IL-2 mediates protection against abscess formation in an experimental model of sepsis.
Little is known regarding the mechanism by which T cells control intraabdominal abscess formation. Treating animals with polysaccharide A (PS A) from Bacteroides fragilis shortly before or after challenge protects against abscess formation subsequent to challenge with different abscess-inducing bacteria. Although bacterial polysaccharides are considered to be T cell-independent Ags, T cells from PS A-treated animals mediate this protective activity. In the present study, we demonstrate that CD4+ T cells transfer PS A-mediated protection against abscess formation, and that a soluble mediator produced by these cells confers this activity. Cytokine mRNA analysis showed that T cells from PS A-treated animals produced transcript for IL-2, IFN-gamma, and IL-10, but not for IL-4. The addition of IL-2-specific Ab to T cell lysates taken from PS A-treated animals abrogated the ability to transfer protection, whereas the addition of Abs specific for IFN-gamma and IL-10 did not affect protection. Finally, administration of rIL-2 to animals at the time of bacterial challenge prevented abscess formation in a dose-dependent manner. These data demonstrate that PS A-mediated protection against abscess formation is dependent upon a CD4+ T cell-dependent response, and that IL-2 is essential to this immune mechanism.
Tzianabos
A O
AO
Department of Medicine, Channing Laboratory, Brigham and Women's Hospital, Boston, MA 02115, USA. atzianabos@channing.harvard.edu
Russell
P R
PR
Onderdonk
A B
AB
Gibson
F C
FC
Cywes
C
C
Chan
M
M
Finberg
R W
RW
Kasper
D L
DL
D018784:Abdominal Abscess / Q000276:immunology* / Q000517:prevention & control; D019264:Adoptive Transfer; D000818:Animals; D000918:Antibody Specificity; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000637:transplantation; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D007106:Immune Sera / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D007376:Interleukin-2 / Q000502:physiology* / Q000627:therapeutic use; D008297:Male; D011135:Polysaccharides, Bacterial / Q000008:administration & dosage / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000627:therapeutic use; D018805:Sepsis / Q000276:immunology* / Q000517:prevention & control; D012995:Solubility
D016207:Cytokines; D007106:Immune Sera; D007376:Interleukin-2; D011135:Polysaccharides, Bacterial; D012333:RNA, Messenger; D011994:Recombinant Proteins