The 15P-1 Cells (Cellosaurus accession CVCL_6552) are a transformed murine Sertoli cell line derived from the testis of a transgenic mouse. The line originates from the work of Paquis-Flucklinger and colleagues, who showed that expression of the polyomavirus large T antigen (PyLT) under control of the viral enhancer-promoter region occurred in the seminiferous epithelium, caused bilateral Sertoli cell tumours in ageing males, and allowed differentiated cell lines to be established from testicular tissue. [1] 15P-1 retains hallmark Sertoli cell features, including transcription of the Wilms' tumour gene WT1 and the Steel (SCF) gene. [2] The line is used in studies of spermatogenesis, Sertoli cell phagocytosis, testicular antimicrobial defence, Sertoli cell transcriptional regulation, and reproductive toxicology.

Key Takeaways

• 15P-1 is a transformed murine Sertoli cell line (C57BL/6 × DBA/2 background) established from the testis of a 6-month-old transgenic male expressing the polyomavirus large T antigen. [1]
• The line transcribes WT1 and Steel/SCF and shows morphological and ultrastructural features characteristic of Sertoli cells. [1] [2]
• In co-culture, 15P-1 cells supported meiotic and post-meiotic differentiation of diploid premeiotic germ cells into haploid, Prm-1-expressing spermatids in the original 1993 report. [2]
• 15P-1 cells show a regulated phagocytic capacity that is switched on by contact with pachytene spermatocytes — one of the best-characterised functional readouts of the line. [3]
• The androgen receptor (AR) is undetectable in 15P-1, while the membrane androgen receptor ZIP9 and functional ESR1 are expressed — a defining feature for hormone-signalling studies. [16] [10]
• The line is tractable for transient transfection, stable knockdown, stable overexpression and reporter/ChIP assays, enabling loss- and gain-of-function work that is impractical in primary Sertoli cells. [7] [15] [19]
• Important caveat: the lines derived in the original study retained a contingent of germinal origin that could not be separated by conventional cloning. 15P-1 should not be assumed to be a pure Sertoli cell population. [1]

What is the 15P-1 Cell Line?

The 15P-1 line was established from the testis of a 6-month-old male transgenic mouse on a C57BL/6 × DBA/2 background. The transgene encoded the large T antigen of polyomavirus under control of the viral enhancer-promoter region; in every transgenic family analysed, expression was found in the seminiferous epithelium — in both Sertoli and germ cells — without pathological consequences for most of the animals' lives. Every old male eventually developed large bilateral testicular tumours arising from Sertoli cell derivatives, and cell lines were established both from these tumours and from still apparently normal testis before the onset of tumour growth. [1] Cellosaurus lists 15P-1 as derived in situ from testis with no tumour entity annotated, which is consistent with — though not formal proof of — derivation before overt tumour formation.

Two points deserve emphasis for anyone planning experiments. First, the lines retained morphological and ultrastructural features characteristic of Sertoli cells, and 15P-1 specifically transcribes WT1 and Steel/SCF. [1] [2] Second, the same original report documented persistent expression of genes normally transcribed during premeiotic and early meiotic spermatogenesis (LDH-X, Hox1.4, c-kit), indicating a co-maintained cellular contingent of germinal origin that remained tightly associated with the Sertoli component even at late passages and could not be separated by conventional cloning. [1] This mixed composition was originally presented as an advantage for studying Sertoli–germ cell interaction, but it means 15P-1 should not be treated as a clonal, pure Sertoli population.

As reviewed by Rahman and Huhtaniemi, tissue-specific oncogene expression in transgenic animals is a productive route to cell lines that preserve differentiated functions often lost during conventional immortalisation. [6] 15P-1 is one such line. It is less widely used than TM4 — the most commonly cited murine Sertoli line — but occupies a distinct niche, particularly where AR-independent signalling or regulated phagocytosis is the subject of study.

