Immunology – classification of eye lens antigens Lens antigens of the eye, which are normally hidden from immune recognition under physiological conditions, are best described as:

Introduction / Context:Certain body sites (eye, brain, testis) are immunologically privileged, meaning their antigens are isolated from the immune system under normal conditions. Eye lens proteins provide a classical example.

Given Data / Assumptions:

• Lens proteins are not normally exposed to immune surveillance.
• Exposure may occur after trauma or surgery.
• Immune response against these antigens may lead to autoimmunity.

Concept / Approach:Sequestrated antigens are hidden (sequestered) in anatomical locations without lymphatic drainage or exposure. When released, they can be recognized as “foreign” by the immune system despite being self-antigens, provoking autoimmunity. This is distinct from cross-reacting antigens (shared epitopes with microbes) and neoantigens (new epitopes created by mutation or chemical alteration).

Step-by-Step Solution:Step 1: Define sequestrated antigens as self-antigens normally hidden from immune system.Step 2: Identify lens proteins as such an example.Step 3: Select “Sequestrated antigens” as correct.

Verification / Alternative check:Clinical examples include sympathetic ophthalmia, an autoimmune condition triggered by lens antigen exposure following ocular injury.

Why Other Options Are Wrong:

• Cross-reacting antigens: involve mimicry with microbial epitopes, not sequestration.
• Neoantigens: result from mutations or modifications, not anatomical sequestration.
• None: incorrect because sequestration is a well-established category.
• Self-antigens with molecular mimicry: different mechanism, not sequestration.

Common Pitfalls:Confusing sequestrated with cross-reactive antigens; only sequestrated antigens are physically hidden from immune surveillance.

Final Answer:Sequestrated antigens.