Int. J. Dev. Biol. 51: 731 - 738 (2007)

https://doi.org/10.1387/ijdb.072442ce

Vol 51, Issue 8

Interleukin-2 induces the proliferation of mouse primordial germ cells in vitro

Open Access | Short Communication | Published: 1 October 2007

Cristina Eguizabal¹, Maria D. Boyano¹, Alejandro Díez-Torre^1,2, Ricardo Andrade^1,2, Noelia Andollo¹, Massimo De Felici³ and Juan Aréchaga*^,1,2

¹Laboratory of Developmental Biology and Cancer, Department of Cell Biology and Histology, Faculty of Medicine and Dentistry, ²General Service for Biomedical Analytical and High Resolution Microscopy, University of the Basque Country, Vizcaya, Spain and ³Section of Histology and Embryology, Department of Public Health and Cell Biology, University of Tor Vergata, Rome, Italy.

Abstract

Primordial germ cells (PGCs) are the stem cell precursors of the germ line. Several growth factors contribute to enlarging the PGC population by acting as mitogens, survival factors or both. Interleukin-2 (IL-2) has a growth-promoting activity for T and B-lymphocytes, but its role in PGCs had not yet been studied. Here, we show that PGCs isolated from 10.5, 11.5 and 12.5 day postcoitum (dpc) mouse embryos constitutively express the three subunits (alpha, beta and gamma) of the IL-2 receptor (IL-2R). In contrast, IL-2 mRNA was not detected in these cells. However, the addition of recombinant IL-2 to the culture medium increased the number of PGCs in vitro via a mitogenic effect, as indicated by bromodeoxyuridine incorporation assays. Neutralization of the IL-2 receptor using anti-IL-2R subunit antibodies inhibited this IL-2-mediated proliferative effect on PGCs from 11.5 dpc embryos. Together, these data are indicative of a paracrine effect of IL-2 on PGC proliferation. In this regard, we also compared the effect of IL-2 with other compounds such as basic fibroblast growth factor (bFGF), steel factor, leukemia inhibitory factor and forskolin, and found that the degree of proliferation induced by IL-2 was similar to that induced by bFGF and forskolin. These observations support the notion that similar patterns of molecular signaling may underlie the developmental pathways of hematopoietic and germ stem cell precursors.

Keywords

germinal cell differentiation, hematopoietic stem cell, HSC, embryonic hematopoiesis