Lecture 1 Flashcards
defense mechanisms which provide protection from infectious disease
immunity
What 2 things comprise the immune system?
cells and molecules which collectively mediate an immune response
Microbes can cause…
an immune response, with tissue injury (immunopathology)… collateral damage
What is an autoimmune response?
A pathological condition in which an immune response occurs against oneself
What are defined as substances which induce an immune response?
antigens
What three things do an antigen include?
proteins, carbohydrates, lipids, and nucleic acids
Microbes have many different _____ which can be recognized by the immune system.
antigens
What determines what an antigen responds to?
antigenic determinants, there can be multiple for one antigen
What is the smallest antigenic determinant to which an antibody can be made of?
three to six amino acids or five to six sugar residues
All large molecules are multideterminant…
have multiple epitopes
What do antibodies bind to?
Conformational antigenic deteminants which are dependent on folding of the molecule.
What do T cell receptors recognize?
linear amino acid sequences
What are Ags that can stimulate an immune response called?
immunogens
All immunogens are antigens but,
not all antigens are immunogens
What cannot create an immune response but can bind to Ab’s or TCR’s?
haptens
What is the first line of defense against infection?
innate immune system
How does the innate immune system work?
It gives rise to the acute inflammatory response. and has some specificity for microbes, but no memory
What immune system takes longer to develop?
Adaptive immune system. It is very highly specific. and remembers that it has encountered a microbe previously.
Innate immunity exists…
before infections and is poised to respond rapidly to infections.
What does innate immunity respond to?
microbes and injured cells
Does innate immunity change the way it reacts when it is exposed to the same thing over and over again?
No
What kind of antigens does innate immunity recognize?
Common antigens belonging to groups of related microbes
Does innate immunity distinguish btw fine differences in microbes?
No
What are the three main principal components of innate immunity?
- physical and chemical barriers
- phagocytic cells(neutrophils, macrophages), dendritic cells, and natural killer (NK) cells and other innate lymphoid cells
- blood proteins, including the complement system and other mediators of inflammation
Give 3 examples of cellular and chemical barriers in innate immunity.
skin, mucosal epithelia, antimicrobial molecules
Give 3 examples of blood proteins in innate immunity,
complement, acute phase proteins, cytokines, others
What type of cells respond to an innate response in innate immunity?
Phagocytes- mcarophages, neutrophils
dendritic cells
natural killer cells
innate lymphoid cells
What cellular and chemical barriers are involved in adaptive immunity?
lymphocytes in epithelia; antibodies secreted at epithelial surfaces
What blood proteins are involved in adaptive immunity?”
antibodies and cytokines
What Cells are involved in adaptive immunity?
B and T Lymphocytes
How much diversity does innate immunity have?
limited, germline encoded
HOw much diversity does adaptive immunity have?
very large; receptors are produced by somatic recombination of gene segments
What specificity does adaptive immunity have?
microbial and nonmicrobial antigens
What specificity does innate immunity have?
for molecules shared by groups of related microbes and molecules produced by damaged host cells.
The innate immune system is a
decision making stage of an immune response in addition to inflammation.
The systems work together…
cells from innate immunity are used in adaptive immune system
How do cells communicate?
Direct cell-to-cell contact.
What does cell communication involve?
cytpkines and chemokines
What are large group of small secreted proteins w diverse stuructes and functions?
cytokines
What do cytokines do?
They regulate and coordinate many activites of the cells of innate and adaptive immunity.
Each cell express a set of
specifice signaling receptors for several cytokines.
What are the functions of cytokines.
Growth and differentiation of all immune cells, activation of effector functions of lymphocytes and phagocytes
What is a large subset of structurally related cytokines?
Chemokines, they regulate cell migration and movement.
What are the two types of lymphocytes?
B cells and T cells
What is critical to the development of specific immunity?
interactions btw T and B cells, and interaction btw Tcells and antigen-presenting cells (APCs)
Where do T cells mature?
the thymus
Why do t cells mature?
stmulation by Ag, give rise to cellular immunity
Where doe B cells mature?
bone marrow.
What do B cells give rise too?
humoral immunity