Immune privileges (IPs) have been demonstrated for several types of quiescent stem cells (SCs) in adult mammalian organisms. Cancer SCs (CSCs) also manifest IPs, which is one of the main concerns in cancer therapy. To elucidate the strength of non-pathological SCs IPs, we implanted bone marrow (BM) of transgenic N-GFPCF1 mice under the renal capsule of non-transgenic mice immunized with enhanced green fluorescent protein (GFP). We show that Nes-GFP+ mesenchymal SCs (MSCs) and other subpopulations of Nes-GFP+ progenitors in mouse BM have strong IPs, since they survive for at least six wk despite targetedly activated against them full immune system. We also demonstrate that MSCs retain their functionality after exposition to such immune pressure by successful retransplantation of the foci into the secondary non-immunized recipients. We suggest that nestin could be a marker for a wide spectrum of quiescent SCs with strong IPs, including CSCs.

Immune privileges of cancer stem cells is a well-known and widely studied problem, as presence of such cells in tumors is associated with refractoriness, recurrence, and metastasis. Accumulating evidence also suggests presence of immune privileges in non-pathological stem cells in addition to their other defense mechanisms against damaging factors. This similarity between pathological and normal stem cells raises the question of why stem cells have such a potentially dangerous property. Regulation of vital processes of autoimmunity control and regeneration realized through interactions between immune cells, stem cells, and their microenvironment are reviewed in this work as causes of formation of the stem cell immune privilege. Deep mutual integration between regulations of stem and immune cells is noted. Considering diversity and complexity of mutual regulation of stem cells, their microenvironment, and immune system, I suggest the term “stem system”.

Epigenetics is a growing section of biologic studies. One of the most studied epigenetic marks is 5mC modification in CpG context. Modern technologies provide solutions to proceed multiple samples and to acquire big massive data for 5mC. Technologies demonstrate high efficiency relative to a single piece of information, but such solutions could be cost ineffective for studies focused on a local DNA region. We previously presented an original method, and here I present improvements to make it faster and more reproducible. The method uses Sanger sequencing of total PCR product from bisulfite converted DNA. The key feature of the method is a utilization of only one fluorophore channel to determine a methylation ratio in a CpG. Stability of a fluorophore signal profile determined by a sequence context is enough to measure methylation of a CpG and a complicated establishing of a rarely presented counter signal from other fluorophore in a read is not required.