El4-CD20 Syngeneic Model Service for Lymphoma

The EL4-CD20 syngeneic model is the reference immunocompetent platform for preclinical anti-CD20 antibody development, engrafting human CD20-transduced murine T-cell lymphoma cells into syngeneic C57BL/6 hosts where intact Fc-receptor biology, complement, and adaptive immunity mirror the clinical action of rituximab-class therapeutics. Alfa Cytology delivers this specialized model as a complete preclinical service — authenticated parental and CD20-engineered cell banking, disseminated intravenous or solid subcutaneous formats, quantitative tumor-burden bioluminescence, rituximab-referenced dose–response and exposure–response testing, and full immunopathology — giving sponsors the pharmacologically faithful system that antibody pharmacokinetic–pharmacodynamic modeling demands.

Overview of EL4-CD20 Syngeneic Model for Lymphoma

EL4 is one of the oldest and most storied murine lymphoma lines in existence: deposited by Melvin Cohn as ATCC TIB-39, it was established from a lymphoma induced in a C57BL/6N mouse by 9,10-dimethyl-1,2-benzanthracene, and its literature reaches back through the classic 1950s tumor-immunology era — Gorer's studies of antibody responses to tumor inoculation, the definition of the Gross leukemia antigen, and the serological mapping of virus-induced tumor surface antigens all employed this line. The cells are T-lymphoblasts growing in suspension with a modal chromosome number of 39, expressing H-2^b and Thy-1.2, distinguished by documented pharmacological quirks — resistance to 0.1 mM cortisol and sensitivity to phytohemagglutinin at 20 μg/mL — and accompanied by a celebrated subline family that includes the high-IL-2-producing EL4.IL-2. Syngeneic with C57BL/6, EL4 is aggressively tumorigenic: a few tens of thousands of intravenously inoculated cells produce uniformly fatal disseminated disease, a property long exploited in cellular immunology, vaccine, and nanoparticle-conjugate studies.

Fig 1. Dose-response and survival of anti-CD20 IgA in the EL4-hCD20 syngeneic lymphoma model. (Pascal, Virginie, et al., 2012)

The line's modern significance, however, stems from a simple piece of engineering with outsized impact: stable introduction of the human CD20 cDNA to create EL4-CD20 (also designated EL4-huCD20). Because murine lymphomas express no human CD20, this derivative converts a fully immunocompetent syngeneic host into a testbed for human anti-CD20 monoclonal antibodies — the platform that pharmacologically validated rituximab-class exposure–response relationships in a way human xenografts, with their Fc-receptor mismatch, cannot. In the landmark application, as few as 8 × 10³ EL4-huCD20-Luc cells injected intravenously into C57BL/6J mice produced disseminated lymphoma with quantitative bioluminescent tracking of burden, dissemination, and progression; untreated animals died within 30 days, while rituximab at 20 mg/kg on day 13 yielded a clinically realistic response distribution — 23% cured, 59% partial response, 18% progression — with serum concentrations inversely correlated to tumor burden, exactly as observed in patients. The model has since generalized across antibody engineering questions: combination with anti-Ly49C/I F(ab′)₂ fragments significantly enhanced anti-CD20-mediated NK-cell degranulation and survival; CD4⁺ T cells (not CD8⁺) were shown to mediate long-lasting protection after anti-CD20 clearance; ADCC quantitation panels of CD20/EL4 clones with graded antigen density — amplified by methotrexate selection — established how target-antigen levels tune antibody efficacy; and CD20-specific chimeric T-cell receptors were benchmarked for antigen-restricted killing of EL4-CD20 versus parental EL4 in the preclinical work that preceded adoptive-cell trials. For sponsors developing anti-CD20 antibodies, bispecifics, or radioimmunoconjugates, EL4-CD20 remains the definitive immunocompetent proving ground.

Cell Line Information: EL4-CD20

EL4-CD20 is the human CD20-transduced derivative of the EL4 murine T-cell lymphoma (ATCC TIB-39; Cellosaurus CVCL_0255; ECACC 85023105). Engineered variants include luciferase co-expression (EL4-huCD20-Luc, for quantitative in vivo tracking) and antigen-density panels (CD20/EL4 clone series). Core characteristics are compiled below.

Our Services

Engaging Alfa Cytology for the EL4-CD20 syngeneic model places the definitive anti-CD20 pharmacology workflow under one accountable team: authenticated EL4, EL4-CD20, and EL4-huCD20-Luc banks are maintained with suspension-culture discipline and verified antigen and luciferase expression, syngeneic C57BL/6 hosts are sourced and acclimated, disseminated intravenous or solid subcutaneous disease is established at the published low-inoculum geometry, and treatment arms — rituximab-referenced dose–response ladders, Fc-engineered variants, bispecifics, or NK-checkpoint combinations — are executed with serial bioluminescence, serum PK sampling, survival analysis, and terminal lymphoid-organ immunopathology, all under IACUC-compliant conditions and returned as an audit-ready data package.

