what activates the classical complement pathway? alternative? mannose-binding lectin?

classical: activated by antibody (adaptive)

mannose binding lectin: activated by binding to mannose on microbial cell surfaces (innate)

alternative: spontaneous activation/hydrolysis (innate)

which event initiates the body's immune response against a pathogen?

PAMP/DAMP -> PPR interactions in primary response

what are the characteristics that distinguish innate immunity and adaptive immunity?

innate: minutes to hours, limited and fixed specificity, same each time; barriers, phagocytes, pattern recognition molecules

adaptive: days, highly diverse, adapts to improve, more rapid and effective with each subsequent exposure, T and B lymphocytes, antigen-specific receptors

which of the following cells are of myeloid origin and which are of lymphoid origin? which are generally considered to be cells of innate immune system and which are generally considered to be cells of the adaptive immune system?

macrophages: myeloid, innate

B cells: lymphoid, adaptive

dendritic cells: myeloid, innate

NK cells: lymphoid, innate

T cells: lymphoid, adaptive

basophils: myeloid, innate

neutrophils: myeloid, innate

what are the three main outcomes of complement activation?

opsonization: facilitating uptake and killing by phagocytes

inflammation: recruitment of inflammatory cells

lysis: perforation of pathogen cell membrane

in terms of memory response, how does the innate immune response change from primary to secondary response? how does the adaptive immune response change from primary to secondary response?

innate: does not change between primary and secondary response because it non-specific and does not have memory

adaptive: adapts to improve between primary and secondary response it is specific and has memory

relative to immune cell receptors, what is meant by the term 'germ-line encoded'? based on that definition, distinguish between receptors of the innate immune system and receptors of the adaptive immune system

germline encoded -> immune cell receptors are coded directly by genes in the DNA, not a product of recombination innate immune receptors are germline, but adaptive immune receptors are a product of recombination

what are the four stage of leukocyte migration/trafficking?

rolling

activation

firm adhesion

diapedesis

what are the three signals involved in the three-signal hypothesis? identify the molecules involved in each signal

signal 1: MHC II/antigen presenting cell which binds with TCR on CD4+ T cell

signal 2: CD80/86 (B7) is an antigen presenting cell which binds with CD28 on CD4+ T cell

signal 3: cytokine on antigen presenting cell which binds to cytokine receptor on CD4+ T cell

list and briefly describe six effector function of antibodies?

neutralization

ADCC

degranulation

agglutination

opsonization

complement activation

define the term epitope. what is the difference between a sequential epitope and a conformational epitope?

epitope: the region of an antigen that is what the antibody recognizes and binds to (antigenic determinant) - immunodominant: bring stronger immune response

a sequential epitope is amino acids the antigen are sequential in terms of linear structure where as conformational epitopes are amino acids that are far apart and brought together during protein folding

for MHC class I and MHC class II list (a) the type of antigen each presents and (b) the cell type that each presents TO

MHC class I presents endogenous antigens to cytotoxic T cells (CD8+), all nucleated cells

MHC class II presents exogenous antigen to helper T cells (CD4+), APCs

how would you define a inflammatory cytokine? an anti-inflammatory cytokine? what are some general examples of each type?

pro-inflammatory: signaling molecules that induce and regulate inflammation (IL-1, IL-6, TNFa, chemokines)

anti-inflammatory: signaling molecules that reduce and stop inflammation (IL-10, TGF-B)

what are the three major types of cells that are 'helped' by helper T cells?

macrophages, cytotoxic T cells, and B cells

commonalities: cell-cell, CD40L on T cell, CD40 on other cell

secretes cytokines

what is a checkpoint inhibitor? what is the important T cell molecule involved in checkpoint inhibition?

checkpoint inhibitor: immunotherapy drug that blocks proteins on immune cells to release the natural "brakes" which allows it to attack cancer cells

important T cell molecules: PD-1

what is meant by the term 'MHC restriction'

the T cell CANNOT recognize antigen that is NOT presented by MHC or put another; only MHC-bound antigen will be recognized by the T cell

B cells not MHC restricted

what is the function of the RAG 1/2 complex?

recombination activating gene (complex)

picks and recombines assemble various gene segments into a segment of DNA that can be expressed

regulate VDJ recombination

list and briefly describe the four types of B cell receptor diversification. which types occur during development? what type occurs after activation?

somatic recombination: random VDJ pairing, during development

combinatorial diversity: the randomness of heavy and light chain pairing, during development

junctional diversity: hairpin overhangs generated by Artemis, leads to new sequence, during development

somatic hypermutation: after activation

briefly distinguish between monoclonal and polyclonal antibodies?

monoclonal: antibodies recognize a single epitope on a single antigen

polyclonal: antibodies recognize multiple epitopes on the same antigen

antibody

what is meant by the term 'allelic exclusion'?

once a successful in frame heavy chain (and light) rearrangement has been made, rearrangement at the other heavy chain locus stops and that allele is no longer expressed