Abstract
Purpose: Progression of viral infection to either acute or chronic state depends on the efficacy of the host immune response. Whereas acute viral hepatitis invites a vigorous, multispecific T-cell response, chronic viral hepatitis is associated with a weaker, narrowly focused response. Specific T-cell hyporesponsiveness in the later could be due to inefficient delivery of antigens to MHC class I molecules. Antigen processing and transport to MHC class I primarily involves, Low molecular weight protein (LMP);2 and7 and Transporter Associated with Antigen Processing (TAP)1 and2 genes. Immune system modifies this complex by addition of these subunits induced by IFN-γ. We hypothesize that proteasome subunits shape the specific T-cell response and it may be dysfunctionally regulated in peripheral blood lymphocytes in chronic infections. Aim: To investigate the expression of antigen processing and presentation genes in acute hepatitis B (AHB), acute hepatitis E (AHE), chronic hepatitis B (CHB) and chronic hepatitis C (CHC) patients. Methods: Fifty subjects were studied:10 of each category, AHB (age 33.3 ± 19.8 yr., M = 7), AHE (age31.7 ± 16.5 yr., M = 7), CHB (age 29.4 ± 13.2 yr., M = 8), CHC (age 45.5 ± 18.1 yr., M = 8) and controls (age 27.9 ± 4.6 yr., M = 7). Total RNA was isolated from PBMC's and cDNA was prepared and mRNA expression of TAP1, TAP2, LMP2 and LMP7 genes was quantified by Real-Time PCR. Results: No significant difference in expression patterns between AHB and AHE was found. LMP2 was upregulated in AHB (P= 0.051) and AHE (0.059) compared to controls. In CHC, LMP2 was significantly downregulated and TAP2 was upregulated in comparison to AHB and AHE. In CHB, TAP 1 and LMP 7 were significantly downregulated compared to controls and AH groups (P= 0.034, 0.006). Conclusion: i) Downregulation of LMP7 and TAP1 in CHBV and LMP2 in CHC suggests that the catalytic subunits of proteasome complex and antigen presentation genes play significant role in HBV and HCV persistence, ii) Similar profile in AHB and AHE suggests that while viral strains differ, acute hepatitis invites similar antigen processing pathways.[figure1]Figure
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
