[Role of interleukin 17 in viral myocarditis and dilated cardiomyopathy].
OBJECTIVE
To explore the role of interleukin-17 (IL-17) in the evolution of viral myocarditis (VMC) into dilated cardiomyopathy (DCM).


METHODS
A mouse model of VMC was established in 100 male Balb/c mice by intraperitoneal injection of coxsackievirus B3. The expression of IL-17 protein in the cardiac tissue of the mice was detected immunohistochemically, and IL-17 mRNA in the splenocytes was examined by reverse transcription-polymerase chain reaction (RT-PCR). IL-17 levels in the plasma, peripheral blood mononuclear cell (PBMC) culture supernatants, and phytohemagglutinin (PHA)-stimulated PBMC culture supernatants were measured in 30 DCM patients, 26 non-DCM patients and 20 normal adults using enzyme-linked immunosorbent assay (ELISA), and IL-17 mRNA expression in the PBMCs was detected using RT-PCR.


RESULTS
The levels of IL-17 mRNA in the splenocytes of the mice with VMC were significantly higher at 4 and 6 weeks than those at 8 weeks (P<0.01), but not detected at 2 weeks. No IL-17 expression was found in the ventricular tissue of the mice at 2 weeks, but peaked at 4 weeks followed by gradual decrease (P<0.01). IL-17 level in PHA-stimulated PBMC culture supernatants but not the plasma, and its mRNA level in PHA-stimulated PBMCs but not the PBMC culture supernatants, were significantly elevated in DCM patients as compared with those in non-DCM patients and normal control subjects.


CONCLUSIONS
The mouse model of VMC in the chronic phase and DCM patients express high levels of IL-17, which may contribute to the transition from VMC to DCM.
Department of Cardiology, Institute of Cardiovascular Diseases, First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China. gxlinsong@hotmail.com
Song
S
Lin
Yan-lan
YL
Huang
Wei-feng
WF
Wu
Yong
Y
Li
Shao-dong
SD
Tang
D000328:Adult; D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D003384:Coxsackievirus Infections / Q000150:complications / Q000378:metabolism; D029822:Enterovirus B, Human; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D009205:Myocarditis / Q000150:complications / Q000378:metabolism* / Q000821:virology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D020381:Interleukin-17; D012333:RNA, Messenger