PSIO 431 Exam 2
What are the specifications for a successful T cell? - ✔️✔️1. It must not recognize self
to bind tightly to become activated
2. It must not recognize free antigen
3. Recognize antigenic peptide plus self MHC.
Explain the process of B cells receiving help from T cells. - ✔️✔️1. B cell binds to
epitope it is specific for.
2. Then endocytoses the bound molecule,and is broken down in endocytic vesicle
3. peptide fragments bind with MHC class II brought by vesicles that fuse with
endosome, and moves the complex to the surface.
4. Thf sees complex antigen+MHCII on B cell surface and binds.
5. then helps B cell with surface interactions and helper lymphokines.
Why can we not treat people with immunodeficiency with mitogens. - ✔️✔️Mitogens
are not specific and can cause T cell activation in which they release cytokines to
produce an inflammatory response.
What are the 3 possibilities for a T cell in the thymus? - ✔️✔️apoptosis, recombination,
and clonal deletion
what is cross presentation? - ✔️✔️Dendritic cells allow peptides from antigens to leak
over into it's intrinsic pathway, and is able to present them on class I and class II MHC
at the same time.
Distinguish Class I and Class II histocompatibility antigens. - ✔️✔️class 1 includes
HLA-a and HLA-b, while class 2 includes HLA-D
Describe the surface markers that are used to distinguish between T and B cells in
humans;
and between helper and cytotoxic T cells. - ✔️✔️Bcells can be distinguished by a
CD20 surface marker
Tcells can be distinguished by CD3 which is on all cells, CD4 on helper t cells and CD8
on CTL cells.
Discuss the main lymphokines made by Th1, Th2, Th17 and Treg cells, and their
biological
functions - ✔️✔️1.IFN-gamma, IL-2
2.IL-4,
3.IL-17
, 4.TGF-beta, IL-10
Define mitogen. Suggest uses for T or B cell mitogens in the clinical laboratory. -
✔️✔️a substance that induces or stimulates mitosis
Define cytokine, lymphokine, and chemokine. - ✔️✔️Cytokine- short range mediator
made by any cell that affect the behavior of same or another cell
Lymphokines- short range mediators, made by lymphocytes, affect same or another cell
Chemokines- small short range mediators, made by any cell, cause inflammation
Distinguish between the effects of a mitogen and an antigen, when added to normal
blood
lymphocytes. - ✔️✔️Mitogen will make the cells differentiate if there is no antigen, then
there will be many in circulation.
If antigen is added than the lymphocytes will be used to clear the antigen and produce
more efficiently and not to much.
Compare and contrast the antigen receptors of T and B cells. - ✔️✔️t cell receptors
need an antigen and MHC by antigen presenting cells to be activated, while B cells can
bind to soluble antigen.
Distinguish between antigen recognition by helper and cytotoxic T cells. Explain the
special role of dendritic
cells in this process. - ✔️✔️Th1 cells recognize antigen by APC, helper T cells migrate
into the follicles, with Bcell abundance and activates the ones who have recognized
antigen, and helps with differentiation for antibody secretions.
Cytotoxic T cells are activated by DC in Lymph node, but they require help from Th1( IL-
2) and other factors for conversion of memory cells
Discuss the structures recognized by T cell receptors - ✔️✔️T cell receptors can only
recognize antigen if it is bound to an MHC.
Discuss what is meant by "MHC-restriction." - ✔️✔️t cells cant see only antigen like
antibodies, but need to be presented the antigen+ MHC by APC.
Describe the role of T cells in ridding the body of a viral infection. - ✔️✔️T cells help
activate macrophages, release toxic chemicals to kill, clear up damage area, cause
inflammation, pain, fever.
Describe the characteristics of T-independent antigens. - ✔️✔️molecules with same
epitope repeated over and over , common in large carbohydrates, Work good with or
without help.
What are the specifications for a successful T cell? - ✔️✔️1. It must not recognize self
to bind tightly to become activated
2. It must not recognize free antigen
3. Recognize antigenic peptide plus self MHC.
Explain the process of B cells receiving help from T cells. - ✔️✔️1. B cell binds to
epitope it is specific for.
2. Then endocytoses the bound molecule,and is broken down in endocytic vesicle
3. peptide fragments bind with MHC class II brought by vesicles that fuse with
endosome, and moves the complex to the surface.
4. Thf sees complex antigen+MHCII on B cell surface and binds.
5. then helps B cell with surface interactions and helper lymphokines.
Why can we not treat people with immunodeficiency with mitogens. - ✔️✔️Mitogens
are not specific and can cause T cell activation in which they release cytokines to
produce an inflammatory response.
What are the 3 possibilities for a T cell in the thymus? - ✔️✔️apoptosis, recombination,
and clonal deletion
what is cross presentation? - ✔️✔️Dendritic cells allow peptides from antigens to leak
over into it's intrinsic pathway, and is able to present them on class I and class II MHC
at the same time.
Distinguish Class I and Class II histocompatibility antigens. - ✔️✔️class 1 includes
HLA-a and HLA-b, while class 2 includes HLA-D
Describe the surface markers that are used to distinguish between T and B cells in
humans;
and between helper and cytotoxic T cells. - ✔️✔️Bcells can be distinguished by a
CD20 surface marker
Tcells can be distinguished by CD3 which is on all cells, CD4 on helper t cells and CD8
on CTL cells.
Discuss the main lymphokines made by Th1, Th2, Th17 and Treg cells, and their
biological
functions - ✔️✔️1.IFN-gamma, IL-2
2.IL-4,
3.IL-17
, 4.TGF-beta, IL-10
Define mitogen. Suggest uses for T or B cell mitogens in the clinical laboratory. -
✔️✔️a substance that induces or stimulates mitosis
Define cytokine, lymphokine, and chemokine. - ✔️✔️Cytokine- short range mediator
made by any cell that affect the behavior of same or another cell
Lymphokines- short range mediators, made by lymphocytes, affect same or another cell
Chemokines- small short range mediators, made by any cell, cause inflammation
Distinguish between the effects of a mitogen and an antigen, when added to normal
blood
lymphocytes. - ✔️✔️Mitogen will make the cells differentiate if there is no antigen, then
there will be many in circulation.
If antigen is added than the lymphocytes will be used to clear the antigen and produce
more efficiently and not to much.
Compare and contrast the antigen receptors of T and B cells. - ✔️✔️t cell receptors
need an antigen and MHC by antigen presenting cells to be activated, while B cells can
bind to soluble antigen.
Distinguish between antigen recognition by helper and cytotoxic T cells. Explain the
special role of dendritic
cells in this process. - ✔️✔️Th1 cells recognize antigen by APC, helper T cells migrate
into the follicles, with Bcell abundance and activates the ones who have recognized
antigen, and helps with differentiation for antibody secretions.
Cytotoxic T cells are activated by DC in Lymph node, but they require help from Th1( IL-
2) and other factors for conversion of memory cells
Discuss the structures recognized by T cell receptors - ✔️✔️T cell receptors can only
recognize antigen if it is bound to an MHC.
Discuss what is meant by "MHC-restriction." - ✔️✔️t cells cant see only antigen like
antibodies, but need to be presented the antigen+ MHC by APC.
Describe the role of T cells in ridding the body of a viral infection. - ✔️✔️T cells help
activate macrophages, release toxic chemicals to kill, clear up damage area, cause
inflammation, pain, fever.
Describe the characteristics of T-independent antigens. - ✔️✔️molecules with same
epitope repeated over and over , common in large carbohydrates, Work good with or
without help.
