KUBY IMMUNOLOGY 2025/2026 QUESTIONS AND
ANSWERS RATED A+
✔✔Regulatory T Cell (Treg) - ✔✔Have the ability to limit normal T-cell responses to
pathogens. Contain CD4 and CD25 on their surfaces.
✔✔Natural Killer T Cells (NKT) - ✔✔Recognize protein peptides. After activation they
release cytotoxic granules that kill target cells, but also release large quantities of
cytokines that can both enhances and suppress the immune response.
✔✔Innate Lymphoid Cells (ILCs) - ✔✔Do not express antigen-specific receptors and
provide a first line of defense against pathogens in the skin and at mucosal tissues by
responding to signals such as infection, damage, or stress.
✔✔1 of 2 strategies to attack a variety of abnormal cells - ✔✔Attack cells that lack MHC
class I molecules. When NK cells have receptors for self-MHC class I and self engage,
it inhibits their ability to kill. When NK cells encounter cells that have lost their MHC
class I, NK cells can release their cytotoxic granules, killing the target cell.
✔✔2 of 2 strategies to attack a variety of abnormal cells - ✔✔NK cells express
receptors for some antibodies. When linking these receptors to antibodies, NK cells can
arm themselves with antibodies specific for pathogenic proteins, particularly viral
proteins present on the surfaces of infected cells. Once antibodies come into contact
with NK cell in contact with targets cells, the NK cell releases its granules and induces
cell death.
✔✔IFN-Gamma - ✔✔A potent macrophage activator that also helps to activate and
shape the adaptive response.
✔✔Activating Receptors - ✔✔Have specificity for various cell surface ligands that serve
as indicators of infection, cancer, or stress.
✔✔Inhibitory Receptors - ✔✔Recognize membrane proteins on normal healthy cells
and inhibit NK cell-mediated cytotoxic killing of those cells.
✔✔Group 1 ILCs - ✔✔Produce cytokines and other mediators contribution to cell-
mediated immunity.
✔✔Group 2 ILCs - ✔✔Produce cytokines supporting immunity to helminth parasites and
wound healing.
✔✔Group 3 ILCs - ✔✔Produce cytokines supporting lymphoid tissue development,
epithelial integrity and homeostasis and immunity to extracellular bacteria and fungi.
, ✔✔Multipotent Stem Cells - ✔✔Arise from embryonic stem cells and can give rise to a
more limited range of cells types.
✔✔Unipotent Stem Cells - ✔✔Can generate only the same cell type as themselves.
✔✔Endosteal Niche - ✔✔Medullary cavity lining the bone. Progenitors of B lymphocytes
are found here.
✔✔Perivascular Niche - ✔✔Medullary cavity lining the blood vessels that run through
the center of the bone. Long-term HSCs are found here.
✔✔Thymocytes - ✔✔Immature T cells that generate unique antigen receptors.
✔✔Negative Selection - ✔✔Thymocytes whose TCRs bind self-MHC/peptide
complexes with too-high affinity are induced to die.
✔✔Positive Selection - ✔✔Thymocytes that bind self-MHC/peptides with intermediate
affinity and migrate to the thymic medulla before entering the circulation.
✔✔Death by Neglect - ✔✔Majority of thymocytes die because they have too-low affinity
for the self-peptide/MHC combinations that they encounter on the surface of thymic
epithelial cells and fail to undergo positive selection.
✔✔Thymic Cortex - ✔✔Thymocytes begin to first express mature TCRs and interact
with cortical thymic epithelial cells.
✔✔Subcapsular Cortex (Thymus) - ✔✔Thymocytes proliferate here.
✔✔Thymic Medulla - ✔✔Thymocytes who are positively selected in the cortex, continue
to mature here and interact with medullary thymic epithelial cells.
✔✔Double Negative (DN) - ✔✔A subset of thymocytes that do not express CD4 or CD8.
At this early stage of T-cell development, these cells do not express the TCR.
✔✔Double Positive (DP) - ✔✔A subset of thymocytes that express both CD4 and CD8
after entering the cortex.
✔✔Corticomedullary Junction - ✔✔T-cell precursors enter the thymus in blood vessels
and mature T cells exit from here that is located between the thymic cortex and medulla.
✔✔Bone Marrow - ✔✔B-cells, monocytes, dendritic cells, and granulocytes mature in
this organ.
