M3L1 Flashcards
A host defense system against infectious disease and foreign (non self) antigens.
IMMUNE SYSTEM
A response generated against a potential pathogen is called
IMMUNE RESPONSE
- first line of defense
- non specific to the invading pathogen
- rapidly mobilized at the initial site of infection
- lacks immunologic memory
INNATE IMMUNITY
A protein that is produced in response to a particular
pathogen is called
ANTIBODY
antibody is synonymous to
IMMUNOGLOBULIN
The substance that induces the production of
antibodies is called
ANTIGEN
- Rapid, immediate response
- Antigen nonspecific
-
No memory, not long-lasting
protection
INNATE IMMUNITY
- Slow response
- Highly antigen specific
- Induces memory, responds rapidly and vigorously to second antigen exposure
ADAPTIVE IMMUNITY
which immunity have these immunoligic components
- Natural barriers to infection – skin, mucous membranes;
- Cells – phagocytes, NK cells, innate lymphoid cells
INNATE IMMUNITY
which immunity have these immunoligic components
Mediators – complement, defensins, cytokines, sensors (TLR, NOD-like receptors, RAG-1)
INNATE IMMUNITY
which immunity have these immunoligic components
Cell – T lymphocytes-cell mediated, B lymphocytes - antibody mediated, APCs
ADAPTIVE IMMUNITY
which immunity have these immunoligic components
Mediators – secreted molecules (cytokines, chemokines, complement)
ADAPTIVE IMMUNITY
2 classification of adaptive immunity
naturally acquired
artificially acquired
CLASSIFICATION OF ADAPTIVE IMMUNITY
- antigens enter the body naturally
- body induces antibodies and specialiazed lymphocytes
ACTIVE IMMUNITY (naturally acquired)
CLASSIFICATION OF ADAPTIVE IMMUNITY
- antibodies pass from mother to fetus via placenta or to infant via the mother’s milk
PASSIVE IMMUNITY (naturally acquired)
CLASSIFICATION OF ADAPTIVE IMMUNITY
- antigens are introduced in vaccines
- body produces antibodies and specialized lymphocytes
ACTIVE IMMUNITY (artificially acquired)
CLASSIFICATION OF ADAPTIVE IMMUNITY
- preformed antibodies in immune serum are introduced by injection
PASSIVE IMMUNITY (artificially acquired)
The skin, airways, gastrointestinal (GI) tract, and genitourinary tract have ________________ as their barrier
EPITHELIAL CELL LAYER
Epithelial cell layer has ____ that help provide proetction against invading pathogens
TIGHT JUNCTIONS
has tight junctions and produces a number of powerful antimicrobial peptides that help provide protection against invading pathogens
EPTHELIAL CELL LAYER
an example of an antimicrobial peptide that dissolves some bacterial cell wall
LYSOZYME
lysozyme is present on the ____ and can help provide
protection against some microorganisms
SKIN
present on the skin and in tears and in respiratory and cervical secretions
LYSOZYME
by virtue of their acid pH and certain chemicals especially fatty acids – have antimicrobial properties that tend to eliminate pathogenic organisms.
SWEAT & SEBACEOUS SECRETIONS
____ microorganisms are capable of penetrating intact skin
FEW
____ can enter sweat and sebaceous glands and hair follicles and establish themselves there.
MANY
The skin produces a variety of antimicrobial agents including a protein with antibacterial properties known as
PSORIASIN
- positively charged peptides
- located primarily in the GI an lower respiratory tracts
- create holes in bacterial cell walls
- disrupts the bacterial membrane
DEFENSINS
NEUTROPHILS in the small intetsine contain ____ that house the α-defensins
AZUROPHILIC GRANULES
released following TLR activation
α-defensins
the defensin that the epethilial cells in the respiratory tract secretes
β-defensin
have also been shown to possess antiviral activity
α-defensin
The ____ of the respiratory tract offers another mode of protection from infection.
MUCOSAL EPITHELIUM
a complex mixture of mucins, proteins, proteases, and protease inhibitors, is a major component of the mucosal epithelium.
MUCUS
Some bacteria attach to the surface epithelial cells by means of
ADHESIVE BACTERIAL SURFACE PROTEINS
the presence of mucus limits bacterial adhesion to these cell surfaces. Once entrapped in the mucus, the bacteria are removed by
CILIARY CLEARANCE
tend to inhibit microbial adhesion and limit exposure time
MUCOSAL SURFACE & CILIATED EPITHELIAL CELLS
has mechanisms to inhibit bacteria
GI TRACT
The ____ of the stomach and the ____ of the small intestine make this environment hostile to many bacteria.
