抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Minimal criteria for defining multipotent mesenchymal stromal cells. The International Society for Cellular Therapy position statement

Stem cell biology has come of age. Unequivocal proof that stem cells exist in the haematopoietic system has given way to the prospective isolation of several tissue-specific stem and progenitor cells, the initial delineation of their properties and expressed genetic programmes, and the beginnings of their utility in regenerative medicine. Perhaps the most important and useful property of stem cells is that of self-renewal. Through this property, striking parallels can be found between stem cells and cancer cells: tumours may often originate from the transformation of normal stem cells, similar signalling pathways may regulate self-renewal in stem cells and cancer cells, and cancer cells may include 'cancer stem cells' - rare cells with indefinite potential for self-renewal that drive tumorigenesis.

/pdf/stem-cells-cancer-and-cancer-stem-cells-3s9b9ssybc.pdf

Stem cells, cancer, and cancer stem cells

Future cell-based therapies such as tissue engineering will benefit from a source of autologous pluripotent stem cells. For mesodermal tissue engineering, one such source of cells is the bone marrow stroma. The bone marrow compartment contains several cell populations, including mesenchymal stem cells (MSCs) that are capable of differentiating into adipogenic, osteogenic, chondrogenic, and myogenic cells. However, autologous bone marrow procurement has potential limitations. An alternate source of autologous adult stem cells that is obtainable in large quantities, under local anesthesia, with minimal discomfort would be advantageous. In this study, we determined if a population of stem cells could be isolated from human adipose tissue. Human adipose tissue, obtained by suction-assisted lipectomy (i.e., liposuction), was processed to obtain a fibroblast-like population of cells or a processed lipoaspirate (PLA). These PLA cells can be maintained in vitro for extended periods with stable population doubling and low levels of senescence. Immunofluorescence and flow cytometry show that the majority of PLA cells are of mesodermal or mesenchymal origin with low levels of contaminating pericytes, endothelial cells, and smooth muscle cells. Finally, PLA cells differentiate in vitro into adipogenic, chondrogenic, myogenic, and osteogenic cells in the presence of lineage-specific induction factors. In conclusion, the data support the hypothesis that a human lipoaspirate contains multipotent cells and may represent an alternative stem cell source to bone marrow-derived MSCs.

/pdf/multilineage-cells-from-human-adipose-tissue-implications-4z32vwpf0q.pdf

Multilineage cells from human adipose tissue: implications for cell-based therapies.

We report here that cells co-purifying with mesenchymal stem cells--termed here multipotent adult progenitor cells or MAPCs--differentiate, at the single cell level, not only into mesenchymal cells, but also cells with visceral mesoderm, neuroectoderm and endoderm characteristics in vitro. When injected into an early blastocyst, single MAPCs contribute to most, if not all, somatic cell types. On transplantation into a non-irradiated host, MAPCs engraft and differentiate to the haematopoietic lineage, in addition to the epithelium of liver, lung and gut. Engraftment in the haematopoietic system as well as the gastrointestinal tract is increased when MAPCs are transplanted in a minimally irradiated host. As MAPCs proliferate extensively without obvious senescence or loss of differentiation potential, they may be an ideal cell source for therapy of inherited or degenerative diseases.

/pdf/pluripotency-of-mesenchymal-stem-cells-derived-from-adult-200s4qlizf.pdf

Pluripotency of mesenchymal stem cells derived from adult marrow

Stem cell maintenance: aMPLe splicing choices

Faculty Opinions recommendation of ANKRD26 is a new regulator of type I cytokine receptor signaling in normal and pathological hematopoiesis.

myeloid leukemia (AML) and induces AML in transgenic mice SALL4, a novel oncogene, is constitutively expressed in human acute

Publisher Summary This chapter focuses on the use of mononuclear cell (MNC) preparations for immunotherapy, including unmanipulated cells as well as cells processed in vitro to serve specific immunologic functions—for example, cytotoxic T-lymphocytes and dendritic cells. Transfusion of MNCs is a relatively new practice; therefore, many of the indications for their usage as well as the protocols for cell preparation are still under development. The infusion of donor cells is referred to in several ways such as donor leukocyte infusion (DLI), adoptive immunotherapy, and allogeneic cell therapy. MNCs can be used for various purposes in the postallogeneic transplant setting. Donor MNCs have been effective in inducing remission when there is relapse of malignancy and are also useful in fighting infections in the post-transplant setting. Orders for DLI must be written by the patient's physician with certain specifications: donor identification, recipient information, dose of desired cell population, required processing (e.g., CD4 selection and expansion of antigen-specific cells), and whether to infuse the cells fresh or after cryopreservation. Both the patient and the donor must be informed of the risks and benefits of the procedure and each should sign a consent form documenting the discussion. There are no absolute indications for DLI as their use is still experimental. Because the use of these cell populations is not standard, all clinical protocols that include infusion of these populations should first be submitted to the local institutional review board for approval.

Mononuclear Cell Preparations

Structure-function analysis of megakaryoblastic leukemia 1 in megakaryocyte polyploidization. target sites. Having defined the functions of the five domains of MKL1 in normal megakaryocyte maturation, future studies may seek to shed on how these domains function in AMKL, how overexpression of MKL1 in leukemic cells the fusion may cell proliferation and megakaryocyte maturation including polyploidization.

Diane S. Krause

Papers

Stem cell maintenance: aMPLe splicing choices

Faculty Opinions recommendation of ANKRD26 is a new regulator of type I cytokine receptor signaling in normal and pathological hematopoiesis.

myeloid leukemia (AML) and induces AML in transgenic mice SALL4, a novel oncogene, is constitutively expressed in human acute

Mononuclear Cell Preparations

Structure-function analysis of megakaryoblastic leukemia 1 in megakaryocyte polyploidization