Cell Culture Information

Advantages of 15P-1 Cells

The principal advantage of 15P-1 is that it retains differentiated Sertoli cell functions that are usually lost on immortalisation. Beyond marker transcription, the line reproduces a genuine Sertoli behaviour: a regulated phagocytic capacity. In resting cultures only a minority of cells are actively phagocytic, but after addition of a defined germ cell fraction essentially all cells internalise latex beads as efficiently as macrophages. The inducing cell type was identified as the pachytene spermatocyte, acting through a formaldehyde-resistant surface signal rather than through changes in Sertoli gene expression. [3] Few immortalised somatic testicular lines reproduce a stage-specific germ cell signal this cleanly.

The line is also amenable to a broad range of molecular interventions. Stable clones expressing physiological levels of a transgene have been generated for microarray-based target identification, [7] stable shRNA-mediated knockdown with subsequent rescue has been used to dissect a phagocytosis pathway, [15] and stable siRNA-based silencing has been applied in toxicology. [11] Promoter work in 15P-1 routinely combines luciferase reporters with 5' deletions, site-directed mutagenesis and ChIP-qPCR. [19] [13] [20] This tractability supports loss- and gain-of-function experiments that are impractical in primary Sertoli cells, which are non-proliferating and finite.

A further practical advantage is the AR-negative background (see Limitations), which turns 15P-1 into a useful counterpart to AR-expressing lines such as TM4 when the goal is to separate classical from non-classical androgen signalling. [16]

Limitations of 15P-1 Cells

Cellular composition. The lines established in the original study were not pure Sertoli cultures. Alongside the dominant Sertoli component, they maintained cells of germinal origin, evidenced by transcription of LDH-X, Hox1.4 and c-kit; the two cell types remained tightly associated even at late passages and resisted separation by conventional cloning. [1] Depending on the assay, this can be a feature or a confounder — for readouts such as secreted factors or bulk transcriptomics it must be accounted for explicitly.

Absent androgen receptor. AR is undetectable in 15P-1, which rules out the line for classical AR-mediated transcription studies. [16] Work comparing 15P-1, TM4 and primary rat Sertoli cells showed that testosterone still activates Notch signalling in 15P-1; ZIP9 knockdown abolished the effect on Notch1/N1ICD and RBP-J activity, but testosterone-induced Hey1 expression was blocked neither by ZIP9 silencing nor by bicalutamide, leading the authors to postulate a further AR- and ZIP9-independent mechanism. [16] Results obtained here therefore cannot be extrapolated to AR-competent Sertoli cells without validation. Note that, in contrast to AR, 15P-1 does express a ligand-dependent, genomically functional ESR1. [10]

Transformation and architecture. As with all immortalised lines, the constitutive PyLT antigen drives continuous proliferation and may alter cell cycle checkpoints and stress responses relative to quiescent primary Sertoli cells. Two-dimensional monolayers also cannot recapitulate the three-dimensional architecture of the seminiferous tubule, although Matrigel-based 3D culture of 15P-1 has been used to model HGF- and GDNF-driven tubular organisation. [22] Findings should be confirmed in primary Sertoli cells, organ culture or in vivo models before conclusions are drawn about testicular physiology.

Suitability limits outside reproductive biology. When 15P-1 was screened alongside nine other invertebrate and vertebrate lines for use in a portable, impedance-based (ECIS) toxicity sensor, only three lines tolerated extended storage on enclosed fluidic biochips — and all three came from ectothermic vertebrates. [9] 15P-1 was therefore not among the lines suited to that field application, a useful reminder that the line's strengths are assay-specific.

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Applications

Spermatogenesis and Germ Cell Communication

The best-known application of 15P-1 is as a somatic support layer for male germ cell differentiation in vitro. Rassoulzadegan and colleagues reported in 1993 that testicular cells explanted from 9-day-old mice — that is, before the first meiosis — underwent meiotic and post-meiotic differentiation when co-cultured with 15P-1 cells, generating groups of four haploid cells with the morphology of round spermatids and initiating Prm-1 transcription. [2] This remains a landmark observation, but it should be read as a single-laboratory result from 1993 rather than as a routinely reproduced protocol; the field's later benchmark for complete in vitro spermatogenesis has been neonatal testis organ culture rather than two-dimensional co-culture. Anyone planning to build on the co-culture system should treat re-establishing the differentiation readout as part of the experimental work.

