from dm vasudevan a textbook of Biochemistry for Medical Students, 11t

from dm vasudevan a textbook of Biochemistry for Medical Students, 11th edition. Write a 2-mark reasoning answer for -the body doesn't produce immunoglobulin against its own proteins

Reading File

Finding Sources

Reading File

I now have excellent source material. The Vasudevan textbook is not in the library, but the concept is clearly and authoritatively explained in Robbins & Cotran Pathologic Basis of Disease and Roitt's Essential Immunology. I can now write a precise 2-mark reasoning answer aligned with standard biochemistry/immunology teaching as covered in Vasudevan.

2-Mark Reasoning Answer

Why does the body not produce immunoglobulins (antibodies) against its own proteins?

This is explained by the concept of immunological tolerance (self-tolerance), which is established during lymphocyte development through two key mechanisms:

Central tolerance - Clonal deletion (Negative selection): During the maturation of lymphocytes, immature B cells and T cells whose antigen receptors happen to recognize self-antigens (the body's own proteins) are identified and eliminated by apoptosis in the primary lymphoid organs - T cells in the thymus and B cells in the bone marrow. This process of physically destroying self-reactive clones before they can reach the periphery is called clonal deletion. The protein AIRE (autoimmune regulator) expressed in the thymus plays a key role by displaying a wide range of tissue-specific self-antigens to developing T cells, ensuring that cells reactive to them are deleted.
Peripheral tolerance - Clonal anergy: Any self-reactive lymphocytes that escape central deletion and enter peripheral tissues are rendered functionally unresponsive (anergic) in the absence of proper co-stimulatory signals, preventing them from mounting an immune response against self-proteins.

In summary: By clonally deleting or inactivating all lymphocytes that carry receptors for self-proteins, the immune system learns to distinguish "self" from "non-self." As a result, no functional B-cell clones capable of producing antibodies (immunoglobulins) against the body's own proteins survive in circulation. This is the principle of Burnet's clonal selection theory.

Note: A breakdown of self-tolerance leads to autoimmune diseases, where the body does begin producing antibodies against its own tissues (e.g., Rheumatoid Arthritis, SLE, Graves' disease).

This is a shared conversation. Sign in to Orris to start your own chat.