Transforming growth factor-beta impairs postburn immunoglobulin production by limiting B-cell proliferation, but not cellular synthesis.
BACKGROUND
Transforming growth factor-beta (TGF-beta) has been shown to be an inhibitor of immunoglobulin (Ig) synthesis and may contribute to decreased Ig synthesis after burn injury. This study investigated the relationship between TGF-beta and Ig synthesis after burn injury.


METHODS
Twenty-four BALB/c mice received either a 30% body surface area full-thickness contact burn or no burn. Splenocytes were isolated 8 days after burn and were cultured with 0, 0.05 or 0.5 ng/mL TGF-beta. After culture, total IgG and total IgM were measured by enzyme-linked immunosorbent assay. The number of IgM-secreting cells per 10(5) cells was measured by enzyme-linked immunoabsorbent spot forming assay. Total IgM per IgM-secreting cell (pg/cell) was calculated.


RESULTS
Total IgG, IgM, IgM-secreting cells, and B-cell number after culture were decreased by burn injury, and the decrease was exacerbated by the presence of TGF-beta. The total IgM per IgM-secreting cells, however, was significantly increased by TGF-beta at 0.5 ng/mL.


CONCLUSIONS
These data demonstrates that TGF-beta does not specifically impair IgM secretion by committed IgM B cells but appears to decrease B-cell proliferation or clonal expansion.
Nishimura
T
T
Department of Surgery and the Jaycee Burn Center, University of North Carolina, Chapel Hill 27599-7210, USA.
Yamamoto
H
H
deSerres
S
S
Meyer
A A
AA
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002056:Burns / Q000276:immunology*; D002452:Cell Count; D002455:Cell Division; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007136:Immunoglobulins / Q000096:biosynthesis*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000166:cytology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D016212:Transforming Growth Factor beta