TLR ligands in the local treatment of established intracerebral murine gliomas.

Local TLR stimulation is an attractive approach to induce antitumor immunity. In this study, we compared various TLR ligands for their ability to affect murine GL261 cells in vitro and to eradicate established intracerebral murine gliomas in vivo. Our data show that GL261 cells express TLR2, TLR3, and TLR4 and respond to the corresponding TLR ligands with increasing MHC class I expression and inducing IL-6 secretion in vitro, while TLR5, TLR7, and TLR9 are essentially absent.

In vivo colocalization of antigen and CpG [corrected] within dendritic cells is associated with the efficacy of cancer immunotherapy.

Immunostimulatory cytidyl guanosyl (CpG) motifs are of great interest as cancer vaccine adjuvants. They act as potent inducers of Th1 responses, including the activation of cytotoxic CD8(+) T lymphocytes (CTL). Whereas animal models have provided clear evidence that CpG enhances antitumor immunity, clinical trials in humans have thus far been less successful.

Elimination of regulatory T cells is essential for an effective vaccination with tumor lysate-pulsed dendritic cells in a murine glioma model.

Both melanoma and glioma cells are of neuroectodermal origin and share common tumor associated antigens. In this article, we report that the melanocyte differentiation antigen TRP2 (tyrosinase-related protein 2) is not predominantly involved in the tumor rejection of a syngeneic murine glioma. Although GL261 glioma cells endogenously expressed TRP2 and were lysed by TRP2 specific cytotoxic T cells (CTLs) in vitro, vaccinations with TRP2 peptide-pulsed dendritic cells (DCs) could only induce minor antiglioma responses in a prophylactic setting and failed to work in a stringent setting where vaccine and tumor were administered on the same day.

CD4+FoxP3+ regulatory T cells gradually accumulate in gliomas during tumor growth and efficiently suppress antiglioma immune responses in vivo.

The suppressive activity of regulatory T cells (Treg) has been implicated as an important factor limiting immune mediated destruction of tumor cells. However, not much is known about the presence and function of Treg within tumors. Here we show in a syngeneic murine glioma model a time-dependent accumulation of CD4+FoxP3+ Treg in brain tumors.

Synergy between in situ cryoablation and TLR9 stimulation results in a highly effective in vivo dendritic cell vaccine.

Dendritic cells (DC) are professional antigen-presenting cells that play a pivotal role in the induction of immunity. Ex vivo-generated, tumor antigen-loaded mature DC are currently exploited as cancer vaccines in clinical studies. However, antigen loading and maturation of DC directly in vivo would greatly facilitate the application of DC-based vaccines.

Toll-like receptor 2 controls expansion and function of regulatory T cells.

Tregs play a central role in the suppression of immune reactions and prevention of autoimmune responses harmful to the host. During acute infection, however, Tregs might hinder effector T cell activity directed toward the elimination of the pathogenic challenge. Pathogen recognition receptors from the TLR family expressed by innate immune cells are crucial for the generation of effective immunity.

Mimicking phosphorylation of the small heat-shock protein alphaB-crystallin recruits the F-box protein FBX4 to nuclear SC35 speckles.

The mammalian small heat shock protein alphaB-crystallin can be phosphorylated at three different sites, Ser19, Ser45 and Ser59. We compared the intracellular distribution of wild-type, nonphosphorylatable and all possible pseudophosphorylation mutants of alphaB-crystallin by immunoblot and immunocytochemical analyses of stable and transiently transfected cells. We observed that pseudophosphorylation at two (especially S19D/S45D) or all three (S19D/S45D/S59D) sites induced the partial translocation of alphaB-crystallin from the detergent-soluble to the detergent-insoluble fraction.

In situ tumor ablation creates an antigen source for the generation of antitumor immunity.

Tumor-destructing techniques, like radiofrequency ablation (RFA), allow eradication of large tumors. Potentially, in situ tumor destruction also can provide the immune system with an antigen source for the induction of antitumor immunity. Antigen-presenting cells could take up antigens in the periphery after which they induce specific immune responses.

Nuclear staining for the small heat shock protein alphaB-crystallin colocalizes with splicing factor SC35.

AlphaB-Crystallin has for a long time been considered a specific eye lens protein. Later on it appeared that this protein belongs to the family of the small heat shock proteins and that it occurs also extra-lenticularly in many different cell types. AlphaB-Crystallin is mainly present in the cytoplasm, but there are some indications that it might have a function in the nucleus too.