Exam 1 - Cellular Immunology Flashcards
Name the two molecules that recognize antigens.
1) B lymphocytes (antibodies)
2) TCR
What does TCR stand for?
T Cell Receptor
What does activation of a TCR produce?
Immune Response
T/F: TCR recognizes antigen.
TRUE
An immune response causes development of CD_+ and CD_+ cells from the precursor T cells.
CD4+
CD8+
T/F: For a B cell to recognize and antigen, it does need to be processed.
FALSE
-For a B cell to recognize an antigen, it does NOT need to be processed and does not require any other molecules
T/F: For T cells, the antigen needs to be taken up by antigen-presenting cells.
TRUE
-Breaks it down; fragment is shown to TCR in presence of 3rd molecule - MHC
Name the two TCR groups.
1) TCR1 (gamma, delta)
2) TCR2 (alpha, beta)
T/F: More than 95% of the TCR are TCR1.
FALSE
-More than 95% of the TCR are TCR2
What type of precursor cells do both TCR groups arise from?
Hematopoietic precursor cells
How do TCR1 and TCR2 differ in terms of antigens?
- Types of antigen recognized
- Mode of antigen presentation
- Recognition and signal transduction pathways
T/F: TCR1 recognizes unprocessed antigen.
TRUE
Which TCR group is a heterodimer with a molecular weight of 90kD and is made up of two peptide chains?
TCR2
T/F: TCR2 recognizes unprocessed antigen.
FALSE
-Recognizes only processed antigen, in context of MHC molecules
T/F: Both B and T cells are capable of recognizing antigen.
TRUE
In antigen recognition for T cells, what needs to happen first?
Antigens need to be taken up by ANTIGEN PRESENTING CELLS
T/F: Antigens are not recognized by T cells in their native conformation.
TRUE
Which type of cells recognize antigens in their native conformation?
B cells
T/F: After uptake by an antigen presenting cell, antigen is degraded and a large piece is presented to T cells.
FALSE
-After uptake by an APC, antigen is degraded and a SMALL piece is presented to T cells
What other, third molecule, is required for antigen recognition by T cells?
MHC
Name the co-stimulatory molecules in antigen recognition.
CD28
CD80/86
When MHC, TCR, and CD molecules are present, this interaction is called?
Tripartide Interaction
What does a naive T cell proliferate into (2)?
TH1
TH2
What is the term for a lack of production of immune response?
Anergy
What molecule is needed for the activation of CD4+ in order to avoid anergy?
CD28 molecule
Where does the downstream signal transduction emanate in T cell activation?
TCR and CD28
What provides the first signal in T cell activation?
Binding of TCR to the antigenic fragment with MHC molecules on the APC
