Altered cytokine genes expression by conA-activated spleen cells from mice infected by lymphocytic choriomeningitis virus

Safety evaluation of the mouse TCRα - transduced T cell product in preclinical models in vivo and in vitro

Adoptive cell therapy (ACT) based on TCR- or CAR-T cells has become an efficient immunotherapeutic approach for the treatment of various diseases, including cancer. Previously, we developed a novel strategy for generating therapeutic T cell products based on chain-centric TCRs, in which either α- or β-chain dominates in cognate antigen recognition. To assess the suitability of our experimental approach for the clinical application and predict its possible adverse effects, in studies here, we evaluated the safety of the experimental TCRα-modified T cell product in mouse preclinical models. Our data showed no tumorigenic or mutagenic activity in vitro of TCRα-transduced T cells, indicating no genotoxicity of viral vectors used for the generation of the experimental T cell product. Adoptive transfer of TCRα-engineered T cells in a wide dose range didn`t disturb the host homeostasis and exhibited no acute toxicity or immunotoxicity in vivo. Based on pharmacokinetics and pharmacodynamics analysis here, modified T cells rapidly penetrated and distributed in many viscera after infusion. Histological evaluations revealed no pathological changes in organs caused by T cells accumulation, indicating the absence of non-specific off-target activity or cross-reactivity of the therapeutic TCRα. Studies here provide valuable information on the potential safety of TCRα-T cell based ACT that could be extrapolated to possible effects in a human host.

Adoptive Immunotherapy Based on Chain-Centric TCRs in Treatment of Infectious Diseases

Complications after vaccination, lack of vaccines against certain infections, and the emergence of antibiotic-resistant microorganisms point to the need for alternative ways of protection and treatment of infectious diseases. Here, we proposed a therapeutic approach to control salmonellosis based on adoptive cell therapy. We showed that the T cell receptor (TCR) repertoire of salmonella-specific memory cells contains 20% of TCR variants with the dominant-active α-chain. Transduction of intact T lymphocytes with the dominant salmonella-specific TCRα led to their enhanced in vitro proliferation in response to salmonella. Adoptive transfer of transduced T cells resulted in a significant decrease in bacterial loads in mice infected with salmonella before or after the adoptive transfer. We demonstrated that adoptive immunotherapy based on T cells, transduced with dominant-specific TCRα could be successfully applied for treatment and prevention of infectious diseases and represent a useful addition to vaccination and existing therapeutic strategies.

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A regular TCR repertoire of memory T cells contains alpha-chain-centric TCRs

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Dominant-active TCRα, paired with random TCRβ, recognizes specific microbial antigens

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Adoptive immunotherapy could be applied for treatment of infections

Implications of infectious agents on results of animal experiments

Report of the Working Group on Hygiene of the Gesellschaft für Versuchstierkunde–Society for Laboratory Animal Science (GV-SOLAS)

GV-SOLAS Working Group on Hygiene: Werner Nicklas (Chairman), Felix R. Homberger, Brunhilde Illgen-Wilcke, Karin Jacobi, Volker Kraft, Ivo Kunstyr, Michael Mähler, Herbert Meyer & Gabi Pohlmeyer-Esch

Analysis of the differential host cell nuclear proteome induced by attenuated and virulent hemorrhagic arenavirus infection

Arenaviruses are important emerging pathogens and include a number of hemorrhagic fever viruses classified as NIAID category A priority pathogens and CDC potential biothreat agents. Infection of guinea pigs with the New World arenavirus Pichindé virus (PICV) has been used as a biosafety level 2 model for the Lassa virus. Despite continuing research, little is known about the molecular basis of pathogenesis, and this has hindered the design of novel antiviral therapeutics. Modulation of the host response is a potential strategy for the treatment of infectious diseases. We have previously investigated the global host response to attenuated and lethal arenavirus infections by using high-throughput immunoblotting and kinomics approaches. In this report, we describe the differential nuclear proteomes of a murine cell line induced by mock infection and infection with attenuated and lethal variants of PICV, investigated by using two-dimensional gel electrophoresis. Spot identification using tandem mass spectrometry revealed the involvement of a number of proteins that regulate inflammation via potential modulation of NF-kappaB activity and of several heterogeneous nuclear ribonuclear proteins. Pathway analysis revealed a potential role for transcription factor XBP-1, a transcription factor involved in major histocompatibility complex II (MHC-II) expression; differential DNA-binding activity was revealed by electrophoretic mobility shift assay, and differences in surface MHC-II expression were seen following PICV infection. These data are consistent with the results of several previous studies and highlight potential differences between transcriptional and translational regulation. This study provides a number of differentially expressed targets for further research and suggests that key events in pathogenesis may be established early in infection.

