Suppression of CXCR4 expression in mast cells upon IgE-mediated antigen stimulation

Extramedullary Osseointegration-A Novel Design of Percutaneous Osseointegration Prosthesis for Amputees

The percutaneous osseointegrated (OI) prostheses have greatly improved the overall quality of life for amputees. However, the long-term maintenance of the OI prostheses is still challenging. A major problem is bone resorption around the bone-implant-skin interface, which might cause implant loosening or osteomyelitis. Another problem is the breakage of connecting components between the intramedullary implant and external prosthesis due to excessive stress. We designed a novel osseointegration implant by changing the bone-implant contact from the inner cortex to the outer surface of cortical bone. In the current study, we compared the extramedullary cap-shaped implants with the intramedullary screw-type implants in rabbits. Osteointegration was confirmed at the interface of bone to implant contact (BIC) in both implant types. The external implant induced intramedullary bone regeneration in the medullary canal and increased the cortical bone density at the end of the stump. This study provides a new perspective on the design of osseointegration implants which might prevent the currently reported complications of the intramedullary OI systems.

Regulation of T(H)2 development by CXCR5+ dendritic cells and lymphotoxin-expressing B cells

Although cognate encounters between CCR7-expressing antigen-bearing dendritic cells (DCs) and CCR7⁺ naïve T cells take place within the T cell zone of lymph nodes, it is unknown whether co-localization of the DCs and T cells within the T cell area is obligate for effector generation. Here, we show that, following nematode infection, antigen-bearing DCs and CD4⁺ T cells upregulate CXCR5 and co-localize in a CXCL13, B cell and lymphotoxin-dependent fashion outside of the T zone. Importantly, lymphotoxin-expressing B cells, CXCL13 and CXCR5-expressing DCs and T cells are also necessary for development of interleukin 4 (IL-4) producing T_H2 cells, suggesting that T_H2 differentiation can initiate outside of the T cell zone.