Question

Question 15 (2 points)

MHC class I interacts primarily to which subclass of T cell

Question 15 options:

	A) CD8 positive
	B) CD3 positive
	C) CD4 positive
	D) CD2 positive

Question 16 (2 points)

T helper cells generally can stimulate B cells to differentiate into:

Question 16 options:

	A) NK cells and cytotoxic T cells
	B) memory cells and plasma cells
	C) anergic cells and effector cells
	D) NK cells and memory cells
	E) anergic cells and memory cells

Question 17 (2 points)

Which descriptions fit with type of immunity conferred by antibodies?

Question 17 options:

	A) alternative
	B) cell mediated
	C) innate
	D) adaptive

Question 18 (2 points)

Granulomas are frequently an outcome of which of the following?

Question 18 options:

	A) TH1/dendritic cell interactions
	B) TH2/dendritic cell interactions
	C) TH2/B-cell interactions
	D) TH1/macrophage interactions

Question 19 (2 points)

The Fc portion of an antibody allows:

Question 19 options:

	A) An antibody to bind diverse antigens that are presented by foreign pathogens
	B) T cells to express antibody under stimulation by a B cell
	C) Antibodies to bind to cell surface receptors on macrophages and other immune cells
	D) Binding to pathogen associated molecular patterns

Question 20 (2 points)

Which T cell subtype is more associated with B-cell activation within the secondary lymphoid tissues?

Question 20 options:

	A) Treg cells
	B) TFH cells
	C) TC cells
	D) T17 cells
	E) none of the above

Question 21 (2 points)

The primary lymphoid tissue associated with the initial development of B cells is the

Question 21 options:

	A) thymus
	B) bone marrow
	C) lymph nodes
	D) mucosal associated lymphoid tissues
	E) none of the above

Question 22 (2 points)

Which of the following describes the order of events in leukocyte migration?

Question 22 options:

	A) rolling, arrest/adhesion, integrin activation, transendothelial migration
	B) Transendothelial migration, arrest/adhesion, rolling, integrin activation
	C) rolling, integrin activation, arrest/adhesion, transendothelial migration
	D) integrin activation, rolling, arrest/adhesion, transendothelial migration

Answer 1

Ans 15: MHC Class I molecules interact with a protein called CD8 on the cytotoxic T cells, which helps to identify this cell type. Cytotoxic T cells require several signals from other cells to be activated, such as from dendritic cells and T helper cells.

Hence option A is correct.

16: he interaction between CD40 ligand and CD40 is required for helper T cells to activate B cells to proliferate and differentiate into memory or antibody-secreting effector cells.

Hence option B is correct.

17: The adaptive defense consists of antibodies and lymphocytes, often called the humoral response and the cell mediated response. The cells of the adaptive immune system are lymphocytes – B cells and T cells. B cells, which are derived from the bone marrow, become the cells that produce antibodies.

Hence option D is correct.

18: A granuloma is a focal, compact collection of inflammatory cells, mononuclear cells predominating; it is usually formed as a result of the persistence of a non-degradable product of active hypersensitivity. The granuloma is an active site of numerous enzymes and cytokines, and, with aging, fibronectin and numerous progression factors. There is a close relationship between activated macrophages bearing increased expression of major histocompatibility complex (MHC) class II molecules and CD4+ Th1 lymphocytes. These T helper cells recognise protein peptides presented to them by antigen presenting cells bearing MHC class II molecules. The T cell induces interleukin-1 on the macrophage and thereafter a cavalcade of chemotactic factors promote granulomagenesis. Interferon gamma (IFN-γ) increases the expression of MHC class II molecules on macrophages, and activated macrophage receptors carry an Fc fraction of IgG to potentiate their ability to phagocytose.

Hence option D is correct.

19: The fragment crystallizable region (Fc region) is the tail region of an antibody that interacts with cell surface receptors called Fc receptors and some proteins of the complement system.  A Fc receptor is a protein found on the surface of certain cells – including, among others, B lymphocytes, follicular dendritic cells, natural killer cells, macrophages, neutrophils, eosinophils, basophils, human platelets, and mast cells – that contribute to the protective functions of the immune system.

So the Fc portion of an antibody allows antibodies to bind to cell surface receptors on macrophages and other immune cells.

Hence option C is correct.

20: I am not sure about this question.

21: B cell development begins in the fetal liver and continues in the bone marrow throughout our lives.

Hence option B is correct.

22: Leukocyte migration involves passage from the tissues to the blood and lymphatic vessels and from the vessels to the tissues (extravasation). They tether to vessel walls via activation of selectins, then bind the endothelium via activation of integrins, which are able to regulate their affinity through rapid conformational change. This conformational change in the integrin structure leads to cell arrest, a mechanism that allows cells to subsequently cross the endothelium.

The phases of the leukocyte extravasation depicted in the schema are: approach, capture, rolling, activation, binding, strengthening of the binding and spreading, intravascular creeping, paracellular migration or transcellular migration.

Hence option C is correct.