TLR Stimulation Produces IFN-β as the Primary Driver of IFN Signaling in Nonlymphoid Primary Human Cells.

Several human autoimmune diseases are characterized by increased expression of type 1 IFN-stimulated genes in both the peripheral blood and tissue. The contributions of different type I IFNs to this gene signature are uncertain as the type I IFN family consists of 13 alphas and one each of β, ε, κ, and ω subtypes. We sought to investigate the contribution of various IFNs to IFN signaling in primary human cell types.

Discovery of PF-06928215 as a high affinity inhibitor of cGAS enabled by a novel fluorescence polarization assay.

Cyclic GMP-AMP synthase (cGAS) initiates the innate immune system in response to cytosolic dsDNA. After binding and activation from dsDNA, cGAS uses ATP and GTP to synthesize 2', 3' -cGAMP (cGAMP), a cyclic dinucleotide second messenger with mixed 2'-5' and 3'-5' phosphodiester bonds. Inappropriate stimulation of cGAS has been implicated in autoimmune disease such as systemic lupus erythematosus, thus inhibition of cGAS may be of therapeutic benefit in some diseases; however, the size and polarity of the cGAS active site makes it a challenging target for the development of conventional substrate-competitive inhibitors.

Immunogenicity of West Nile virus infectious DNA and its noninfectious derivatives.

The exceptionally high virulence of the West Nile NY99 strain makes its suitability in the development of a live WN vaccine uncertain. The aim of this study is to investigate the immunogenicity of noninfectious virus derivatives carrying pseudolethal mutations, which preclude virion formation without affecting preceding steps of the viral infectious cycle. When administered using DNA immunization, such constructs initiate an infectious cycle but cannot lead to a viremia.

Biological properties of chimeric West Nile viruses.

Recently, we have described a lineage 2 attenuated WN virus suitable for the development of a live WN vaccine. To design vaccine candidates with an improved immunogenicity, we assembled an infectious clone of the NY99 strain and created several chimeric constructs with reciprocal exchanges of structural protein genes between attenuated W956 and virulent NY99 and investigated their biological properties. Our data indicated that, while the growth rates of NY99 and chimeric viruses in tissue culture are determined primarily by properties of the structural proteins, determinants responsible for a highly cytopathic phenotype of NY99 or lack thereof for W956 are located within the nonstructural protein region of the WN genome.

The suitability of yellow fever and Japanese encephalitis vaccines for immunization against West Nile virus.

Seven volunteers involved in flavivirus studies have been immunized with commercial Japanese encephalitis and yellow fever vaccines JE-VAX and YF-VAX. Strong homologous and cross-reactive with West Nile virus (WNV) antibody responses with titers 1:1600 to 1:51200 were found in all donors. All donors developed high levels of yellow fever virus (YFV) and Japanese encephalitis virus (JEV) neutralizing antibodies with titers 1:50 to 1:1600 and 1:20 to 1:640, respectively, and WNV neutralizing antibodies with titers 1:10 to 1:80.