CEF8, Influenza Virus NP (383-391)

Product Name: CEF8, Influenza Virus NP (383-391)

Sequence One Letter Code: SRYWAIRTR

Sequence Three Letter Code: H-Ser-Arg-Tyr-Trp-Ala-Ile-Arg-Thr-Arg-OH

Chemical Formula:C59H92N20O16

Molecular Weight: 1208.4

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Inflammation and Immunology Research

Source / Species: Influenza

Conjugation: Unconjugated

Code Nacres: NA.26

Application: CEF8 is a synthetic peptide corresponding to amino acid residues 383–391 of the influenza virus nucleoprotein and represents a well-characterized HLA-B3501–restricted CD8⁺ T cell epitope. This peptide is widely used in immunology and virology research to investigate antigen processing and presentation via major histocompatibility complex class I molecules. CEF8 enables precise evaluation of virus-specific cytotoxic T lymphocyte responses in individuals expressing HLA-B3501. It serves as a defined antigenic stimulus for assessing T cell activation, cytokine production, and cytolytic function in ex vivo and in vitro assays. The peptide is also applied in immune monitoring studies, vaccine evaluation, and mechanistic analyses of antiviral immunity. By providing a reproducible and immunologically relevant epitope, CEF8 supports research into influenza-specific cellular immune responses, immune memory formation, and MHC-restricted T cell recognition mechanisms in both basic and translational settings.

Current Research: CEF8 is a synthetic peptide corresponding to amino acid residues 383–391 of the influenza virus nucleoprotein and is recognized as a well-defined HLA-B*3501–restricted CD8⁺ T cell epitope. As a minimal class I–restricted antigenic determinant, CEF8 is extensively used in immunology and virology research to investigate antigen presentation, cytotoxic T lymphocyte (CTL) activation, and MHC-restricted immune recognition. Influenza nucleoprotein is a highly conserved internal viral antigen that plays a central role in viral replication and genome packaging. Because of its relative sequence conservation across influenza strains, nucleoprotein-derived epitopes are frequently targeted by CD8⁺ T cells during natural infection. CEF8 represents one such immunodominant epitope presented in the context of HLA-B*3501, enabling focused analysis of virus-specific cellular immunity in HLA-matched individuals. In antigen processing and presentation studies, CEF8 serves as a defined ligand for major histocompatibility complex (MHC) class I molecules. Exogenous peptide loading onto antigen-presenting cells bypasses upstream proteasomal degradation and transporter-associated processing steps, allowing direct assessment of peptide–MHC binding and T cell receptor (TCR) recognition. This controlled experimental setup facilitates precise evaluation of CTL specificity, avidity, and functional responsiveness. CEF8 is widely employed in ex vivo assays to quantify influenza-specific CD8⁺ T cell responses in peripheral blood mononuclear cells (PBMCs). Upon peptide stimulation, antigen-specific T cells can be assessed for activation markers, cytokine secretion—such as interferon-γ and tumor necrosis factor-α—and cytolytic mediator expression, including granzyme B and perforin. Functional readouts are commonly measured using ELISpot, intracellular cytokine staining, flow cytometry, and cytotoxicity assays. These applications make CEF8 a valuable reagent for profiling effector and memory T cell populations following infection or vaccination. In vaccine research, CEF8 is used to evaluate the magnitude and quality of cellular immune responses induced by candidate influenza vaccines. Because T cell–mediated immunity contributes to cross-strain protection, monitoring responses to conserved nucleoprotein epitopes provides insight into the breadth and durability of vaccine-induced protection. The peptide’s defined HLA restriction ensures reproducibility in immune monitoring studies involving HLA-B*3501–positive cohorts. Beyond immune monitoring, CEF8 supports mechanistic investigations into TCR–peptide–MHC interactions. Structural and functional studies can examine how specific amino acid residues contribute to MHC binding stability and TCR engagement. Such analyses enhance understanding of immunodominance hierarchies, clonal expansion dynamics, and the formation of long-lived memory CD8⁺ T cells. CEF8 is also relevant in translational research exploring antiviral immunity and immune regulation. By providing a consistent antigenic stimulus, it enables comparative analysis of T cell function in healthy individuals, immunocompromised patients, or those with chronic inflammatory conditions. These studies contribute to understanding how host factors influence virus-specific cellular responses. Overall, CEF8 represents a reproducible and immunologically relevant epitope for studying influenza-specific CD8⁺ T cell responses in the context of HLA-B*3501. Its well-characterized restriction profile and defined sequence make it an essential tool for antigen presentation research, immune monitoring, vaccine evaluation, and mechanistic studies of MHC class I–restricted T cell recognition in both basic and translational settings.