A comparison of gene transfer and antigen-loaded dendritic cells for the generation of CD4+ and CD8+ cytomegalovirus-specific T cells in HLA-A2+ and HLA-A2− donors

Abstract

Dendritic cells have been used effectively to select for human cytomegalovirus (CMV)-specific T cells for immunotherapy applications. The ability to process and present relevant major histocompatibility complex class I and II peptides to T cells makes them ideal for selecting CD4+ and CD8+ T cells regardless of HLA tissue type. This study compared the generation of CMV-specific T cells by using dendritic cells loaded with either CMV pp65495-503 peptide or CMV lysate or transduced with adenovirus encoding the pp65 gene (Ad5pp65GFP) for the generation of CD4+ and CD8+ CMV-specific T cells in HLA-A2+ and HLA-A2 - donors. In HLA-A2+ donors, CD8+ tetramer+ T cells increased with all antigens but were greatest in peptide- and Ad5pp65GFP-stimulated T cells. The CD4+ /CD8+ ratio in the stimulated T-cell cultures proved to be dependent on the antigen used. CMV lysate-stimulated cells were primarily CD4+, whereas peptide- and Ad5pp65GFP-stimulated cultures were mostly CD8+. Analysis of cells from lysate-stimulated or gene-transduced-stimulated cultures showed expansion of CMV-specific CD4+ T cells, indicating that major histocompatibility complex class II peptides were present in both antigens. Furthermore, CMV-specific T cells were generated from HLA-A2 - donors by using Ad5pp65GFP transduction or CMV lysate stimulation and were able to recognize a pp65 peptide restricted to the HLA-B35 allele. These data indicate that either CMV lysate or adenovirus encoding CMV antigenic genes may be useful for the generation of both CD4+ and CD8+ CMV-specific T cells in donors irrespective of HLA tissue type and may be applicable to clinical immunotherapy.

Stimulation by means of dendritic cells followed by Epstein–Barr virus-transformed B cells as antigen-presenting cells is more efficient than dendritic cells alone in inducing Aspergillus f16-specific cytotoxic T cell responses

“…For this purpose, monocyte-derived DC have been studied extensively as APC in expanding antigen-specific CTL precursors [16,17,28,[32][33][34]. Although DC are proved to be the most potent APC of the immune system, their use to expand CTL lines to clinically feasible numbers is limited by the volume of blood required for the DC preparations, especially for weak antigens that may require repetitive priming to generate responses.…”

Langerhans-Type Dendritic Cells Genetically Modified to Express Full-Length Antigen Optimally Stimulate CTLs in a CD4-Dependent Manner

“…Even the peptide-pulsed LCs stimulated a background CD4 ϩ T cell response (ϳ5%), presumably due to a bystander effect from cytokines secreted during the initial stimulatory culture. Importantly, the CD4 ϩ T cell responses that we detected were not confounded by the introduction of exogenous cytokines that are often used to expand T cells for adoptive immunotherapy (11)(12)(13)(14)21).…”

“…Our intention was not to expand large numbers of T cells ex vivo for adoptive immunotherapy, where the role of CD4 ϩ T cells in such expansion has been difficult to distinguish from the role of exogenous cytokines (11)(12)(13)(14). Furthermore, even though most tumor Ags are either self or self-differentiation Ags, we considered recall responses against an immunogenic viral Ag useful for establishing the principal parameters of Ag presentation by gene-transduced LCs.…”

Strategic use of an adenoviral vector for rapid and efficient ex vivo‐generation of cytomegalovirus pp65‐reactive cytolytic and helper T cells

“…They also have the capacity to present peptides from endocytosed proteins on class I molecules, a process known as cross-presentation (Albert et al, 1998;Rock, 2003;Burgdorf et al, 2007). We and others have shown that DCs transduced with an adenoviral vector expressing the full length CMV pp65 protein (Adpp65) or transfected with mRNA encoding CMV pp65 primarily induce pp65-specific CD8 + T cells while DCs pulsed with CMV lysate primarily induce CD4 + T cells (Carlsson et al, 2003(Carlsson et al, , 2005Foster et al, 2004;Heine et al, 2006). We have also shown that DCs transfected with pp65 mRNA and pulsed with recombinant pp65 protein activates pp65-specific CD8 + and CD4 + T cells simultaneously (Carlsson et al, 2005).…”