Module 5-1 - Immune System Flashcards
Types of Blood Cell
Monocytes/Macrophages
Lymphocytes (B and T Cells)
Granulocytes (Polymorphonuclear leukocytes: Neutrophils, Eosinophils, Basophils, Mast Cells)
RBC
Platelet
Granulocytes
blood cells with granules like heparin and histamine in the cytoplasm
Neutrophils (bacteria), Eosinophils (parasites and algae), Basophils (become mast cells)
In what situation does Neutrophilia and Microcytosis occur?
Infection
In what situation does Eosinophilia occur?
Allergies
In what situation does Lymphocytosis occur?
Viral Infection
Hematopoietic Stem Cell
an undifferentiated cell that can go down a progenitor line to make a very differentiated cell
What are the Host Defense Systems?
- Physical and Chemical Barriers to Infection
- Inflammatory Response (Non Specific)
- Immune Response (Specific)
Physical and Chemical Barriers to Infection
Skin
Mucous Membranes and Secretions
Inflammatory Response
Non specific response
occurs after tissue injury or infection
causes fever and inflammation
phagocytic WBCs, antimicrobial substances, and natural killer cells accumulate
Immune Response
Specific Response
Identifies self from non self (host v foreign)
Recognizes and eliminates altered host cells
Antigen-Antibody response
What induces fever?
Prostaglandins
Classic Infection Signs
Redness
Swelling
Pain
Warmth
What sort of trauma can cause an inflammatory response
Mechanical
Thermal
Chemical
Antigen
Immunogen
A molecule that can stimulate and immune response
It is usually a protein or large CHO (NOT LIPIDS OR NUCLEIC ACIDS)
Epitope / Antigenic Determinant
Discrete immunologically active sites on antigens
A single antigen has several antigenic determinants on it
Each can stimulate a distinct clone of lymphocytes
Antibodies attach here
Hapten and Hapten Carrier complex
Low molecular weight compound - Basically Hapten is a small compound
Can combine with carrier protein molecules to act like an antigen
Ex: Penicillin cannot cause a reaction alone so by carrying it on a carrier protein it is then large enough to cause an immune response
Protein structure?
Long chains of amino acids
Partial or Incomplete Antigen
The situation in which hapten can only induce antibodies if bound to another carrier protein or molecule
How many epitopes are on an antigen?
Multiple
They stick out all over
Why is each epitope different on an antigen?
They have different amino acid patterns so the antibody must be specific
The amino acids have a variable and constant portion and each site has a different shape so antibodies need to be specific to just that site
Names of Immune Cell Lymphocytes are based on…
their location of maturation
T Cell = Thymus
B Cell = Bone
Regulatory Lymphocytes
Assist in the immune response
These are Helper T cells
They activate other immune cells
Effector Lymphocytes
Final stage cells of the immune response
These are killer T cells
They ensure removal of foreign invaders
B Lymphocytes
10-20%
Mature in bone marrow
Used in Humoral or Antibody Mediated Immunity
Secrete Antibodies
T Lymphocytes
60-70% (Predominant)
Mature in Thymus
Used in Cell Mediated Immunity
Do not involve antibody production - they do cell-to-cell killing
T4 Lymphocytes
The “Quarterback”
Helper T Cells
Secrete chemical messages that amplify or stimulate other things to happen, such as recruiting and activating cells to do things such as killing
Send Orders
Have CD4 Markers
Speed up or slow down the immune response, but do not do the direct killing
T8 Lymphocytes
Effector Cells
Natural Killer T Cells
Carry out the T4’s orders
The final immune response stage
There are a variety of them, but they all wait to seek and destroy until the T4 orders them to do so
Major Histocompatibility Complex (MHC)
These are the markers on the cells surface also known as Human Leukocyte Antigens (HLA)
They are four closely linked groups of genes (loci) on Chromosome 6 that code for specific cell surface molecules
MHC 1
HLA-A, HLA-B, HLA-C
On all NUCLEATED cells in the body and on platelets
Tells the immune system you are you
Present the processed antigen to cytotoxic T cells to tell which cells are “you”
MHC 2
Mostly on antigen presenting cells like B Cells, Macrophages, and APCs
Present processed antigen to helper T Cells to give orders (so it can get antibodies made and tell cytotoxic T cells what to attack and what not to attack)
The antibody will then go onto the antigens on cells that need to be destroyed and “lock up” so a macrophage can come get it
Types of Immunity
Cell mediated immunity
Humoral or Immunoglobulin mediated immunity
Which type of immunity involves the production of antibodies?`
Humoral or Immunoglobulin mediated immunity
T8 Suppressor Cell
tells when the immune response it over and no longer needed
Reduces the humoral response
Memory T Cell
Does not forget the antigen and response to the specific antigen in cell mediated immunity - since there are no antibodies made, this cell remembers and can launch an attack faster if the same invader enters the body
Remains dormant until second exposure
Cell Mediated Immunity
T Cells respond directly to antigens (helper, killer, suppressor, memory)
Involves destruction of target cells through secretion of lymphokines rather than antibodies
Humoral or Immunoglobulin Mediated Immunity
B cells mature into plasma cells and produce specific antibodies that mark things for destruction
Provides for elimination of bacteria, neutralization of bacterial toxins, and prevention of viral infection
Which type of immunity is fastest? Slowest?
