Activation, dysfunction and retention of T cells in vaccine sites after injection of incomplete Freund’s adjuvant, with or without peptide

Abstract

We conducted a randomized clinical trial in 45 patients with resected AJCC stage IIB-IV melanoma to characterize cellular and molecular events at sites of immunization with incomplete Freund’s adjuvant (IFA) alone, or a melanoma vaccine in IFA. At a primary vaccine site, all patients received a multi-peptide melanoma vaccine in IFA. At a replicate vaccine site, which was biopsied, group 1 received IFA only; group 2 received vaccine in IFA. Lymphocytes isolated from replicate vaccine site microenvironments (VSME) were compared to time-matched peripheral blood mononuclear cells (PBMC) in ELISpot and flow cytometry assays. Compared to PBMC, the VSME had fewer naïve and greater proportions of effector memory CD8+ T cells (TCD8). The vast majority of TCD8 within the VSME were activated (CD69+), with a concentration of antigen-specific (tetramerpos) cells in the VSME, particularly in vaccine sites with peptide (group 2). CXCR3+ lymphocytes were concentrated in the VSME of all patients, suggesting IFA-induced chemokine recruitment. TCD8 expression of retention integrins αEβ7 and α1β1 was elevated in VSME, with the highest levels observed in antigen-specific cells in VSME containing peptide (group 2). TCD8 retained in the VSME of both groups were strikingly dysfunctional, with minimal IFN-γ production in response to peptide stimulation and few tetramerpos cells producing IFN-γ. These data suggest that vaccine-induced selective retention and dysfunction of antigen-specific TCD8 within VSME may represent a significant mechanism underlying transient immune responses and low clinical response rates to peptide vaccines administered in IFA.

Immunologic hierarchy, class II MHC promiscuity, and epitope spreading of a melanoma helper peptide vaccine

“…Therefore, the ability of helper peptides to induce CD4 responses and de novo CD8 T cell anti-tumor responses in the absence of GM-CSF may exceed those observed in the present study. Recent evidence also suggests that T cells primed with peptides in IFA may not migrate to tumor locations but be retained at the vaccine site, where they undergo dysfunction and subsequent apoptosis [24, 25]. Although this has been demonstrated with short (9-mer) peptides in IFA, such an effect may be circumvented by employing longer peptide epitopes due to requisite presentation by dendritic cells in local lymph nodes, away from the effects of IFA at the vaccine site [26].…”

Safety and tolerability evaluation of the use of Montanide ISA™51 as vaccine adjuvant: A systematic review

“…After removing duplicate entries, 462 studies were evaluated for inclusion based on the title and/or abstract, after which 114 potentially relevant studies were included for full-text examination; the majority of excluded studies were reviews or animal studies and 6 studies were not reported in English. From the 114 studies, full-text was unavailable for one study 13 , 2 studies were duplicates published under different titles 14,15 , one study only described the study design 16 and 6 studies did not report safety, tolerability and/or toxicity results 7,[17][18][19][20][21] . These together with 11 case reports [22][23][24][25][26][27][28][29][30][31][32] and 2 letters to the editor were excluded 33,34 .…”

Defining the effects of age and gender on immune response and outcomes to melanoma vaccination: a retrospective analysis of a single-institution clinical trials’ experience

“…For the Mel48 trial (NCT00705640), all patients received the same vaccine of 12MP plus tetanus helper peptide (MELITAC 12.1), but differed in whether the vaccine peptides were administered at one or two sites [26-27]. …”