Antibody Profiling by Proteome Microarray Reveals the Immunogenicity of the Attenuated Smallpox Vaccine Modified Vaccinia Virus Ankara Is Comparable to That of Dryvax

Abstract

Modified vaccinia virus Ankara (MVA) is a highly attenuated vaccinia virus that is under consideration as an alternative to the conventional smallpox vaccine Dryvax. MVA was attenuated by extensive passage of vaccinia virus Ankara in chicken embryo fibroblasts. Several immunomodulatory genes and genes that influence host range are deleted or mutated, and replication is aborted in the late stage of infection in most nonavian cells. The effect of these mutations on immunogenicity is not well understood. Since the structural genes appear to be intact in MVA, it is hypothesized that critical targets for antibody neutralization have been retained. To test this, we probed microarrays of the Western Reserve (WR) proteome with sera from humans and macaques after MVA and Dryvax vaccination. As most protein sequences of MVA are 97 to 99% identical to those of other vaccinia virus strains, extensive binding cross-reactivity is expected, except for those deleted or truncated. Despite different hosts and immunization regimens, the MVA and Dryvax antibody profiles were broadly similar, with antibodies against membrane and core proteins being the best conserved. The responses to nonstructural proteins were less well conserved, although these are not expected to influence virus neutralization. The broadest antibody response was obtained for hyperimmune rabbits with WR, which is pathogenic in rabbits. These data indicate that, despite the mutations and deletions in MVA, its overall immunogenicity is broadly comparable to that of Dryvax, particularly at the level of antibodies to membrane proteins. The work supports other information suggesting that MVA may be a useful alternative to Dryvax.

A Burkholderia pseudomallei protein microarray reveals serodiagnostic and cross-reactive antigens

“…Our finding that these cross-reactive antigens also reacted equally with sera from individuals in the USA suggests that cross-reactive antibodies may be responsible for these signals. This finding contrasts markedly to our previous studies with Francisella tularensis (7,29), Borrelia burgdorferi (5), Plasmodium falciparum (6), and vaccinia (8), where reactivity of arrayed proteins with naïve patient sera was minimal or not seen.…”

“…These arrays can be used to address basic questions about the interactions of a given pathogen with the host immune system (8)(9)(10), and allows the identification of proteins which can be used as diagnostic reagents or for inclusion in vaccines (3). The empirical data gathered from this type of array can also be used to evaluate and improve the accuracy of in silico antigen prediction of a proteome.…”

Vaccinomics for the Major Blood Feeding Helminths of Humans

“…Cell-free protein expression systems, whether they be components of prokaryotic or eukaryotic cells, do not possess the cellular machinery to process secreted proteins and will not always faithfully reproduce the correct fold. Nonetheless, the high-throughput nature of this expression system lends itself well to immunomic studies and has proven to be an excellent tool for identifying antigens from a range of single celled pathogens at least (Crompton et al, 2010;Davies et al, 2008;Eyles et al, 2007).…”

Long-Term Immunity against Actual Poxviral HLA Ligands as Identified by Differential Stable Isotope Labeling

“…Dryvax, the only currently licensed vaccine against smallpox, carries the highest rate of side effects of any approved vaccine. Therefore, modified vaccinia virus Ankara (MVA), an attenuated replication-deficient strain of VACV, is currently being tested as a safer third-generation vaccine (5,(7)(8)(9). A more detailed understanding of the CTL response to MVA allows both the development of epitope-based vaccines promising a safe, stable, and handy alternative to traditional vaccination strategies, as well as the monitoring of clinical trials by following MVA-specific T cell responses (10,11).…”