Cellular and humoral immune responses to alphavirus replicon vaccines expressing cytomegalovirus pp65, IE1, and gB proteins.
Development of vaccines against cytomegalovirus (CMV) is an important public health priority. We used a propagation-defective, single-cycle RNA replicon vector system derived from an attenuated strain of an alphavirus, Venezuelan equine encephalitis virus, to produce virus-like replicon particles (VRP) expressing various combinations of pp65, IE1, or gB proteins of human CMV. Protein expression in VRP-infected cells was highest with single-promoter replicons expressing pp65, IE1, a pp65/IE1 fusion protein, or the extracellular domain of gB and with double-promoter replicons expressing pp65 and IE1. Protein expression was lower with double- and triple-promoter replicons expressing gB, especially the full-length form of gB. BALB/c mice immunized with VRP expressing gB developed high titers of neutralizing antibody to CMV, and mice immunized with VRP expressing pp65, IE1, or a pp65/IE1 fusion protein developed robust antigen-specific T-cell responses as measured by gamma interferon enzyme-linked immunospot assay. Three overlapping immunodominant pp65 peptides contained a nine-amino-acid sequence (LGPISGHVL) that matches the consensus binding motif for a major histocompatibility complex H2-D(d) T-cell epitope. These data provide the basis for further development and clinical evaluation of an alphavirus replicon vaccine for CMV expressing the pp65, IE1, and gB proteins.
Reap
Elizabeth A
EA
AlphaVax, Inc., 2 Triangle Drive, P.O. Box 110307, Research Triangle Park, NC 27709-0307, USA. reap@alphavax.com
Dryga
Sergey A
SA
Morris
John
J
Rivers
Bryan
B
Norberg
Pamela K
PK
Olmsted
Robert A
RA
Chulay
Jeffrey D
JD
D000818:Animals; D000917:Antibody Formation; D002522:Chlorocebus aethiops; D003587:Cytomegalovirus / Q000276:immunology*; D005260:Female; D006801:Humans; D017874:Immediate-Early Proteins / Q000276:immunology*; D007111:Immunity, Cellular; D007114:Immunization / Q000379:methods; D007117:Immunization, Secondary; D051379:Mice; D008807:Mice, Inbred BALB C; D010750:Phosphoproteins / Q000276:immunology*; D012093:Replicon / Q000276:immunology*; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000276:immunology*; D014764:Viral Proteins / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
C088645:IE1 protein, cytomegalovirus; D017874:Immediate-Early Proteins; D010750:Phosphoproteins; D014759:Viral Envelope Proteins; D014763:Viral Matrix Proteins; D014764:Viral Proteins; D014765:Viral Vaccines; C065418:cytomegalovirus matrix protein 65kDa; C040495:glycoprotein B, Simplexvirus