Migration patterns of thymus-derived gamma delta T cells during chicken development

Area of Science:

• Immunology
• Developmental Biology
• Avian Biology

Background:

• Intestinal gamma delta T cells originate from thymocytes in early life, colonizing the gut in two waves.
• The colonization patterns of gamma delta T cells in the spleen remain less understood compared to the intestine.

Purpose of the Study:

• To investigate the origin and colonization dynamics of splenic gamma delta T cells in avian models.
• To compare the migration, distribution, and survival of gamma delta T cells in the spleen versus the intestine.

Main Methods:

• Congenic chick strains expressing the ov antigen marker were used for cell transfer experiments.
• Thymic lobes were engrafted into thymectomized recipients to trace gamma delta T cell migration.
• Tissue section analysis examined the distribution and entry points of gamma delta T cells in the intestine.

Main Results:

• Splenic colonization by gamma delta T cells follows a similar pattern to intestinal colonization, originating from the thymus.
• Thymus-derived gamma delta T cells migrate to both spleen and intestine in distinct waves, with sustained seeding.
• Splenic gamma delta T cell migrants have a significantly shorter survival time compared to intestinal migrants, which form long-lived clones.

Conclusions:

• The thymus is a crucial source for seeding both the spleen and intestine with gamma delta T cells early in life.
• Distinct survival kinetics exist for gamma delta T cells in the spleen versus the intestine, suggesting organ-specific regulation.
• Founder thymic migrants contribute to the long-term persistence of gamma delta T cells within the intestinal epithelium.