Compartmentalization of Hepatitis C Virus Genotypes between Plasma and Peripheral Blood Mononuclear Cells

Abstract

Differences in hepatitis C virus (HCV) variants of the highly conserved 5 untranslated region (UTR) have been observed between plasma and peripheral blood mononuclear cells (PBMC). The prevalence and the mechanisms of this compartmentalization are unknown. Plasma and PBMC HCV variants were compared by single-strand conformation polymorphism (SSCP) and by cloning or by genotyping with a line probe assay (LiPA) in 116 chronically infected patients, including 44 liver transplant recipients. SSCP patterns differed between compartments in 43/109 analyzable patients (39%). Differences were significantly more frequent in patients with transplants (21/38 [55%] versus 22/71 [31%]; P < 0.01) and in those who acquired HCV through multiple transfusions before 1991 (15/20; 75%) or through drug injection (16/31; 52%) than in those infected through an unknown route (7/29; 24%) or through a single transfusion (5/29; 17%; P < 0.001). Cloning of the 5 UTR, LiPA analysis, and nonstructural region 5B sequencing revealed different genotypes in the two compartments from 10 patients (9%). In nine patients, the genotype detected in PBMC was not detected in plasma and was weak or undetectable in the liver in three cases. This genotypic compartmentalization persisted for years in three patients and after liver transplantation in two. The present study shows that a significant proportion of HCV-infected subjects harbor in their PBMC highly divergent variants which were likely acquired through superinfections.Hepatitis C virus (HCV) frequently leads to chronic infection contributing to liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped, positive-stranded RNA virus that circulates in vivo as a population of closely related variants collectively referred to as a quasispecies. This quasispecies nature may be involved in viral persistence at the early stages of infection (12), allowing the emergence of immune escape mutants (11, 13). The infection of immune cells could be another viral mechanism of evasion contributing to host failure in eradicating the virus (32). The issue of extrahepatic replication of HCV is still debated. Detection of HCV RNA in extrahepatic compartments can be due to the adsorption of plasma variants (17, 31). However, the minus-stranded HCV RNA, the replicative intermediate, which is not detected in plasma, has been detected in peripheral blood mononuclear cells (PBMC) in many studies (4,8,10,15,18,21,22,23,25,28,37), but this is not sufficient to demonstrate that a complete and productive replication of HCV really occurs in these cells.Another point supporting autonomous HCV replication in PBMC is the common finding in these cells of HCV variants differing from those circulating in serum (26, 31). The study of different blood cell subsets also revealed that quasispecies compositions can differ significantly between peripheral B and T lymphocytes, monocytes, and plasma (1). We have recently shown that this compartmentalization is a frequent phenomenon (10).Compartmentalization of HCV variants has been mai...

Extrahepatic replication of HCV: Insights into clinical manifestations and biological consequences

“…[79][80][81] While some of these data should be viewed cautiously, as a variety of techniques were utilized and a limited number of samples [82][83][84] Interestingly, sequence analysis has subsequently revealed that certain viral variants may be selected for growth in extrahepatic cell types, implying that HCV diversity directly impacts cell tropism. 85,86 Furthermore, several studies have described a non-random distribution of HCV sequences in hepatic and extrahepatic compartments, 72,[87][88][89][90][91][92][93][94][95][96] leading to the conclusion that the presence of tissue-specific sequences is compatible with independent viral replication in extrahepatic sites. It has also been speculated that HCV variants within distinct compartments may differ in their sensitivity to interferon, although this hypothesis has not been formally tested.…”

IRES complexity before IFN‐alpha treatment and evolution of the viral load at the early stage of treatment in peripheral blood mononuclear cells from chronic hepatitis C patients

“…The presence of negative-strand RNA in PBMCs from infected patients has been demonstrated (Ducoulombier et al, 2004;Lanford et al, 1995;Laskus et al, 2000;Lerat et al, 2000;Moldvay et al, 1994) which suggests the existence of a potentially important extrahepatic site of HCV replication (Bain et al, 2001;Laporte et al, 2003;Roque Afonso et al, 1999;Roque-Afonso et al, 2005). Many viruses possess strategies for evading or limiting the interferon-induced antiviral response and lead to progression of a disease.…”

Mixed Genotypes in Hepatitis C Virus Infection

“…Compartmentalization between different tissues of the same patient (serum-brain, serumsaliva, serum-peripheral blood mononuclear cells) was described in several studies (Radkowski et al, 2002;Roque Afonso et al, 2005). Furthermore, the existence of different genotypes and/or viral variants in different tissues of the same patient has been also demonstrated (Radkowski et al, 2002;Roy et al, 1998) and particularly, peripheral blood mononuclear cells can harbor distinct HCV variants that are not detected in plasma samples (Di Liberto et al, 2006, Roque-Afonso et al, 2005; adding a potential complication to the assessment of the correct HCV genotype.…”

“…Although peripheral blood mononuclear cells (PBMC) are not the primary site of HCV replication, previous reports emphasize their role as viral reservoirs (Radkowski et al, 2005;Pham et al, 2004). Furthermore, different genotypes have been reported both in plasma and PBMC (Roque Afonso et al, 2005) and it has also been speculated that extrahepatic HCV diversity may be an important determinant of treatment response (Blackard et al, 2007). The final purpose of our study was to investigate the existence of unapparent HCV mixed infections in the hemophilic population in Argentina, analyzing the HCV genotypes detected in plasma or serum samples and comparing them to viral strains emerging under long-term PBMC cultures.…”

“…Furthermore, the existence of different genotypes and/or viral variants in different tissues of the same patient has been also demonstrated (Radkowski et al, 2002;Roy et al, 1998) and particularly, peripheral blood mononuclear cells can harbor distinct HCV variants that are not detected in plasma samples (Di Liberto et al, 2006, Roque-Afonso et al, 2005; adding a potential complication to the assessment of the correct HCV genotype. As a consequence of unknown and multiple host-viral factors, different HCV genotypes between compartments (liver and extrahepatic reservoirs) could be reflecting true different viral variant proportions.…”