Immune cells and protein components
Describe the difference between an infection, disease, and pathogenesis
Infection: when a microbe invades the body and multiplies
disease: tissue damage because of infection
Pathogenesis: molecular and cellular events that cause tissue damage and disease
What causes a barrier to fail (4)
1. breach of intact skin
2. Virulence factor of microbes
3. immunosupression
4. Loss of normal flora
Where are B cells and T cells from, where do they mature
Define herd immunity
Enough people are vaccinated that it prevents the pathogen from spreading, protecting those who cannot be vaccinated
1. to protect ourselves from life threatening infections
2. To achieve herd immunity
What cells are antigen presenting cells?
macrophages, dendritic cells, sometimes B cells
What type of MHC does a CD4 cell and a CD8 cell have?
CD4 = MHC2
CD8 = MHC1
What is central tolerance
How the body checks if B cells and T cells are auto reactive or too weak. If they are then they are lysed
Active natural: getting the disease
Active induced: vaccination
Passive natural: from breast milk
Passive induced: Ab from therapy
Describe the function of memory B and T cells
To help provide a faster and stringer response if you encounter the pathogen again
Describe the process of antigen presentation
1. phagocytosis of bacteria by antigen presenting cell
2. digestion of microbial antigens
3. presentation of antigen on MHC2 to T cell
What are the four signs of inflammation
redness, pain, heat, and swelling
Describe the function of CD4 cells and CD8 cells
CD4: antigen presentation and activating the rest adaptive immune system
CD8: phagocytosis of pathogens
Define inherited vs acquired immunodeficiency
Inherited: very rare, due to genetic mutations
acquired: obtained throughout life, HIV, diabetes
Describe the 4 functions of the immune system
1. prevent or limit infection
2. identify and eliminate damaged or abnormal cells
3. prevent inadvertent damage to the host
4. prepare for future exposure to previous pathogen
Describe the functions of cytokines and chemokines
Cytokines: responsible for cell to cell communication during immune response
chemokines: draw immune cells towards sites of infection or inflammation
What forms do PRRs take on innate immune cells, what are their functions?
- Toll-like receptors: activate cell signaling
- Fc receptors: Activates phagocytosis
- Complement receptors: Activates phagocytosis
Which Ig has an active complement, does not do opsonization, does not cross the placenta, but is a natural Ab in blood
IgM
Give an example of the 4 hypersensitivities
Type 1: anaphylactic shock
type 2: blood transfusion reaction, maternal fetal incompatibility
type 3: lupus, RA, self antigen driven diseases
type 4: TB test, contact dermatitis
Describe the mechanical barriers of the skin
keratinocytes proliferate, dead skin cells shed, perspirations
Describe the components of the complement system
Amplification: C3 cleaves into C3a and C3b, C3b goes back and amplifies this process
Opsonization: complement proteins tag a pathogen for phagocytosis (C3b)
MAC formation: C5b pokes holes in pathogen membrane, leads of phagocytosis and lysis
Describe the 3 parts of inflammation initiation
1. activation: mast cells and macrophages release inflammatory mediators causing swelling, heat, and fever
2. migration: increased vascular permeability via (TNF-alpha) allowing leukocytes into the area
Fever: Systemic response to infection, hypothalamus releases prostaglandin to increase body temp
What Ig can cross the placenta
IgG
Define the 6 types of vaccines
1. Live attenuated: have not viral form of pathogen
2. Whole cell inactivated: contain the killed pathogen
3. Viral vector: contain non pathogenic virus to give host cell genetic code
4. Subunit vaccine: contain protein from the pathogen
5. Toxoid vaccines: contain inatcivated toxins from the pathogen
6. mRNA vaccine: use pathogens genetic code to make the body make pathogen proteins
quickly describe the 5 key events of B cell response
Phagocytosis: Macrophages and neutrophils phagocytize bacteria
Complement: Amplifies inflammation
T cell response: Eliminate bacteria and activate the rest of the adaptive immune system
B cell/antibody response: release antibodies