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105 Cards in this Set
- Front
- Back
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During segment rearrangement random nucleotides are added to generate tremendous antigenic diversity by what enzyme?
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TdT enzyme- responsible for N nucleotide additions
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With no RAG (recombination activation gene) you'll have what?
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you'll have NO mature B and T cells. RAG is aka VDJ Recombinase
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An induced Common progenitor lymphoid cell with Notch-1, GATA-3 will produce what?
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Pro T cells in the thymus
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An induced Common Progenitor Lymphoid cell (CLP cells) with EBF, EF2A and Pax-5 will produce what?
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Pro- B cells in the bone marrow
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Immunoglobulins can become soluble factors. T or F?
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TRUE!!!! TCR can NOT.
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How does ProB differ from PreB?
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Pro B does not have a receptor and Pre B does. Pre B expresses heavy chain
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Allelic exclusion, what is it?
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one H chain allele is rearranged and expressed while the other remains unrearranged
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What expresses surface markers CD19 and CD10?
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Pro B cell
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When do you express cytoplasmic u in B cell development?
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Pre-B
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What is due to failure of B cells to mature?
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XLA
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What causes XLA to occur?
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Failure caused by a mutation/deletion in the gene for Bruton tyrosine
kinase (Btk) |
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What is involved in transduction of signals from the preBCR required for survival, differentiation and proliferation of pre-B cells?
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Btk
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An induced Common progenitor lymphoid cell with Notch-1, GATA-3 will produce what?
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Pro T cells in the thymus
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An induced Common Progenitor Lymphoid cell (CLP cells) with EBF, EF2A and Pax-5 will produce what?
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Pro- B cells in the bone marrow
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Immunoglobulins can become soluble factors. T or F?
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TRUE!!!! TCR can NOT.
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How does ProB differ from PreB?
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Pro B does not have a receptor and Pre B does. Pre B expresses heavy chain
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Allelic exclusion, what is it?
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one H chain allele is rearranged and expressed while the other remains unrearranged
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An induced Common progenitor lymphoid cell with Notch-1, GATA-3 will produce what?
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Pro T cells in the thymus
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What expresses surface markers CD19 and CD10?
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Pro B cell
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An induced Common Progenitor Lymphoid cell (CLP cells) with EBF, EF2A and Pax-5 will produce what?
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Pro- B cells in the bone marrow
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When do you express cytoplasmic u in B cell development?
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Pre-B
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Immunoglobulins can become soluble factors. T or F?
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TRUE!!!! TCR can NOT.
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How does ProB differ from PreB?
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Pro B does not have a receptor and Pre B does. Pre B expresses heavy chain
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What is due to failure of B cells to mature?
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XLA
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Allelic exclusion, what is it?
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one H chain allele is rearranged and expressed while the other remains unrearranged
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What causes XLA to occur?
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Failure caused by a mutation/deletion in the gene for Bruton tyrosine
kinase (Btk) |
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What expresses surface markers CD19 and CD10?
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Pro B cell
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What is involved in transduction of signals from the preBCR required for survival, differentiation and proliferation of pre-B cells?
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Btk
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When do you express cytoplasmic u in B cell development?
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Pre-B
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What is due to failure of B cells to mature?
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XLA
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What causes XLA to occur?
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Failure caused by a mutation/deletion in the gene for Bruton tyrosine
kinase (Btk) |
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What is involved in transduction of signals from the preBCR required for survival, differentiation and proliferation of pre-B cells?
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Btk
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A patient presents with :
recurrent bacterial infections- > low or undetectable serum Ig > reduced or absent numbers of B cells (blood and periphery); T cell numbers unaffected > absence of lymph node germinal centers > lack of plasma cells in tissues What do you suspect? |
XLA
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What is a choice of therapy for a patient with XLA?
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passive immunity via periodic injections of pooled gamma
globulin preparations. |
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What marker is specific for B cells?
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B220
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When in B cell development do you have only a Membrane IgM?
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Immature B cell
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When in B cell development do you have both Membrane IgM and IgD?
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Mature B cell
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When do you have B220lo in B cell developement?
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Pre B cell
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What is the hallmark of Pre B cells?
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cytoplasmic u
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What is the process by which developing lymphocytes that express antigen receptors specific for self antigens are eliminated, thereby contributing to the maintainence of self tolerance?
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Negative Selection
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What is a form of self-tolerance that is induced in generative lymphoid organs as a consequence of immature self-reactive lymphocytes recognizing antigens leading to their death or inactivation?
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Central tolerance
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What prevents the emergence of lymphocytes with high affinity receptors for ubiquitous self antigens that are present in the bone marrow or thymus?
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Central tolerance
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Some self-Ags induce activation of _______________genes which rearrange the L chain DNA to generate a new L chain with new specificity.
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RAG1/RAG2 genes
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What is a process by which some immature B cells that recognize self antigens in the bone marrow may be induced to change their immunoglobulin (Ig) specificities?
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Receptor Editing
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What involves reactivation of RAG genes, additional light cahin VJ recombinations, and production of a new Ig light chain?
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Receptor Editing
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What B cells are self-sustained?
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B1-B cells from Fetal Liver
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What type of B cells do you find in lymph nodes?
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Follicular B2-B cells
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What type of B cells do you find in the spleen?
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Marginal Zone B2-B cells
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What B2-B cell expresses IgM and IgD?
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Follicular B2-B cells in lymph node
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What B2-B cell expresses IgM and CD21/CR2?
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Marginal Zone B2-B cells in Spleen
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B1-B cells express what? Where do you find B1-B cells?