ACIDITY OF STOMACH
PROTEOLYTIC ENZYMES of small intetsine
An additional barrier to microbial invasion is the effect of the
CHEMICAL ENVIRONMENT
the presence of an ____ pH in sweat and
sebaceous secretions and the ____ pH of the stomach have antimicrobial properties.
HIGH ph in sweat & sebaceous
LOW ph in stomach
the production of ____ on the skin also tends to eliminate pathogenic organisms
FATTY ACIDS
a good barrier because it is dry
bacteria needs water to grow
SKIN
are parts of immune response
they are good immune response
FEVER & INFLAMMATION
When a pathogen enters the skin, it is confronted by macrophages and other phagocytic cells possessing
MICROBIAL SENSORS
Recognize presence of pathogens
MICROBIAL SENSORS
3 MAJOR GROUPS OF MICROBIAL SENSORS
TLRs
NOD-like receptors (NLRs)
RIG-1-like helicase & MDA5
- best studied of the microbial sensors
- Type 1 transmembrane proteins that recognize pathogen-associated molecular patterns
- constitue a first line of defense
- play a critical role in initiating the immune response
- generates a rapid and robust inflammatory response marked by cellular activation & cytokine release
TLRs
Toll-like receptors
how many TLRs have been identified to date
10
- intracellular sensors for microbial products
- located in the cytoplasm
- activate the nuclear factor and drive inflammatory responses similar to TLRs
NLRs
NOD-like receptors
cytoplasmic sensors of viral ssRNA
RIG-1like helicase & MDA5
these target viruses
INTERFERONS
The cells of the innate and adaptive immune systems originate in
BONE MARROW
give rise to red blood cells, platelets, and the cells of the innate immune system.
MYELOID CELLS
give rise to cells essential to adaptive immunity, such as T-lymphocytes, B-lymphocytes, and natural killer cells
LYMPHOID CELLS
- MAJOR PHAGOCYTIC CELL
- short half-life
- destroys pathogens within intracellular vesicle
NEUTROPHILS
monocytes mature into
MACROPHAGES
- small leuokocytes
- circulate in the blood
- found in almost all tissues
MONOCYTES
- critical cells
- engulf & kill pathogens
- process and present antigen
- regulate immune reactivity by producing variety molecules
MACROPHAGES
monocytes in the liver
KUPFFER CELLS
responsible for histamine production
BASOPHILS
- present in the blood, lymphoid tissue, liver, spleen, lung, and other tissues
- responsible for the uptake and removal of foreign antigen
PHAGOCYTES
a T lymphocyte but works for innate immune system
NATURAL KILLER CELL
origin of all lymphocytes
LYMPHOID PROGENITOR CELL
- densely staining granules
- It includes the neutrophils, eosinophils, and basophils
GRANULOCYTES
phagocytic vesicle is also called
PHAGOSOME
a multistep process whereby a phagocytic cell recognizes the pathogen, ingests it, and then destroys the engulfed organism
PHAGOCYTOSIS
the neutrophil recognizes, engulfs, and internalizes he pathogen into an endocytic vesicle called
P
PHAGOSOME
when the neutrophil completes its mission, it undergoes ____
APOPTOSIS
- They are leukocytes that have no granules
- It includes monocytes and macrophages
AGRANULOCYTES
macrophage in the nervous tissues
MICROGLIAL CELLS
destruction of parasites, attach to the parasite if it is big
EOSINOPHIL
- They are also phagocytic cells and can degrade pathogens.
- Their main role is to activate T cells in the adaptive immune response by acting as an antigen-presenting cell and by producing regulatory cytokines.
DENDRITIC CELLS
IN ORDER
MECHANISM OF PHAGOCYTOSIS
CHEMOTAXIS
ADHERENCE
INGESTION
DIGESTION
chemical signals attract phagocytes to microorganisms
CHEMOTAXIS
attachment of phagocytes to the surface of microorganism
ADHERENCE
Microorganism is engulfed by the phagocyte
INGESTION
Microorganisms are digested inside the phagolysosome (fusion of phagosome and lysosome)
DIGESTION
fusion of phagosome and lysosome
PHAGOLYSOSOME
- Large, granular lymphocytes morphologically related to T cells, which make up 10 – 15% of blood leukocytes.
- can recognize and kill virus-infected cells and tumor cells.
NATURAL KILLER CELLS
NK cells can recognize what type of cells
2
virus-infected cells
tumor cells
A natural killer (NK) cell recognizes ____ on a healthy cell and does not kill it.
MHC I
An ____ does not present the MHC I, but does present ligands for the activating receptor. Thus, the NK cell will trigger a response that kills the cell.
INFECTED CELL
basis for health cell detection
MHC I
the complement system consists of approximately ____ proteins found in the serum or on the membrane of selected cells that interact in a cascade
30
it initiates a series of biochemical reactions that ultimately culminate in cellular lysis or destruction of the pathogen.
