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STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI : I. EFFECTS OF PROTEOLYTIC ENZYMES ON

R C Lancefield1

  • 1Hospital of The Rockefeller Institute for Medical Research.

The Journal of Experimental Medicine
|October 30, 2009
PubMed

Insights

Proteolytic enzymes degrade M antigen in group A hemolytic streptococci, preventing M antibody formation. This method yields specific anti-T sera, aiding in the analysis of streptococcal antigens.

Area of Science:

  • Microbiology
  • Immunology
  • Biochemistry

Background:

  • Group A hemolytic streptococci possess type-specific M antigens crucial for virulence.
  • Understanding streptococcal antigens is vital for developing effective vaccines and diagnostics.

Purpose of the Study:

  • To investigate the effect of proteolytic enzymes on the M antigen of group A hemolytic streptococci.
  • To develop a method for producing specific anti-T sera free from M antibodies.

Main Methods:

  • Treatment of group A hemolytic streptococci (both cell-free extracts and whole cells) with proteolytic enzymes.
  • Injection of enzyme-treated cultures into rabbits to assess antibody production.
  • Subculture and animal inoculation to evaluate bacterial recovery and virulence.

Main Results:

  • Proteolytic enzymes effectively destroy the M antigen, whether in extracts or on living cells.
  • Enzyme treatment prevents the formation of M antibodies but induces T antibody production.
  • Exposure to enzymes does not kill the bacteria; virulence and M substance production are restored upon subculture.

Conclusions:

  • Proteolytic enzymes offer a tool to selectively remove M antigen from streptococci.
  • This enzymatic approach enables the preparation of specific anti-T sera, valuable for antigenic analysis.
  • The findings provide novel techniques for dissecting the antigenic composition of group A hemolytic streptococci.

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