What are the 4 functions of the immune system?
- 1. Dectecting pathogen invasion
- 2. Initial innate immune response
- 3. Inflammatory response
- 4. Activate the adaptive immune response (T,B cells)
What are two types of microorganism in the human body and state their purpose.
- 1. Commensal: live with us, do not cause disease.Enhancehuman nutrition by processing digested food and making several vitamins. Protect us from disease
- 2. Pathogen: Invade or produce toxins, which damage host tissue and cause disease
Name 4 examples of pathogens that cause human disease.
- parasites (protozoans and worms)
What are the common pathogen's routes of infection?
- Pathogens will invade through all parts of the body where it is open to the outside world.
- Skin: cuts or insect bites
- Gastrointestinal tract: fecal-oral transmission
- Respiratory tract: aerosal transmission
- Urogenital tract: sexual transmission
- Mucosal System: surface lined with mucus secreting epithelial cells in organ systems that open to the environment.
Name 2 sites of pathogen replication.
- Extracellular infection: mucosal surfaces tissues interstitial
- Intracellular Infection: cell cytoplasm, endosomal vesicles, or nucleus
When there is an infection in the interstitial spaces, blood, or lymph what organism are the pathogens and what are the protective immunity?
- a. Viruses
- b. Bacteria
- c. Protozoa
- d. Fungi
- e. Worms
- Protective Immunity
- a. Complement
- b. Phagocytosis
- c. Antibodies
When there is an infection in the epthelial surfaces what organism are the pathogens and what are the protective immunity?
- Pathogen: Bacteria, worms
- Protective immunity: Antimicrobial peptides (defesin), Ab (IgA)
When there is an infection in the cytoplasmic (intracellular) what organism are the pathogens and what are the protective immunity?
- Pathogens: Viruses, Bacteria, Protozoa
- Protective Immunity: NK cells, Cytotoxic T cells
When there is an infection in the vesicular (intracellular) what organism are the pathogens and what are the protective immunity?
- Pathogen: Bacteria
- Protective Immunity: T cell and NK cell depedent macrophage activation
2 Types of pathogen infections
- Acute infection
- Chronic Infection
What are the factors that affect the type of infection you get?
- Pathogen replication strategy
- Host immune response
- Pathogen immune evasion and immune suppression
When infection occurs, how do you know when you get infected?
PAMP (pathogen associated molecular pattern) is the molecule that is specific and common to the pathogen. PAMP will be recognized by a receptor called PRR (pattern recognition receptor).
When the pain is recognized, then what?
It is a quick response (innate immune response) and the response evoke is inflammation. The next step is to evoke a more powerful response called adaptive immune response (after pathogen invades) which causes T and B lymphocyte response.
What are the three tiers of the immune system?
- Anatomical and Physiological Barriers
- Innate Immunity
- Adaptive Immunity
What does the anatomical and physiological barriers provide?
- Block invasion of pathogen - skin
- Removing out (coughing) - cilliary clearance, intestine
- Secreting certain factors - low stomach pH, lysozyme in tears and saliva
- Not only forming a barrier but also prevent attachment, remove, and kill pathogens (secrete antimicrobial mechanism)
What happen if you don't have a barrier resistance?
You will die quickly cause by infections.
Describe Innate Immunity.
- It is there all the time.
- Quick response.
What are effector cells?
Eats bacteria, kill virus infected cells, attack protozoan parasites
What is complement?
It helps the effector cells by marking pathogen with molecular flags and also attack pathogens.
Describe the pathogen invasion process.
Invasion. Cell needs to figure it out (macrophage and DC through their PRR recognizes PAMP). After macrophage recognize they will produce cytokines to produce an inflmmation response. DC goes to the lymph node and give a singal to activate T cells by presenting the Ag. Which starts the adaptive immune response.
What are cytokines?
Cytokines are P factor that work with cells to trigger an innate response. Cytokines causes the vessels to dilate, increase permeability, and blood flow which causes the skin to warm and redden (inflammation).
What happens when cytokines causes local dilation of blood capillaries?
When there is a vasodilation there will be gaps between the cells of the endothelium (thin layer of specialized epithelium that lines the interior of blood vessels). This makes the endothelium permeable and increases the leakage of blood plasma into the connective tissue. And lead to edema.
What is the adapative immune response?
- When it recognize specific Ab, B cell will make antibodies and T cell will differientiate different cells (helper, cytotoxic, and regulatory).
- Development of memory immune reponse so that nect time you are infected with the same pathogen the response is faster and more effective.
What are lymphocytes?
WBC that helps the innate immune response slow the the spread of infection.
What do PAMP have to help PRR recognize it?
- Surface components
- Nucleic acid
- Metabolic and replication products
What is the site of infection for B cells called?