Expansion of Cytomegalovirus pp65 and IE-1 Specific Cytotoxic T Lymphocytes for Cytomegalovirus-Specific Immunotherapy Following Allogeneic Stem Cell Transplantation

Abstract

Adoptive immunotherapy with antigen specific cytotoxic T lymphocytes (CTL) has been shown to be effective in restoring cellular immunity to cytomegalovirus (CMV) and preventing viral reactivation following allogeneic stem cell transplantation (SCT). In order to develop a cost-effective, relatively rapid method of CMV CTL expansion, we investigated the use of a pool of overlapping CMV peptides. Since the possibility exists of vaccinating CMV sero-negative donors, and these individuals may have T cell responses predominantly against IE-1, commercially available peptide mixes for pp65 as well as IE-1 were used to stimulate CTL from ten sero-positive donors. In four of these ten donors, responses were present to pp65 only, one donor did not respond to pp65 or IE-1, four donors responded to both pp65 and IE-1, and one donor to IE-1 only. These CMV specific T cells included a mixture of CD4+ and CD8+ effectors, and specific cytotoxicity correlated with IFN-γ production. The costs associated with a 28 day maintenance course of intravenous ganciclovir, cidofovir, foscarnet, and valganciclovir, as well as the preparation and shipping a single dose of CTL, were determined. The price of generating CMV CTL using this method was comparable to or less expensive than a 28-day maintenance course for these agents, not including the costs associated with drug administration, supportive care, and the treatment of drug-related complications. Considering the relative ease, low cost, and the fact that CTL administration can result in CMV specific immune reconstitution, this option should be considered for patients with CMV reactivation, or for prophylaxis in patients at high risk for infection.

Adoptive Immunotherapy With CMV-specific Cytotoxic T Lymphocytes for Stem Cell Transplant Patients With Refractory CMV Infections

“…CMV pp65 or IE1 specific cytotoxicity and IFN-γ production was present in each of these donors, and data from donor CTL that were infused are presented in Figure 1. This is consistent with our previous findings in which CMV pp65 or IE1 specific CTL could be cultured from the majority of healthy donors 17 . The average pp65 specific cytotoxicity for the products was 37 % (range 21-58 %) and 30% for IE1 (range 21%-38%).…”

“…Multiple-color staining of immunophenotypic markers, both surface and intracellular, was performed as previously described 17 . In brief, T cells were incubated with equal numbers of stimulators, including autologous BB pulsed with pp65 and IE1 overlapping peptides or B blasts infected with either vaccinia encoding pp65 or IE1, and autologous and allogeneic BB, in RPMI 1640 with 10% FCS and in the presence of 10 μg/ml brefeldin A (Sigma) at 37°C for 5 hours.…”

Immune Reconstitution Following Unmanipulated HLA-Mismatched/Haploidentical Transplantation Compared with HLA-Identical Sibling Transplantation

“…Therefore, attention should be focused on adoptive cellular immunotherapy, such as donor-derived NK subsets [38], as well as CMV specific cytotoxic T lymphocytes [39]. These approaches can potentially improve early immune recovery and decrease the incidence of CMV antigenemia following unmanipulated haploidentical transplantation.…”

Expanding Cytotoxic T Lymphocytes from Umbilical Cord Blood that Target Cytomegalovirus, Epstein-Barr Virus, and Adenovirus

“…We and others have shown that such T cells are safe, efficacious, and cost-effective. [15][16][17] Here, we show that this approach can also be extended to cord blood.…”