Granzyme B production distinguishes recently activated CD8+ memory cells from resting memory cells

Abstract

For immune diagnostic purposes it would be critical to be able to distinguish between ongoing immune processes, such as active infections, and long-term immune memory, for example imprinted by infections that have been cleared a long time ago or by vaccinations. We tested the hypothesis that the secretion of Granzyme B, as detected in ex vivo ELISPOT assays, permits this distinction. We studied EBV-, flu-and CMV-specific CD8 + cells in healthy individuals, Vaccinia virus-reactive CD8 + cells in the course of vaccination, and HIV-specific CD8 + cells in HIV-infected individuals. Antigen-specific ex vivo GzB production was detected only transiently after Vaccinia immunization, and in HIV-infected individuals. Our data suggest that ex vivo ELISPOT measurements of granzyme B permit the identification of actively ongoing CD8 + cell responses -a notion that is pertinent to the immune diagnostic of infections, transplantation, allergies, autoimmune diseases, tumors, and vaccine development.

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

“…Thus, in contrast to the virus‐peptide reactions, only few resting memory cells are thought to persist in peripheral blood of drug‐allergic patients in remission state (29). As resting memory T cells need an intermittent maturation and expansion step to synthesize GzB (30, 31), stimulation period of 48–72 h was required to detect drug‐induced CTLs in peripheral blood of drug‐allergic patients using GzB ELISPOT. Thus, the GzB assay in drug allergy probably consists of two elements: activation of drug‐specific cells and expansion of GzB‐producing T and NK cells.…”

Genotypic Variation and Phenotypic Characterization of Granzyme B Gene Polymorphisms

“…Furthermore, Granzyme B ELISPOT assay measures the release of a cytolytic protein (14) and was documented to correlate with the frequency of cytotoxic T lymphocytes after HLA-identical living-related kidney transplantation (15) and to measure ex vivo antigen-specific cytotoxicity of PBMC in clinical trials for cancer vaccines (16). Moreover, ex vivo ELISPOT measurements of Granzyme B within 24 hours after antigen challenge also allowed for discrimination of active memory CD8+ cells from resting memory cells (22). …”

De Novo Recruitment of Antigen-Experienced and Naive T Cells Contributes to the Long-Term Maintenance of Antiviral T Cell Populations in the Persistently Infected Central Nervous System

“…This is characteristic of memory CD8 T cells and leads to decreased cytotoxicity. However, memory cells upregulate expression of granzyme B after activation and expansion in culture (32,33) and resting memory CD8 T cells that are poorly cytolytic as measured by in vitro 51 Cr release assays eliminate target cells rapidly in vivo in LCMV-infected mice (34). Therefore, we argue that the antivirus CD8 T cell function is not significantly impaired in rJ2.2-infected mice.…”