PCB 3233 Exam 4 Study guide |
Immunology (Latest 2026/ 2027 Update)
Review| Questions & Answers |100%
verified | Grade A
start of chapter 7
Where does T-cell maturation take place?
T-cell maturation takes place in the thymus
Be able to understand some similarities and differences between B cell and T cell development.
a. Examples: Where do they derive? What cellular mechanisms or processes are shared between
the two? What comprises their cell lineages?
Both B-cells and T-cells derive from the bone marrow stem cells but the T-cell moves to the
thymus to mature while the B-cell stays in the bone marrow. Both undergo gene rearrangement
which produces antigen receptors. T cells have two lineages.
Regarding the initial stages of T-cell maturation, explain the direction of its migration using
"subcapsular region", "medulla", and "cortex" as references in your description. Where would
you expect to find macrophages? What about dendritic cells?
As the T-cell matures, it migrates from the subcapsular region of the thymus to the inner cortex
and to the medulla. Macrophages are found in both the cortex and the medulla. Dendritic cells
are found in the medulla.
, PCB 3233 Exam 4 Study guide |
Immunology (Latest 2026/ 2027 Update)
Review| Questions & Answers |100%
verified | Grade A
In the thymus, what is the role of macrophages? Where are Hassal's corpuscles found?
Macrophages remove the thymocytes that do not mature properly. Hassal's corpuscles is found in
the medulla of the thymus and it induces the development of regulatory T cells.
Evident from patient's who demonstrate DiGeorge's syndrome, the development of a functional
T-cell repertoire is crucial to an individual's health. What causes DiGeorge's syndrome? Know
the chromosome affected. Identify what is NOT being produced in this clinical condition, and
what further consequences are associated. Can DiGeorge's syndrome be cured?
DiGeorge's syndrome is caused by a deletion in chromosome 22 where the thymus fails to
develop and T cells are absent. The lack of T cells and thymus increases susceptibility to a wide
range of opportunistic infections and it resembles SCID (severe combined immunodeficiency
disease). Cannot be cured.
The thymus is considered to be completely developed before birth. However, its deterioration
results with natural aging, indicating that the younger you are, the more active it is. Knowing
this, would you expect T-cell immunity to become defective overtime? Why or why not? What
about in the case of a thymectomy (removal of thymus); would you expect impairment then?
T-cell immunity does not become defective over age. The thymus just does not develop as many
T-cells over time. T-cells stay in circulation for several years. T-cells do not become defective
even after a thymectomy.
How does the life of a T cell differ from that of a B cell? Which lives longer and why do you
think that is? (Hint: understand what "self renewing" means in this context)
, PCB 3233 Exam 4 Study guide |
Immunology (Latest 2026/ 2027 Update)
Review| Questions & Answers |100%
verified | Grade A
T cells are long-lived and self-renewing. T cells are in circulation in the blood stream for several
months. Self-renewing cells divide to maintain the amount of cells.
Double-Negative (DN) thymocytes vs. Double-Positive (DP) thymocytes:
a. When/why are they called DN thymocytes?
i) What cell-surface proteins are expressed? Which are NOT being expressed?
ii) What is the importance of Notch 1 for these thymocytes?
b. When/why are they called DP thymocytes?
i) What cell-surface proteins are being expressed at this point?
a. T cells that express the αβ TCR but do not express CD4/CD8/NK cell markers. This happens
when the progenitor T cell expresses T-cell specific adhesion molecule CD2 and other molecules
but not TCR complex.
i) CD2 and CD5 are expressed. CD4 and CD8 are not expressed.
ii) Notch 1 keeps the T-cell on the T-cell path.
b. T cells that express both CD4 and CD8.
i) CD2, CD5, CD4, and CD8 are being expressed.
The two T-cell lineages: α:β and γ:δ
a. Which is considered to be the majority and which is the minority?
b. Do the loci lineages derive from a common DN or DP thymocyte precursor?
c. Which loci (α, β, γ, δ) begin their rearrangement roughly at the same time?
