On of the following is involved in cell mediated response :

IGNOU PB Bsc Nsg.Entrance-2026

Applied Microbiology & Infection control

Easy

Appeared in: IGNOU PB Bsc Nsg.Entrance-2026

Explanation

T-lymphocytes (T-cells) are the primary cells responsible for cell-mediated immunity (CMI).
CMI is an immune response that does not involve antibodies but relies on the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines.
T-cells mature in the thymus and differentiate into helper T-cells (CD4+) and cytotoxic T-cells (CD8+) to orchestrate the immune attack against intracellular pathogens and tumor cells.
This type of immunity is also responsible for delayed-type hypersensitivity reactions and transplant rejection.

Option A: B-lymphocytes are the principal cells of humoral immunity, not cell-mediated immunity. Their primary function is to differentiate into plasma cells and produce antibodies.
Option C: Basophils are granulocytes that are primarily involved in allergic reactions and inflammation by releasing substances like histamine. They are not a key component of the adaptive cell-mediated response.
Option D: Monocytes are precursors to macrophages. While macrophages are crucial as antigen-presenting cells (APCs) that activate T-cells, they are considered part of the innate immune system and serve to initiate, rather than execute, the specific cell-mediated response which is directed by T-cells.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Cell-mediated vs. Humoral Immunity as background academic context rather than a clinical decision trigger.
Understanding the difference between cell-mediated and humoral immunity is fundamental for nursing. It helps in understanding vaccine mechanisms, autoimmune diseases, transplant rejection, and interpreting diagnostic tests like the Mantoux test for tuberculosis, which relies on a T-cell mediated response.
Nurses may administer immunosuppressive drugs post-transplant that specifically target T-cell function to prevent organ rejection, which is a classic example of a cell-mediated process.
What if? If a patient has a deficient thymus (e.g., DiGeorge syndrome), their T-cell count and function will be severely impaired. This leads to a defective cell-mediated immunity, making them highly susceptible to viral and fungal infections, even if their B-cell count and antibody production (humoral immunity) are relatively normal.

How to Approach the Question

First, identify the key phrase in the question: 'cell mediated response'.
Recall the two main arms of the adaptive immune system: humoral immunity and cell-mediated immunity.
Associate humoral immunity with B-lymphocytes and antibodies, which work primarily on extracellular pathogens.
Associate cell-mediated immunity with T-lymphocytes, which work primarily on intracellular pathogens and infected cells.
Evaluate the given options based on this core distinction. B-lymphocyte is humoral. Basophil is for allergies. Monocyte is an antigen-presenter. T-lymphocyte is the direct answer for cell-mediated response.

Concept Tested & Keywords

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