RL / RL-luc Orthotopic Mouse Model Service for Lymphoma

The RL / RL-luc orthotopic mouse model establishes a CD10-positive, CD20-positive human diffuse large B-cell lymphoma — one of the oldest continuously curated DLBCL lines, maintained at DSMZ with full immunophenotypic and growth documentation — in the hematolymphoid system of immunodeficient mice. Alfa Cytology delivers this activated B-cell-like DLBCL substrate with authenticated banking, subcutaneous or systemic luciferase-imaging configurations, and study designs organized around B-cell receptor pathway pharmacology, so your BTK, PI3K, MALT1, and epigenetic-targeting programs are evaluated on a line whose slow, disciplined growth kinetics reward careful experimental planning.

Overview of RL / RL-luc Orthotopic Mouse Model for Lymphoma

RL was established in 1983 from the ascites of a 52-year-old man with diffuse, undifferentiated B-cell non-Hodgkin lymphoma and is curated by DSMZ as ACC 613 with unusually complete documentation. The cells are lymphoid, growing singly or in clumps in suspension, with a strikingly deliberate pace — a population doubling time of roughly five to eight days and a maximum culture density near 1.8 × 10⁶ cells/mL — characteristics that demand patient, low-density culture handling but translate into measured, low-noise xenograft kinetics. Its immunophenotype is unambiguous mature B cell: CD3 negative with CD10, CD19, CD20, CD37, CD38, cytoplasmic CD79a, and HLA-DR positive, expressing surface/cytoplasmic IgM with lambda light chain restriction. Classified within the activated B-cell-like (ABC) subtype — the DLBCL category defined by chronic, mutation-driven B-cell receptor signaling — RL has served for years as a working substrate for the pathway that ibrutinib made druggable, appearing across BTK, PI3K, MALT1, and epigenetic-modulator studies.

Fig 1. Schematic summarizing germinal center (GC) biology and the genetic lesions of GC-derived lymphomas (Burkitt, follicular, GCB- and ABC-DLBCL) recapitulated in GEMMs, providing the disease-biology framework within which the RL follicular lymphoma xenograft model is positioned. (Meyer, Stefanie N., et al., 2021)

In vivo, RL xenografts in immunodeficient mice form the slow-growing, treatment-responsive tumors that ABC-DLBCL pharmacology requires: unlike the furious kinetics of leukemia lines, RL tumors progress on a timescale of weeks, giving combination regimens and epigenetic agents room to demonstrate class-appropriate effects. The RL-luc configuration adds firefly luciferase for quantitative whole-body bioluminescence in vivo, enabling imaging-guided staging of systemic disease designs and caliper-independent tracking of subcutaneous cohorts. Because the parental line doubles only every five to eight days in vitro, study timelines and randomization thresholds are planned around deliberately conservative growth curves — an operational reality that in vivo service teams must internalize to avoid under-powering slow-response studies. Together, the line's authenticated provenance, its mature B-cell antigen profile compatible with CD20-targeted formats, and its measured growth behavior make RL a distinctive choice when a program needs DLBCL biology that punishes haste and rewards design discipline.

Cell Line Information: RL / RL-luc

RL (DSMZ ACC 613) grows in suspension in vitro in RPMI-1640 with 20% heat-inactivated fetal bovine serum, seeded at about 1 × 10⁶ cells/mL and maintained between 0.7 and 1.5 × 10⁶ cells/mL with subculture every two to five days. Its slow doubling time and low maximum density make culture discipline — never over-seeding, never starving — a genuine experimental variable rather than an afterthought. The line is mycoplasma-negative by microbiological culture and PCR, biosafety level 1, and fully authenticated. The RL-luc derivative adds firefly luciferase for quantitative imaging in vivo, with monoclonal selection of high-signal clones in vitro recommended for uniform bioluminescence.

Our Services

Slow-growing lines are where operational sloppiness shows: over-seeded cultures drift phenotypically, and under-planned studies end before the tumors declare themselves. Alfa Cytology runs RL programs with density-disciplined expansion in vitro (0.7–1.5 × 10⁶ cells/mL, subculture before confluence stress), conservative timeline projections matched to the five-to-eight-day doubling behavior, monoclonal luciferase banks for imaging cohorts, and endpoint panels organized around the B-cell receptor pathway readouts — phospho-BTK, phospho-ERK, and NF-κB signaling — that this line's science is built on.

Workflow of RL / RL-luc Orthotopic Mouse Model Construction

RL model construction is deliberately conservative: the line's five-to-eight-day doubling time dictates patient culture handling, measured engraftment expectations, and randomization thresholds that respect the biology. The workflow below details construction and execution from density-disciplined cell preparation through pathway-anchored endpoints.

