Exam 2: Lymphocytes and Co-stimulatory Receptors Flashcards
Lymphocytes involved in innate immune response
Nk cells
Lymphocytes involved in cellular immune response
T cells
Lymphocytes involved in humoral immune response
B cells
CD lymphocytes receptors for CD3 found in
T cells
CD lymphocytes receptors for CD4
Helper t cells
Receptor for MHC II
CD lymphocytes receptors for CD8
Cytotoxic T cells
Receptor for MHC I
Integrins
Heterodimeric proteins that prolong and stabilize cell itneracitons and allows successful antigen recognition
Selectins
regulate immigration of lymphocytes into tissues (P, L and E selectin)
Lymphocyte Mitogens
sitmulate lymphocytes to divide
These are molecules/receptors that can regulate the lymphocyte function:
a. Cytokines
b. Antibodies
c. Complement
d. Antigen
e. All teh above
E. all the above
CD4 and CD8 are expressed on B cells and NK cells. T/F
False
Helper T Cells Function
regulate immune response
Cytotoxic T cells Function
Destroy cells expressing endogenous antigens
Regulatory T Cells Function
Control everything
B Cells Function
produce antibodies
Immunoglobulin Superfamily Properties:
- found on all cell surfaces
- none have enzymatic activity
- many cellular responses are triggered by 2 interactions between 2 different members of the superfamily (TCR and MHC)
TCR alpha/beta most abundant in
humans, mice and most non-ruminants
TCR gamma/delta most abundant in
calves, lambs and piglets
B1 integrins (CD29/CD49)
Fibronectin, laminin, Collagen
B2 integrins (CD11/CD18)
ICAM-1
Lymphocyte Mitogens
PHA- phytohemagglutinin, LPS- lipopolysaccharide, Con A- Concanvalin A, Pokeweed, BCG- Bacille Calmette-Guerin
Complementary Determining Region
a binding groove that comes in contact with antigen on the variable domain of the TCR
What are the signal transducing proteins on the T cell?
CD3 Complex: made up of 5 protein dimers (gamma, delta, epsilon, L, N)
*protein dimers
80% of T cell CD3 complex protein sequence
alpha, beta- gamma, epsilon- delta epsilon- zeta, zeta
CD4 on TH2 cells bind to
MHC II on APC
CD8 on Tc Cells bind to
MHC I on virus infected or abnormal cells
CD4/ CD8 function to
- promote T cell responses
* link T cell to APC, to ensure an active signal between the cells
What part of the TCR-CD3 recognizes antigen and MHC?
TCR alpha
What part of the TCR- CD3 recognizes antigen?
TCR beta, gamma, delta
What part of the TCR- CD3 is the signal transducer?
CD3 gamma, delta, epsilon, zeta, nu
what part of the TCR- CD3 recognizes MHC II?
CD4
What part of the TCR-CD3 recognizes MHC I?
CD8
CD80 is found on
dendritic cells, macrophages and activated B cells
CD86 is found on
B cells
The binding of antigen to TCR stimulates T cell expression of
CD40 ligand
The CD40 ligand on the T cells stimulates expression of (blank) on the APC.
CD40
The CD40 binding CD40 stimulates expression of (blank) on T cells and (blank) on APC.
CD28/152 on T cell
CD80/86 on APC
Ligand CD 152 binding to CD 80/86 causes
T Cell suppression: production of in doleamine dioxygenase which destroy tryptophan. Absence of tryptophan –> T cells can’t respond to antigen–> T cell response is terminated
Ligand CD28 binding to CD86 causes
- eight-fold activation
* T cells IL-2: upregulate cell survival genes, increase energy metabolism, promotes T cell division
The variable domain of the TCR is explicit for binding a specific antigen. T/F
False
TCR, BCR, MHC1 and MHC2 are not members of the IG superfamily. T/F
False
If a processed and presented antigen bind in a correct manner on a T cell. T cell is activated and initiates the immune response by: A.cytokine production B. Mitosis C. Cell differentiation D. All the above
D. All the above
CD3 is found in all T Cells and it has a main role in the signal transduction into the T cell. T/F
True
