B cells, as an important part of the humoral immune response, are generated in the BM, migrate to secondary lymphoid organs, and upon activation, differentiate into antibody-producing memory B cells or plasma cells. Despite the pivotal roles that they play in different diseases, a comprehensive characterization in healthy rhesus macaques, which serve as valuable models for a variety of human diseases, is still missing. With the use of multiparameter flow cytometry, we analyzed B cells in BM collected from two locations, i.e., the iliac crest (BMca) and the femur (BMfem), PB, as well as secondary lymphoid organs of healthy rhesus macaques. We assessed the frequencies of immature and mature B cells, as well as CD19(+) CD20(-) CD38(+/++) CD138(+/++) plasmablasts/plasma cells. Furthermore, we found site-specific differences in the expression of markers for B cell activation and proliferation, chemokine receptors and Igs, as well as the distribution of memory B cell subpopulations. As secondary lymphoid organs harbor the highest frequencies of naive B cells, expression of CD80, CD95, and Ki67 was lower compared with B cells in the periphery and BM, whereas expression of IgD, CXCR4 (CD184), and CCR7 (CD197) was higher. Interestingly, BMca differed from BMfem regarding frequencies of B cells, their expression of CD80 and CXCR4, T cells, and plasma cells. In summary, these data identify baseline values for the above-mentioned parameters and provide the foundation for future studies on B and plasma cells in different diseases.

In superficial tinea and pityriasis versicolor, the causative fungi are for the most part confined to the stratum corneum which is barely reached by leukocytes. Therefore, a role of non-cellular components in the epidermal antifungal defence was suggested. To investigate the presence of such factors in these infections, the expression of human beta defensins 2 and 3 (hBD-2, hBD-3), RNase 7, psoriasin, toll-like receptors 2, 4 and 9 (TLR2, TLR4 and TLR9) and dectin 2 was analysed by use of immunostainings in skin biopsies. We found that hBD2, hBD3, psoriasin, RNase7, TLR2 and TLR4 were significantly more often expressed in distinct layers of lesional epidermis as compared with uninfected epidermis. In both infections but not in normal skin, hBD2 and hBD3 were commonly expressed within the stratum corneum and in the stratum granulosum. Similarly, psoriasin was seen more often in the upper skin layers of both infections as compared with normal skin. No significant differences between normal and infected skin were found for the expression of TLR9 and dectin 2. Our findings clearly show the expression of specific antimicrobial proteins and defence-related ligands in superficial tinea as well as in pityriasis versicolor, suggesting that these factors contribute to fungal containment.

Ligament-to-bone and tendon-to-bone interfaces (entheses, osteotendinous junctions [OTJs]) serve to dissipate stress between soft tissue and bone. Surgical reconstruction of these interfaces is an issue of considerable importance as they are prone to injury and the integration of bone and tendon/ligament is in general not satisfactory. We report here the stem cell-dependent spontaneous formation of fibrocartilaginous and fibrous entheses in heterotopic locations of the mouse if progenitors possess a tenogenic and osteo-/chondrogenic capacity. This study followed the hypothesis that enhanced Bone Morphogenetic Protein (BMP)-signaling in adult mesenchymal stem cells that are induced for tendon formation may overcome the tendon-inherent interference with bone formation and may thus allow the stem cell-dependent formation of tendon-bone interfaces. The tenogenic and osteo-/chondrogenic competence was mediated by the adenoand/or lentiviral expression of the biologically active Smad8 signaling mediator (Smad8ca) and of Bone Morphogenetic Protein 2 (BMP2). Modified mesenchymal progenitors were implanted in subcutaneous or intramuscular sites of the mouse. The stem cell-dependent enthesis formation was characterized histologically by immunohistological approaches and by in situ hybridization. Transplantation of modified murine stem cells resulted in the formation of tendinous and osseous structures exhibiting fibrocartilage-type OTJs, while, in contrast, the viral modification of primary human bone marrow-derived mesenchymal stromal/stem cells showed evidence of fibrous tendonbone interface formation. Moreover, it could be demonstrated that Smad8ca expression alone was sufficient for the formation of tendon/ligament-like structures. These findings may contribute to the establishment of stem celldependent regenerative therapies involving tendon/ligaments and to the improvement of the insertion of tendon grafts at bony attachment sites, eventually. STEM CELLS

Immunomagnetic separation of MSC by specific aptamers linked to magnetic particles is feasible, effective and combines a specific separation and labeling technique to a "one stop shop" strategy.

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