The role of interleukin 6 in interferon-gamma production in thermally injured mice.
Following traumatic injury, patients suffer from compromised immunity increasing their susceptibility to infection. Previous studies from this laboratory demonstrated that female BALB/c mice subjected to a 15% total body surface area (TBSA) scald injury exhibit a decrease in cell-mediated immunity 10 days post-burn. Studies described herein revealed that concanavalin A (Con A; 2 microg/ml)-stimulated splenocytes from sham treated animals produced 3557+/-853 pg/ml of IFN-gamma while splenocytes from burn injured animals released two-fold more cytokine (P<0.05). To determine whether leukocyte production of IFN-gamma was under the influence of macrophages, splenic macrophage supernatants generated from burned animals were incubated with splenic lymphocytes from sham and burn animals. The amount of IFN-gamma released by lymphocytes from sham animals increased when cultured with macrophages from burned mice (P<0.05). This suggests that the increase in IFN-gamma production by unfractionated splenocytes in burned mice relative to sham treated animals is macrophage-dependent. Macrophage supernatants from burned mice released twice as much IL-6 as supernatants from sham animals (P<0.05), and when IL-6 was blocked in vivo, the amount of IFN-gamma production in burned mice decreased to sham levels (P<0.05). Thus, IL-6 mediates IFN-gamma production following burn.
Durbin
E A
EA
Department of Cell Biology, Neurobiology, and Anatomy, Loyola University Medical Center, 2160 South First Avenue, Maywood, IL 60153, USA.
Gregory
M S
MS
Messingham
K A
KA
Fontanilla
C V
CV
Duffner
L A
LA
Kovacs
E J
EJ
D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D007371:Interferon-gamma / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000378:metabolism / Q000502:physiology*; D007962:Leukocytes / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D013154:Spleen / Q000166:cytology; D013696:Temperature
D015850:Interleukin-6; D008070:Lipopolysaccharides; D003208:Concanavalin A; D015847:Interleukin-4; D007371:Interferon-gamma