Immunotherapy has changed the way researchers and clinicians think about treating leukemia. From CAR-T cells to NK cell engagers and checkpoint inhibitors, the field is moving faster than ever. Behind almost every one of these advances is a set of carefully chosen leukemia cell lines that serve as the starting point for in vitro testing.
Picking the right cell line is not a minor decision. The model you choose determines what biological questions you can answer, which surface markers you can target, and how confident you can be when translating results toward clinical use.
This article covers the best leukemia cell lines currently used in immunotherapy research, organized by leukemia type, with a clear explanation of what each one brings to the table and where it fits best.
Why Leukemia Cell Lines Matter in Immunotherapy
In immunotherapy research, cell lines serve a specific and demanding role. They are the target cells that researchers use to evaluate whether an immune effector, a CAR construct, a bispecific antibody, or a checkpoint blocker actually works.
For a cell line to be useful in this context, it needs to express the surface antigens being targeted, respond predictably to immune effector cells, and produce results that are reliable across experiments. Inconsistency in cell behavior is one of the biggest sources of irreproducible data in preclinical immunotherapy work.
Leukemia cell lines are also valuable because different subtypes of leukemia behave so differently from one another. Acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, and chronic lymphocytic leukemia each have distinct biology, different surface marker profiles, and different responses to immune-based interventions. Choosing a model that actually represents the subtype you are studying is what separates meaningful data from noise.
Leukemia Subtypes and the Cell Lines That Represent Them
Before diving into specific lines, it helps to understand how they map onto leukemia biology. Most leukemia cell lines fall into one of four categories based on origin:
Myeloid leukemia lines represent AML and CML, originating from myeloid progenitor cells. These are particularly relevant for NK cell research, CAR-T targeting of myeloid antigens such as CD33, CD123, and CD47.
Lymphoid leukemia lines represent ALL and CLL, originating from lymphoid progenitors. They are central to CAR-T research targeting CD19, CD22, and related B or T cell antigens.
Understanding where a cell line sits on this spectrum shapes everything about how it should be used.
Best Leukemia Cell Lines for Immunotherapy Research
K562 — The NK Cell Research Standard
K562 is derived from a patient with chronic myeloid leukemia in blast crisis and carries the BCR-ABL fusion gene responsible for driving CML. It is naturally deficient in MHC class I expression, which makes it exquisitely sensitive to NK cell killing.
This property makes K562 the most widely used target cell line for evaluating NK cell cytotoxicity. In virtually every NK cell expansion or activation study, K562 serves as the benchmark target. It is also used extensively in CAR-NK research and as a calibration standard for effector-to-target killing assays.
Leukemia subtype: Chronic myeloid leukemia (CML) Primary use: NK cell cytotoxicity assays, CAR-NK development, BCR-ABL inhibitor studies
Jurkat — The T Cell Leukemia Model for CAR Research
Jurkat was established from a patient with T cell acute lymphoblastic leukemia and has become one of the most referenced cell lines in immunology broadly, not just in leukemia research. It expresses CD3 and TCR-associated signaling machinery, making it an ideal model for studying T cell activation and signaling pathways.
In the context of immunotherapy, Jurkat cells are widely used to screen and validate CAR constructs before moving to primary T cells. When a CAR-expressing Jurkat cell line is co-cultured with target cells, upregulation of activation markers like CD69 confirms that the CAR construct is functional. This makes Jurkat an efficient first-pass screening tool that saves significant time and resources in CAR-T development programs.
Leukemia subtype: T cell acute lymphoblastic leukemia (T-ALL) Primary use: CAR-T construct validation, T cell signaling research, checkpoint biology
HL-60 — The AML Differentiation and Drug Screening Model
HL-60 was derived from a patient with acute promyelocytic leukemia and has been in continuous use since the late 1970s. It retains the capacity to differentiate along multiple lineages in response to chemical inducers, which is a rare and valuable property.
In immunotherapy research, HL-60 is used to study how differentiation status affects susceptibility to immune killing. It expresses several myeloid surface markers targeted by current and investigational immunotherapies, including CD33. It is also a standard inclusion in multi-cell-line panels for AML drug screening because of its well-characterized pharmacological profile accumulated over decades of published work.
