Question

Globule leukocyte are considered subpopulation of
(A) T lymphocyte
(B) B lymphocyte
(C) Eosinophils
(D) Neutrophils

• A. T lymphocyte
• B. B lymphocyte
• C. Eosinophils
• D. Neutrophils

Hint:

Globule leukocytes are closely linked to mucosal immunity against helminths.
Though they look like granulocytes under a microscope, their surface markers identify them as specialized T-lymphocytes.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Globule leukocytes are specialized granulated immune cells found primarily in the mucosal epithelia of digestive and respiratory tracts in domestic animals.
These cells are characterized by large, refractive, acidophilic cytoplasmic globules.
Identifying their cellular lineage has been a major focus of comparative veterinary immunology.

Step 2: Detailed Explanation:
Historically, globule leukocytes were mistaken for eosinophils or mast cells due to their prominent acidophilic cytoplasmic granules.
- Modern immunological research using immunohistochemistry and flow cytometry has clarified their origin.
- These cells express specific cell-surface markers (such as CD3 and T-cell receptors) that belong to the T-lymphocyte lineage.
- Consequently, globule leukocytes are classified as a specialized subpopulation of mucosal intraepithelial T lymphocytes.
- They play an active role in mucosal immunity, particularly in defense mechanisms against gastrointestinal helminth parasites.
- During parasitic infections, these cells migrate into the epithelial layer and release their granular contents to help expel the parasites.
Therefore, they are classified under the T-lymphocyte lineage rather than B-lymphocytes, eosinophils, or neutrophils.

Step 3: Final Answer:
Globule leukocytes are considered a subpopulation of T lymphocytes. This corresponds to option (A).