COMPLEMENT SYSTEM
- antibody binds to antigen of microorganism
- series of reaction
- first pathway to be discovered
CLASSICAL PATHWAY
- can be activated by the **infectious agents **
- factors B, D, and properdin
- first line of pathway
ALTERNATIVE PATHWAY
- mannose-binding lectin (MBL) binds to microorganism
MB LECTIN PATHWAY
a common systemic manifestation of the inflammatory response and is a cardinal symptom of infectious disease
FEVER
main regulator of body temperature
HYPOTHALAMUS
BIOLOGIC EFFECTS OF COMPLEMENT
- The lysis of cells, such as bacteria, virus-infected cells, and tumor cells.
- cells burst
- This process occurs through the development of the membrane attack complex (MAC) (C5b, 6, 7, 8, 9), which inserts into the membrane of an organism or cell.
- The MAC creates holes in the cell membrane, which leads to loss of osmotic integrity and rupture of the microbe or cell.
CYTOLYSIS
BIOLOGIC EFFECTS OF COMPLEMENT
- directed movement of leukocytes up a gradient concentration toward the site of infection
- most important chemotactic substances is C5a
CHEMOTAXIS
BIOLOGIC EFFECTS OF COMPLEMENT
- A term used to describe how antibodies or C3b can enhance phagocytic engulfment of microbes.
- Macrophages and neutrophils have receptors for C3b and therefore can bind C3b-coated organisms. This binding trigger phagocytosis.
OPSONIZATION
BIOLOGIC EFFECTS OF COMPLEMENT
- It is a local response resulting from a damage/injury to the body’s tissues.
- The damage can be caused by microbial infection, physical agent, or chemical agent.
- promote vasodilation and increase vascular permeability
INFLAMMATION / ANAPHYLATOXINS
- a result of any injury to tissues or following the establishment and multiplication of microorganisms. It is the protective local response to injury
INFLAMMATORY RESPONSE
Activation of the ____ leads to the release of
cytokines like interleukin-1 (IL-1) and other mediators like prostaglandin and leukotriene, causing pain and inflammation
MACROPHAGES
- It is a vascular reaction whose net result is the delivery of fluid, dissolved substances, and cells from the circulating blood into the interstitial tissues in an area of injury.
INFLAMMATORY RESPONSE
- source: mast cells, basophil, platelets
- effect: Vasodilation and increased permeability of bloodvessels
HISTAMINE
- source: Blood plasma
- effect: chemotaxis
KININ
- source: Damaged cells
- effect: Intensify the effects of histamine and kinins and help phagocytes move through capillary walls
PROSTAGLANDIN
- source: Mast cell and basophil
- effect: Increase permeability of blood vessels and help attach phagocytes to pathogens
LEUOKTRIENES
- source: Blood plasma
- effect: Stimulates release of histamine, attracts phagocytes, and promotes phagocytosis
COMPLEMENT
- source: Fixed Macrophage
- effect: Vasodilation and increased permeability of blood vessels
CYTOKINES
Five Cardinal Signs of Inflammation
- Rubor (redness)
- Calor (heat)
- Tumor (swelling)
- Dolor (pain)
- LOSS OF FUNCTION (Functio laesa altered function)
during inflammation there is ____ because of dilation
HEAT
phagocytes are usually where
INSIDE THE BLOOD VESSELS
FEVER is induced by
PYROGENS
hence, anti-pyretic
- cell structure that is capable of inducing fever
- gram negative
- in the outer membrane
ENDOTOXIN
PYROGENS
fever inducing agents
CYTOKINES
ENDOTOXIN
BENEFITS OF ????
- a defense against disease
- increases T-cell proliferation and antibody
production - speeds up the body’s reactions which help the body tissues to repair themselves more quickly.
FEVER
fever activates ____
IL-1
interunit 1 (cytokine)
fever stregthen the effect of
INTEFERONS
fever increases production of ____ (decreased iron)
TRANSFERRIN
if the body temperature is ↑, the body’s reactions is
MAS MABILIS
main cause of fever
BACTERIAL INFECTION
blood vessels are ____ during fever
CONSTRICTED
tragets mainly VIRUSES
INTERFERONS
- These are proteins produced during viral infections.
- They help control viral replication by inhibiting protein synthesis in cells.
- It includes alpha interferon, beta-interferon, and gamma-interferon (produced by T-lymphocytes).
INTERFERONS
signals neighboring uninfected cells to destroy RNA & reduce protein synthesis
IFN-α
signals neigboring infected cells to undergo apoptosis
IFN-β
activates immune cells
IFN-γ