Influenza Proteins & Matching Peptide Tools for T-Cell Research
Influenza Hemagglutinin (HA): A Master Target for CD4+ T-Cell Immunity & Cross-Protection
While Influenza A and B Hemagglutinins (HA) are classically known as the primary targets for neutralizing antibodies, HA is also a critical driver of CD4+ helper T-cell responses. CD4+ T cells directed against HA provide essential B-cell help for durable antibody generation and mediate cross-reactive protection against emerging seasonal strains.
For immunologists, HA represents a unique target: its sequence contains both highly variable antigenic sites and immunodominant, promiscuous CD4+ epitopes. Targets like HA 306–318 (HA 322–334) bind broadly across multiple HLA-DR alleles, making them indispensable positive controls for evaluating recall responses, mapping TCR kinetics, and benchmarking universal flu vaccine candidates.
Precise HA-derived peptide tools form the foundation of robust immunomonitoring. Overlapping peptide pools allow broad epitope screening, while single epitopes are necessary for deconvoluting specific HLA-restricted responses.
peptides&elephants' Influenza HA Peptides for Translational Research & Immune Profiling
To support translational research, human immunomonitoring, and preclinical model evaluations, peptides&elephants provides a high-quality HA-derived peptide pool and single reference epitopes categorized by host restriction:
Influenza A (H1N1) HA Peptide Pool: Complete sequence coverage of H1N1 Hemagglutinin for robust CD4+ and CD8+ T-cell immunomonitoring, epitope mapping, and cross-strain vaccine research.
Human MHC Class II / CD4+ Epitopes
- Influenza A HA 116-131 Peptide (YDVPDYASLRSLVASS): Extended 16-mer CD4+ epitope containing the core YDVPDYASL sequence within the HA1 region. Validated for broad binding across HLA-DRB1*01:01, HLA-DRB1*04:01, and HLA-DRB1*07:01.
- Influenza A HA 271-286 Peptide (RGYFKMRTGKSSIMRS): Broadly recognized 16-mer CD4+ helper epitope for population-wide immunomonitoring across diverse HLA Class II alleles (HLA-DR1, DR10, DQ6).
- Influenza A HA 306-318 Peptide (PKYVKQNTLKLAT, also annotated as HA 322–334, when including the 16-aa signal peptide): One of the most widely cited helper T-cell epitopes from HA1. Demonstrates exceptional promiscuous binding across HLA-DRB1*01:01, DRB1*04:01, DRB1*07:01, DRB1*11:01, and DRB5*01:01 and more.
- Influenza A HA 322-333 Peptide (PKYVKQNTLKLA): A key 12-mer linear CD4+ epitope derived from the HA1 subunit (H3N2 A/Aichi/2/1968). Specifically restricted to HLA-DRA*01:01 / DRB1*01:01 for targeted recall assays.
- Influenza B HA 322-334 Peptide (PYYTGEHAKAIGN): Essential HA-derived reference target for mapping lineage-specific CD4+ T-cell responses against Influenza B, enabling accurate lineage cross-reactivity profiling alongside Influenza A HA panels.
Murine MHC-Restricted Epitopes
Influenza A HA 332-340 (H-2Db)
Influenza A HA 462-470 (H-2Kd)
Influenza A HA 533-541 (H-2Kd)
Stay tuned as we feature more key target proteins in upcoming Peptide Insights.
Matrix Protein 1 (M1): The Structural & Functional Backbone of Influenza
As the most abundant viral protein, M1 coordinates every stage of the replication cycle—from viral entry and uncoating to nuclear transport and budding. Dive into its domain architecture, structural shifts, and essential roles in the viral life cycle.
➔ Read our full Peptide Insights Article: Matrix Protein 1 of Influenza Virus