15P-1 has been more consistently productive as a platform for dissecting germ cell signals to Sertoli cells. A promoter-trap library built in 15P-1 identified loci whose activity changes on addition of germ cells; one was Fra1, an AP-1 component. Fra1 mRNA accumulation was induced in both 15P-1 and freshly explanted Sertoli cells by round spermatids or by nerve growth factor, acting via the TrkA receptor and the ERK1/ERK2 pathway, with a characteristic biphasic transcription profile. [5] Together with the phagocytosis work described below, this established 15P-1 as a tool for mapping paracrine germ-to-Sertoli signalling.

Testicular Antimicrobial Defence and Defensin Biology

The testis is immune-privileged, yet must protect developing germ cells from microbial threats. Grandjean and colleagues showed that 15P-1 cells, primary Sertoli cultures and explanted testicular tissue all release protease-sensitive material with broad-spectrum antibacterial activity. [4] A nucleotide sequence corresponding to the conserved first exon of the mouse cryptdin and cryptdin-related genes was detected in 15P-1 RNA and in testis, and immunohistochemistry demonstrated cryptdins of the cryp-1, -2, -3, -6 group in 15P-1 cells. In the testis, these peptides localised to Sertoli cells at stages corresponding to spermatid maturation — and, notably, also to Leydig cells in the interstitium, so the response is not exclusively Sertoli-derived. Antibacterial activity in 15P-1 conditioned medium was increased 10- to 50-fold by fractions enriched in round spermatids and by nerve growth factor.

More recent work has addressed individual defensin family members. Jin and colleagues characterised Defb19, a β-defensin expressed in both Sertoli and germ cells. Overexpression of Defb19 in 15P-1 decreased cell junction molecule expression and promoted matrix adhesion and migration of Sertoli cells, and conditioned medium from Defb19-overexpressing 15P-1 cells promoted migration of the GC2-spd spermatocyte line. [18] Independently of the cell line work, CRISPR/Cas9 knockout of Defb19 in mice caused male subfertility with testicular and epididymal atrophy, increased apoptosis and reduced sperm counts — an in vivo confirmation of the in vitro phenotype.

Sertoli Cell Signalling, Phagocytosis, and Gene Regulation

Phagocytic clearance of apoptotic germ cells and residual bodies is a core Sertoli function, and 15P-1 is one of the few lines in which it can be measured. Building on the original bead-uptake assay, [3] Jin and colleagues used 15P-1 cells stably depleted of endogenous Lmcd1 to show that LMCD1 controls Sertoli cell phagocytosis via the NFAT1/Txlna axis: LMCD1 expression is induced by germ cell-derived TNF-α through TNFR1, suppressed by oxidative stress in a STAT3-dependent manner, and required for the dephosphorylation and nuclear translocation of NFAT1 that drives Txlna transactivation. Knockdown impaired residual body binding and uptake, and a constitutively active NFAT1 mutant rescued the defect. [15]

Transcriptional regulation of Sertoli cell adhesion and signalling genes is a second productive area. Nguyen and Martin showed that the AP-1 factors JUNB and FOSL2 cooperatively activate the Cdh3 (P-cadherin) promoter in 15P-1, with both factors recruited to an AP-1 element at −47 bp, confirmed by ChIP-qPCR, 5' deletions and site-directed mutagenesis. [19] The same laboratory used 15P-1 alongside TM4 to show that cJUN cooperates with SOX8 or SOX9 to regulate Gja1/connexin43 [13] and that JUNB cooperates with NR5A1 to activate the Axl promoter. [20] Earlier, stable 15P-1 clones expressing physiological levels of RHOX5 were used to identify Rhox5-regulated genes and to link them to AR-dependent transcription in the testis. [7]

