Insulin receptor substrate 1 (IRS1) is a key mediator of insulin signal transduction. Perturbations involving IRS1 complexes may lead to the development of insulin resistance and type 2 diabetes (T2D). Surprisingly little is known about the proteins that interact with IRS1 in humans under health and disease conditions. We used a proteomic approach to assess IRS1 interaction partners in skeletal muscle from lean healthy control subjects (LCs), obese insulin-resistant nondiabetic control subjects (OCs), and participants with T2D before and after insulin infusion. We identified 113 novel endogenous IRS1 interaction partners, which represents the largest IRS1 interactome in humans and provides new targets for studies of IRS1 complexes in various diseases. Furthermore, we generated the first global picture of IRS1 interaction partners in LCs, and how they differ in OCs and T2D patients. Interestingly, dozens of proteins in OCs and/or T2D patients exhibited increased associations with IRS1 compared with LCs under the basal and/or insulin-stimulated conditions, revealing multiple new dysfunctional IRS1 pathways in OCs and T2D patients. This novel abnormality, increased interaction of multiple proteins with IRS1 in obesity and T2D in humans, provides new insights into the molecular mechanism of insulin resistance and identifies new targets for T2D drug development.

Outer membrane vesicles (OMVs) isolated from Salmonella Typhimurium are potentially useful for developing subunit vaccines because of high immunogenicity and protective efficacy. However, flagella might remain in OMV pellets following OMV purification, resulting in non-essential immune responses and counteraction of bacterial protective immune responses when developing a vaccine against infection of multiple serotypes Salmonella. In this study, a flagellin-deficient S. Typhimurium mutant was constructed. Lipopolysaccharide profiles, protein profiles and cryo-electron microscopy revealed that there were no significant differences between the wild-type and mutant OMVs, with the exception of a large amount of flagellin in the wild-type OMVs. Neither the wild-type OMVs nor the non-flagellin OMVs were toxic to macrophages. Mice immunized with the non-flagellin OMVs produced high concentrations of IgG. The non-flagellin OMVs elicited strong mucosal antibody responses in mice when administered via the intranasal route in addition to provoking higher cross-reactive immune responses against OMPs isolated from S. Choleraesuis and S. Enteritidis. Both intranasal and intraperitoneal immunization with the non-flagellin OMVs provided efficient protection against heterologous S. Choleraesuis and S. Enteritidis challenge. Our results indicate that the flagellin-deficient OMVs may represent a new vaccine platform that could be exploited to facilitate the production of a broadly protective vaccine.

bThe conventional hemagglutinin (HA)-and neuraminidase (NA)-based influenza vaccines need to be updated most years and are ineffective if the glycoprotein HA of the vaccine strains is a mismatch with that of the epidemic strain. Universal vaccines targeting conserved viral components might provide cross-protection and thus complement and improve conventional vaccines. In this study, we generated DNA plasmids and recombinant vaccinia viruses expressing the conserved proteins nucleoprotein (NP), polymerase basic 1 (PB1), and matrix 1 (M1) from influenza virus strain A/Beijing/30/95 (H3N2). BALB/c mice were immunized intramuscularly with a single vaccine based on NP, PB1, or M1 alone or a combination vaccine based on all three antigens and were then challenged with lethal doses of the heterologous influenza virus strain A/PR/8/34 (H1N1). Vaccines based on NP, PB1, and M1 provided complete or partial protection against challenge with 1.7 50% lethal dose (LD 50 ) of PR8 in mice. Of the three antigens, NP-based vaccines induced protection against 5 LD 50 and 10 LD 50 and thus exhibited the greatest protective effect. Universal influenza vaccines based on the combination of NP, PB1, and M1 induced a strong immune response and thus might be an alternative approach to addressing future influenza virus pandemics.T he conventional influenza vaccines that are available currently to prevent seasonal flu outbreaks depend mainly on the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA) (1, 2). However, HA-and NA-based conventional influenza vaccines sometimes fail to prevent flu epidemics because the HA and/or NA in the vaccine strains is a mismatch with that in circulating virus strains (3-7). Universal influenza vaccines (UIVs) that induce effective and long-term cross-protection and address the risk of mismatch may overcome the shortcomings of conventional influenza vaccines. Therefore, the development of a UIV capable of inducing long-term immunity and cross-protection remains a priority in influenza vaccine research (8).Influenza viruses are classified as type A, B, or C based on their nucleoprotein (NP) and matrix protein (M). Among the three subtypes, influenza A virus has been the target of UIVs, because the diverse influenza A strains frequently trigger influenza epidemics and pandemics. A previous study indicated that humans mount a good response to the highly conserved internal proteins NP, M1, and polymerase basic 1 (PB1) of influenza A virus (9); therefore, these highly conserved influenza A virus antigens are the basis of UIVs. Multiple studies have investigated the potential of NP (10-13), matrix protein 1 (M1) (14-17), and ion channel (M2, mainly M2e) (18-27) as alternative vaccine antigens for the prevention of seasonal and pandemic flu outbreaks. PB1 has also shown protective potential but requires further investigation for inclusion in UIVs. Košík et al. (28) constructed a DNA vaccine based on PB1, which provided some protective immunity in a mouse model. We previously constructed DNA vaccines ...