Cell VS. Humoral Innate Immunity Flashcards
the study of a host’s reactions when foreign substances are introduced into the body
immunology
the condition of being resistant to infection
immunity
a foreign substance that induces an immune response
antigen
the practice of deliberately exposing an individual to material from smallpox lesions
variolation
discovered a remarkable relationship between exposure to cowpox and immunity to smallpox
deliberately injected individuals with material from cowpox lesions to protect them from smallpox, known as vaccination
edward jenner (1700s)
the phenomenon in which exposure to one agent produces protection against another agent
cross-immunity
often called the “father of immunology”
discovered his attenuated vaccine while working with the bacteria that caused chicken cholera
louis pasteur (1800s)
change
may occur through heat, aging, or chemical means
attenuation
discovered phagocytosis (cells that eat cells)
hypothesized that immunity to a disease was based on the action of the scavenger cell
ellie metchnikoff (late 1800s)
demonstrated that diphtheria and tetanus toxins, which are produced by specific microorganisms as they grow
could be neutralized by the noncellular portion of the blood of animals previously exposed to the microorganisms, giving birth to the theory or humoral immunity
emil von behring
linked the two theories by showing that the immune response involved both cellular and humoral elements
he observed that certain humoral, or circulating, factors called opsonins acted to coat bacteria so that they became more susceptible to ingestion by phagocytic cells
these serum factors include specific proteins known as antibodies, as well as other factors called acute-phase reactants that increase nonspecifically in any infection
almroth wright (1903)
the important process in host defense by which particles or complexes are made readily ingestible for uptake by phagocytic cells
specific serum proteins, known as opsonins, coat particles and cause the particles to bind avidly to phagocytes and trigger ingestion
opsonization
a cellular process for ingesting and eliminating particles, including foreign substances, microorganisms, and apoptotic cells
phagocytosis
The movement of phagocytes toward an increasing
concentration of some attractant such as bacterial
factors (bacterial proteins, capsules, LPS,
peptidoglycan, teichoic acids, etc.), complement
proteins (C5a), chemokines (chemotactic cytokines
such as interleukin-8 secreted by various cells), fibrin
split products, kinins, and phospholipids released by
injured host cells
DIAPEDESIS
o The movement of le
chemotaxis
The movement of leukocytes (neutrophils) out of the
blood vessels and towards the site of tissue damage or
infection
diapedesis
Both cells and soluble factors play essential parts
Designed to recognize molecules that are unique to
infectious organisms
White blood cells seek out and destroy foreign cells by
participating in phagocytosis
internal defense system
Normal serum constituents that increase rapidly by at
least 25 percent due to infection, injury, or trauma to the
tissues
Produced primarily by hepatocytes within 12-24 hours
in response to an increase intercellular signaling
polypeptides – cytokines
acute-phase reactants
Elevated in bacterial infections, rheumatic fever, viral
infections, malignant diseases, tuberculosis, and after a
heart attack
Capable of opsonization (the coating of foreign
particles), agglutination, precipitation, and activation of
complement by the classical pathway
C-reactive proteins
An apolipoprotein that is synthesized in the liver,
associated with HDL cholesterol, removing cholesterol
from cholesterol-filled macrophages
At the site of tissue injury, facilitates recycling of cell
membrane cholesterol and phospholipids for reuse in
building membranes of new cells required during acute
inflammation
serum amyloid A
Refers to a series of serum proteins that are normally
present and whose overall function is mediation of
inflammation
Major functions of complement are opsonization,
chemotaxis, and lysis of cells
complement
An opsonin able to recognize foreign carbohydrates
such as mannose and several other sugars found
primarily on bacteria, some yeasts, viruses, and several
parasites
mannose-binding protein (MBP)
A general plasma inhibitor of proteases (enzymes that
contributes to the virulence of bacteria) released from
leukocytes, especially elastase
alpha-1 antitrypsin
an endogenous enzyme that can
degrade elastin and collagen
elastase
Binds irreversibly to free hemoglobin released by
intravascular hemolysis, the complex is cleared rapidly
by Kupffer and parenchymal cells in the liver, thus
preventing loss of free hemoglobin
haptoglobin
The most abundant of the coagulation factors in
plasma, and it forms the fibrin clot, formation of a clot
also creates a barrier that helps prevent the spread of
microorganisms further into the body
fibrinogen
The principal copper-transporting protein in human
