Adoptive suppression of granuloma formation

Area of Science:

• Immunology
• Parasitology
• Pathology

Background:

• Granulomas are key to controlling Schistosoma mansoni infection but can cause pathology.
• Granuloma size decreases with chronic infection duration.

Purpose of the Study:

• To investigate the mechanisms behind reduced granuloma size in chronic Schistosomiasis mansoni.
• To determine if serum or cellular components from chronically infected mice mediate this suppression.

Main Methods:

• Passive serum transfer from chronically infected mice to acutely infected recipients.
• Passive cellular transfer (spleen and lymph node cells) from chronically infected mice to acutely infected recipients.
• Assessment of hepatic granuloma size in recipient mice.

Main Results:

• Serum transfer did not alter granuloma size.
• Spleen and lymph node cells from chronically infected mice significantly suppressed granuloma formation.
• Spleen cells from early-infected mice showed some suppressive capacity.
• Sequential cell transfers enhanced suppression.

Conclusions:

• Cellular immunity, mediated by spleen and lymph node cells, is responsible for granuloma size reduction in chronic S. mansoni infection.
• The suppressive capacity of these cells increases with infection chronicity.
• Repeated administration of immune cells may be a therapeutic strategy.