ANSWERS RATED A+
✔✔Regulatory T Cell (Treg) - ✔✔Have the ability to limit normal T-cell responses to
pathogens. Contain CD4 and CD25 on their surfaces.
✔✔Natural Killer T Cells (NKT) - ✔✔Recognize protein peptides. After activation they
release cytotoxic granules that kill target cells, but also release large quantities of
cytokines that can both enhances and suppress the immune response.
✔✔Innate Lymphoid Cells (ILCs) - ✔✔Do not express antigen-specific receptors and
provide a first line of defense against pathogens in the skin and at mucosal tissues by
responding to signals such as infection, damage, or stress.
✔✔1 of 2 strategies to attack a variety of abnormal cells - ✔✔Attack cells that lack MHC
class I molecules. When NK cells have receptors for self-MHC class I and self engage,
it inhibits their ability to kill. When NK cells encounter cells that have lost their MHC
class I, NK cells can release their cytotoxic granules, killing the target cell.
✔✔2 of 2 strategies to attack a variety of abnormal cells - ✔✔NK cells express
receptors for some antibodies. When linking these receptors to antibodies, NK cells can
arm themselves with antibodies specific for pathogenic proteins, particularly viral
proteins present on the surfaces of infected cells. Once antibodies come into contact
with NK cell in contact with targets cells, the NK cell releases its granules and induces
cell death.
✔✔IFN-Gamma - ✔✔A potent macrophage activator that also helps to activate and
shape the adaptive response.
✔✔Activating Receptors - ✔✔Have specificity for various cell surface ligands that serve
as indicators of infection, cancer, or stress.
✔✔Inhibitory Receptors - ✔✔Recognize membrane proteins on normal healthy cells
and inhibit NK cell-mediated cytotoxic killing of those cells.
✔✔Group 1 ILCs - ✔✔Produce cytokines and other mediators contribution to cell-
mediated immunity.
✔✔Group 2 ILCs - ✔✔Produce cytokines supporting immunity to helminth parasites and
wound healing.
✔✔Group 3 ILCs - ✔✔Produce cytokines supporting lymphoid tissue development,
epithelial integrity and homeostasis and immunity to extracellular bacteria and fungi.
, ✔✔Multipotent Stem Cells - ✔✔Arise from embryonic stem cells and can give rise to a
more limited range of cells types.
✔✔Unipotent Stem Cells - ✔✔Can generate only the same cell type as themselves.
✔✔Endosteal Niche - ✔✔Medullary cavity lining the bone. Progenitors of B lymphocytes
are found here.
✔✔Perivascular Niche - ✔✔Medullary cavity lining the blood vessels that run through
the center of the bone. Long-term HSCs are found here.
✔✔Thymocytes - ✔✔Immature T cells that generate unique antigen receptors.
✔✔Negative Selection - ✔✔Thymocytes whose TCRs bind self-MHC/peptide
complexes with too-high affinity are induced to die.
✔✔Positive Selection - ✔✔Thymocytes that bind self-MHC/peptides with intermediate
affinity and migrate to the thymic medulla before entering the circulation.
✔✔Death by Neglect - ✔✔Majority of thymocytes die because they have too-low affinity
for the self-peptide/MHC combinations that they encounter on the surface of thymic
epithelial cells and fail to undergo positive selection.
✔✔Thymic Cortex - ✔✔Thymocytes begin to first express mature TCRs and interact
with cortical thymic epithelial cells.
✔✔Subcapsular Cortex (Thymus) - ✔✔Thymocytes proliferate here.
✔✔Thymic Medulla - ✔✔Thymocytes who are positively selected in the cortex, continue
to mature here and interact with medullary thymic epithelial cells.
✔✔Double Negative (DN) - ✔✔A subset of thymocytes that do not express CD4 or CD8.
At this early stage of T-cell development, these cells do not express the TCR.
✔✔Double Positive (DP) - ✔✔A subset of thymocytes that express both CD4 and CD8
after entering the cortex.
✔✔Corticomedullary Junction - ✔✔T-cell precursors enter the thymus in blood vessels
and mature T cells exit from here that is located between the thymic cortex and medulla.
✔✔Bone Marrow - ✔✔B-cells, monocytes, dendritic cells, and granulocytes mature in
this organ.
