Immunological System Pathology 1 - Immune Reactions Flashcards
The role of B lymphocytes is categorized as what kind of immunity?
Humoral
What is produced with humoral immunity?
Antibodies
The role of T lymphocyte is categorized as what kind of immunity?
Cell-mediated
What type of chemical activates components of the immune system ie. activates macrophages, PMNs etc.?
Lymphokines
Which white blood cell is the most numerous in the blood stream?
Neutrophil
What is the function of basophils?
They function in the inflammation response by releasing histamine and other chemicals that act on the blood vessels
Basophils become what in peripheral tissue?
Mast cells
What is the function of neutrophils?
They recognize foreign antigens and destroy them through phagocytosis
What is the function of eosinophils?
They release IgE and destroy parasitic organisms
Once maturing, where do eosinophils migrate to from bone marrow?
After 3-8 hours in the blood stream, they migrate to the skin, lungs, and GI tract
What is the function of monocytes/macrophages?
They engulf foreign antigens and cell debris and process antigen and present it.
Give examples of monocytes throughout the body.
Liver Kupffer cells, pulmonary alveolar macrophages, dendritic antigen-presenting cells, sinus lining cells of the spleen and lymph node, and free macrophages of the synovial, pleural, and peritoneal fluid.
What is the function of B lymphocytes?
They are independently able to identify foreign antigens and differentiate into antibody producing plasma and memory cells
What human cytokine stimulates B lymphocytes?
Interleukin-2
What is the role of T lymphocytes?
T helper cells induce B lymphocytes, T suppressor cells recognize and kill virus infected cells
What is the function of natural killer cells?
Cells that bond to and lyse other cells especially those infected with virus
What on a cell’s surface marks it as an antigen-presenting cell?
MHC class II expression
The four loci of the human leukocyte antigen (hla) system have a strong influence on what physical states?
(1) Human allotransplantation
(2) Transfusions in refractory patients
(3) Specific disease associations
What cells are classified as antigen-presenting dendritic cells?
Langerhans’ cells in skin, dendritic reticulum cells of lymph nodes, follicular dendritic cells, interstitial dendritic cells, microglia of CNS
What is the principal immunoglobulin in exocrine secretions e.g. breast milk, respiratory and intestinal mucous, saliva and tears?
IgA
What immunoglobulin can move across the placenta thus becoming an important immunoglobulin for newborns?
IgG
What is the main immunoglobulin in serum?
IgG
What immunoglobulin activates complement and is important in opsonization?
IgG
What immunoglobulin attaches to mast cells in the respiratory and intestinal tracts and plays an important role in allergic response?
IgE
What immunoglobulin is the first to form in response to an attack?
IgM
What immunoglobulin controls the A, B, O blood group antibody responses?
IgM
Antigens present on all nucleated cells in the body that identify a cell as self are called what?
Hla
What is a hapten?
A substance that normally does not act as an antigen
Complement is activated in what kind of immune response?
B-cell mediated immune response
What kind of proteins are involved in vasodilation, chemotaxis, opsonization of antigen, lysis of cells and blood clotting?
Complement
In the complement activation system what is the difference between the classic and alternative pathway?
The classic pathway is activated by CI’s contact with antigen-antibody complexes and the alternative pathway is activated by C3’s contact with various structures (e.g. bacterial polysaccharides, complex polysaccharides, or aggregated IgA). Both result in cleaving of C3 and the activation of complement.
Which complements are responsible for the release of histamine by mast cells?
C3a and C5a (known as anaphylatoxins)
Which complement is responsible for leukocyte activation, adhesion, and chemotaxis?
C5a
Which complements are responsible for the membrane attack complex?
C5b-C9
Which complement acts as an opsonin for phagocytes?
C3b
What is opsonization?
A coat is placed on cells so that they can be recognized
What role does interferon play?
They are released when invading organism is a virus. They inhibit production of virus in infected cells, prevent viral spread, enhance activity of macrophages, NK cells, cytotoxic T cells and inhibit growth of tumor cells.
Which interleukin permits cells of immune system to talk to one another and initiates response?
Interleukin-1
Which interleukin promotes cellular immunity ie. promote growth and activity of macrophages and B cells?
Interleukin-2
Which interleukins promote humoral immunity?
Interleukins-4, -5 and -10
Allergies are what type of hypersensitivity reaction?
Type I
How does the cell first respond to an antigen in a normal and an allergic Type I hypersensitivity reactions?
(1) Normal: Bound B-cell goes to a T-cell to be activated with initial exposure to an antigen
(2) In allergies: the B-cell goes to a Type 2 T-helper cell, which releases IL-4 and causes the B-cell to produce IgE antibodies to the antigen
What happens during the second exposure to an antigen in an allergic Type I hypersensitivity reaction?
(1) In the second exposure, the antigen binds to bound IgE, causing release of histamine and leukotriene granules from mast cells and basophils
(2) Degranulation causes vasodilation, vascular permeability, smooth muscle contraction and varying degrees of response from hives to anaphylactic shock
What occurs during anaphylactic shock?
Vascular permeability causes fluid accumulation in the lung, dropping blood pressure and triggering shock. Bronchioles are constricted.
What is a Type II hypersensitivity reaction?
A cytotoxic reaction from an antigen-antibody response, in which cytotoxic cells and complement are activated
What are two examples of a Type II hypersensitivity reaction?
Goodpasture’s syndrome
Pernicious anemia
What is a Type III hypersensitivity reaction?
Immune complexes are deposited in vessels or tissue, activating complement
What are three examples of Type III hypersensitivity reaction?
Polyarteritis nodosa
Acute glomerulonephritis
Serum sickness
A cell mediated or delayed reaction mediated by the interaction of antigen with T lymphocytes and subsequent release of lymphokines is an example of what type of hypersensitivity reaction?
Type IV
What are examples of Type IV hypersensitivity reactions?
Contact dermatitis
Thyroiditis
Allograft rejection
IgE is formed in what type of hypersensitivity reaction?
Type I
The reaction of antigen and antibody in extracellular fluid spaces is what type of hypersensitivity reaction?
Type III
What Type III hypersensitivity reactions occur in systemic lupus erythematosis (sle)?
(1) Vasculitis: damage to blood vessels, causing the characteristic butterfly rash and damaging heart valves
(2) Glomerulonephritis: damage to kidney glomeruli
(3) Arthritis: damage to synovial joints
Tuberculosis is an example of what type of hypersensitivity reaction?
Type IV
Loss of normal tolerance by the immune system of “self” antigens on the surface of the body’s cells with destruction of normal tissue with autoantibodies is defined as what?
Autoimmunity
During an infection or inflammatory state otherwise latent anti-self lymphocytes become activated by foreign pathogens resembling self, they then produce an immune reaction to the foreign substance and the self is called what?
Molecular mimicry or cross-reaction autoimmunity
What is an example of molecular mimicry?
An initial streptococcal infection can be followed by rheumatic heart disease because antibodies to the streptococcal M protein cross-react with cardiac glycosides
