Anti-CR1 monoclonal antibody, clone F22 [FITC]

The complement system and Toll-like receptors (TLRs) are essential contributors of innate immunity. Separate activation of these systems has been shown to play a role in initiating and shaping the adaptive immune response, however the modulation of various B cell functions by the simultaneous involvement of these two systems has not yet been uncovered. We demonstrate here that occupancy of complement receptor type 1 (CR1, CD35) by its natural, complement component C3-derived ligand significantly and dose dependently reduces the TLR9-induced expression of activation markers, cytokine production, proliferation, and antibody production by human B cells, but has no effect on the TLR7-induced functions. The synergistic response to the simultaneous engagement of either TLR9 or TLR7 along with the BCR however, is significantly inhibited by CR1 occupancy. Our findings imply that both under physiological and pathological conditions, when complement- and TLR-activating microbial and damage products are present in the B cell environment, the cooperation between CR1 and TLR7 or TLR9 provides additional levels of the regulation of human B cell functions.

The study is focused on the synthesis and characterization of (La0.75Ca0.25)(0.95)Cr1-xFexO3-delta (x = 0.3 - 0.9) perovskites as potential materials for solid oxide fuel cell (SOFC) cathode and anode. These materials possessanorthorhombically-distorted structure at room temperature whilst heating above 800-1100 K induces reversible transformation into the rhombohedral symmetry. The transition temperature increases with iron content. The linear thermal expansion coefficients vary in the range (10.5-11.1)x10(-6) K-1 and slightly grow on Fe-doping. The volume changes upon reduction are within 0.16%. The electronic conductivity exhibits a thermally-activated character and increases on Fe introduction, in particular due to an enhancement of the number of sites available for electronic transfer; this trend is observed both under oxidizing and reducing conditions. The low level of the electronic conductivity seems to be responsible for an insufficient electrochemical activity of (La0.75Ca0.25)(0.95)Cr1-xFexO3-delta-based cathodes. Under anodic conditions, other factors, such as electrode microstructure or surface-related properties, affect the electrochemical behavior.