Immunodominant “Asymptomatic” Herpes Simplex Virus 1 and 2 Protein Antigens Identified by Probing Whole-ORFome Microarrays with Serum Antibodies from Seropositive Asymptomatic versus Symptomatic Individuals

Abstract

cHerpes simplex virus 1 (HSV-1) and HSV-2 are medically significant pathogens. The development of an effective HSV vaccine remains a global public health priority. HSV-1 and HSV-2 immunodominant "asymptomatic" antigens (ID-A-Ags), which are strongly recognized by B and T cells from seropositive healthy asymptomatic individuals, may be critical to be included in an effective immunotherapeutic HSV vaccine. In contrast, immunodominant "symptomatic" antigens (ID-S-Ags) may exacerbate herpetic disease and therefore must be excluded from any HSV vaccine. In the present study, proteome microarrays of 88 HSV-1 and 84 HSV-2 open reading frames(ORFs) (ORFomes) were constructed and probed with sera from 32 HSV-1-, 6 HSV-2-, and 5 HSV-1/HSV-2-seropositive individuals and 47 seronegative healthy individuals (negative controls). The proteins detected in both HSV-1 and HSV-2 proteome microarrays were further classified according to their recognition by sera from HSV-seropositive clinically defined symptomatic (n ‫؍‬ 10) and asymptomatic (n ‫؍‬ 10) individuals. We found that (i) serum antibodies recognized an average of 6 ORFs per seropositive individual; (ii) the antibody responses to HSV antigens were diverse among HSV-1-and HSV-2-seropositive individuals; (iii) panels of 21 and 30 immunodominant antigens (ID-Ags) were identified from the HSV-1 and HSV-2 ORFomes, respectively, as being highly and frequently recognized by serum antibodies from seropositive individuals; and (iv) interestingly, four HSV-1 and HSV-2 cross-reactive asymptomatic ID-A-Ags, US4, US11, UL30, and UL42, were strongly and frequently recognized by sera from 10 of 10 asymptomatic patients but not by sera from 10 of 10 symptomatic patients (P < 0.001). In contrast, sera from symptomatic patients preferentially recognized the US10 ID-S-Ag (P < 0.001). We have identified previously unreported immunodominant HSV antigens, among which were 4 ID-A-Ags and 1 ID-S-Ag. These newly identified ID-A-Ags could lead to the development of an efficient "asymptomatic" vaccine against ocular, orofacial, and genital herpes.

Human Asymptomatic Epitopes Identified from the Herpes Simplex Virus Tegument Protein VP13/14 (UL47) Preferentially Recall Polyfunctional Effector Memory CD44highCD62LlowCD8+TEMCells and Protect Humanized HLA-A*02:01 Transgenic Mice against Ocular Herpesvirus Infection

“…The HSV-1-derived tegument virion phosphoproteins (VPs), which are located between the capsid and the outer viral envelope proteins, contain a large number of possible protective CD8 ϩ T-cell epitopes (11). However, only a few epitopes have been reported so far.…”

“…Relative mRNA expression levels were calculated using the following formula: ratio ϭ (E target Δ CP target (control Ϫ Tetramer-VP13/14 peptide staining. Fresh PBMCs were analyzed for the frequency of CD8 ϩ T cells recognizing the VP13/14 peptide-tetramer complexes, as we previously described (9)(10)(11)(12). The cells were incubated with the VP13/14 peptide-tetramer complex for 30 to 45 min at 37°C.…”

“…Among the 84-plus open reading frames (ORFs) of the HSV-1 genome, those encoding tegument protein Ags are the least immunologically characterized (9)(10)(11)(12). In animal models of herpesvirus infection and disease, HSV-specific CD8 ϩ T cells play a critical role in aborting attempts of virus reactivation from latency and in clearing herpetic disease (2,4,14,(23)(24)(25).…”

Recent advances in vaccine development for herpes simplex virus types I and II

“…T cells respond differently to HSV epitopes depending on whether the individual is "symptomatic" or "asymptomatic," or having no recurrent clinical disease vs. having clinical, orofacial and or genital episodes, respectively. 1,45 Vaccine research now needs to isotype distribution, much like the previous study using the MVA. 36 Increases in T cell number and response have been observed in mice across prime-boost strategy studies, and both CD4+ and CD8+ T responses were observed in humans following the delivery of the antigen by pDNA followed by that of the recombinant vaccinia virus.…”

“…gD2 is expressed as efficiently as wild-type HSV-2 infection and can lead to a 150-fold reduction in wild-type HSV-2 viral replication in cells co-infected with CJ2-gD2 and wild-type HSV-2 at the same multiplicity of infection. [44][45][46] A DNA prime-formalin-inactivated-HSV-2 (FI-HSV2) boost vaccine approach has recently been tested in the guinea pig model of acute and recurrent HSV-2 genital disease. Two groups were primed with plasmid DNAs encoding the secreted form of glycoprotein D2 (gD2t) and either the helicase (UL5) and DNA polymerase (UL30) genes or the single-stranded DNA binding protein (UL29) and primase (UL52) genes.…”