Immunology Flashcards
Immune complex
Aka Antibody antigen complex. Each antibody molecule can bind to to antigen particles. This clumping of antigens which facilitates the recognition and destruction by the immune system.
What is the cellular signaling pathway for degranulation of antibody tagged pathogens
Calcium channels open and calcium entry is a signal for exocytosis. This is similar to the release of vesicle contents in an endocrine cell.
What is antibody-dependent cell-mediated cytotoxicity
When NK cells degranulate and destroy antibody tagged pathogens
What are 5 key anti body functions
- Inactivate bacterial toxins
- Act as opsonins
- Trigger degranulation of immune cells
- Activate compliment proteins
- Activate B lymphocytes
How does an antibody acting as a opsonin help destroy a pathogen
It tags the immune complex for destruction. When bacteria aren’t recognized by phagocytes the bacteria is coated with the antibody.The receptor binds to the stem of the antibody and phagocytosis is triggered for the entire immune complex.
In regard to anti bodies, Adaptive immunity is subdivided in to what 2 categories
Passive immunity and active immunity
What do activated T lymphocytes develop into
- Cytotoxic T cells (Tc)
- Helper T (Th)cells
- Regulatory T (Tregs) cells
What kind of receptor do T lymphocytes have
T cell receptors. They can only bind to antigen that is displayed on MHC proteins on a target cell.
What can B cell receptors bind to
Antigen that is free floating in the extracellular fluid
What is humoral immunity
The soluble antibodies of the plasma
What do regulatory T cells do
They do not directly attack pathogens and infected cells. They bind to MHC 2 Complexes. Their activation suppresses immune cell function to help prevent excessive immune responses.
What is the body’s integrated immune response
The innate response starts 1st and it is reinforced by the more specific adaptive response
Define immunity
The body’s ability to protect itself
3 major functions of the immune system
- Try to recognize and remove abnormal “self” cells created when normal cell growth and development go wrong
- Removes dead or damaged cells
- Protects the body from disease causing pathogens
3 categories of immune pathologies
- Incorrect response
- Overactive response
- Lack of response
Incorrect response pathology
Mechanism for distinguishing self from non self fail and immune system attacks the body’s normal cells
Over active response pathology
Condition in which the immune system creates a response that is out of proportion to the threat posed by antigen, hypersensitivity reaction
The lack of response pathology
Immuno deficiency diseases, Some component of immune system fails to work. Inherited, acquired through virus infection, drug or radiation.
2 types of infections common in the US
Bacterial or viral
Pathogens common in other parts of the world
Parasites, prions, protists
List structure, living conditions, reproduction, and susceptibility to drugs of bacteria
- True cells have, no organelles usually surrounded by cell wall, some have additional capsule
- Most can survive and exist outside host
- With the right nutrients temperature and ph they can survive and reproduce outside host
- Most can be killed by antibiotics. Plasmid are capable of transferring genetic information to become antibiotic resistant
List structure, living conditions, reproduction, and susceptibility to drugs of virus
- Not cells, nucleic acid said core enclosed in protein capsid, some have external envelope
- Parasitic, must have a host cell to reproduce
- Must use intracellular machinery of host to replicate, spreads by rupturing and spreads to others
- Can only be treated with antivirals to target specific stages of viral replication
What are the 2 categories of human immune response
Innate immunity and adaptive immunity
What is innate immunity
Present from birth, Bodies in media immune response, Non specific to any pathogen, Begins within minutes to hours, The immune response to pathogen is not remembered and is triggered anew with each exposure
What is stop adaptive immunity
It is directed at particular invaders and his body’s specific immune response, Can take days to weeks, With re exposure memory cells remember and react quicker. Consist of antibody mediated and cell mediated immunity
What is antibody mediated immunity
It is also known as humoral immunity. It uses antibody protein secreted by immune cells to carry out immune response. Immune cells find to foreign substances and make more visible or disable them.
What is cell mediated immunity
It requires contact dependent signaling between immune cell and receptors on its target cell
What are the lymphoid tissues of the body
Thymus gland, bone marrow, spleen, lymph nodes, tonsils, cells in skin, MALT, and GALT
Which lymport tissue primary monitor the blood for pathogens
Spleen and lymph nodes
What is MALT
Mucosa associated lymphoid tissues
What is GALT
Gut associated lymphoid tissues
What are granulocytes
Cells with prominent granules in cytoplasm. They release granule contents by exocytosis. They include basophils, eosinophils, and neutrophils
What are phagocytes
They ingest materials from the antigen-presenting cells and from the ECF by phagocytosis. This is a receptor mediated event. They include neutrophils, macrophages and dendritic cells.
Cytotoxic cells
Contact killers. They include T lymphocytes and eosinophils
Antigen presenting cells (APCs)
They have the ability to display bits of antigen on their surface as a signal to the other immune cells. These include macrophages, dendritic cells, and B cells
Basophils
1%–>Rare in circulation. Develop in bone marrow and mature in tissues. They are usually in the blood and mast cells in tissue. They migrate and accumulate to inflammation sites where they can leave blood vessels and enter tissue space. They release histamine, serotonin and and heparin. Increased affinity receptors for IgE. Part of innate immune response. Live for less than 2 weeks. Long lived mast cells.
Eosinophils
1-4%, Few found in peripheral circulation. Most functioning found in digestive tract, lungs, urinary genital epithelial and connective tissue of skin. They attach to large antibody coated parasites and release substance from their granules damaging and killing them. Participate in allergic reactions really seem toxic enzymes and oxidate of substances. Live 8 to 18 hours in blood and 2 to 14 days in tissue.
