THE EFFECT OF A TISSUE ENZYME UPON PNEUMOCOCCI

Area of Science:

• Immunology
• Microbiology
• Biochemistry

Background:

• Polymorphonuclear leucocytes possess an enzyme capable of altering pneumococcal characteristics.
• This enzyme affects the basophilic nature of heat-killed pneumococci and the type-specific polysaccharide antigen.
• The enzyme's action does not lead to bacterial cell disintegration or capsular polysaccharide decomposition.

Purpose of the Study:

• To investigate the properties and source of the enzyme found in polymorphonuclear leucocytes.
• To understand the enzyme's effect on pneumococcal components.
• To explore the implications of these findings on antibody production in rabbits.

Main Methods:

• Extraction and purification of the enzyme from polymorphonuclear leucocytes and animal tissues.
• Comparison of the extracted enzyme with purified pancreatic enzymes.
• Analysis of the enzyme's effect on heat-killed pneumococci (R and S variants).
• Evaluation of antibody production in rabbits immunized with heat-killed pneumococci.

Main Results:

• The enzyme destroys the basophilic character of heat-killed pneumococci and inactivates the type-specific polysaccharide antigen.
• The enzyme does not disintegrate bacterial cells or decompose the capsular polysaccharide.
• The enzyme appears identical to a purified enzyme from pancreatin that decomposes yeast nucleic acid.
• Rabbits failed to produce type-specific carbohydrate antibodies when immunized intradermally with heat-killed encapsulated pneumococci.

Conclusions:

• The identified enzyme plays a role in modifying pneumococcal antigens.
• The enzyme's inability to degrade the bacterial cell or polysaccharide may influence immune responses.
• The findings suggest a potential mechanism for the observed failure in antibody production in rabbits.