Introduction to Immunology Flashcards
What are the two major branches of the immune system?
Innate and Adaptive
What are the main features of the innate response?
It is the first responder and is a physical and chemical system. It is capable of rapid responses and is destructive and has no memory.
What are the main features of the adaptive response?
It can recognize antigens and has a specific memory of them. It can also distinguish with high precision between self and foreign.
What is the initial barrier to infection?
Skin and mucosa
What can skin make as a response to breach to mitigate the effect of infection?
Defensins, which are antimicrobial peptides
What are the innate defense strategies used by mucosa?
They range from mucus that can trap invaders, constantly beating cilia that eject particles from the lung to very low pH in gastric secretions, the vagina and urine.
How do innate immune cells detect danger?
They do so by sensing molecular patterns unique to microbes or damaged cells.
What are the molecular patterns that are recognized by innate immune cells called?
Pathogen-associated molecular patterns (PAMPs)
Damage -associated molecular patterns (DAMPs)
What receptors are used to detect the PAMPs and DAMPs?
TOLL Like Receptors (TLR)
What is activated as the PAMPs and DAMPs bind to the TLRs?
Phagocytic and killing mechanisms of the cell
What are the two pathways that innate immunity uses to deal with danger detection?
- Circulating proteins
- Immune effector cells
What is the role of leukocytes in innate immunity?
They are characterized by the ability to respond rapidly and in large numbers.
What about leukocytes allows them to perform their function and why may this be harmful to the host?
Their cytoplasm contains granules that are loaded with killer/hydrolytic/oxidizing molecules that are released in response to a perceived threat. The released chemicals cannot discriminate between tissues and pathogens.
What is used as the method of communication between the innate and the adaptive systems?
Cytokines (two chain polypeptides encoded by different genes and their polymorphism allows for variety in communication)
What is a common antigen that is recognized by the innate system?
Mannose
What is the relationship between the innate and the adaptive immune system?
The innate system defends the host while the adaptive response prepares its defense.
What is the main cell of the adaptive system?
Lymphocyte.
What are some of the properties of the lymphocytes?
- Has specific antigen receptors
- Communicates with other cells by cytokines and receptors
What are the two types of lymphocytes?
B Cells
T Cells
What is the function of B cells?
B cells differentiate into plasma cells that can produce highly specific antibodies that bind to pathogens and can destroy them by several mechanisms
What is the function of T cells?
T cells that have helper and killer functions. These cells also regulate the immune response by controlling cytokine production
Which of the immune systems is faster?
Innate
Which of the immune systems is more specific?
Adaptive
Which of the immune systems has memory?
Adaptive
What is the ON switch for the activation of an innate response?
Activation of the TLR
What is the most common leukocyte in the blood?
Neutrophils
What is the function of eosinophils?
They are closely related to neutrophils but have specialized granules that were originally developed to drill holes in large parasites like worms.
Over time they have become pathologic mediators of several types of allergic reactions.
What is the function of the basophils and mast cells?
Basophils and Mast cells are the least common leukocytes found in peripheral blood.
These cells can act as antigen presenting cells and also have specialized granules and receptors that are important in specialized antibody reactions and parasite defense.
What is the function of the monocyte and macrophage?
Eating and breaking down of of foreign cells
What is the function of dendritic cells?
They are the sentinel cells of the immune system and the critical cell that activates the adaptive system.
What is the function of natural killer cells?
Natural Killer Cells (NK) are large granular lymphocytes that most likely developed in response to the debut of viruses in the scheme of things.
Although they contain granules, they are usually called lymphocytes, not granulocytes.
