Changes in the Distribution Pattern of Hepatitis C Virus Genotypes Among Chronic Hepatitis Patients: a Cross-Sectional Study

BACKGROUND

Hepatitis C virus (HCV) is a major cause of liver diseases. It has been determined that HCV genotypes have a distinct geographical distribution, clinical outcome, and response to antiviral therapy. Over the past years, many studies have reported that HCV genotype 1a is the dominant genotype in Ahvaz city. In recent years, changes in the distribution pattern of HCV genotypes of different geographical regions have attracted a great deal of attention; hence, the aim of this study was to accurately evaluate such probable changes in Ahvaz in southwestern Iran.

METHODS

This is a cross-sectional study conducted from September 2017 to August 2020, including 262 patients suffering from chronic hepatitis C. HCV-RNA was extracted, and HCV genotyping was performed by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) method. To evaluate the association between HCV genotype, age, gender, and viral load, statistical analyses were done by SPSS software.

RESULTS

HCV genotyping was done on 260 patients where genotype 3a had the highest prevalence over the period of 4 years with an average of 48.1%, followed by genotype 1a (46.5%). HCV genotype of two patients was not typeable. Although the difference between the two genotypes is currently small, the main result was finding an increasing trend in the prevalence of genotype 3a in recent years.

CONCLUSIONS

The present study showed that the distribution pattern of HCV genotypes is gradually changing among chronic hepatitis C patients in Ahvaz city. The most important cause of such changes could be the alteration in HCV transmission routes and the increase in migration from areas where genotype 3 is dominant.

Listeriolysin O immunogenetic adjuvant enhanced potency of hepatitis C virus NS3 DNA vaccine

Hepatitis C virus (HCV) is a major health problem all over the world. Among HCV proteins, nonstructural protein 3 (NS3) is one of the most promising target for anti-HCV therapy and a candidate for vaccine design. DNA vaccine is an efficient approach to stimulate antigen-specific immunity but the main problem with that is less immunogenic efficiency in comparison with traditional vaccines. Several approaches have been applied to enhance the immunogenicity of DNA. Recently, bacteria-derived substances are considered as one of the most attractive adjuvants for vaccines, which among them, Listeriolysin O (LLO) of Listeria monocytogenes is a toxin with an extremely immunogenic feature. We investigated detoxified form of LLO gene as genetic adjuvant to modulate NS3 DNA vaccine potency. Immunogenic truncated NS3 gene sequence of HCV (1095-1380aa) and detoxified LLO gene region (5-441aa) were amplified by PCR and cloned into the pcDNA3.1 plasmid separately. The expression of recombinant proteins (pc-NS3, pLLO) was confirmed in HEK293T cell line by western blotting. BALB/c mice models received three doses of different formula of plasmids in two-week intervals and two weeks after the final immunization, the immune responses were evaluated by specific total antibody level, lymphocyte proliferation, cytotoxicity, and cytokine levels assays. To evaluate in vivo cytotoxic activity, tumor challenge was performed. The recombinant plasmids were successfully expressed in mammalian cell line, and coadministration of pc-NS3 with pLLO induced the highest titer of total IgG against NS3 antigen compared with other controls. Determination of IgG subclasses confirmed the efficient increase in mixed responses with Th1 dominancy. Furthermore, significant levels of cytokines (p < .05) and lymphocyte proliferation responses (p < .05) indicated the superiority of this regimen. The findings may have important implication for LLO gene application as genetic adjuvant in immune response against HCV.