Leukemia subtype: Acute promyelocytic leukemia (AML-M3) Primary use: AML drug panels, differentiation studies, CD33-targeted therapy testing
THP-1 — The Monocytic AML Model for Immune Interaction Studies
THP-1 is a human acute monocytic leukemia cell line that holds a unique position in leukemia research. Its monocytic lineage means it expresses immune-relevant surface receptors and can be differentiated into macrophage-like cells by treatment with PMA.
For immunotherapy studies, THP-1 is valuable in two ways. As a target cell, it expresses CD4, CD11b, CD64, and other myeloid markers relevant to several investigational therapies. As a macrophage model after differentiation, it is used to study immune evasion mechanisms and how leukemia cells interact with the tumor immune microenvironment. Research into CAR-T targeting of CD4-positive AML cells regularly uses THP-1 as a key target model.
Leukemia subtype: Acute monocytic leukemia (AML-M5) Primary use: CAR-T target validation, macrophage biology, tumor microenvironment studies
MOLM-13 — FLT3-Mutant AML for Targeted Immunotherapy
MOLM-13 is derived from relapsed AML and carries an internal tandem duplication in the FLT3 gene, one of the most common and clinically significant mutations in AML. This makes it a primary model for studying FLT3-targeted therapies including midostaurin and gilteritinib, and increasingly for evaluating bispecific antibodies and CAR-T constructs designed around FLT3-mutant disease.
It also expresses CD33, CD123, and CD47, surface targets that are central to several active immunotherapy programs. Because MOLM-13 comes from relapsed disease, it is particularly useful for modeling therapy resistance and testing strategies designed to overcome it.
Leukemia subtype: Acute myeloid leukemia with FLT3-ITD mutation Primary use: FLT3-targeted therapy, bispecific antibody testing, relapsed AML modeling
OCI-AML3 — The NPM1 and DNMT3A Mutant Reference Line
OCI-AML3 carries two of the most common genetic alterations in adult AML: the NPM1 type A mutation and the DNMT3A R882 mutation. NPM1 mutations occur in approximately 30 percent of adult AML cases, making OCI-AML3 one of the most clinically representative cell lines available.
For immunotherapy research, OCI-AML3 is used in studies evaluating NK cell killing, antibody-dependent cellular cytotoxicity, and checkpoint protein expression. It expresses B7-H3, CD33, and CD123 at levels that make it a productive target for antibody and CAR-based approaches. Its defined mutational background also makes it useful for correlating drug response with specific genetic alterations.
Leukemia subtype: Acute myeloid leukemia (AML-M4) Primary use: NPM1-mutant biology, NK cell killing assays, antibody-drug conjugate testing
Kasumi-1 — The t(8;21) AML Model
Kasumi-1 carries the t(8;21) chromosomal translocation generating the AML1-ETO fusion protein, one of the most frequent cytogenetic abnormalities in AML. It represents a biologically distinct subtype of AML with relatively favorable prognosis, but one that still requires effective therapeutic strategies.
In immunotherapy research, Kasumi-1 is used in NK cell cytotoxicity panels, CAR-T target studies, and evaluation of compounds targeting the AML1-ETO fusion. It expresses CD33, CD34, and CD117, making it relevant to several ongoing clinical programs. It is a standard inclusion in multi-line AML panels designed to capture the heterogeneity of the disease.
Leukemia subtype: AML with t(8;21) translocation Primary use: AML1-ETO biology, NK cell panels, multi-subtype AML screening
MOLT-4 — T-ALL Model for Lymphoid Immunotherapy
MOLT-4 is a T cell acute lymphoblastic leukemia line that complements Jurkat in lymphoid leukemia research. While Jurkat is predominantly used for signaling and CAR construct screening, MOLT-4 is used more as a target cell in cytotoxicity assays and in studies evaluating drugs that act on T-ALL biology directly.
