Lecture Quiz 9 Terms to Know

what is the source of antibodies

cells of the b cell lineage

how many kinds of IgG molecule does each B cell produce

1

what do antibodies and BCRs that are produced by the same B cell have

the same ABSs

what do all descendants of a B cell produce

molecules with the same ABSs

how many total B cells are in a human adult

570 billion

how many B cells are in circulation in an adult human

10 billion

where does maturation into mature antigenetically committed B cells occur

the bone marrow

what happens to mature B cells in peripheral lymphoid tissue

antigen-dependent proliferation and differentiation into plasma and memory cells

what kind of Ig complex is typically embedded in the cytoplasmic membrane of a B cell

IgD

what is the structure of a B-cell receptor (BCR)

CD79 heterodimer is noncovalently bound to Ig complex

what is sufficient for signaling to CD79

binding of antigen to two BCRs via conformational change

give the function of CD79

signaling cytoplasmic proteins, ultimately resulting in multiple responses by the B cell

give 3 types of b cell responses

proliferation, differentiation of daughter cells into plasma cells, increased Ab production

what is a difference between TCRs and BCRs

TCRs have only one ABS

what is the structure of CD79

transmembrane protein consisting of alpha and beta subunits forming a heterodimer

what does ADCP stand for

antibody dependent cellular phagocytosis

what is one function of antibodies

serving as adaptors for physical contact between a virtually infinite number of antigens and a limited number of phagocyte receptors

what are FcRs

cell surface proteins on phagocytes that bind to antibodies

what connects to make a handle shape

Fc regions

what happens when FcR binds to both Fc regions

signal transduction is initiated in host cell

what is RTS,S/AS01

the first functional malaria vaccine, presented in October 2021

what is the name of the WHO endorsed malaria vaccine presented in 2023

R21/Matrix -M

who co-developed R21/Matrix-M

University of Oxford and Serum Institute of India

what was the first nation to deploy R21/Matrix-M, and when

Ivory Coast in July 2024

what is the only lineage with an adaptive immune response

vertabrates

what is the lag phase of the primary response

5 days

what is the lag phase of the secondary response

1-2 days

what is the predominant Ig in the primary response

IgM

what is the predominant Ig in secondary and subsequent responses

IgG

does the primary or secondary response have lower sensitivity to the antigen

primary

which response has a stronger increase in IgG

secondary and subsequent

what does an effective vaccine present

an antigen of a pathogen which induces the primary response

what do “booster shots” do

induce secondary and subsequent responses

what does having more Ig molecules mean

faster recognition, faster response, lower likelihood of evasion by pathogen

what are 2 ideal outcomes of any vaccination

selective proliferation of B cells that produce the right Ig molecules and increase in serum Ig molecules that target the antigen

what is the full name of HSPG

heparan sulfate proteoglycan

what is the structure of HSPG

one core protein covalently bound to any of several linear glycans, including heparan sulfate

where are HSPGs present

transmembranal or found in the ECM of all animal tissues

what connects the ECM to the cytoskeleton

transmembranal syndecans

give 3 functions of syndecans

mediate cell binding, cell signaling, and cytoskeletal organization

what is heparan sulfate composed of

50 to 200 linear disaccharide units of GLCE and NAG

what is the full name of NAG

N-acetylglucosamine

what is the full name of GLCE

glucuronic acid

what is the full name of PfCSP

plasmodium falciparum circumsporozoite protein

what is CSP

a membranal protein that contributes to the ability of plasmodium to bind to human hepatocytes

what is required for successful invasion

successful binding

what is present in the TSR domain of CSP from all five infectious species of plasmodium

the CSVTCG amino acid sequence

what does PfCSP bind to

HSPGs on host hepatocytes

what does CSVTCG do as the first act of entry into human cells

binds noncovalently to heparan sulfate of HSPG on target human cells

when is TSR covered and cannot make contact with HSPG

in the collapsed configuration, non invasive

what is the structure of the open configuration of CSP

TSR is exposed and can bind to HSPG, invasive

what is Hepatitis B surface antigen (HBsAg)

a protein that is naturally present in the envelope of the Hepatitis B virus

what can HBsAg self assemble into

spherical virus like particles about 22nm in diameter

what does VLP stand for

virus like particle

what can be used as presentation platforms for antigens of our choosing

VLPs

how do we use PfCSP as an antigen

we build VLPs that are made of HBsAg covalently attached to the C-terminal of plasmodium CSP

what triggers the primary response against CSP

R21 VLPs in solution, administered as a vaccine

how effective is R21

77% effective over 12 months

what is neutralization

the binding of specific antibodies to antigens, thereby preventing them from attaching to target cells

what do malaria vaccine induced antibodies bind to

the TRS domain of CSP

what happens when plasmodium sporozoites cannot invade hepatocytes

neutrophils arrive and phagocytose sporozoites via ADCP