Functional profile of human influenza virus-specific cytotoxic T lymphocyte activity is influenced by interleukin-2 concentration and epitope specificity

Abstract

SummaryThe ability of influenza A virus-specific cytotoxic T lymphocytes (CTL) to degranulate and produce cytokines upon antigenic restimulation was studied in four HLA-A*0101 and HLA-A*0201 positive subjects. Peripheral blood mononuclear cells of these subjects were stimulated with influenza A virus in the presence of high or low interleukin (IL)-2 concentrations. CD8 + T cell populations specific for the HLA-A*0101 restricted epitope NP 44-52 and the HLA-A*0201 restricted epitope M1 58-66 were identified by positive staining with tetramers of peptide major histocompatibility complexes (MHC) (NP-Tm and M1-Tm, respectively). Within these populations, the proportion of cells mobilizing CD107a, or expressing interferon (IFN)-g g g g and tumour necrosis factor-(TNF)-a a a a upon short-term peptide restimulation was determined by flow cytometry. Independent of IL-2 concentrations, large subjectdependent differences in the mobilization of CD107a and expression of IFN-g g g g and TNF-a a a a by both NP-and M1-specific T cells were observed. In two of the four subjects, the functional profile of NP-Tm + and M1-Tm + cells differed considerably. Overall, no difference in the proportion of NP-Tm + or M1-Tm + cells expressing CD107a was observed. The proportion of M1-Tm + cells that produced IFN-g g g g ( P < 0·05) was larger than for NP-Tm + cells, independent of IL-2 concentration. When cultured under IL-2 hi concentrations higher TNF-a a a a expression was also observed in M1-Tm + cells ( P < 0·05). The IL-2 concentration during expansion of virus-specific cells had a profound effect on the functionality of both M1-Tm + and NP-Tm + cells.

In vitro detection of cytotoxic T and NK cells in peripheral blood of patients with various drug‐induced skin diseases

“…Both GzB ELISPOT and the degranulation marker CD107a have been used successfully to detect peptide‐specific CTLs in patients with chronic virus infections and in vaccine clinical trials (24, 26–28). These peptide‐specific T cells are primed in vivo and can be detected within 5–20 h in GzB ELISPOT assays.…”

The Hypervariable Immunodominant NP418-426Epitope from the Influenza A Virus Nucleoprotein Is Recognized by Cytotoxic T Lymphocytes with High Functional Avidity

“…Regression analysis between functional avidity (EC 50 in M) and the frequency of epitope-specific CTL (number of epitope-specific IFN-␥ ϩ cells per 15,000 effector cells) performed on all available data points (each symbol represents a peptide) obtained from all study subjects tested for all nine epitopes (A), the conserved epitopes (B), or the variable epitopes (C) and on the average values for all nine epitopes (D), the conserved epitopes (E), and the variable epitopes (F). the nature of infection (chronic versus acute), the viruses and/or the epitopes that were studied, or the source and nature of the T cells that were used for the analysis (ex vivo T cells versus in vitro-expanded T cells) (7). We wanted to use polyclonal effector cell populations, which were obtained after stimulation with virus-infected cells, since this would better reflect the in vivo situation than, for example, the use of single T-cell clones specific for the nine peptides that were tested.…”

In vitro diagnosis of T cell‐mediated drug allergy

“…Therefore this test detects molecules secreted by individual cells present in low frequencies and seems to be the most robust method to detect cytotoxic cells in peripheral blood of drug allergic patients. Both Granzyme B ELISPOT as well as the degranulation marker CD107a have been already used successfully to detect peptide‐specific cytotoxic T lymphocytes in patients monitored in vaccine trials and in patients with chronic virus infections [45, 47–48]. Some preliminary data showed that serum granulysin levels in patients with SJS/TEN were elevated before skin detachment or mucosal lesions develop [49].…”