UCL I&D Flashcards
Integrin molecules on the surface of neutrophils can bind to which molecule on the surface of blood vessel endothelium?
IL-8
IL-1ß
PAMP
ICAM-1
LPS
ICAM-1
Which of the following is the correct order of neutrophil migration to damaged tissue?
Activation, Adhesion, Rolling, Diapedesis
Rolling, Activation, Diapedesis, Adhesion
Rolling, Activation, Adhesion, Diapedesis
Activation, Rolling, Adhesion, Diapedesis
Rolling, Adhesion, Activation, Diapedesis
Rolling, Activation, Adhesion, Diapedesis
Regarding Interferon alpha and beta, what is the mechanism of their action against viral infections?
They attach directly to a virus, preventing it from entering cells
They stimulate cells surrounding a virus to produce proteins that prevent viral replication
They signal the innate immune system to respond to viral antigens with phagocytes
They bind to a cell that has been infected by a virus and prevent it from lysing
They bind to cells surrounding the virus to prevent transmission
They stimulate cells surrounding a virus to produce proteins that prevent viral replication
Why do NK cells attack host cells infected with a virus but do NOT attack host tumor cells?
NK cells recognise cells that are not displaying MHC Class I molecules. Host cells infected with a virus do not display MHC Class I while host tumors cells do
NK cells recognise cells that are not displaying MHC Class I molecules. Host cells infected with a virus display MHC Class I while host tumors cells do not
NK cells do not recognise cells that are proliferating
NK cells recognise viral antigens directly and have no way of recognising tumor cells
NK cells can only recognise cells nucleated cells and tumor cells are non-nucleated.
NK cells recognise cells that are not displaying MHC Class I molecules. Host cells infected with a virus do not display MHC Class I while host tumors cells do
Why is phosphatase activity that inhibits the NK cell activation response essential?
It allows NK cells to recognise cells that have been infected by a virus
It prepares NK cells to destroy a cell that is not displaying MHC Class I proteins on its surface
It allows NK cells to recognise non-nucleated cells
It prevents NK cells from responding to cells infected by a bacterium
It prevents NK cells from killing normal cells
It prevents NK cells from killing normal cells
Which of the following is a component of the lectin pathway of complement activation?
Factor B
Factor D
C1q
MASP-1
C3bBb3b
MASP-1
Which complement pathway is NOT correctly matched with its activators?
Alternative — microbial sugars
Classical — antibody antigen complexes
Classical — CRP
Lectin — microbial sugars
Alternative — microbial structures
Alternative — microbial sugars
In a patient, it was observed that macrophages are abundant but do not seem to be phagocytosing antigen efficiently. What complement factor may be deficient in this patient?
C3a
C5a
C4
C5b6789
C3b
C3b
If there is a massive increase in basophil and mast cell degranulation, which complement factors may be upregulated?
C5a, C5b6789
C3a, C5b6789
C3a, C5a
C3a, C3b
C3b, C5a
C3a, C5a
C3 convertase and C5 convertase are critically important to complement activation because…
They help activate lymphocytes that respond to antigens that activate complement
They mediate complement by halting converting active complement factors back to their inactive form
They stimulate degranulation of mast cells and basophils
They are responsible for the cleavage of C3 and C5, creating C3a/C3b and C5a/C5b — which are responsible for activating the bulk of the complement immune response
They are active early in the classical pathway of complement activation
They are responsible for the cleavage of C3 and C5, creating C3a/C3b and C5a/C5b — which are responsible for activating the bulk of the complement immune response
Two molecules which TLR4 is able to detect are?
Peptidoglycan and Advanced Glycation Endproducts
HMGB1 and LPS
LPS and Peptidoglycan
CpG and uric acid
N-acetylglucosamine and mannose
HMGB1 and LPS
Pattern Recognition Receptors ability to be both specific and broad based refers to?
The ability to recognise very specific structures that are common to large groups of organisms.
The ability to recognise host and pathogens.
The ability to recognise a variety of pathogens while being able to distinguish them from the host.
The ability to recognise a variety of organisms while identifying which ones are threats.
The ability to recognise both PAMPs and DAMPs from a variety of cells.
The ability to recognise very specific structures that are common to large groups of organisms.
Pattern Recognition Receptors (PRRs) can be present in all of the following forms EXCEPT…?
…cytosolic.
…as a cell surface molecule.
…as a secreted soluble receptor.
…nucleic.
…endosomal.
nucleic
Which of the following is NOT true about the inflammasome?
Include the receptor NLRP3.
Recognises the presence of Uric Acid.
Recognises DAMPs from damaged cells.
Recognises viral single stranded RNA.
Is a cytosolic PRR.
Recognises viral single stranded RNA.
Which of the following does not develop in the thymus?
Helper T cell
Cytotoxic T cell
Treg
T cell precursor
T cell precursor
‘Double positive’ T-cells in the thymus express both…
An αβ and a γδ T-cell receptor
CD4 and CD8
A TCR and a BCR
MHC class I and MHC class II
CD3 and CD4
CD4 and CD8
The first step in thymic education that occurs in the cortex of the thymus is…?
…positive selection: T cells that recognise self MHC undergo apoptosis.
…positive selection: assigning CD4 and CD8 molecules to T cells- making them double positive.
…negative selection: selecting out any T cells that are CD4 or CD8 negative.
…positive selection: T cells that can recognise self MHC are saved from apoptosis.
…negative selection: T cells that recognise self MHC undergo apoptosis.
…positive selection: T cells that can recognise self MHC are saved from apoptosis.
Negative selection is important to ensure that…?
…mature T cells contain either CD4 or CD8.