Workflow of EL4-CD20 Syngeneic Model Construction

EL4-CD20 studies are defined by a single design choice — disseminated intravenous versus solid subcutaneous — wrapped around suspension-culture quality control and the model's celebrated low-cell geometry. A standard program proceeds as follows.

1. Cell preparation and quality control: EL4-CD20 or EL4-huCD20-Luc cells are expanded at low passage in suspension, confirmed mycoplasma-free, and human CD20 expression quantified by flow cytometry against a reference standard; luciferase activity is validated in vitro before animal work.
2. Host selection and acclimation: Male or female C57BL/6 or C57BL/6J mice, typically 6–10 weeks of age, are quarantined and acclimated in a specific-pathogen-free barrier facility.
3. Implantation: disseminated intravenous route. A low-volume cell suspension — classically as few as 8 × 10³ cells — is administered via the lateral tail vein into C57BL/6J mice; the small inoculum exploits the line's aggressive tumorigenicity while permitting quantitative dissemination mapping.
4. Implantation: solid subcutaneous route. For caliper-based efficacy arms, cells are injected into the flank at a defined inoculum; solid tumors establish rapidly and support volume-based randomization within the first week.
5. Baseline imaging and randomization: For luciferase-tagged cohorts, baseline bioluminescence imaging after intraperitoneal D-luciferin injection confirms engraftment and quantifies starting burden; mice are randomized by signal intensity to balance dissemination across arms.
6. Treatment and pharmacokinetic sampling. Test articles: rituximab-referenced anti-CD20 mAbs, Fc-engineered variants, bispecifics, or NK-checkpoint combinations — are administered on protocol schedules (classically a single dose ~13 days post-inoculation in the benchmark design); serum samples are drawn at defined times for concentration measurement by ELISA.
7. Longitudinal monitoring: Whole-body bioluminescence imaging on the protocol cadence tracks tumor burden, dissemination, and progression; body weight and clinical signs are recorded daily, with humane endpoints predefined.
8. Endpoint analysis and reporting: Kaplan–Meier survival with log-rank analysis serves as the primary endpoint, complemented by exposure–response modeling of serum concentrations against tumor burden; terminal lymphoid organs undergo ex vivo bioluminescence mapping and H&E with CD20, CD8, CD4, NK1.1, and Fc-receptor immunohistochemistry, with all data consolidated into the final report.

Fig 2. El4-CD20 Syngeneic Model construction workflow.

Case Study-EL4-CD20 Syngeneic Model Development

Alfa Cytology has applied the EL4-CD20 syngeneic platform to preclinical programs spanning anti-CD20 dose–response and exposure–response modeling, Fc-engineering and ADCC optimization, bispecific and radioimmunoconjugate evaluation, and NK-checkpoint combination studies in lymphoma. In these engagements, quantitative bioluminescence tracked tumor burden and dissemination in individual animals, serum pharmacokinetics were modeled against response, and terminal lymphoid-organ immunopathology completed the pharmacological assessment. Study parameters — format, inoculum, dosing schedule, and endpoint panels — are tailored to each program. Case materials can be shared under confidentiality agreements upon request.

Why Choose Alfa Cytology?

EL4-CD20 rewards teams that respect its arithmetic: the 8 × 10³-cell disseminated geometry, the day-13 rituximab benchmark, the exposure–response modeling — every parameter is published, and every deviation is visible. Alfa Cytology fields the antibody pharmacology, bioluminescence, and immunopathology capabilities in-house, making the EL4-CD20 / EL4-huCD20-Luc syngeneic model a dependable backbone for your lymphoma program.

• Authenticated multi-variant banking — EL4 parental, EL4-CD20, and EL4-huCD20-Luc with verified antigen expression.
• Published low-inoculum geometry, deploying the 8 × 10³-cell disseminated format natively.
• Rituximab benchmark fluency, applying the day-13 dosing and 6–40 mg/kg ladder as reference standards.
• Exposure–response modeling capability, pairing serum PK with bioluminescent burden quantification.
• Fc-engineering and ADCC expertise, with antigen-density clone panels available for mechanistic arms.
• Both formats mastered — disseminated intravenous and solid subcutaneous — with NK-checkpoint combination experience.
• IACUC-compliant, documentation-rich operations delivering audit-ready records throughout the study.

Contact Us

If your lymphoma program involves anti-CD20 or Fc-engineered antibodies, contact us today to discuss EL4-CD20 study design, format selection, dose ladders, and exposure–response endpoints with our scientific team. Reach out for a confidential consultation and project quotation — Alfa Cytology looks forward to advancing your next preclinical study.

For research use only. Not intended for any clinical use.