Far Red Fluorescent Proteins: Where Is the Limit of the Acylimine Chromophore?

The search for new near-infrared probes for fluorescence imaging applications is a rapidly growing field of research. Monomeric fluorescent proteins that autocatalyze their chromophore are the most versatile markers for in vivo applications, but the development of bright far-red fluorescent proteins (RFPs) has proven difficult. In this contribution, we search for the theoretical limit of the red shift and how it can be reached without sacrificing the fluorescence quantum yield.

Recombination and chemical energy accommodation coefficients from chemical dynamics simulations: O/O2 mixtures reacting over a β-cristobalite (001) surface.

A microkinetic model is developed to study the reactivity of an O/O(2) gas mixture over a β-cristobalite (001) surface. The thermal rate constants for the relevant elementary processes are either inferred from quasiclassical trajectory calculations or using some statistical approaches, resting on a recently developed interpolated multidimensional potential energy surface based on density functional theory. The kinetic model predicts a large molecular coverage at temperatures lower than 1000 K, in contrary to a large atomic coverage at higher temperatures.

Presence of neutrophil-bearing antigen in lymphoid organs of immune mice.

Neutrophils play a crucial early role during the innate response, but little is known about their possible contribution when an adaptive immune response is installed. A robust neutrophilia and a T helper 1 (Th1) immune response are present after immunization with Complete Freund Adjuvant (CFA). We show that when FITC-labeled OVA was injected into the footpad of OVA/CFA immunized mice, the main OVA-FITC+ cells recruited in draining popliteal lymph nodes (LNs) were neutrophils, with most of them arriving at the LN by means of lymphatic vessels.

In vivo, dendritic cells can cross-present virus-like particles using an endosome-to-cytosol pathway.

Recombinant parvovirus-like particles (PPV-VLPs) are particulate exogenous Ags that induce strong CTL response in the absence of adjuvant. In the present report to decipher the mechanisms responsible for CTL activation by such exogenous Ag, we analyzed ex vivo and in vitro the mechanisms of capture and processing of PPV-VLPs by dendritic cells (DCs). In vivo, PPV-VLPs are very efficiently captured by CD8alpha- and CD8alpha+ DCs and then localize in late endosomes of DCs.

CpG-DNA stimulates cellular and humoral immunity and promotes Th1 differentiation in aged BALB/c mice.

We examined whether CpG-DNA could be used as adjuvant to induce a T helper cell type-1 (Th1) immunity in aged BALB/c mice that showed a Th2 polarization. Bordetella pertussis and complete Freund's adjuvant (CFA) were used as well. Immunization with ovalbumin (OVA)/CpG-DNA showed that the immunoglobulin G (IgG)2a/IgG1 ratio and OVA-specific T cell response were similar in young and aged mice.