Fast - Cell Mediated
Slow - Humoral (can take months to make antibodies)
Why is specific immune response special?
the antigens can allow responses from infected cells and viral cells (inside) - unlike just neutrophil response - and T cells can do surveillance for cancer cells and mutated cells
Do cell mediated and humoral responses occur at the same time?
Often they do
What sort of immune response is launched regarding a transplanted organ?
Cell Mediated Response
It is recognized as non self and is attacked
What do T lymphocytes function in?
Activating other T cells and B cells
Controlling viral infections
Rejecting foreign tissue graft
Delayed hypersensitivity reactions (ex: poison ivy)
Regulating and amplifying T and B cell response
High Lymphocyte count indicates what?
A viral infection
Cytotoxic (CD8+) T Lymphocytes
T8 Killer Cells
They bind to the surface of an invading cell, disrupt the membrane, and release toxic chemicals
They have the CD8+ markers
Helper (CD4+) T Lymphocytes
Helper T4 Cells - Quarterback
Have CD4+ marker
Secrete cytokines to direct cells
Facilitate cell mediated response
Stimulates B cells to proliferate and mature into plasma cells for humoral response
Natural Killer (NK) Cells
Large granular lymphocytes with CD16 and CD56 markers
Non specific effector cells that kill tumor cells and virus infected cells
Its programmed killing is inhibited by contact with MHC I (Self Molecules)
It pokes holes in cells so cytotoxic enzymes can destroy it
What determines the activity of NK cells? What enhances NK cell activity?
Determined by:
Perforins
Enzymes
Toxic Cytokines
Enhanced By:
IL-2 (from T4 helper)
What are the main communicators between WBCs?
Interleukins
Macrophages
Phagocytic Effector cells in both humoral and cell mediated responses
Do not have surface receptors for specific antigens, but can ingest an antigen to put on its surface to present to a T4 cell to activate the T Lymphocyte Response
They do have the Fc region antigens and for the constant complement portion of an antibody tough
Non specific response role in bacterial infection
secretes Cytokines
Variable versus Constant Portion
Variable Portion is the unique portion of an antigen while the constant is the same on every antigen
Macrophages can only read the constant portion, and activation of this portion by antibodies gets them to come over and eat it
Antigen Presenting Cells
APCs
B Cells
Macrophages
Cytokines
small hormone like polypeptides
“Interleukins”
Act on immune cells to regulate inflammatory responses including movement, proliferation and differentiation of leukocytes and other cells (the T4’s messages)
They end up enhancing the production and maturation of B Lymphocytes into Plasma Cells
Usually have multiple jobs or mult kinds can do one job
How are Cytokines named?
For the cell type that makes them (ex: Lymphokines)
International nomenclature - ex: interleukin 1 through 17
the biologic property first ascribed to them - ex: interferon
ILs
Interleukins
Cytokine
Involved in fever, inflammation, and regulation of immune cell response
IF
Interferons
Cytokine
Augments natural killer cell activity and exerts antiviral activity to boost immune system response (when given as an IV)
TNF
Tumor Necrosis Factor
Cytokine
Destroys things by directing cytotoxins toward tumors
CSF
Colony Stimulating Factor
Cytokine
Stimulates different colonies of WBC to be produced
Reticuloendothelial System
RES
Tissue Macrophages - localized to different regions and tissues and given different names based on their area
Wherever the macrophages are migrating to with the system they may stay their entire life
Alveolar Macrophages
Lung Macrophage
Kupffer’s Cells
Liver macrophage
Peyer’s Patches
Intestine Macrophage