CD4 (26-396) Human, Sf9
Description
Production and Purification
The protein is expressed in Sf9 cells via recombinant baculovirus vectors, followed by purification using proprietary chromatographic techniques . This system ensures proper glycosylation and folding, mimicking native human CD4 structure .
Binding and Signaling
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MHC Class II Interaction: CD4’s D1 domain binds MHC class II β2-domain, stabilizing T-cell receptor (TCR)-MHC interactions and enhancing T-cell activation .
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HIV gp120 Interaction: Residues within the V1 domain (amino acids 1–106) mediate high-affinity binding to HIV envelope glycoprotein gp120, facilitating viral entry .
Cellular Dynamics
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Endocytosis: In Sf9 cells, phorbol ester (PMA) induces CD4 internalization via a calmodulin-dependent pathway, independent of protein kinase C (PKC) .
Table 1: Key Applications of CD4 (26-396) Human, Sf9
Comparative Analysis with Other CD4 Constructs
Critical Research Findings
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HIV Control: Elevated granzyme A expression in HIV-specific CD4+ T cells correlates with slower disease progression, highlighting CD4’s role in adaptive immunity .
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Therapeutic Targeting: Soluble CD4 fragments (e.g., residues 1–106) inhibit HIV infection by blocking gp120 interaction, informing antibody-like drug designs .
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Clinical Relevance: Higher CD4 counts (>500 cells/µl) reduce AIDS/death risk by 4% per 100 cells/µl in virally suppressed patients .
Product Specs
Product Science Overview
CD4 is a glycoprotein found on the surface of immune cells such as T-helper cells, monocytes, macrophages, and dendritic cells. It plays a crucial role in the immune system by assisting in the activation of T-cells. CD4 acts as a co-receptor that enhances the interaction between the T-cell receptor (TCR) and the major histocompatibility complex (MHC) class II molecules on antigen-presenting cells.
The CD4 molecule consists of four immunoglobulin-like domains (D1 to D4). The fragment CD4 (26-396) includes these extracellular domains, which are essential for its interaction with MHC class II molecules. The interaction between CD4 and MHC class II molecules is critical for the activation of T-helper cells, which in turn orchestrate the immune response by signaling other immune cells.
The recombinant CD4 (26-396) protein is expressed in Sf9 insect cells using the baculovirus expression system. This system is widely used for producing recombinant proteins because it allows for proper folding and post-translational modifications, which are essential for the protein’s functionality. The expressed protein is a single, glycosylated polypeptide chain containing 377 amino acids and has a molecular weight of approximately 42.1 kDa .
Recombinant CD4 (26-396) is used in various research applications, including:
- Immunology Studies: Understanding the role of CD4 in T-cell activation and immune response.
- HIV Research: CD4 is the primary receptor for HIV entry into host cells. Studying the interaction between CD4 and HIV can help in developing therapeutic strategies.
- Drug Development: Screening potential drugs that can modulate CD4 function or its interaction with other molecules.
