Introduction To Immunity And Inflammation Flashcards
Three R’s of the immune system
- recognize
- respond
- remember
Foreign proteins that stimulate an immune response
Antigen (Ag)
An antigen that is very antigenic
Immunogen
-robust antibody genesis
Immune-reactive protein made in response to exposure to foreign Ag
Antibody (Ab)
Magic bullets that locate and attach to target
Disease-causing microorganism
Pathogen
What percentage of micro organisms are pathogenic?
Les than 10%
What are the two types of lymphocytes
B-cells
T cells
Plasma cells that make antibodies specific to each Ag
B-cells
Termed Ab-mediated immunity
B cells
What are the two types of T cells
- cytotoxic lymphocytes ((Tc/CD-8)
- T-helper lymphocytes (Th/CD-4)
Attack infected/mutant/foreign cells
Cytotoxic lymphocytes (Tc/CD-8)
Regulate immune response, traffic cop
T helper lymphocytes (Tc/CD4)
AIDs attacks these cells
T helper cells
How do you gauge the damage done by AIDS
CD4 count
Cells that kill and eat
Phagocytes
What are the two main phagocytes
Macrophages and neutrophils
Cell that ingests pathogens and cellular debris and presents antigens to Th-cells
Macrophages
Ingests pathogens and cellular debris, but do not present antigens to Th cells
Neutrophils
What is the main difference between macrophages and neutrophils
Macrophages present antigens to the Th-cells
Neutrophils do not present antigens to the Th-cells
What activates specific immunity?
Phagocytes
Where do T cells mature?
Thymus
Where do all blood cells develop?
Bone marrow
Where does B cells mature?
Bone marrow
What is the 1st line of defense of the immune system
Non-specific, barriers
-skin, mucus, HCL
What is the second line of defense in the immune system
Non-specific-cellular
- phagocytosis
- inflammation
- complement
- fever
What is the 3rd line of defense for the immune system
Specific - immunity
- antibodies
- B cells
- T cells
- directed by cytokines (messengers)
- phagocytosis
- compliment
What two things are both involved with innate and adaptive (non specific and specific) immunity?
Phagocytosis and complement
What is considered innate immunity
1st line and second line of defense
What is considered adaptive immunity
3rd line
What are the two basic types of immunity
Innate and adaptive
Innate immunity
- natural resistance with which a person is born
- non-specific
- non-inducible
- no memory produced
- acts early in immune response
What type of immunity is always on
Innate
Adaptive (acquired) immunity
True immunity
- responds less rapidly than innate immunity but more effectively
- specific
- inducible
- shows memory
- demonstrates self tolerance
What happens when adaptive immunity can not differentiate between self and non self?
Autoimmune disorders
What phagocyte is innate only?
Neutrophils
What phagocyte is innate and adaptive?
Macrophages
Non specific barriers (skin)
First line
Physical and chemical (oil retards, sweat/tears kill)
Non specific barriers: digestive
HCL kills, intestinal bacteria compete
First line
Non specific barriers: respiratory
Nostril hair and mucus trap potential pathogens
First line
Tears contain bacteriolysis agent called
Lysozyme
Sweat contains bacteriocidal agent called
Dermcidin
What walls offender off and allows WBCs to clean house?
Inflammation
These coat invaders to make them more appetizing for phagocytes. They have an alternate and classical pathway
Complement proteins
What pathway of the complement proteins requires antibodies?
Classical (specific)
What pathway of complement proteins does not require antibodies?
Alternate (non specific)
What are the 5 steps of inflammation?
- Initial phagocytosis
- Capillaries dilate and become more permeable
- Foreign matter contained
- More leukocytes migrate to area
- Leukocytes clear infection
Initial phagocytosis in inflammation
Macrophages and neutrophils engulf debris and foreign matter
What causes the capillaries to dilate and become more permeable in inflammation
Histamine released from mast cells
Four hallmarks of inflammation
- redness (rumor)
- heat (color)
- swelling (tumor)
- pain (dolor)
Which hallmarks of inflammation are due to histamine and which is not?
- redness (rubor)
- heat (calor)
- Swelling (tumor)
Pain (dolor) does not require histamine
What is the pain in inflammation due to?
Neural receptors stimulated by kinins
Phagocytosis in inflammation
- chemotaxis
- neutrophils arrive within 1 hour
- macrophages arrive within 10 hours
- tissue macrophages (antigen presenting cells) (tonsils, spleen, nodes)
What is another name for neutrophils
Segs or polys
What’s another name for macrophages
APCs (antigen presenting cells)
Leukocyte migration and proliferation in the inflammation process
Cytokines travel to bone marrow
Stimulate production of leukocytes
Increase WBC circulating numbers 4-5 times
How much does the WBC count circulating in the blood increase during inflammation
4-5 times
What secretes cytokines?
