Description
CD8 and CD19-Based Therapy
- Gene Information: CD8: Encoded by CD8A and CD8B, located on chromosome 2p11.2. A dimeric glycoprotein (CD8A/CD8B) acting as a crucial cytotoxic T-cell co-receptor. CD19: is a transmembrane glycoprotein, located on chromosome 16p11.2. It belongs to the immunoglobulin superfamily and plays a critical role in B-cell development, activation, and maintenance throughout the immune system.
- Protein Expression: CD8: Predominantly and stably expressed on cytotoxic T lymphocytes, identifying antigen-experienced T cells. CD19: Expressed exclusively across B-cell lineage stages from early pre-B cells to mature B cells, overexpressed in B-cell malignancies.
- Signaling Pathway: CD8: Recruits Lck kinase upon TCR-MHC I binding to initiate cytotoxic activation cascades. CD19: Recruits Lyn and PI3K to amplify BCR signaling. CD8-targeted delivery specifically redirects cytotoxic T cells to eliminate CD19⁺ target cells.
- Therapeutic Application: CD8 × CD19 targeted platforms (such as in vivo CAR-T vectors or bispecific engagers) direct CAR gene delivery or cytotoxicity specifically to CD8⁺ cytotoxic T cells, enabling precise and potent clearance of CD19⁺ B-cell malignancies.
CD8 Protein Expression in spleen
Strain-specific CD8 expression analysis in homozygous B-hCD8/hCD19 ad mice by flow cytometry. Splenocytes were collected from homozygous B-hCD8/hCD19 ad mice (H/H, female, n = 3, 9-week-old), and analyzed by flow cytometry with species-specific anti-CD8 antibody (anti-human CD8A, BioLegend, 300908; anti-mouse CD8A, BioLegend, 100730; anti-human CD8B, BD, 742392).
CD19 Expression in Spleen
Mouse and human CD19 expression analysis in splenocytes. Splenocytes were collected from wild-type C57BL/6JNifdc mice and B-hCD8/hCD19 ad mice. CD19 expression was analyzed by flow cytometry using anti-mouse CD19 antibody (BioLegend, 115507) and anti-human CD19 antibody (BioLegend, 302234).
In vivo B Cells Depletion by in vivo CAR-T
Evaluation of B cell depletion efficacy of hCD8-tLNP (hCD19 CAR) in B-hCD8/hCD19 ad mice. B-hCD8/hCD19 ad mice were received tail vein injections of hCD8-tLNP8 encapsulating hCD19 CAR mRNA for day 1 and day 4. and the frequencies of B220⁺ B cells in peripheral blood were analyzed by flow cytometry on days -1, 2, and 5. The hCD8-tLNP (hCD19 CAR) treatment resulted in a progressive and significant decrease in B220⁺ B cell frequency, demonstrating its potent depleting efficacy in vivo.
* When publishing results obtained using this animal model, please acknowledge the source as follows: The animal model [B-hCD8/hCD19 ad mice] (Cat# 115078) was purchased from Biocytogen.
