Age-dependent changes in antigenic promotion, a Th-2 type of activity

Area of Science:

• Immunology
• Cellular immunology
• T-cell responses

Background:

• Secondary immune responses can be influenced by prior exposure to determinants.
• T-helper cell (Th) involvement is crucial for adaptive immunity.
• The hapten carrier effect describes how small molecules (haptens) elicit responses when linked to larger carriers.

Purpose of the Study:

• To investigate the T-helper 2 (Th-2) cell-mediated help in secondary immune responses.
• To determine if Th-2 help is independent of the hapten carrier bridge.
• To analyze the ontogeny and hapten-dependency of Th-2 helper effects.

Main Methods:

• In vitro culture of mouse spleen cells (A/J and C57BL/6).
• Immunization with various macromolecules and subsequent exposure to sensitizing and unrelated antigens.
• Assessment of indirect plaque-forming cell responses to evaluate Th-2 reactivity.

Main Results:

• A Th-2 type helper effect, independent of the hapten carrier bridge, was observed in the indirect plaque-forming response.
• This Th-2 help was demonstrated with spleen cells from mice immunized with various macromolecules.
• The onset of detectable Th-2 capacity showed age polymorphism, appearing after sexual maturity and varying with hapten type (2,4-dinitrophenyl vs. p-azobenzene sulfonic acid).

Conclusions:

• Th-2 cells can provide help for secondary immune responses independently of a direct hapten carrier bridge.
• The development of Th-2 helper capacity is age-dependent and influenced by the chemical nature of the hapten.
• Mouse strain differences (A/J vs. C57BL/6) in the age of Th-2 capacity detection were observed, particularly with p-azobenzene sulfonic acid.