Role of interferon in streptococcal infection in the mouse.
In previous studies, we have shown the rapid in vitro induction of IFN gamma from human T cells by highly purified peptic extracts of M proteins from Streptococcus pyogenes. The present report extends these in vitro studies and shows that a mixture of both alpha/beta and gamma IFN were present in spleen cell homogenates after in vivo treatment with M protein wild-type (M+) or mutant (M-) S. pyogenes strains. The levels of bacterial-induced IFN were found to be greater in M+ treated animals. Additional studies in vivo showed that pretreatment of mice with heat-killed M+ S. pyogenes organisms significantly protected mice to pneumococcal infection compared to similarly treated M- or control animals (P less than 0.001). Further, antibodies to mouse IFN alpha/beta and antibodies specific to a synthetic N-terminal peptide of mouse IFN gamma enhanced the death of animals due to pneumococcal infection and blocked the protection observed in animals previously treated with heat-killed M+ organisms. Most importantly, treatment of mice with either type of IFN alone enhanced the survival of mice to levels similar to that observed by treatment with M+ organisms (P less than 0.05). The results strongly suggest that IFN can play a crucial role, directly or indirectly, in controlling infection by Streptococcus pneumoniae and perhaps other streptococci.
Weigent
D A
DA
Department of Microbiology, University of Texas Medical Branch, Galveston 77550.
Huff
T L
TL
Peterson
J W
JW
Stanton
G J
GJ
Baron
S
S
D000818:Animals; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000276:immunology; D002352:Carrier Proteins; D005260:Female; D007372:Interferons / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D011008:Pneumococcal Infections / Q000276:immunology* / Q000517:prevention & control; D013297:Streptococcus pyogenes / Q000276:immunology
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein; D007372:Interferons