In this model, recipient CD4 cells are critically important for CD8 tolerance. To evaluate the role of CD4 cells recognizing donor MHC class II directly, we used class II-deficient donor marrow and were not able to achieve chimerism unless recipient CD8 cells were depleted,

indicating that directly alloreactive CD4 cells were necessary, for CD8 tolerance. To identify the MHC class II+ donor cells promoting this tolerance, we used donor BM lacking certain cell populations CDK and cancer or used positively selected cell populations. Neither donor CD11c(+) dendritic cells, B cells, T cells, nor donor-derived IL-10 were critical for chimerism induction. Purified donor B cells induced early chimerism and donor-specific cell-mediated lympholysis tolerance in both strain combinations tested. In contrast, positively selected CD11b(+) monocytes/myeloid cells did not induce early chimerism in either strain combination. Donor cell preparations containing B cells were able to induce early deletion of donor-reactive TCR-transgenic 2C CD8 T cells, whereas those devoid of B cells had reduced activity. Thus, induction of stable mixed chimerisin depends on the expression of MHC class 11 on the donor marrow, but no

requisite donor cell lineage was identified. Donor BM-derived B cells induced early chimerism, donor-specific cell-mediated lympholysis tolerance, and deletion of donor-reactive CD8 T cells, whereas CD11b(+) cells did not. selleck chemical Thus, BM-derived B cells are potent tolerogenic Smoothened Agonist APCs for alloreactive CD8 cells.”
“Identification of murine mammary stem cells (MaSCs) has been attempted with various in vitro and in vivo assays. While, the in vivo repopulation assay remains as the most definitive assay for

MaSC detection, it is expensive, time-consuming, and technically challenging. The in vitro mammosphere assay was considered unreliable because of major concerns about its clonal origin. In the current study, co-culture experiments with mammary cells from fluorescent protein transgenic mice and time-lapse video microscopy revealed that >90% mammospheres formed from sorted basal epithelial-enriched cells were of clonal origin in terms of stem cell. These basal-cell derived mammospheres were further distinguished morphologically in a 3-dimensional extracellular matrix culture and functionally in the in vivo repopulation assay. Transplant of single mammospheres or the resultant 3-dimensional solid structures into gland-free mammary fat pads yielded a 70% success rate of multilineage mammary gland reconstitution. Thus, this in vitro sphere formation and differentiation assay is a reliable alternative to the in vivo repopulation assay for the study of MaSCs. (C) 2013 Elsevier B.V. All rights reserved.