Identification of Ostertagia ostertagi specific cells in bovine abomasal lymph nodes

Area of Science:

• Veterinary Immunology
• Parasitology
• Cell Biology

Background:

• Ostertagia ostertagi is a significant gastrointestinal parasite in cattle.
• Understanding the bovine immune response to O. ostertagi is crucial for developing effective control strategies.
• In vitro assays are valuable for dissecting cellular contributions to immune responses.

Purpose of the Study:

• To identify specific bovine cell subpopulations responsible for in vitro immune responses to Ostertagia ostertagi third larval antigen extract (L3).
• To investigate the role of T-cells (CD4, CD8, gammadelta) and B-cells in the proliferative response to O. ostertagi L3 antigen.

Main Methods:

• Bovine abomasal lymph node cells were depleted of specific cell populations.
• Cell suspensions were stimulated with O. ostertagi L3 antigen extract.
• Proliferative responses were measured using flow cytometry and cell depletion techniques.
• Depletion of CD2+ CD4- CD8- and MHC II+ cells was assessed for impact on proliferation.

Main Results:

• Proliferative responses to O. ostertagi L3 antigen were primarily associated with a CD2+ CD4- CD8- cell population.
• MHC class II-positive (MHC II+) cells, distinct from B-cells, were important for the response.
• Depletion of CD4+, CD8+, CD4+CD8+, IgM+, or CD21+ cells did not significantly reduce proliferation.
• Depletion of gammadelta T-cells only reduced proliferation in one out of several animals tested.

Conclusions:

• A non-conventional T-cell population (CD2+ CD4- CD8-) and non-B MHC II+ cells are key players in the in vitro response to O. ostertagi L3.
• The role of gammadelta T-cells in this response remains uncertain, possibly indicating involvement or the presence of other unidentified cell types.
• Further research is needed to elucidate the precise function and mechanisms of these cell populations during O. ostertagi infection.