Post-translational regulation has also been examined in Sertoli-derived cells. Sengupta and colleagues showed that both mouse and human Sertoli cells undergo apoptosis when sumoylation is inhibited chemically or by siRNA, identified proteome changes dominated by ER/stress-related proteins, implicated sumoylation in NOTCH signalling, and demonstrated that knockdown of the SUMO ligase KAP1/TRIM28 in a Sertoli-derived line almost completely inactivates sumoylation. [17] Separately, 15P-1 was used to show that cigarette smoke extract down-regulates CDK14 protein and β-catenin levels, more strongly than in the GC-1 spermatogonial line — evidence that smoke preferentially perturbs Wnt signalling in the Sertoli compartment. [12]

Heavy Metal Toxicity and Lactate Transport

Sertoli cells supply lactate as the primary energy substrate for developing germ cells, so disrupted lactate production or export impairs spermatogenesis. Yu and colleagues used 15P-1 cells to compare lead and cadmium. Lead acetate significantly decreased LDH activity and Ldh mRNA, intracellular and extracellular lactate, and MCT4 and CD147 protein, while increasing Mct4 and Cd147 mRNA; glucose uptake and Glut1/Glut3 expression were unaffected. The authors concluded that lead acts principally by inhibiting LDH activity and thereby reducing lactate production. [14]

Cadmium chloride produced a distinct profile in the same system: intracellular lactate rose while extracellular lactate fell, glucose uptake, LDH activity and Glut1, Glut3 and Ldh mRNA all increased, but MCT4 and CD147 decreased at both mRNA and protein level, with dose-dependent loss of MCT4–CD147 co-localisation at the membrane. Cadmium therefore appears to impair lactate export rather than synthesis. [14] Cadmium toxicity in 15P-1 has also been linked to the blood-testis barrier: CdCl₂ raises dermatopontin expression via p38 signalling, and DPT silencing in 15P-1 partly prevents the CdCl₂-induced fall in claudin-11. [11] The controlled in vitro setting isolates Sertoli-specific effects from the multicellular interactions of intact tissue, which is precisely what makes the line useful for mechanistic reproductive toxicology.

Androgen Signalling and Non-Classical Receptors

Because AR is undetectable in 15P-1 while ZIP9 is expressed, the line is well suited to isolating non-classical androgen actions. Kamińska and colleagues used 15P-1, TM4 and primary rat Sertoli cells to show that testosterone increases Notch1/N1ICD expression and RBP-J transcriptional activity in Sertoli cells, and that AR and ZIP9 make different contributions: AR-dependent signalling governs Hey1, whereas ZIP9-dependent signalling governs Hes1. In 15P-1, ZIP9 silencing fully blocked testosterone-induced Notch pathway activation, but the effect on Hey1 persisted despite ZIP9 knockdown or bicalutamide, indicating at least one additional androgen-responsive mechanism in AR-negative Sertoli cells. [16] This is exactly the kind of dissection that an AR-negative background makes possible.

The estrogen side of the picture is complementary: 15P-1, TM4 and MSC-1 as well as purified primary mouse Sertoli cells all contain ESR1 mRNA and protein, and estradiol induces the estrogen-responsive gene Greb1 through ESR1 binding to estrogen response elements. [10] 15P-1 therefore supports classical estrogen signalling while lacking classical androgen signalling — a combination worth stating explicitly when designing hormone experiments.

