In vivo changes in complement induced with peptidoglycan-polysaccharide polymers from streptococcal cell walls

Area of Science:

• Immunology
• Microbiology
• Biochemistry

Background:

• Streptococcal cell wall fragments can induce arthritis.
• The complement system plays a crucial role in immune responses and inflammation.

Purpose of the Study:

• To investigate the dynamic changes in serum hemolytic activity following injection of arthropathogenic streptococcal cell wall fragments in rats.
• To assess the impact on the alternative complement pathway and its components.

Main Methods:

• Rats were injected with an arthropathogenic dose of streptococcal cell wall fragments.
• Serum hemolytic activity was measured at various time points post-injection (24 h, days 2-6, days 16, day 40).
• Levels of alternative complement pathway activity, C3, and factor D were assessed.

Main Results:

• Serum hemolytic activity showed an initial decrease within 24 hours.
• Hemolytic activity significantly increased from day 2 to day 6 and remained elevated at days 16 and 40.
• Alterations in the activity of the alternative complement pathway, C3, and factor D were observed.

Conclusions:

• Streptococcal cell wall fragments induce significant and prolonged alterations in serum hemolytic activity in rats.
• These changes in hemolytic activity correlate with modifications in the alternative complement pathway, suggesting its involvement in the host response to streptococcal components.