…mature T cells recognise self MHC.
…mature T cells do not recognise autoantigen.
…mature T cells are double negative.
…mature T cells do not exhibit central tolerance.
…mature T cells do not recognise autoantigen.
What is the main B cell zone of the lymph node?
Medulla
Medullary sinus
Capsule
Cortex
Paracortex
Cortex
Where does the adaptive immune response become activated?
Bloodstream
Secondary lymphoid tissues
Thymus
Bone Marrow
Mucosal surfaces
Secondary lymphoid tissues
Some metastatic cancer can invade lymph nodes. What vessel would be responsible for transporting the metastatic cells in the lymph into the lymph node?
Afferent lymphatic vessel
High endothelial venule
Efferent lymphatic vessel
Lymph node artery
Medullary sinus
Afferent lymphatic vessel
In comparison to the primary immune response, the secondary immune response…?
…is less specific.
…involves B-cells but not T-cells.
…is of greater magnitude.
…is slower to be initiated.
…cannot generate memory cells.
…is of greater magnitude.
Clonal selection allows the immune system to…?
…constantly produce antibodies to any antigen humans can encounter.
…produce a tailored response to a wide variety of prior exposed antigens.
…ensure that it recognises RBCs that are at risk for haemolysis
…respond to specific pathogens it has not encountered before.
…immediately respond to antigens that it encounters.
…produce a tailored response to a wide variety of prior exposed antigens.
Which of the following are the two products of B cell differentiation and their CORRECT function?
Plasma cell — antibody secretion & Naïve B cell — antigen recognition.
Memory B cells — antibody secretion & Plasma cells — secondary immune response.
Plasma cell — antibody secretion & Monocytes — phagocytosis.
Memory B cells — secondary immune response & Dendritic cells — antigen presentation.
Plasma cell — antibody secretion & Memory B cells — secondary immune response.
Plasma cell — antibody secretion & Memory B cells — secondary immune response.
Why are Memory B cells key in the human adaptive immune response?
They are responsible for mounting the secondary immune response, which is qualitatively and quantitatively superior to the primary immune response.
They ensure that B cell differentiation is efficient and rapid.
They recruit T cells to help respond to antigens.
They secrete cytokines which cause the naïve B cells to differentiate into a specific antigen target.
They secrete antibodies which are capable of binding the antigen they encounter and mounting a secondary immune response.
They are responsible for mounting the secondary immune response, which is qualitatively and quantitatively superior to the primary immune response.
Which statement best describes dendritic cells in the lymph node?
They have CD80 molecules on their cell surface
They are highly phagocytic
They have mostly arrived directly from the blood circulation
They enter the lymph node via the efferent lymphatic vessels
They are specialised to present antigen to B-cells
They have CD80 molecules on their cell surface
Which of the following statements accurately describes dendritic cells?
They are present in secondary lymphoid tissues as naive, unactivated phagocytic cells
They are initially phagocytic but once activated switch to an antigen presentation mode
They never lose their ability to phagocytose antigens
They present antigens to B cells in the bloodstream
They are made in the thymus and mature in the bone marrow
They are initially phagocytic but once activated switch to an antigen presentation mode
What is the correct sequence of migration of dendritic cells?
Thymus → blood → tissues → afferent lymphatics → lymph node
Bone marrow → blood → tissues → afferent lymphatics → lymph node
Blood → afferent lymphatics → lymph node → efferent lymphatics
Lymph node → efferent lymphatics → blood → tissues
Blood → lymph node → afferent lymphatics → tissues
Bone marrow → blood → tissues → afferent lymphatics → lymph node
Which molecules are upregulated on the surface of a dendritic cell to convert it from phagocytic to antigen presenting?
MHC Class II, CD3 and CD5
MHC Class I, CD 80, CD86
MHC Class I, CD3 and CD5
MHC Class II, CD80
MHC Class II, CD80 and CD86
MHC Class II, CD80 and CD86
Naive T-cells differentiate and become all of the following except?
Cytotoxic T cells
Memory T cells
Dendritic Cells
Helper T cells
Effector T cells
Dendritic Cells
What is a ligand for CD80?
CD86
B7.1
B7.2
CD28
CD40
CD28
Anergy refers to…
…inactivation of T cell during clonal differentiation.
…functional inactivation of T cells by APCs following costimulation.
…apoptosis of a T cell due after response to self antigen.
…downregulation of cytokines that produce a costimulatory response.
…functional inactivation of the T cell following stimulation of the antigen receptor only.
…functional inactivation of the T cell following stimulation of the antigen receptor only.
Binding of CD40 to CD40 Ligand causes…?
…dendritic cells to upregulate expression of CD80 & CD86 and release cytokines.
…upregulation of CD40 in response to antigen.
…cytokine release from naive T cell.
…activation and differentiation of T cells.
…blockage of costimulation signals.
…dendritic cells to upregulate expression of CD80 & CD86 and release cytokines.
Which of the following receives lymphocytes from efferent lymphatics migrating via the thoracic duct?
Blood
Afferent lymphatics
Lymph node
Spleen
Thymus
Blood
What combination of cells need to interact in order to mount an adaptive immune response?
Dendritic cells, Memory T cells, and Memory B cells
Dendritic cells, Helper T cells, and Memory T cells
Dendritic cells, Memory T cells and B cells specific for same antigen
Dendritic cells, and Helper T cells and B cells specific for the same antigen
Dendritic cells, Helper T cells, and antibodies produced by Plasma cells
Dendritic cells, and Helper T cells and B cells specific for the same antigen
In what cases might a B cell be activated without t lymphocyte activation?
When the antigen is large with repeating antigenic determinants e.g. LPS.
