Peripheral Immune Tolerance & Treg Cells — Advanced MCQs (Q21–Q40)

बहुत अच्छा — अब हम अगले 20 MCQs (Q21–Q40) लेंगे उसी टॉपिक से:

👉 Peripheral Immune Tolerance, Regulatory T Cells (Tregs), Mechanisms, Cytokines, and Related Diseases.

ये questions CSIR-NET Part B level के होंगे — यानी conceptual + memory mixed।

आंसर सारे नीचे एक साथ दिए गए हैं ताकि पहले आप खुद कोशिश कर सको।

🌿 Peripheral Immune Tolerance & Treg Cells — Advanced MCQs (Q21–Q40)

Q21. Peripheral immune tolerance primarily acts at which stage of immune response?

A. During T cell development in thymus

B. After lymphocytes exit the thymus

C. Before antigen exposure

D. Only during infection

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Q22. Which transcription factor is the master regulator of Treg cell development?

A. NF-κB

B. FOXP3

C. STAT1

D. NFAT

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Q23. Mutation in FOXP3 gene leads to which autoimmune disorder?

A. IPEX syndrome

B. Myasthenia gravis

C. Hashimoto’s thyroiditis

D. Lupus erythematosus

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Q24. Treg cells suppress other immune cells mainly by secreting:

A. IL-2 and IFN-γ

B. IL-10 and TGF-β

C. TNF-α and IL-12

D. IL-6 and IL-17

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Q25. Which surface marker is characteristic of Treg cells?

A. CD4⁺ CD25⁺

B. CD8⁺ CD28⁺

C. CD19⁺ CD20⁺

D. CD3⁻ CD16⁺

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Q26. Peripheral tolerance mechanisms exclude which of the following?

A. Anergy

B. Clonal deletion

C. Positive selection

D. Suppression by Tregs

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Q27. Which cytokine is essential for survival and proliferation of Treg cells?

A. IL-2 

B. IL-4

C. IL-6

D. IL-12

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Q28. Treg-mediated suppression is often antigen-________.

A. Nonspecific 

B. Specific only to one antigen

C. Irreversible

D. Dependent on antibodies

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Q29. In tumor microenvironments, Treg cells are often:

A. Absent

B. Overactive and promote immune evasion 

C. Completely inactive

D. Mutated to helper cells

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Q30. Which cell type is the main target of Treg-mediated suppression?

A. Dendritic cells 

B. RBCs

C. Platelets

D. Neutrophils

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Q31. Peripheral tolerance prevents:

A. Autoimmunity 

B. Antigen presentation

C. Phagocytosis

D. Apoptosis

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Q32. Which molecule on Treg cells binds to CD80/CD86 on APCs to suppress them?

A. CD28

B. CTLA-4 

C. PD-1

D. ICOS

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Q33. Induced Tregs (iTregs) differentiate in:

A. Thymus

B. Peripheral tissues 

C. Bone marrow

D. Lymph nodes only

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Q34. Natural Tregs (nTregs) originate from:

A. Bone marrow

B. Thymus 

C. Lymph nodes

D. Peripheral blood

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Q35. Which enzyme do Tregs express to deplete extracellular ATP and reduce inflammation?

A. Adenosine deaminase

B. CD39/CD73 

C. Caspase 3

D. Hexokinase

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Q36. Peripheral tolerance involves deletion of T cells by:

A. Fas–FasL-mediated apoptosis 

B. IL-10 secretion

C. Complement activation

D. Antibody neutralization

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Q37. Which of the following hormones can enhance Treg function?

A. Cortisol 

B. Adrenaline

C. Insulin

D. Thyroxine

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Q38. Loss of peripheral tolerance is strongly associated with:

A. Allergy and autoimmunity 

B. Memory T cell expansion

C. Enhanced wound healing

D. Reduced cytokine signaling

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Q39. Which immune checkpoint molecule has a mechanism similar to Treg suppression?

A. PD-1 

B. CD8

C. CD19

D. CD16

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Q40. In experimental models, depletion of Tregs leads to:

A. Complete immune paralysis

B. Severe multi-organ autoimmunity 

C. Immunodeficiency

D. Increased tolerance

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✅ Answer Key (Q21–Q40)

Q Ans Q Ans Q Ans Q Ans

21 B 26 C 31 A 36 A

22 B 27 A 32 B 37 A

23 A 28 A 33 B 38 A

24 B 29 B 34 B 39 A

25 A 30 A 35 B 40 B

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क्या आप चाहेंगे कि मैं अब Q41–Q60 बनाऊं — जिसमें clinical angle (autoimmune diseases, immunotherapy, and organ transplant tolerance) भी जोड़ दूँ ताकि ये पूरे topic का mastery set बन जाए?