It expresses TdT, CD3, CD4, and CD8, a marker profile useful for studies on T cell leukemia surface antigens and for evaluating immune effectors that target T-ALL. It is a standard cell line in preclinical studies assessing apoptosis induction, cell cycle effects, and drug sensitivity in the T-ALL context.
Leukemia subtype: T cell acute lymphoblastic leukemia (T-ALL) Primary use: T-ALL drug testing, cytotoxicity assays, apoptosis research
U937 — A Monocytic Line for Checkpoint and Macrophage Research
U937 is derived from a pleural effusion of a patient with histiocytic lymphoma and behaves as a monocytic cell line with strong macrophage differentiation capacity. It is included in most AML immunotherapy panels because of its broad surface marker expression including CD33, CD64, and CD4.
U937 is particularly useful in studies exploring how leukemia cells evade immune surveillance and in checkpoint inhibitor research where immune-modulatory surface protein expression is the focus. Several published studies evaluating novel immunotherapeutic agents against AML use U937 as a primary or validation target alongside MOLM-13 and THP-1.
Leukemia subtype: Monocytic leukemia / histiocytic lymphoma Primary use: Immune checkpoint research, macrophage biology, AML immunotherapy panels
Building a Leukemia Cell Line Panel for Immunotherapy Studies
Using a single cell line is rarely sufficient for immunotherapy work. Because leukemia is genetically diverse, a finding observed in one line may not hold across subtypes. Researchers typically build panels of three to five lines that represent distinct genetic backgrounds and surface marker profiles.
A practical AML immunotherapy panel might include K562 as the NK cell standard, THP-1 for monocytic biology, MOLM-13 for FLT3-mutant disease, and OCI-AML3 for NPM1-mutant context. Adding Kasumi-1 covers the t(8;21) subtype and broadens the representativeness of the data.
For T cell leukemia or lymphoid work, Jurkat and MOLT-4 together provide coverage of CAR construct screening and direct cytotoxicity evaluation.
The goal of a panel approach is not completeness for its own sake. It is to make sure that when a result looks promising, it holds across the biological diversity that patients actually represent.
Frequently Asked Questions
What leukemia cell lines are most used in CAR-T research?
Jurkat is the most commonly used leukemia cell line for CAR-T construct screening because it allows rapid functional validation of CAR expression and signaling. For myeloid targeting, THP-1, MOLM-13, and HL-60 are frequently used as target cells in CAR-T cytotoxicity assays.
What is the K562 cell line used for in immunotherapy?
K562 is the standard target cell line for evaluating NK cell cytotoxicity. Its low MHC class I expression makes it sensitive to NK cell killing, which is why it is used across virtually all NK cell expansion, activation, and CAR-NK development studies as the benchmark effector-to-target assay.
What are the most common leukemia cell lines for AML research?
The most commonly used AML cell lines in research are HL-60, THP-1, MOLM-13, OCI-AML3, Kasumi-1, U937, and MV4-11. Each represents a genetically distinct subset of AML and is selected based on the specific mutations, surface markers, or biological question being studied.
Which leukemia cell line carries the BCR-ABL fusion gene?
K562 carries the BCR-ABL fusion gene generated by the Philadelphia chromosome translocation t(9;22), which is the defining genetic event in chronic myeloid leukemia
Do leukemia cell lines need to be authenticated before use?
Yes. Cell line misidentification is a documented problem in biomedical research.
What surface markers on leukemia cell lines are most targeted in immunotherapy?
The most actively targeted surface markers in leukemia immunotherapy research include CD33, CD123, CD19, CD22, CD47, FLT3, and CD3. Cell line selection in immunotherapy studies should be guided by which markers are expressed on the specific line and how expression levels compare to primary patient samples.
Closing Note
The leukemia cell lines described here are not interchangeable. Each has a distinct genetic background, a different surface marker profile, and a history of published use that makes it credible or limited for specific applications.
For immunotherapy research in 2026, where the questions being asked are increasingly precise, choosing the right model from the start matters more than ever. Use what fits the biology. Validate results across multiple lines. And always source authenticated, characterized cells from a supplier whose quality controls you can rely on.