New triple-decker complexes with bridging tetramethylcyclopentadienyl ligands were synthesized by the reaction of electrophilic metal fragments with octamethylferrocene, Cp′2Fe (Cp′ = C5Me4H). The reaction of coordinatively unsaturated ruthenium cations [(C5R5)Ru]+ (R = H, CH3) with Cp′2Fe afforded purple-colored heterometallic triple-decker complexes [(C5R5)Ru(μ-Cp′)FeCp′]+ by direct electrophilic addition. Surprisingly, the analogous reaction with the coordinatively unsaturated manganese cation [Mn(CO)3]+ and Cp′2Fe produced a blue homometallic triple-decker complex, [Cp′Fe(μ-Cp′)FeCp′]+, by ring abstraction and subsequent addition of the newly generated cation [Cp′Fe]+ to an equivalent of Cp′2Fe. Three air-stable triple-decker complexes, [Cp′Fe(μ-Cp′)FeCp′]+ (2), [CpRu(μ-Cp′)FeCp′]+ (3), and [Cp*Ru(μ-Cp′)FeCp′]+ (4), have been characterized by NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction.

Antigens recognized by T helper (Th) cells in the context of MHC class II molecules have vaccine potential against cancer and infectious agents. We have described previously a melanoma patient's HLA-DR7-restricted Th cell clone recognizing an antigen, which is shared among melanoma and glioma cells derived from various patients. Here, this antigen was cloned using a novel antigen phage display approach. The antigen was identified as the ribosomal protein L8 (RPL8). A peptide of RPL8 significantly stimulated proliferation and/or cytokine expression of the Th cell clone and lymphocytes in four of nine HLA-DR7 + melanoma patients but not in healthy volunteers. The RPL8 antigen may represent a relevant vaccine target for patients with melanoma, glioma, and breast carcinoma whose tumors express this protein. [Cancer Res 2007;67(8):3555-9]

No abstract

No abstract