Expression of PE_PGRS 62 protein in Mycobacterium smegmatis decrease mRNA expression of proinflammatory cytokines IL-1beta, IL-6 in macrophages.
The pathogenesis of tuberculosis causing Mycobacterium bovis is largely due to its successful entry and survival in macrophages. Previous research indicated that mycobacteria-specific PE_PGRS genes code for cell surface proteins which may have role in mediating interactions with macrophages. In this study, we expressed PE_PGRS 62 gene in a non-pathogenic fast growing Mycobacterium smegmatis strain and found that the recombinant Mycobacterium smegmatis decreased macrophages livability in a dosage-dependent manner and time-dependent manner, compared with parental strain containing the vector only. To explore whether PE_PGRS 62 modulates the gene expression profile of macrophages, we stimulated macrophages by the M. smegmatis strain expressing PE_PGRS 62 as well as the control strains, followed by real-time RT-PCR assay for the mRNA expression level of IL-1beta, IL-6, and iNOS. The results showed that the expression of IL-1beta, IL-6 in macrophages were down-regulated by stimulation with the M. smegmatis strain expressing PE_PGRS 62 compared to the control strains (P < 0.05). In contrast, there were no measurable differences in the expression of iNOS. Overall, we demonstrated that PE_PGRS 62 protein altered the immune environment of the host cells, which suggest that the pathogenic PE_PGRS 62 protein altering the immune mechanism maybe involved in the pathogenesis of mycobacterial disease.
Huang
Ying
Y
National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
Wang
Yang
Y
Bai
Yu
Y
Wang
Zhi Gang
ZG
Yang
Lifeng
L
Zhao
Deming
D
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D015536:Down-Regulation; D015964:Gene Expression Regulation, Bacterial; D018836:Inflammation Mediators / Q000378:metabolism*; D053583:Interleukin-1beta / Q000235:genetics*; D015850:Interleukin-6 / Q000235:genetics*; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D020102:Mycobacterium smegmatis / Q000235:genetics / Q000276:immunology*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D008565:Membrane Proteins; C440642:PE-PGRS protein, Mycobacterium; D012333:RNA, Messenger; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse