogens that other Ig take care of (parasites, no added protection of IgA in tears, etc.)
Term
What are the two pathways of the complement system?
Definition
  1. Alternate (innate) pathway
  2. Classical (humoral) pathway
Term
How is the alternate pathway activated?
Definition
Most commonly activated by microbial surfaces or cell components (e.g. lipopolysaccharides)
Term
What type of immunity (innate or adaptive) is associated with the alternate pathway?
Definition
Innate
Term
What type of immunity (innate or adaptive) is associated with the classical pathway?
Definition

Adaptive (humoral)

 

Term
How is the classical pathway activated?
Definition
  • It is activated by antigen/antibody complexes containing IgM or IgG
  • It is the major effector of the humoral immunity
Term
What are the two major biological activities of complement products?
Definition
  1. Membrane Attack Complex acts as a molecular drill to puncture cell membranes
  2. Complement cleavage products promote: opsonization (enhancement of phagocytosis) inflammatory responses, degranulation, etc.
Term
What is the pathological basis of DiGeorge Syndrome and what is the result?
Definition
  • Deletion of a portion of chromosome 22
  • Babies are born without a thymus
Term
For patients with DiGeorge Syndrome, what is the effect of thymus absence on maturation of T cells?
Definition
  • Basically, patient will not have maturation of T-cells, because this is where T cells mature
  • Since the baby does not have a thymus, its body will rely on bone marrow
  • However, T-cells will not have their coreceptors (CD4 or CD8) and therefore no T-helper cells or Cytotoxic T cells
  • There will be an accumulation of B cells that won't be stimulated

 

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