60 Questions
Which immunoglobulin subclass is primarily made in the primary immune response?
IgM
What type of immune response determines the production of IgA, IgE, and IgG subclasses?
Secondary immune response
What is the main function of T cell receptors (TCRs) when recognizing antigens?
Recognize linear arrays of amino acids
Which term refers to the specific sites on antigens that antibodies or T cell receptors bind to?
Paratopes
How are antigens presented to T cells for recognition?
Via linear arrays of amino acids
What is the root of the term 'polyclonal' in the context of antibodies?
Antibodies from multiple B cell clones
What structural similarities do the BCR and TCR have?
Both involve repeating units of structural domains known as immunoglobulin folds
What distinguishes the BCR from the TCR in terms of solubility?
TCR is always cell-associated, while BCR can be soluble (antibody)
Why do complex antigens like pathogens give rise to polyclonal responses?
Complex antigens have many epitopes, eliciting responses from multiple B cell clones
Where does the antigen recognition reside in BCR and TCR?
In the variable regions
What aspect of the BCR and TCR structure differs between them?
The number of antigen binding sites but not constant regions differ
What percentage of circulating T cells are γδ T cells?
1-5%
Which of the following is NOT a major site for γδ T cells?
Bone marrow
How does the antigen recognition by γδ T cells differ from that of αβ T cells?
γδ T cells recognize antigen presented in CD1, while αβ T cells recognize antigen presented in MHC.
What is the function of γδ T cells?
Their function is still not clear, according to the text.
Which of the following statements about the TCR genes of γδ T cells is true?
The γ and δ TCR genes are less diverse than those of α and β.
What is the primary function of the CD3 complex in the T cell receptor complex?
To provide signaling capability for the T cell receptor
Which of the following statements about the structure of the CD3 complex is correct?
The γε and εδ dimers have extracellular immunoglobulin-like folds and one ITAM each
What is the primary function of the coreceptors (CD4 and CD8) in the T cell receptor complex?
To determine the specificity of the T cell for MHC class I or class II molecules
Which of the following statements about T cell antigen recognition is correct?
T cells recognize and respond to foreign peptide antigens only when presented by MHC molecules
What is the role of the randomly generated TCR variants in T cells?
To enable each T cell to recognize a diverse range of peptide antigens
Which of the following statements about the T cell receptor (TCR) is correct?
The αβ TCR on T cells can recognize antigens presented by the major histocompatibility complex (MHC).
Which of the following statements accurately describes superantigens?
Superantigens can activate T cells independently of antigen specificity.
In the context of pathogen invasion, which of the following statements is true?
Pathogens carry multiple antigens, each with several epitopes, resulting in a polyclonal immune response.
Which of the following statements accurately describes the γδ T cell receptor (TCR)?
The γδ TCR recognizes antigens (often lipids) presented by CD1 molecules.
In the context of antigen recognition, which of the following statements is correct?
The BCR can recognize antigens in their native form, without the need for processing or presentation.
Which of the following antigens on a virus or bacterium could potentially be recognized by the T cell receptor (TCR)?
All of the above antigens could potentially be recognized by the TCR, provided they are processed and presented by the MHC.
An immunogen is a substance that can stimulate the immune system to produce an immune response.
True
Antigen receptors are specific proteins found on antigen-presenting cells, B cells, and T cells.
False
The main function of B cell receptors is to directly kill invading pathogens.
False
The term 'immune memory' refers to the ability of the immune system to respond more quickly and effectively upon a second encounter with a pathogen.
True
The T cell receptor and B cell receptor have identical structures due to their similar functions.
False
Antigen presenting cells play a crucial role in activating T cells by presenting antigens to them.
True
The epitope recognized by the TCR includes only amino acids from the presented peptide and not from the MHC.
False
Superantigens are processed by antigen-presenting cells before binding to TCRs.
False
CD4 and CD8 are not involved in ensuring the stability of the immunological synapse formed by TCR binding to peptide/MHC complex.
False
T cell activation is initiated by the interaction of variable regions of TCR αβ chains with the MHC only.
False
Superantigens are effective at high concentrations in activating T-helper cell populations.
False
Non-classical T cell activation involves superantigens that bind to polymorphic sequences of MHCII β-chain.
False
γδ T cells account for the majority of circulating T cells.
False
γδ T cells recognize antigens using the same proteins as αβ T cells.
False
γδ T cells primarily recognize antigens presented in MHC, similar to αβ T cells.
False
The genes for the γδ TCR are more diverse than those for the αβ TCR.
False
γδ T cells are mainly found in epithelial-rich tissues like mucosa.
True
Immunogens are a subset of antigens.
True
Haptens can elicit an immune response on their own.
False
Soluble antigens cannot enter the body through breaks in the skin or mucous membranes.
False
Adjuvants decrease the effectiveness of dendritic cells and macrophages.
False
Benzene is an example of a complex antigen.
False
Pattern Recognition Receptors are a type of adaptive antigen receptor.
False
NK cells use killer activatory immunoreceptors (KARs) for antigen recognition.
True
B cells recognize the 3D conformation of antigens via the T cell receptor (TCR).
False
Alum is an example of an adjuvant used in vaccination.
True
Epitopes are parts of antigens that bind to specific receptors on lymphocytes.
True
The αβ TCR on T cells can recognize antigens even when not presented by the MHC.
False
Superantigens made by pathogens activate T cells dependent on antigen specificity.
False
Polymorphic responses result in the expansion of many clones of B and T cells recognizing the same antigen.
False
The gd TCR primarily recognizes proteins presented in CD1.
False
Each T cell produces a TCR with a variable region that allows binding to various antigens.
True
CD4 or CD8 are NOT included in the TCR complex.
False
Study Notes
- IgM is produced in the primary immune response, while subclasses like IgA, IgE, and IgG depend on the type of immune response.
- Antigen receptors for B cells are called B cell receptors (BCR), and for T cells, they are T cell receptors (TCR).
- T cells bind linear arrays of approximately 9 amino acids via the TCR, which are processed and presented to T cells by molecules on the surface of antigen-presenting cells.
- Monoclonal antibodies come from a single B cell clone and recognize a single epitope, while polyclonal antibodies come from multiple B cell clones and can recognize a range of epitopes.
- The structure of BCR and TCR both involve repeating units of immunoglobulin folds with constant and variable regions, but they differ in the number of regions and antigen binding sites.
- Complex antigens like pathogens elicit a polyclonal response, activating different T and/or B cell clones in the adaptive immune response.
- TCRs on T cells can only recognize antigens when presented by Major Histocompatibility Complex Molecules (MHC), requiring accessory cells for T cell activation.
Test your knowledge on immunoglobulin subclasses and T cell receptors in the immune response. This quiz covers topics such as the structure of T cell receptors, differences between T and B cell antigens, and superantigens.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
