Detection of Genotype-Specific Antibody Responses to Glycoproteins B and H in Primary and Non-Primary Human Cytomegalovirus Infections by Peptide-Based ELISA

• Main Authors: Federica Zavaglio, Loretta Fiorina, Nicolás M. Suárez, Chiara Fornara, Marica De Cicco, Daniela Cirasola, Andrew J. Davison, Giuseppe Gerna, Daniele Lilleri
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Viruses
• Subjects: human cytomegalovirus; glycoprotein B; glycoprotein H; genotype; antibody; primary infection
• Online Access: https://www.mdpi.com/1999-4915/13/3/399

Background: Strain-specific antibodies to human cytomegalovirus (HCMV) glycoproteins B and H (gB and gH) have been proposed as a potential diagnostic tool for identifying reinfection. We investigated genotype-specific IgG antibody responses in parallel with defining the gB and gH genotypes of the infecting viral strains. Methods: Subjects with primary (<i>n</i> = 20) or non-primary (<i>n</i> = 25) HCMV infection were studied. The seven gB (gB1-7) and two gH (gH1-2) genotypes were determined by real-time PCR and whole viral genome sequencing, and genotype-specific IgG antibodies were measured by a peptide-based enzyme-linked immunosorbent assay (ELISA). Results: Among subjects with primary infection, 73% (<i>n</i> = 8) infected by gB1-HCMV and 63% (<i>n</i> = 5) infected by gB2/3-HCMV had genotype-specific IgG antibodies to gB (gB2 and gB3 are similar in the region tested). Peptides from the rarer gB4-gB7 genotypes had nonspecific antibody responses. All subjects infected by gH1-HCMV and 86% (<i>n</i> = 6/7) infected by gH2-HCMV developed genotype-specific responses. Among women with non-primary infection, gB and gH genotype-specific IgG antibodies were detected in 40% (<i>n</i> = 10) and 80% (<i>n</i> = 20) of subjects, respectively. Conclusions: Peptide-based ELISA is capable of detecting primary genotype-specific IgG responses to HCMV gB and gH, and could be adopted for identifying reinfections. However, about half of the subjects did not have genotype-specific IgG antibodies to gB.