Identification of differentially activated cell-signaling networks associated with pichinde virus pathogenesis by using systems kinomics

Phosphorylation plays a key role in regulating many signaling pathways. Although studies investigating the phosphorylated forms of signaling pathways are now commonplace, global analysis of protein phosphorylation and kinase activity has lagged behind genomics and proteomics. We have used a kinomics approach to study the effect of virus infection on host cell signaling in infected guinea pigs. Delineating the host responses which lead to clearance of a pathogen requires the use of a matched, comparative model system. We have used two passage variants of the arenavirus Pichinde, used as a biosafety level 2 model of Lassa fever virus as it produces similar pathologies in guinea pigs and humans, to compare the host cell responses between infections which lead to either a mild, self-limiting infection or lethal disease. Using this model, we can begin to understand the differences in signaling events which give rise to these markedly different outcomes. By contextualizing these data using pathway analysis, we have identified key differences in cellular signaling matrices. By comparing these differentially involved networks, we have identified a number of key signaling "nodes" which show differential phosphorylations between mild and lethal infections. We believe that these nodes provide potential targets for the development of antiviral therapies by acting at the level of the host response rather than by directly targeting viral proteins.

Urokinase is required for T lymphocyte proliferation and activation in vitro

We have previously demonstrated that urokinase-deficient (uPA-/-) mice do not increase lung T lymphocyte number and fail to mount protective immune responses during pulmonary Cryptococcus neoformans infection. These observations suggest a previously unconsidered role for urokinase-type plasminogen activator (uPA) in T lymphocyte-mediated immune responses. Accordingly, we sought to determine whether uPA is required for T cell receptor-mediated (TCR-mediated) lymphocyte proliferation and activation. Splenocytes from uPA-/- and uPA+/+ mice were stimulated with concanavalin A (Con A). The uPA-/- mice had diminished T cell proliferation as compared with uPA+/+ mice. Coculturing uPA-/- T cells with uPA+/+ accessory cells led to the restoration of proliferation. Similarly, T cell proliferation induced by CD3 cross-linking was diminished in uPA-/- mice as compared with uPA+/+ mice. T lymphocyte activation, defined as the induced expression of antigens and the elaboration of cytokines, was determined. The expression of CD69 and that of CD49d were diminished in response to Con A stimulation in uPA-/- mice as compared with uPA+/+ mice. The elaboration of cytokines in response to Con A was also altered in the uPA-/- mice. The production of the Th1 cytokines interferon-gamma and interleukin-12 was diminished in uPA-/- mice as compared with uPA+/+ mice. The uPA-/- mice produced increased amounts of interleukin-10, a Th2 cytokine. We conclude that the lack of uPA results in impaired T cell activation and proliferation in response to TCR-mediated signaling and the expression of a less Th1-polarized profile of cytokines. These findings suggest that the inability of uPA-/- mice to combat Cryptococcus neoformans infection may be caused by the impairment of T lymphocyte immune responses in the absence of uPA.

Natural pathogens of laboratory mice, rats, and rabbits and their effects on research

Laboratory mice, rats, and rabbits may harbor a variety of viral, bacterial, parasitic, and fungal agents. Frequently, these organisms cause no overt signs of disease. However, many of the natural pathogens of these laboratory animals may alter host physiology, rendering the host unsuitable for many experimental uses. While the number and prevalence of these pathogens have declined considerably, many still turn up in laboratory animals and represent unwanted variables in research. Investigators using mice, rats, and rabbits in biomedical experimentation should be aware of the profound effects that many of these agents can have on research.

Differential immune recognition of LCMV nucleoprotein and glycoprotein in transgenic mice expressing LCMV cDNA genes

We have generated doubly transgenic (DT) mice that independently express cDNA genes for the nucleocapsid protein (NP) and the surface glycoproteins (GP) of lymphocytic choriomeningitis virus (LCMV). By RT-PCR, transcription of both transgenes was detected at low levels in brain and kidney but was not observed in the thymus. Additionally, transcription of the GP transgene was observed in the spleen. Following challenge with exogenous LCMV, an anti-NP CTL response was induced in LCMV-infected DT mice, suggesting that nonresponsiveness to NP had not been established. In contrast, LCMV- infected DT mice were nonresponsive to GP and failed to mount any CTL response against GP, either at Day 7 or Day 30 postinfection or following expansion of splenocyte populations in vitro. A significant number (33%) of adult DT mice survived intracerebral infection with LCMV, suggesting that virus-induced immunopathology in the central nervous system can be diminished by combined expression of the transgenes whereas no protective effect was conferred on singly transgenic mice, expressing NP or GP alone. The DT mice therefore create a novel host genetic background for comparative studies of the anti-LCMV immune responses relative to parental C57Bl/6 mice.