title: Lentiviral Protein Transfer Vectors Are an Efficient Vaccine Platform and Induce a Strong Antigen-Specific Cytotoxic T Cell Response.
abstract: To induce and trigger innate and adaptive immune responses, antigen-presenting cells (APCs) take up and process antigens. Retroviral particles are capable of transferring not only genetic information but also foreign cargo proteins when they are genetically fused to viral structural proteins. Here, we demonstrate the capacity of lentiviral protein transfer vectors (PTVs) for targeted antigen transfer directly into APCs and thereby induction of cytotoxic T cell responses. Targeting of lentiviral PTVs to APCs can be achieved analogously to gene transfer vectors by pseudotyping the particles with truncated wild-type measles virus (MV) glycoproteins (GPs), which use human SLAM (signaling lymphocyte activation molecule) as a main entry receptor. SLAM is expressed on stimulated lymphocytes and APCs, including dendritic cells. SLAM-targeted PTVs transferred the reporter protein green fluorescent protein (GFP) or Cre recombinase with strict receptor specificity into SLAM-expressing CHO and B cell lines, in contrast to broadly transducing vesicular stomatitis virus G protein (VSV-G) pseudotyped PTVs. Primary myeloid dendritic cells (mDCs) incubated with targeted or nontargeted ovalbumin (Ova)-transferring PTVs stimulated Ova-specific T lymphocytes, especially CD8(+) T cells. Administration of Ova-PTVs into SLAM-transgenic and control mice confirmed the observed predominant induction of antigen-specific CD8(+) T cells and demonstrated the capacity of protein transfer vectors as suitable vaccines for the induction of antigen-specific immune responses.
  
  
  OBJECTIVE
  This study demonstrates the specificity and efficacy of antigen transfer by SLAM-targeted and nontargeted lentiviral protein transfer vectors into antigen-presenting cells to trigger antigen-specific immune responses in vitro and in vivo. The observed predominant activation of antigen-specific CD8(+) T cells indicates the suitability of SLAM-targeted and also nontargeted PTVs as a vaccine for the induction of cytotoxic immune responses. Since cytotoxic CD8(+) T lymphocytes are a mainstay of antitumoral immune responses, PTVs could be engineered for the transfer of specific tumor antigens provoking tailored antitumoral immunity. Therefore, PTVs can be used as safe and efficient alternatives to gene transfer vectors or live attenuated replicating vector platforms, avoiding genotoxicity or general toxicity in highly immunocompromised patients, respectively. Thereby, the potential for easy envelope exchange allows the circumventing of neutralizing antibodies, e.g., during repeated boost immunizations.
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Katharina M
authors.initials: KM
authors.lastname: Uhlig
authors.affiliation: Molecular Allergology, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schülke
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Vivian A M
authors.initials: VA
authors.lastname: Scheuplein
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Anna H
authors.initials: AH
authors.lastname: Malczyk
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Reusch
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Kugelmann
authors.affiliation: Molecular Biotechnology and Gene Therapy, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Muth
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Vivian
authors.initials: V
authors.lastname: Koch
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hutzler
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Bianca S
authors.initials: BS
authors.lastname: Bodmer
authors.affiliation: Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Schambach
authors.affiliation: Molecular Biotechnology and Gene Therapy, Paul-Ehrlich-Institut, Langen, Germany German Cancer Consortium, Heidelberg, Germany.
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Buchholz
authors.affiliation: Novel Vaccination Strategies and Early Immune Responses, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Waibler
authors.affiliation: Molecular Allergology, Paul-Ehrlich-Institut, Langen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Scheurer
authors.affiliation: Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut, Langen, Germany Michael.Muehlebach@pei.de.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Mühlebach
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000276:immunology*; D016466:CHO Cells; D003412:Cricetulus; D003713:Dendritic Cells / Q000276:immunology; D005822:Genetic Vectors / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000096:biosynthesis; D057809:HEK293 Cells; D006801:Humans; D019426:Integrases / Q000096:biosynthesis / Q000235:genetics; D016086:Lentivirus / Q000235:genetics; D008213:Lymphocyte Activation / Q000276:immunology; D008459:Measles virus / Q000235:genetics; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D010047:Ovalbumin / Q000276:immunology*; D021381:Protein Transport; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000276:immunology*; D000071177:Signaling Lymphocytic Activation Molecule Family Member 1; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection; D022223:Vaccines, Subunit / Q000276:immunology; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics; D014760:Viral Fusion Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D015703:Antigens, CD; C028391:G protein, vesicular stomatitis virus; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D022223:Vaccines, Subunit; D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins; D049452:Green Fluorescent Proteins; D000071177:Signaling Lymphocytic Activation Molecule Family Member 1; D010047:Ovalbumin; C045073:Cre recombinase; D019426:Integrases