Quality Breakdown,OVA peptide257-264

The OVA 257-264 peptide, also known by its sequence SIINFEKL, is a highly significant molecule in the field of immunology. This octameric peptide is derived from ovalbumin (OVA), a protein commonly found in egg whites. Its primary importance lies in its role as a class I (Kb)-restricted peptide epitope of OVA. This means it is a specific fragment of the ovalbumin protein that is recognized and presented by a particular type of MHC Class I molecule, specifically H-2Kb, on the surface of cells.

The OVA 257-264 peptide has garnered considerable attention due to its well-characterized nature and its utility in a variety of immunological studies. Researchers frequently utilize this ovalbumin-derived peptide to investigate cellular immune responses, particularly those mediated by CD8+ cytolytic T-cell response. The high-purity OVA (257-264) peptide is often employed as a gold standard in mouse CD8+ T cell assays and the development of immunological models.

Properties and Applications of the OVA 257-264 Peptide

The OVA (257-264) sequence is an antigenic peptide, meaning it can trigger an immune response. Its specific sequence, SIINFEKL, allows it to bind effectively to the H-2Kb molecule, forming a complex that is then presented to T cells. This interaction is crucial for initiating adaptive immunity. The 257-264 range within the ovalbumin protein is particularly important for this presentation.

One of the key applications of the OVA 257-264 peptide is its use in stimulating T cells. It is used to stimulate T cells in PBMCs (Peripheral Blood Mononuclear Cells) and to quantify peptide epitope specificity and IFN-γ releasing effector cells by methods such as the ELISPOT assay. This allows researchers to assess the reactivity of T cells against this specific antigen. Furthermore, subcutaneous immunization with this peptide can induce an OVA-specific immune response, making it valuable for studying immune sensitization and tolerance.

The OVA 257-264 peptide is also instrumental in understanding antigen presentation pathways. It is known to arise from the natural processing of ovalbumin in H-2b mouse cells. This natural processing highlights the biological relevance of the OVA (257-264) sequence. The ability to cross-present the OVA257–264-peptide (SIINFEKL) is restricted to certain dendritic cells (dDCs) that express specific markers like CD11c+, CD86+, and MHC-II+.

Variations and Related Research

While SIINFEKL is the most commonly studied sequence, variations of the OVA 257-264 peptide exist, offering further insights into T cell recognition. For example, the OVA-T4 Peptide (SIITFEKL) is a low-affinity variant that still exhibits similar binding to the H-2Kb MHC molecule. Another variant is the OVA G4 peptide (SIIGFEKL), which also represents a modification of the agonist ovalbumin (OVA) peptide (257-264). These variants, such as OVA-T4 Peptide and OVA G4 peptide, allow researchers to explore the fine-tuning of T cell receptor interactions and the impact of subtle amino acid changes on immune recognition.

The OVA peptide family extends beyond the 257-264 region, with other peptides like Ovalbumin 323-339 peptide also being subjects of immunological interest, particularly in the context of allergic responses. However, the OVA 257-264 peptide remains a cornerstone for studying Class I MHC interactions and cytotoxic T lymphocyte (CTL) responses.

In summary, the OVA 257-264 peptide, particularly in its SIINFEKL form, is a critical tool for immunological research. Its well-defined role as a class I (Kb)-restricted peptide epitope of OVA, presented by the H-2Kb MHC molecule, makes it indispensable for studying T cell activation, antigen presentation, and the development of cellular immunity. The availability of high-purity OVA (257-264) peptide ensures reproducible and reliable experimental outcomes.