plasma, circulating copper is absorbed out by the liver
and either combined with ceruloplasmin and returned to
the plasma or excreted into the bile duct
ceruloplasmin
Contain a large number of neutral staining granules,
which are classified as primary, secondary, and tertiary
granules
neutrophils
contain enzymes such as myeloperoxidase, elastase,
proteinase 3, lysozyme, cathepsin G, and defensins,
small proteins that have antibacterial activity
✓ Attracted to a specific area by chemotactic factors
Primary granules/azurophilic granules
characterized by the presence
of collagenase, lactoferrin, lysozyme, reduced
nicotinamide adenine dinucleotide phosphate (NADPH)
oxidase, and membrane proteins normally associated
with the plasma membrane
secondary granules
gelatinase and plasminogen
activator
tertiary granules
chemical messengers that cause cells to migrate in a particular direction
chemotaxins
Primary granules contain acid phosphatase and
arylsulfatase, while eosinophil-specific granules contain
several different proteins: major basic protein,
eosinophil cationic protein, eosinophil peroxidase, and
eosinophil-derived neurotoxin
Most important role is neutralizing basophil and mast
cell products and killing certain parasites
eosinophils
Constituents of these granules are histamine, a small
amount of heparin, and eosinophil chemotactic factor-
A, all of which have an important function in inducing
and maintaining immediate hypersensitivity reactions
basophils
They are connective tissue cells of mesenchymal origin,
and they have a long-life span of between 9 and 18
months. They are widely distributed throughout the
body and are larger than basophils
mast cells
These granules are actually of two types, one of which
contains peroxidase, acid phosphatase, and
arylsulfatase; this indicates that these granules are
similar to the lysosomes of neutrophils. The other type
of granule may contain β-glucuronidase, lysozyme, and
lipase, but no alkaline phosphatase
monocytes
Monocyte-macrophage system plays an important role
in initiating and regulating the immune response,
functions include microbial killing, tumoricidal activity,
intracellular parasite eradication, phagocytosis,
secretion of cell mediators, and antigen presentation
Killing activity is enhanced when macrophages become
“activated” by contact with microorganisms or with
chemical messengers called cytokines, which are
released by T lymphocytes during the immune
response
tissue macrophages
Main function is to phagocytose antigen and present it
to helper T lymphocytes
After capturing antigen in the tissue by phagocytosis or
endocytosis, they migrate to the blood and to lymphoid
organs, where they present antigen to T lymphocytes to
initiate the acquired immune response. They are the
most potent phagocytic cell in the tissue
dendritic cells
The process of phagocytosis consists of four main steps:
- Physical contact between the white cell and the foreign particle
- Formation of a phagosome
- Fusion with cytoplasmic granules to form a phagolysosome
- Digestion and release of debris to the outside
Enhanced by opsonins, a term derived from the Greek word meaning _____
“to prepare for eating.”
serum proteins that attach to a foreign substance and help prepare it for phagocytosis
opsonins
3 important opsonins
C-reactive protein
complement components
antibodies
Overall reaction of the body to injury or invasion by an infectious agent, cellular and humoral mechanisms are involved
inflammation
Four cardinal signs or clinical symptoms of inflammation
redness
swelling
heat
pain
Major events associated with the process of inflammation are:
- Increased blood supply to the infected area
- Increased capillary permeability caused by retraction of endothelial cells lining the vessels
- Migration of white blood cells, mainly neutrophils, from the capillaries to the surrounding tissue
- Migration of macrophages to the injured area
Chemical mediators such as _____ which are released from injured mast cells, cause dilation of the blood vessels and bring additional blood flow to the affected area, resulting in redness and heat. The increased permeability of the vessels allows fluids in the plasma to leak to the tissues
histamine
____ which are mobilized within 30 to 60 minutes after the injury, are the major type of cell present in
acute inflammation.
neutrophils
Neutrophil emigration may last ______ and is proportional to the level of chemotactic factors present in the area
24
to 48 hours
Migration of macrophages from surrounding tissue and from blood monocytes occurs several hours later and peaks at ______
16 to 48 hours
When the inflammatory process becomes prolonged, it
is said to be ______, and tissue damage and loss of
function may result
chronic
Events in the inflammatory response:
- Increased blood supply to the affected area
- Increased capillary permeability
- Migration of neutrophils and macrophages to the
tissues. - Phagocytosis
- Clinical signs at the site include erythema and
edema - Tissue healing
