The CD4 Knockout 143B Polyclonal Cells comprise a CRISPR/Cas9-edited polyclonal knockout population derived from the 143B human osteosarcoma line, carrying a disruption in the CD4 gene. This heterogeneous pool provides a loss-of-function model suitable for population-level studies, avoiding clonal selection artifacts. It supports robust screening and functional assays where consistent knockout across the culture is not required.
The 143B human osteosarcoma cell line is a highly tumorigenic and metastatic model widely used in cancer research and drug testing. Its aggressive phenotype and ease of genetic manipulation make it an ideal host for gene disruption. In a CD4 knockout context, this non-immune background enables study of CD4 functions when ectopically expressed, and off-target assessment of CD4-directed therapies.
CD4 acts as a TCR co-receptor by binding MHC class II, enhancing T-cell antigen sensitivity. It recruits Lck to phosphorylate CD3 ITAMs, initiating a cascade through ZAP-70, LAT, SLP-76, and PLC??1, ultimately activating NFAT, NF-??B, and AP-1 transcription factors and cytokine production (e.g., IL-2). Lineage is governed by Th-POK and Runx3 silencing. Additionally, CD4 is the primary receptor for HIV-1 via gp120 engagement, critical for viral entry.
In 143B cells, CD4 knockout creates a controlled system for HIV-1 entry assays when CD4 and co-receptors are introduced, allowing dissection of fusion steps. It also serves as a negative control for CD4-targeted immunotherapies, confirming antibody specificity. This model can uncover potential non-immune roles of CD4 in osteosarcoma progression and metastasis, leveraging the host??s tumorigenic properties.
Researchers employ flow cytometry, western blotting, and RT-qPCR to confirm CD4 disruption. Functional investigations include HIV infectivity, co-culture with antigen-presenting cells, and T-cell activation assays after CD4 reconstitution. Immunofluorescence and drug response profiling are also standard. Contact Ascent Research for further assistance.
