Role of plasma cells in humoral immunity What do plasma cells produce in large quantities for release into the bloodstream?
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AAntigens
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BAntibodies
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CHelper T cells
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DVirus fragments
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ECytokines only, without secreting any immunoglobulins
Answer
Correct Answer: Antibodies
Explanation
Introduction:Plasma cells are terminally differentiated B lymphocytes specialized for high-rate antibody secretion. Their function underpins humoral immunity, neutralization, opsonization, and complement activation.
Given Data / Assumptions:
- Plasma cells arise after B cell activation and differentiation.
- They expand rough endoplasmic reticulum and Golgi for protein secretion.
- Secreted product is immunoglobulin (antibody) specific to the initiating antigen.
Concept / Approach:
Identify the effector molecule produced by plasma cells. Antibodies circulate to bind antigens, block pathogen entry, and recruit effector mechanisms via Fc regions.
Step-by-Step Solution:
1) B cell recognizes antigen and receives T cell help.2) Germinal center reactions refine affinity and isotype.3) Differentiation yields plasma cells that secrete immunoglobulins.4) Antibodies enter blood and tissues to mediate protection.Verification / Alternative check:
Serum immunoglobulin spikes after vaccination or infection mirror plasma cell activity.
Why Other Options Are Wrong:
Option A: Antigens are foreign substances, not produced by plasma cells.
Option C: Helper T cells arise from T lineage, not B cell differentiation.
Option D: Virus fragments may be present during infection but are not plasma cell products.
Option E: Plasma cells secrete large amounts of immunoglobulins; cytokines may be produced by other immune cells.
Common Pitfalls:
Confusing antibody production (B lineage) with cytokine-focused T cell functions.
Final Answer:
Antibodies