Human monocyte-derived dendritic cells are a source of several complement proteins.
OBJECTIVE
Little is known about the role of local production of complement components by dendritic cells (DCs) during the generation of specific immune responses. In this study, we demonstrate that human DCs are an extrahepatic source of several soluble complement proteins.


METHODS
Reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot were used to evaluate the expression and production of several complement proteins.


RESULTS
We show that DCs produce C3, C5, C9, Factor (F)I, FH, FB, FD and properdin at levels similar to macrophages. Treatment of DCs with lipopolysaccharide (LPS) promoted an increase in the expression of C3 and FI mRNAs and a decrease in C5 mRNA, while C9, FH, FB, FD and properdin mRNA levels were not affected. Treatment with interleukin (IL) -1 or dexamethasone induced a modest increase in C3 mRNA levels and did not affect the expression of other complement components.


CONCLUSIONS
DCs are a source of complement proteins whose synthesis may be regulated in response to different inflammatory stimuli.
Reis
E S
ES
Laboratório de Complemento, Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1730, CEP 05508-900, São Paulo, SP, Brazil.
Barbuto
J A M
JA
Isaac
L
L
D003165:Complement System Proteins / Q000096:biosynthesis* / Q000235:genetics; D003713:Dendritic Cells / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D009000:Monocytes / Q000166:cytology; D012333:RNA, Messenger / Q000096:biosynthesis
D012333:RNA, Messenger; D003165:Complement System Proteins