أسئلة السابعة ميكرو PPPM (قبل التعديل)

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary role of IL-2 in the activation of helper T (Th) cells?

Directly activating B cells to produce antibodies without antigen binding.
Inhibiting macrophage activation to prevent excessive inflammation.
Suppressing the production of IFN-gamma to regulate immune responses.
Stimulating the Th cells to proliferate and activate themselves. (correct)

A researcher is investigating the mechanisms of B cell activation. Which condition would bypass the requirement for T cell help in B cell activation?

Providing a constant supply of IL-2, IL-4, and IL-5 to the B cells.
Blocking the interaction between CD40 on B cells and CD40L on T helper cells.
Administering a drug that inhibits the interaction between B cell receptors (BCRs) and antigens.
Using an antigen that can directly cross-link multiple BCRs on the B cell surface. (correct)

What is the key function of plasma cells, which are differentiated from activated B cells?

Producing and secreting antibodies to neutralize or eliminate pathogens. (correct)
Secreting cytokines that enhance the activity of other immune cells.
Presenting antigens to T cells to initiate the adaptive immune response.
Phagocytosing pathogens directly from the bloodstream.

For a CTL to effectively kill a virus-infected cell, what two conditions must be met?

The target cell must express class I MHC molecules bound to a specific antigen, and the CTL must receive IL-2 and IFN-γ from activated helper T cells. (B) Signup and view all the answers

A patient undergoing a kidney transplant is maintained on immunomodulatory drugs. What is the primary goal of this therapeutic approach?

To suppress the immune system's ability to reject the transplanted kidney, while preventing severe infections. (D) Signup and view all the answers

Which mechanism primarily explains how adjuvants enhance vaccine effectiveness?

Stimulating the immune system and boosting the response to a vaccine without specific antigenic effect. (C) Signup and view all the answers

Why are aluminum salts commonly used as adjuvants in human vaccines?

They effectively prolong antigen retention, increase antigen size, and boost local immune cell influx. (D) Signup and view all the answers

What is the primary application of immunosuppressive drugs following organ transplantation?

Preventing the recipient's immune system from rejecting the transplanted organ. (A) Signup and view all the answers

How do anti-proliferative drugs induce immunosuppression?

By inhibiting the synthesis of purines, which are essential for cell division and lymphocyte proliferation. (D) Signup and view all the answers

What is the mechanism by which drugs like Tacrolimus exert their immunosuppressive effects?

Inhibiting T cell activation and subsequent immune responses. (C) Signup and view all the answers

What is the primary effect of anti-inflammatory drugs in the context of immune modulation?

Inhibiting the secretion of inflammatory cytokines, reducing the inflammatory response. (B) Signup and view all the answers

How does a drug that depletes cells by binding to CD3 molecules induce immunosuppression?

By activating complement-dependent cytotoxicity to lyse T cells expressing CD3. (A) Signup and view all the answers

What is the crucial role of MHC class II molecules in the context of antigen presentation by antigen-presenting cells (APCs)?

To present processed antigens to helper T cells, which then coordinate the immune response. (A) Signup and view all the answers

What is the most critical function of IFN-gamma in adaptive immune responses?

Activating macrophages and enhancing phagocytosis. (A) Signup and view all the answers

How does the interaction between helper T (Th) cells and B cells facilitate B cell activation?

Th cells provide co-stimulatory signals and cytokines, such as IL-2 and IL-4, to B cells. (A) Signup and view all the answers

A researcher aims to enhance the cytotoxic activity of CTLs against tumor cells. Which approach would directly augment CTL-mediated killing?

Blocking the interaction between PD-1 on CTLs and PD-L1 on tumor cells. (D) Signup and view all the answers

In the context of organ transplantation, which of the following strategies would be LEAST effective in preventing graft rejection?

Enhancing the expression of MHC class I molecules on the donor organ. (B) Signup and view all the answers

A patient with rheumatoid arthritis is prescribed a TNF-alpha inhibitor. What is the primary mechanism by which this drug alleviates symptoms?

Blocking the interaction of TNF-alpha with its receptors, reducing inflammation. (C) Signup and view all the answers

How might increasing antigen size enhance the immune response?

By facilitating phagocytosis and antigen presentation by macrophages. (C) Signup and view all the answers

Why is the mechanism of action of Tacrolimus critical in preventing graft rejection?

It inhibits T cell activation, a key step in the rejection process, but with potentially less kidney damage compared to cyclosporine. (C) Signup and view all the answers

What is a potential consequence of using anti-inflammatory drugs long-term for immune modulation?

Impaired wound healing and increased risk of opportunistic infections due to inhibited inflammatory cell migration and cytokine secretion. (C) Signup and view all the answers

What is the most likely reason killed Mycobacteria are included with the initiation injection?

To induce a strong, initial inflammatory response that recruits immune cells to the injection site, enhancing antigen presentation. (C) Signup and view all the answers

How does blocking IL-2 binding to its receptor lead to immunosuppression?

By inhibiting T cell proliferation, which is essential for clonal expansion and a robust immune response. (B) Signup and view all the answers

What is the primary mechanism by which anti-proliferative drugs induce immunosuppression?

Inhibiting the synthesis of purines required for cell division, thereby suppressing lymphocyte proliferation. (C) Signup and view all the answers

In the context of antigen presentation by APCs, what would be the most significant consequence if class II MHC molecules were non-functional?

Helper T cells would not be activated, impairing the coordination of the adaptive immune response. (B) Signup and view all the answers

What is the expected outcome after administering a drug that depletes cells by binding to CD3 molecules?

Depletion of T cells, resulting in immunosuppression due to T cells role in immune response. (C) Signup and view all the answers

Flashcards

Helper T Cell Activation

IL-2 acts on helper T cells, leading to their proliferation and activation. IFN-gamma activates macrophages and enhances phagocytosis.

B Cell Activation Signals

B cell activation requires binding of antigen to BCR (signal 1) and cytokines from Th cells (signal 2, T cell help).

B Cell Differentiation

Activated B cells differentiate into plasma cells (secrete antibodies) and memory B cells.

CTL Target Recognition

CTLs recognize and bind to peptide antigens bound to class I MHC molecules on target cells, leading to target cell death.