1. Density-Disciplined Cell Expansion and Quality Control: RL or RL-luc cells are expanded in vitro in RPMI-1640 + 20% heat-inactivated FBS, seeded at ~1 × 10⁶ cells/mL and maintained at 0.7–1.5 × 10⁶ cells/mL with subculture every 2–5 days; batches are confirmed mycoplasma-negative, STR-authenticated, and verified for CD19/CD20/CD10 expression, with monoclonal luciferase populations confirmed for tagged lines.
2. Host Selection and Acclimatization: BALB/c nude, NOD-SCID, or NSG mice, typically 5–7 weeks of age, are acclimatized for approximately one week under SPF conditions and health-screened before assignment to study cohorts.
3. Route Selection and Inoculation: The configuration is chosen — subcutaneous flank implantation for localized benchmarking or intravenous/intraperitoneal delivery for systemic disseminated designs — with inoculum sized conservatively to the line's slow growth and implantation day recorded for the dosing calendar.
4. Engraftment Monitoring with Conservative Thresholds: Given the 5–8 day doubling behavior, tumor establishment is monitored on an extended schedule — caliper for flank cohorts and weekly bioluminescence in vivo for luciferase designs — rather than the rapid-screening cadence used for leukemia lines.
5. Randomization and Treatment: Animals are randomized once tumors reach predefined volumes or flux thresholds; test agents are dosed on study-defined schedules — BTK, PI3K, MALT1, SYK, or epigenetic-targeting compounds, alone or in combination — with body weight and clinical condition recorded throughout.
6. Longitudinal Monitoring: Tumor kinetics are tracked by caliper (flank) or bioluminescence quantification (systemic designs) in vivo on a schedule matched to the slow growth curve, avoiding premature efficacy calls that short timelines would force.
7. Survival Follow-Up: Animals are followed to humane endpoints with Kaplan–Meier analysis on timelines adjusted for the line's measured growth behavior.
8. Endpoint Analysis and Reporting: At termination, tumors and spleens are harvested and weighed, disseminated organs are inspected and imaged ex vivo for luciferase studies, and tissues are processed for phospho-BTK, phospho-ERK, and NF-κB pathway immunohistochemistry alongside cleaved caspase-3, Ki-67, and H&E; tumor-growth inhibition, bioluminescence kinetics, pathway markers, and survival data are compiled into the final report.

Fig 2. RL / RL-luc orthotopic mouse model construction workflow.

Case Study-RL / RL-luc Orthotopic Mouse Model Development

RL xenografts are a longstanding substrate for activated B-cell-like DLBCL pharmacology, and the platform has carried a broad range of Alfa Cytology client programs — B-cell receptor pathway inhibitors evaluated as single agents and in combination, epigenetic and transcriptional-targeting agents benefiting from the line's measured kinetics, and CD20-directed antibody formats matched to its mature B-cell antigen profile. Across these programs, readouts have combined longitudinal caliper or bioluminescence kinetics in vivo, BCR-pathway immunohistochemistry, and survival analysis. Anonymized case summaries and representative deliverable formats are available on request.

Why Choose Alfa Cytology?

RL rewards patience and punishes hurry — and operationalizing that distinction is exactly where an experienced CRO adds value. Alfa Cytology has built its DLBCL slow-line service around the discipline this line demands.

• A fully documented DSMZ-curated line — established 1983, authenticated, with complete growth parameters on record.
• Distinctive slow-growth kinetics (5–8 day doubling) ideal for epigenetic agents and combinations that need time to act.
• Unambiguous mature B-cell immunophenotype (CD10/CD19/CD20/CD38/HLA-DR, IgM lambda) compatible with CD20-targeted formats.
• Density-disciplined expansion in vitro (0.7–1.5 × 10⁶ cells/mL) that protects phenotype through study-scale preparation.
• Conservative randomization thresholds and extended monitoring schedules matched to the measured growth curve.
• BCR-pathway endpoint depth: phospho-BTK, phospho-ERK, and NF-κB immunohistochemistry as standard panels.
• Monoclonal, high-signal luciferase banks with quantitative imaging in vivo for systemic configurations.

Contact Us

If your DLBCL program needs an authenticated ABC-substrate whose measured kinetics give slower mechanisms room to show themselves, the RL / RL-luc orthotopic model is a distinctive choice — and Alfa Cytology runs it with the timeline discipline the line demands. Reach out to us to review configuration options, pathway endpoint panels, and conservative study timelines, and receive a customized study quotation today.

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