Vaccinia Virus B8R (20-27)

Product Name: Vaccinia Virus B8R (20-27)

Sequence One Letter Code: TSYKFESV

Sequence Three Letter Code: H-Thr-Ser-Tyr-Lys-Phe-Glu-Ser-Val-OH

Chemical Formula:C44H65N9O15

Molecular Weight: 960.1

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Antiviral

Source / Species: Vaccinia virus

Conjugation: Unconjugated

Code Nacres: NA.26

Application: This peptide corresponds to residues 20–27 of the vaccinia virus B8R protein, a viral factor structurally related to the interferon-γ (IFN-γ) receptor. B8R functions as a soluble decoy receptor that binds IFN-γ and neutralizes its antiviral activity, facilitating viral immune evasion. The peptide is used in studies of viral cytokine-binding mechanisms, interferon signaling modulation, and host–pathogen interactions. It supports research into viral immune suppression strategies and structural determinants of cytokine–receptor mimicry. This reagent is relevant for investigations of viral pathogenesis and immune regulatory mechanisms.

Current Research: Viruses have evolved sophisticated strategies to evade host immune defenses, allowing them to replicate and spread within infected organisms. Among the most important host defense mechanisms is the interferon (IFN) system, a cytokine-mediated network that activates antiviral responses and coordinates immune signaling. Interferon-γ (IFN-γ) plays a particularly critical role in controlling viral infections by stimulating macrophage activation, enhancing antigen presentation, and promoting the expression of antiviral genes. To counteract these defenses, some viruses produce proteins that directly interfere with interferon signaling. One well-characterized example is the vaccinia virus B8R protein, a viral factor that functions as a soluble decoy receptor for IFN-γ. Peptides derived from B8R, including the 20–27 residue fragment, provide valuable tools for studying viral immune evasion mechanisms and cytokine–receptor interactions. Vaccinia Virus and Immune Evasion Strategies Vaccinia virus belongs to the Poxviridae family, a group of large DNA viruses known for their complex interactions with host immune systems. Poxviruses encode numerous proteins specifically dedicated to modulating host immune responses, including cytokine-binding proteins, complement regulators, and chemokine inhibitors. These molecules allow the virus to suppress inflammation, prevent antiviral signaling, and enhance viral survival within host tissues. One notable strategy involves the production of viral cytokine receptor mimics. These viral proteins resemble host cytokine receptors but are typically secreted or expressed in forms that neutralize cytokines rather than transmit intracellular signals. By binding host cytokines before they reach their cellular receptors, these viral proteins effectively block immune signaling pathways. The Role of B8R as a Viral IFN-γ Decoy Receptor The B8R protein of vaccinia virus is a prime example of cytokine receptor mimicry. Structurally related to the extracellular domain of the mammalian IFN-γ receptor, B8R acts as a soluble decoy receptor that binds IFN-γ with high affinity. When IFN-γ is captured by B8R, it can no longer interact with its natural receptor on immune cells. As a result, downstream signaling events that normally activate antiviral defenses are suppressed. This mechanism provides a significant advantage to the virus. IFN-γ normally stimulates a range of immune responses, including activation of macrophages, enhancement of antigen presentation through major histocompatibility complex (MHC) molecules, and induction of antiviral gene expression. By neutralizing IFN-γ, vaccinia virus can attenuate immune activation and promote viral replication. The ability of B8R to mimic host cytokine receptors highlights an important evolutionary strategy used by viruses: structural imitation of host immune regulators. Understanding the molecular interactions between IFN-γ and viral decoy receptors is therefore essential for elucidating viral immune evasion mechanisms. B8R-Derived Peptides for Mechanistic Studies Short peptides derived from viral proteins can provide valuable insights into protein–protein interaction interfaces and binding determinants. The peptide corresponding to residues 20–27 of the vaccinia virus B8R protein represents a region implicated in interactions related to cytokine recognition and receptor mimicry. Using a defined peptide fragment allows researchers to investigate how specific amino acid sequences contribute to cytokine binding and receptor-like activity. Such peptides are particularly useful in structural and biochemical studies, where simplified models can help identify key residues involved in molecular recognition. Experimental approaches may include binding assays, structural modeling, and mutational analysis to determine how this region contributes to the interaction between B8R and IFN-γ. Insights from these studies can clarify how viral proteins adapt host receptor structures to create functional decoy molecules. Applications in Host–Pathogen Interaction Research The B8R-derived peptide is frequently used in studies examining viral modulation of cytokine signaling and the broader dynamics of host–pathogen interactions. By isolating specific functional regions of the viral protein, researchers can explore how viruses disrupt immune communication networks. For example, this peptide may be applied in investigations of interferon signaling pathways, helping researchers understand how viral proteins interfere with immune activation. Such studies contribute to a broader understanding of how pathogens manipulate host defense mechanisms to establish infection. Additionally, the peptide can serve as a model for studying cytokine–receptor mimicry, a strategy not limited to vaccinia virus. Many viruses encode molecules that resemble host receptors or signaling proteins, allowing them to hijack immune pathways. Investigating these mechanisms can reveal general principles of viral immune suppression. Relevance to Viral Pathogenesis and Immunology Research into viral immune evasion mechanisms has significant implications for both basic immunology and therapeutic development. Understanding how viral proteins such as B8R neutralize cytokines can help identify vulnerabilities in viral replication strategies. These insights may ultimately inform the design of antiviral therapies or improved vaccine approaches. The B8R-derived peptide provides a focused experimental tool for dissecting the structural determinants of IFN-γ binding and immune modulation. By enabling detailed studies of viral cytokine-binding mechanisms, it supports investigations into how viruses evade immune surveillance and establish infection. As research into host–pathogen interactions continues to advance, peptide reagents derived from viral immune-modulatory proteins will remain valuable for exploring the molecular basis of viral pathogenesis and immune regulation.