Up to 40% of HIV-1 infected individuals are coinfected with human pegivirus type 1 (HPgV-1). The majority of studies, but not all, have reported a beneficial effect of HPgV-1 coinfection on HIV-1 disease progression. So far, the impact of different HPgV-1 genotypes on different HIV-1 subtypes remains unclear.
Peptides derived from HPgV-1 envelope protein E2, and representing different viral genotypes, were synthesized using Fmoc/t-Bu-based solid phase peptide synthesis. The inhibitory effect of these peptides on the infection of reporter cell lines was tested using an HIV-1 subtype panel representing clades A (n = 2), AG (n = 2), B (n = 6), C (n = 2), D (n = 2), F (n = 2), G (n = 1), G/H (n = 1), and group O (n = 2).
HIV-1 infection was blocked more efficiently by peptides derived from HPgV-1 GT2 than GT1 (P = 0.05). The HIV-1 subtype did not affect the degree of inhibition by a peptide derived from HPgV-1 GT2. All CXCR4-/dual-tropic isolates (n = 12), but only half (four out of eight) CCR5-tropic viruses were inhibited by this peptide (P = 0.014).
Our data indicate that the inhibitory effect of peptides derived from HPgV-1 E2 protein is dependent on the genotype, suggesting that coinfection with HPgV-1 GT1 is less likely to confer a beneficial effect on HIV-1 disease progression than GT2. The preferential suppression of more pathogenic CXCR4-tropic HIV-1 by peptides derived from HPgV-1 GT2 may explain the favorable effect in patients harboring these HIV-1 isolates. Consequently, HPgV-1 genotype and HIV-1 coreceptor tropism are likely determinants for the beneficial effect of HPgV-1 co-infection in HIV-1-infected individuals.
aInstitute of Clinical Microbiology and Hygiene, University of Regensburg, Regensburg
bDepartment of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg
cGemeinschaftspraxis Alte Mälzerei
dInfectious Diseases, University Hospital of Regensburg, Regensburg
eInstitute of Clinical and Molecular Virology, Friedrich-Alexander-Universität Erlangen-Nürnberg
fInstitute of Medical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany.
Correspondence to Barbara Schmidt, MD, Institute of Clinical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany. Tel: +49 941 944 6404; fax: +49 941 944 6402; e-mail: email@example.com
Received 18 January, 2018
Revised 5 May, 2018
Accepted 14 May, 2018
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