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IgM and CD5, find in the GUT
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What are Immunoreceptor Tyrosine-based Activation Motifs and what is their role?
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ITAMs and they are the sites for intracellular signalling
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What are the cytoplasmic chains of the TCR?
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Zeta chains
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What are a subset of developing T cells in the thymus that do not express either CD4 or CD8?
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Double negative Thymocytes, PRO-T cells!!!!!!!!!!
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Pro T cells express what?
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CD25+ (IL2) and are only expressed on activated T lymphocytes
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What are cells that express CD25+ and never turn it off?
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Treg cells (aka regulatory cells)
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What has the highest affinity for self antigens among T cells?
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Treg cells
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What is the effector function of Treg cells?
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Immunosuppression
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Once a cell becomes a Pre-T cell what does it do?
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Rearranges Beta chain
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What are a subset of developing T cells in the thymus that express both CD4 and CD8?
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Double Positive, after Pre-T cell and during this time the alpha chain is rearranged as well.
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Why can Double Positve cells bind to antigen but they can't signal?
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because low CD3. they have the receptors but can't signal yet. receptors useful for positive selection
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What is it called when developing T cells whose antigen receptors bind to self MHC are rescued from cell death but those who do not recognize self MHC undergo apoptosis?
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Positive selection
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What ensures that mature T cells are self-MHC restricted?
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Positive Selection
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What cells undergo Positive Selection?
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Double Positive cells of the developing T lymphocytes
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Where do Positive Selection take place?
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Cortex of Thymus
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What is a maturing T cell precursor in the thymus that expresses CD4 or CD8 molecules but not both?
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Single Positive Thymocyte
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Single Positive Thymocytes are found mainly where?
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in the medulla of the thymus
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What developing T cells undergo Negative Selection?
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Single Positive Thymocytes
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What developing T cell expresses CD4 or CD8 and CD3hi?
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Single Positive T cell
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What developing T cell expresses CD4, CD8 and CD3lo?
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Double Positive T cell
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Where does activation and proliferation of T cells occur?
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in the Periphery
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What will happen when TCR has low affinity for
Peptide-MHC complex? |
survival of T cell
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What is a gene expressed by thymic epithelial cells and encodes for every self antigen in your body?
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AIRE- autoimmune regulator gene
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Where do you have activation of Naive T cells and development of Effector T cells?
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lymph node
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Where do you have activation of Effector T cells and eradication of microbes?
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site of infection
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What can recognize conformational and linear epitopes?
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Immunoglobins
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What recognizes antigens presented on APC cells?
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TCRs
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What type of epitope determinant will Ig bind to determinant in both native and denatured proteins?
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Linear Epitope
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What Ig has a hydrophobic transmembrane region?
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Membrane Ig
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What has a u heavy chain C region?
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Membrane IgM
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What has a gamma heavy chain C region?
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Membrane IgG
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What antibody chain is made up of one V domain and one C domain?
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Light chain
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What antibody chain is made up of a V domain and 3-4 C domains?
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Heavy chain
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What consists of 2 layers of B-pleated sheets held together by a disulfide bridge?
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Ig domain
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Each variable region contains what?
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hypervariable regions, aka CDRs
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What hypervariable region has the greatest variability?
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CDR3s
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What contains a whole light chain attached to the V and first C domain of a heavy chain?
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Fab- portion of antibody required for antigen recognition
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What part of the Immunoglobin is responsible for most of the biologic activity and effector functions of the antibodies?
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Fc regions
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What enables Fab regions to simutaneously bind to antigen epitopes that are seperated from one another by varying distances?
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Hinge region of antibody
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Antibodies that contain different heavy chains are known as what?
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Isotypes (IgM, IgD, IgG, IgA, IgE)
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Complement binding site on what immunoglobins activates complement pathways?
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IgM and IgD
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What determines whether or not a Immunoglobin will be a Secreted IgM or Mebrane IgM?
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where you add the poly A tail.
Poly A tail added AFTER transmembrane and cytoplasmic region then Membrane IgM. added BEFORE then secreted IgM |
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Plasma cell selects from 300 variable genes, 50 diveristy genes, 4 joiner genes, and 8 constant genes. What is it forming?
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Heavy Chain. you know this because a D gene is involved.
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What happens first, VDJ joinging or D-J joining?
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D-J joining of Germinline DNA THEN VDJ joining during Rearranging DNA
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What is NOT always expressed on APC and only comes on when dendritic cell is infected or becomes exposed to pathogen?
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secondary signal (B7)
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WHat costimulatory signal is always expressed on T cell?
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CD28
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What activate a costimulator of an APC?
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Innate immune response to a microbe
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What gives TCR increased receptor diveristy?
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Tdt and VDJ recombinase (RAG genes)
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If no RAG gene then what would T and B cells be like?
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stuck in Pre-T and Pre-B phase. you'll have NO mature B and T cells
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What results in the elimination of cells that can recognize self Ags with high affinity?
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Central tolerance of B and T cells
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What is is the process whereby CD4CD8-double positive T cells become either CD4 or CD8 T cells through MHC-peptide-TCR interactions?
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Positive Selection of T lymphocytes
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What is mediated by professional APC within the thymus and involves induction of apoptosis signals in T cells possessing TCR with high affinity for self Ags.
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T cell negative selection
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What represent highly variable regions within the epitope binding domains of Ag receptors which allow for recognition of countless foreign Ags?
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CDRs
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What can be secreted or surface bound and have the capacity to flex in response to cell surface Ags?
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Antibodies
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During ____________ random nucleotides are added to generate tremendous antigenic diversity by the TdT enzyme.
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segment rearrangement
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