Environmental Toxicology and Further Applications

Beyond heavy metals, 15P-1 has been used across reproductive toxicology. Bisphenol A reduces viability and induces apoptosis, collapse of vimentin intermediate filaments and altered Bcl-2/Bax expression in 15P-1; ginsenosides attenuated these effects via ERK1/2 and antioxidant mechanisms. [8] The flame retardant and plasticiser TEHP induces apoptosis in 15P-1, and integrated RNA sequencing plus biochemical work identified ER stress, p38 MAPK activation and blocked autophagic flux as the mediating mechanisms. [21]

Finally, the line has been moved into three-dimensional formats. In Matrigel-based 3D culture, GDNF enhanced HGF-induced formation and branching of tubular structures by 15P-1 cells and increased ZO-1 and phospho-c-MET levels, pointing to a synergistic effect on Sertoli cell organisation. [22] This is a promising direction for addressing the architectural limitation of monolayer culture.

Conclusion

15P-1 is a differentiated, genetically tractable murine Sertoli cell model with a clearly defined profile: it transcribes WT1 and Steel, reproduces stage-specific regulated phagocytosis, lacks AR while expressing ZIP9 and functional ESR1, and carries a co-maintained germ cell contingent that must be accounted for in experimental design. Over three decades it has supported work on germ-to-Sertoli signalling, defensin biology, phagocytosis and NFAT signalling, promoter regulation of Sertoli adhesion genes, and reproductive toxicology from heavy metals to plasticisers. It is not a universal substitute for primary Sertoli cells, and results — particularly those involving androgen action or bulk expression readouts — should be confirmed in complementary systems. Where an AR-negative, phagocytosis-competent, transfectable Sertoli background is the right tool, few alternatives are as well characterised. Explore the full specifications or order 15P-1 Cells at cytion.com.

