Inclusion of the Bovine Neutrophil Beta-Defensin 3 with Glycoprotein D of Bovine Herpesvirus 1 in a DNA Vaccine Modulates Immune Responses of Mice and Cattle

Abstract

Bovine herpesvirus 1 (BoHV-1) causes recurrent respiratory and genital infections in cattle and predisposes them to lethal secondary infections. While modified live and killed BoHV-1 vaccines exist, these are not without problems. Development of an effective DNA vaccine for BoHV-1 has the potential to address these issues. As a strategy to enhance DNA vaccine immunity, a plasmid encoding the bovine neutrophil beta-defensin 3 (BNBD3) as a fusion with truncated glycoprotein D (tgD) and a mix of two plasmids encoding BNBD3 and tgD were tested in mice and cattle. In mice, coadministration of BNBD3 on the separate plasmid enhanced the tgD-induced gamma interferon (IFN-␥) response but not the antibody response. BNBD3 fused to tgD did not affect the antibody levels or the number of IFN-␥-secreting cells but increased the induction of tgD-specific cytotoxic T lymphocytes (CTLs). In cattle, the addition of BNBD3 as a fusion construct also modified the immune response. While the IgG and virus-neutralizing antibody levels were not affected, the number of IFN-␥-secreting cells was increased after BoHV-1 challenge, specifically the CD8؉ CTLs. While reduced virus shedding, rectal temperature, and weight loss were observed, the level of protection was comparable to that observed in pMASIA-tgD-vaccinated animals. These data show that coadministration of BNBD3 with a protective antigen as a fusion in a DNA vaccine strengthened the Th1 bias and increased cell-mediated immune responses but did not enhance protection from BoHV-1 infection.

Porcine β-defensin 2 inhibits proliferation of pseudorabies virus in vitro and in transgenic mice

“…In terms of β-defensins, human β-defensin (HBD) 3 and a synthetic β-defensin analog constituted by domains of HBD-1 and HBD-3 have been confirmed to inactivate HSV [20,25,26]. Bovine neutrophil β-defensin 3 has been found to show inhibitory activity against bovine herpes virus 1 [27,28]. Besides, HBD-2 has been reported to inhibit varicella zoster virus infection [29].…”

Immunogenicity of a Bovine Herpesvirus 1 Glycoprotein D DNA Vaccine Complexed with Bovine Neutrophil Beta-Defensin 3

“…In our quest for this ideal vaccine, we previously studied the immune response-enhancing capacity of BNBD3 (34) in a DNA vaccine as a fusion construct with tgD of BoHV-1. This vaccination strategy increased cell-mediated immune responses, including the induction of CTLs, and was protective against BoHV-1, but these improvements did not result in improved clinical responses, compared to the DNA vaccine encoding tgD alone, which could have been because the vaccine did not concurrently increase humoral responses (22). We then hypothesized that the same cationic peptide, BNBD3, might improve the humoral responses without loss of robust CMI responses if it was formulated in a complex with pMASIA-tgD.…”

“…Following overnight incubation at 4°C, the plates were washed, and bound IgG1 and IgG2a were detected using biotinylated goat anti-mouse IgG1 and IgG2a antibodies (Caltag Laboratories, Burlingame, CA, USA) for 1 h at RT followed by streptavidin-alkaline phosphatase (AP) for 1 h at RT. Bound IgG was detected as described previously (22). All reactions were visualized with 0.01 M p-nitrophenyl phosphate (PNPP) (Sigma-Aldrich), and absorbance was read at 405 nm.…”

“…1). The plasmids pMASIA and pMASIA-tgD (which encodes truncated glycoprotein D [tgD] of BoHV-1) were detailed previously (22). These plasmids were amplified in Escherichia coli JM109 cells and purified with Endofree Plasmid Giga kits (Qiagen, Montreal, PQ, Canada).…”

“…In cattle, a DNA vaccine encoding the DC-chemotactic bovine neutrophil beta-defensin 3 (BNBD3) as a fusion construct with truncated glycoprotein D (tgD) showed protective efficacy against BoHV-1 through increased Th1-type cell-mediated responses (22). The vaccine was unable to improve the clinical responses of BoHV-1-challenged cattle over those observed in animals vaccinated with a DNA vaccine encoding the tgD antigen alone, however, which might have been because the vaccine failed to improve humoral responses.…”