Neutrophils
50-70%, Most abundant. Imature cells are found in circulation and live 1 to 2 days. They are attracted to extravascular site of damage or inflection. They ingest bacteria in foreign particles and release said cytokines like pyrgens, inflammatory chemical mediators. Kill 5 to 20 bacteria in lifespan
Macrophages and monocytes
Monocytes are the precursor cells of tissue macrophages. 2-8%. Spend 8 hours in transit from bone marrow to perminent tissue site. Is lost once and tissue they and large and to Fargo citic macrophages and scavenge tissues patrolling by amoebic motion or sedentary. They remove large particle such as red blood cells and dead neutrophil. Ingest 100 bacteria in Lifespan.
How do macrophages participate as APCs
They are APC’s. They are the 1st white blood cells to identify a bacterium as pathogen and ingest them via phagocytosis. They digest them and display bits of digested pathogen on their cell surface to attract cells in the adaptive immune response
Lymphocytes
20 to 40% in circulation. The body contains a trillion lymphocytes at any one time. Most are found in circulation. They are the primary effector cell for antigens specific responses of adaptive immunity. The 3 subtypes are T cells, B cells, and natural killer cells.
What are dendritic cells
They are relatives of macrophages with long thin processes that resemble dendrites of neurons. They are located in the skin, nose, lungs, stomach and intestines.
What 3 things do dendritic cells do
- At like amoebas and take bacteria to lymph system
- Fact does messengers between innate and adaptive immune systems
- They are an APC and they can stimulate naive T cells
What are 3 examples of physical barriers against foreign invaders
Skin, Mucosa, Mucus
Describe how the skin is a physical barrier against foreign invaders
It is the 1st line of defense. It is dry, salty, multi layer that sloughs off. It has tight junctions, fatty acids on skin, phagocytes called Langerhan cells
How are mucous membrane 1st line of defense against foreign invaders
They trap bacteria and viruses from and entering their tight junctions and they have phagocytes called M cells in the membranes
How does me this form a physical barrier against foreign invaders
They are sticky, have lysosomes, enzymes that breakdown bacteria
What are PAMPs
Pathogen associated molecular patterns. They are part of the innate immune response. Some immune cells recognize classes of molecules that are unique to microorganisms. They bind to leukocyte PRRs
What are PRRs
Pattern recognition receptor. PAMPs bind to leukocyte PRRs and activate responses that attempt to kill or ingest the invader
What are chemotaxins
Chemical signal molecules that attract leucocytes to help fight infection. They’re sent out at areas of invasion. They include bacterial toxins or cell well components that act as PAMPs
What are 2 primary phagocytic immune cells responsible for defense
Tissue macrophages and neutrophils
What is pus
Thick whitish to greenish substance with living and dead neutrophil and macrophages, tissue fluid, cell debris, and other remnants
Opsonin
Molecules that coat foreign particles to make them visible like food for phagocytic leukocytes
Examples of opsonins
Acute phase proteins, complement proteins, Creative proteins
What feature allows some bacteria to hide from phagocytes
Some pathogens lack markers that react with pattern recognizing receptors. Bacteria have evolved a polysaccharide capsule that masks their surface markers from their host immune system. They are not recognized and grow unchecked.
How does your immune system deal with bacteria that hide.
Once recognized they make antibodies against them
How do natural killer cells recognize and destroy pathogens
They are programmed to recognize virus infected cells and induced them to commit suicide by apoptosis before they can replicate.
Some viruses invade by blocking MHC protein synthesis on host cell. How do NK cells get rid of these pathogens
NK cells don’t need MHC markers they look for low levels of MHC-1 and destroy those pathogens
What are the effects of interferons
Interferons are cytokines that inhibit viral replication and modulate immune response. They change the chemistry of nearby cells to protect them and promote synthesis of antiviral proteins
What are the primary phagocytes of innate immune response
Neutrophils and macrophages
What are the primary APC’s for adaptive immune response
Macrophages and dendritic cells
What are the 3 roles inflammation has in fighting infection
Attracting immune cells and chemical mediators to the site, Producing a physical barrier to retard the spread of infection, Promoting tissue repair once infection is under control
What cells initiate the inflammatory response
Mast cells and basophils degranulation releases histamines
What chemical messengers or cytokines are involved in the inflammatory response
Histamines, bradykin, prostaglandins, leukotrines, integrins, C reactive protein , complement proteins, antiproteases
What do basophils and mast cells release
Histamines
What is the response created by histamine action
Attraction of leucocytes to the injury site to kill bacteria and remove cellular debris. This is done by the dilation of blood vessels which increases blood flow and by opening pores of capillaries. This makes capillaries more leaky and allows plasma proteins to escape into ISF, Pulling water with them and causing edema.
What are the hallmarks of inflammation
Red, hot, and swelling around wound or infection site and pain
Interleukins
Cytokines secreted by leukocytes to act primarily on other leukocytes.
What is IL-1
Interleukin 1. It is secreted by macrophages and modulates and innate immune response. It brings about and an inflammatory response and induced fever. It causes the appearance of intergins on the surface of endothelial cells. They fish for neutrophils allowing cells to leave blood and enter tissues. This increases acute phase proteins, C reactive protein, antiproteases. It causes other cells to release cytokines and convert lignin to bradykinin and activates complement cascade.