Key Publications

1. Paquis-Flucklinger V, Michiels JF, Vidal F, et al. (1993) Expression in transgenic mice of the large T antigen of polyomavirus induces Sertoli cell tumours and allows the establishment of differentiated cell lines. Oncogene 8:2087–2094. PMID: 8393161
2. Rassoulzadegan M, Paquis-Flucklinger V, Bertino B, et al. (1993) Transmeiotic differentiation of male germ cells in culture. Cell 75:997–1006. PMID: 7504588 · DOI: 10.1016/0092-8674(93)90543-y
3. Grandjean V, Sage J, Ranc F, et al. (1997) Stage-specific signals in germ line differentiation: control of Sertoli cell phagocytic activity by spermatogenic cells. Dev Biol 184:165–174. PMID: 9142992 · DOI: 10.1006/dbio.1997.8518
4. Grandjean V, Vincent S, Martin L, et al. (1997) Antimicrobial protection of the mouse testis: synthesis of defensins of the cryptdin family. Biol Reprod 57:1115–1122. PMID: 9369178 · DOI: 10.1095/biolreprod57.5.1115
5. Vidal F, Lopez P, López-Fernández LA, et al. (2001) Gene trap analysis of germ cell signaling to Sertoli cells: NGF-TrkA mediated induction of Fra1 and Fos by post-meiotic germ cells. J Cell Sci 114:435–443. PMID: 11148144 · DOI: 10.1242/jcs.114.2.435
6. Rahman NA, Huhtaniemi IT (2004) Testicular cell lines. Mol Cell Endocrinol 228:53–65. PMID: 15541572 · DOI: 10.1016/j.mce.2003.05.001
7. Hu Z, Dandekar D, O'Shaughnessy PJ, et al. (2009) Androgen-induced Rhox homeobox genes modulate the expression of AR-regulated genes. Mol Endocrinol 24:60–75. PMID: 19901196 · DOI: 10.1210/me.2009-0303
8. Wang L, Hao J, Hu J, et al. (2012) Protective effects of ginsenosides against Bisphenol A-induced cytotoxicity in 15P-1 Sertoli cells via ERK1/2 signalling and antioxidant mechanisms. Basic Clin Pharmacol Toxicol 111:42–49. PMID: 22269103 · DOI: 10.1111/j.1742-7843.2012.00857.x
9. Curtis TM, Collins AM, Gerlach BD, et al. (2013) Suitability of invertebrate and vertebrate cells in a portable impedance-based toxicity sensor: temperature mediated impacts on long-term survival. Toxicol In Vitro 27:2061–2066. PMID: 23891577 · DOI: 10.1016/j.tiv.2013.07.007
10. Lin J, Zhu J, Li X, et al. (2014) Expression of genomic functional estrogen receptor 1 in mouse Sertoli cells. Reprod Sci 21:1411–1422. PMID: 24615934 · DOI: 10.1177/1933719114527355
11. Yang Q, Hao J, Chen M, et al. (2014) Dermatopontin is a novel regulator of the CdCl₂-induced decrease in claudin-11 expression. Toxicol In Vitro 28:1158–1164. PMID: 24909373 · DOI: 10.1016/j.tiv.2014.05.013
12. Pollack D, Xiao Y, Shrivastava V, et al. (2015) CDK14 expression is down-regulated by cigarette smoke in vivo and in vitro. Toxicol Lett 234:120–130. PMID: 25680692 · DOI: 10.1016/j.toxlet.2015.02.006
13. Ghouili F, Roumaud P, Martin LJ (2018) Gja1 expression is regulated by cooperation between SOX8/SOX9 and cJUN transcription factors in TM4 and 15P-1 Sertoli cell lines. Mol Reprod Dev 85:875–886. PMID: 30080944 · DOI: 10.1002/mrd.23049
14. Yu J, Sun J, Fan Y, et al. (2019) Exposure to Pb and Cd alters MCT4/CD147 expression and MCT4/CD147-dependent lactate transport in mice Sertoli cells cultured in vitro. Toxicol In Vitro 56:30–40. PMID: 30615929 · DOI: 10.1016/j.tiv.2019.01.001
15. Jin X, Zhang S, Ding T, et al. (2020) Testicular Lmcd1 regulates phagocytosis by Sertoli cells through modulation of NFAT1/Txlna signaling pathway. Aging Cell 19:e13217. PMID: 32840323 · DOI: 10.1111/acel.13217
16. Kamińska A, Marek S, Pardyak L, et al. (2020) Crosstalk between androgen-ZIP9 signaling and Notch pathway in rodent Sertoli cells. Int J Mol Sci 21:8275. PMID: 33167316 · DOI: 10.3390/ijms21218275
17. Sengupta A, Nanda M, Tariq SB, et al. (2021) Sumoylation and its regulation in testicular Sertoli cells. Biochem Biophys Res Commun 580:56–62. PMID: 34624570 · DOI: 10.1016/j.bbrc.2021.09.066
18. Jin J, Li X, Ye M, et al. (2022) Defb19 regulates the migration of germ cell and is involved in male fertility. Cell Biosci 12:188. PMID: 36414976 · DOI: 10.1186/s13578-022-00924-1
19. Nguyen HT, Martin LJ (2023) The transcription factors Junb and Fosl2 cooperate to regulate Cdh3 expression in 15P-1 Sertoli cells. Mol Reprod Dev 90:27–41. PMID: 36468795 · DOI: 10.1002/mrd.23656
20. Diawara M, Martin LJ (2024) The transcription factors NR5A1 and JUNB cooperate to activate the Axl promoter in mouse Sertoli cell lines. Mol Biol Rep 51:982. PMID: 39271559 · DOI: 10.1007/s11033-024-09934-3
21. Chen P, Song Y, Tang L, et al. (2024) Integrated RNA sequencing and biochemical studies reveal endoplasmic reticulum stress and autophagy dysregulation contribute to TEHP-induced cell injury in Sertoli cells. Environ Pollut 360:124536. PMID: 39029862 · DOI: 10.1016/j.envpol.2024.124536
22. Durkut-Kuzu B, Celik-Ozenci C (2025) GDNF enhances HGF-induced tubulogenesis and organization of Sertoli cell. J Assist Reprod Genet 42:2083–2098. PMID: 40402398 · DOI: 10.1007/s10815-025-03493-7

Cell line record: Cellosaurus CVCL_6552. Please cite the line as 15P-1 (RRID:CVCL_6552).