Immunology (Latest 2026/ 2027 Update)
Review| Questions & Answers |100%
verified | Grade A
start of chapter 7
Where does T-cell maturation take place?
T-cell maturation takes place in the thymus
Be able to understand some similarities and differences between B cell and T cell development.
a. Examples: Where do they derive? What cellular mechanisms or processes are shared between
the two? What comprises their cell lineages?
Both B-cells and T-cells derive from the bone marrow stem cells but the T-cell moves to the
thymus to mature while the B-cell stays in the bone marrow. Both undergo gene rearrangement
which produces antigen receptors. T cells have two lineages.
Regarding the initial stages of T-cell maturation, explain the direction of its migration using
"subcapsular region", "medulla", and "cortex" as references in your description. Where would
you expect to find macrophages? What about dendritic cells?
As the T-cell matures, it migrates from the subcapsular region of the thymus to the inner cortex
and to the medulla. Macrophages are found in both the cortex and the medulla. Dendritic cells
are found in the medulla.
, PCB 3233 Exam 4 Study guide |
Immunology (Latest 2026/ 2027 Update)
Review| Questions & Answers |100%
verified | Grade A
In the thymus, what is the role of macrophages? Where are Hassal's corpuscles found?
Macrophages remove the thymocytes that do not mature properly. Hassal's corpuscles is found in
the medulla of the thymus and it induces the development of regulatory T cells.
Evident from patient's who demonstrate DiGeorge's syndrome, the development of a functional
T-cell repertoire is crucial to an individual's health. What causes DiGeorge's syndrome? Know
the chromosome affected. Identify what is NOT being produced in this clinical condition, and
what further consequences are associated. Can DiGeorge's syndrome be cured?
DiGeorge's syndrome is caused by a deletion in chromosome 22 where the thymus fails to
develop and T cells are absent. The lack of T cells and thymus increases susceptibility to a wide
range of opportunistic infections and it resembles SCID (severe combined immunodeficiency
disease). Cannot be cured.
The thymus is considered to be completely developed before birth. However, its deterioration
results with natural aging, indicating that the younger you are, the more active it is. Knowing
this, would you expect T-cell immunity to become defective overtime? Why or why not? What
about in the case of a thymectomy (removal of thymus); would you expect impairment then?
T-cell immunity does not become defective over age. The thymus just does not develop as many
T-cells over time. T-cells stay in circulation for several years. T-cells do not become defective
even after a thymectomy.
How does the life of a T cell differ from that of a B cell? Which lives longer and why do you
think that is? (Hint: understand what "self renewing" means in this context)
, PCB 3233 Exam 4 Study guide |
Immunology (Latest 2026/ 2027 Update)
Review| Questions & Answers |100%
verified | Grade A
T cells are long-lived and self-renewing. T cells are in circulation in the blood stream for several
months. Self-renewing cells divide to maintain the amount of cells.
Double-Negative (DN) thymocytes vs. Double-Positive (DP) thymocytes:
a. When/why are they called DN thymocytes?
i) What cell-surface proteins are expressed? Which are NOT being expressed?
ii) What is the importance of Notch 1 for these thymocytes?
b. When/why are they called DP thymocytes?
i) What cell-surface proteins are being expressed at this point?
a. T cells that express the αβ TCR but do not express CD4/CD8/NK cell markers. This happens
when the progenitor T cell expresses T-cell specific adhesion molecule CD2 and other molecules
but not TCR complex.
i) CD2 and CD5 are expressed. CD4 and CD8 are not expressed.
ii) Notch 1 keeps the T-cell on the T-cell path.
b. T cells that express both CD4 and CD8.
i) CD2, CD5, CD4, and CD8 are being expressed.
The two T-cell lineages: α:β and γ:δ
a. Which is considered to be the majority and which is the minority?
b. Do the loci lineages derive from a common DN or DP thymocyte precursor?
c. Which loci (α, β, γ, δ) begin their rearrangement roughly at the same time?