Phagocytes
How do phagocytes secrete cytokines?
-triggered by attachment of antigen to phagocyte
What are the secretory products of macrophages
Cytokines
What are some cytokines that are secreted by macrophages
Interleukins (ILs) & tumor necrosis factor (TNF)
What are the actions of ILs and TNF
-communication between WBCs
What is the action of ILs and TNF in bone marrow
Produce/secrete more leukocytes
What is the action of ILs and TNF in hypothalamus?
Fever (pyrogens)
-mediated though prostaglandins (pgE)
What is the action of ILs and TNF in liver
Acute phase proteins
-CRP (C relative protein, used to track fever and inflammation)
What are the local effects of TNF-a
Activates vascular endothelium and increases vascular permeability, which leads to increased entry of IgG, complement, and cells
What are the systemic effects of TNF-a
Fever, mobilization of metabolites of shock
What are the local effects of IL-6?
Lymphocytes activation, increased antibody production
What are the systemic effects of IL-6?
Fever, induces acute phase proteins from liver
What are the acute phase proteins that IL-6 induce in hepatocytes?
- C-reactive protein
- fibrinogen
What is C-reactive protein
- acute phase protein induced from hepatocytes from IL-6
- binds to bacterial surface, opsonizes bacteria and activates complement
What is fibrinogen?
- acute phase protein induced by IL-6 (in hepatocytes)
- has to do with clotting
ESR
Erythrocytes sedimentation rate
Used to determine inflammation
Used to determine if a drug is working for inflammation or not
What are the actions of complement proteins when activated?
- pokes holes in bacteria via membrane attack complex (MAC attack)
- stimulat histamine release (initiating inflammation)
- chemotaxis (scent trail for phagocytes)
- opsinization (coat pathogens to enhance phagocytosis like icing on cake)
What is the third line of immune system characterized by?
- specificity
- inducible and diversity
- memory
- self tolerant
Key players in third line immune system
- macrophages (kill and activate immune system)
- lymphocytes (B cells produce antibodies, T cells are traffic cops)
Professional phagocytes and antigen presenting cells
Macrophages
What are macrophages activated by?
Th cytokines and bacteria
What do macrophages do?
- engulf/digest bacteria (non specific response)
- present/adorn membrane with foreign antigens
What happens when the macrophage adorns/presents foreign antigens
- trigger immune response
- T and B cells check macrophage out
- cell-cell signaling via cytokines
- lottery winners proliferate
Examples of macrophages: professional antigen presenting cells (APCs)
- histiocytes
- hepatic Kuppfer cells
- Dendritic histiocytes and interdigitating reticulum cells in lymphoid organs
- langerhans cells in skin and lymph nodes
- langerhans cells in conjunctiva and cornea
What are some immunologically protected sites?
Eye and brain, don’t want inflammation here
Where is every blood cell formed?
Bone marrow
Where do T cells form?
Bone marrow
Where do T cells mature
Thymus
T helper cells/Th/CD4
Activate B cells, T-cells, and macrophages
Cytotoxic T cells/Tc/CD8
Kill ‘different’ cells (foreign virus-infected/mutant)
What do T cells do?
Regulate the immune system (Th); kill cancer cells and virus-infected cells, cause delayed hypersensitivity, and tissue rejection (Tc)
What is responsible for organ rejection?
CD8 cells
Where do B cells form and mature
Bone marrow
What do B cells do?
Produce antibodies
- mark specific Ag for destruction
- B cell makes only one Ab
What is the piece of antigen that antibodies bind to?
Epitope, antigens can have many epitope
What is the function of an antibody?
- Neutralize and agglutinate antigens
- tag/identify specific invaders for phagocytosis (opsonization)
- activate complement
- enhance NK cell activity
What is the only lymphocyte that is part of the innate immune system?
Natural killer cell
Placenta has antibody receptor for ______
IgG
FcG receptor
All antibodies do what to antigens?
Bind to and neutralize them
Between IgM and IgG, which is more specific?
IgG is very specific, IgM is least specific because it is an early response (acute)
What is the biggest antibody?
IgM
What is the only antibody that can cross the placenta?
IgG
What antigen would you look for to see if someone had an infection that happened longer ago?
IgG, since it is very specific and takes a while to get produced
What is the most common and important antibody class?
IgG
This antibody predominates in secondary immune responses and crosses the placenta
IgG
Role of IgG in antigen disposal
Activates complement
____ is the predominant antibody in primary immune responses
IgM
IgM role in antigen disposal
Activates complement
What two antibodies activate complement?
IgM and IgG
