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Objective There are currently no definitive disease-modifying therapies for traumatic brain injury (TBI). In this study, we present a strong therapeutic candidate for TBI, immunomodulatory nanoparticles (IMPs), which ablate a specific subset of hematogenous monocytes (hMos). We hypothesized that prevention of infiltration of these cells into brain acutely after TBI would attenuate secondary damage and preserve anatomic and neurologic function. Methods IMPs, composed of US Food and Drug Administration-approved 500nm carboxylated-poly(lactic-co-glycolic) acid, were infused intravenously into wild-type C57BL/6 mice following 2 different models of experimental TBI, controlled cortical impact (CCI), and closed head injury (CHI). Results IMP administration resulted in remarkable preservation of both tissue and neurological function in both CCI and CHI TBI models in mice. After acute treatment, there was a reduction in the number of immune cells infiltrating into the brain, mitigation of the inflammatory status of the infiltrating cells, improved electrophysiologic visual function, improved long-term motor behavior, reduced edema formation as assessed by magnetic resonance imaging, and reduced lesion volumes on anatomic examination. Interpretation Our findings suggest that IMPs are a clinically translatable acute intervention for TBI with a well-defined mechanism of action and beneficial anatomic and physiologic preservation and recovery. Ann Neurol 2020;87:442-455.

Inflammatory signals present in demyelinated multiple sclerosis lesions affect the reparative remyelination process conducted by oligodendrocyte progenitor cells (OPCs). Interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and interleukin (IL)–6 have differing effects on the viability and growth of OPCs, however the effects of IL-17A are largely unknown. Primary murine OPCs were stimulated with IL-17A and their viability, proliferation, and maturation were assessed in culture. IL-17A-stimulated OPCs exited the cell cycle and differentiated with no loss in viability. Expression of the myelin-specific protein, proteolipid protein, increased in a cerebellar slice culture assay in the presence of IL-17A. Downstream, IL-17A activated ERK1/2 within 15 min and induced chemokine expression in 2 days. These results demonstrate that IL-17A exposure stimulates OPCs to mature and participate in the inflammatory response.

The growing prevalence of nanotechnology in the fields of biology, medicine, and the pharmaceutical industry is confounded by the relatively small amount of data on the impact of these materials on the immune system. In addition to concerns surrounding the potential toxicity of nanoparticle (NP)-based delivery systems, there is also a demand for a better understanding of the mechanisms governing interactions of NPs with the immune system. Nanoparticles can be tailored to suppress, enhance, or subvert recognition by the immune system. This 'targeted immunomodulation' can be achieved by delivery of unmodified particles, or by modifying particles to deliver drugs, proteins/peptides, or genes to a specific site. In order to elicit the desired, beneficial immune response, considerations should be made at every step of the design process: the NP platform itself, ligands, and other modifiers, the delivery route, and the immune cells that will encounter the conjugated NPs can all impact host immune responses.

Orchardgrass (Dactylis glomerata L.) is one of the most important cool-season forage grasses around the world, and is among the fourth top selling grass seed behind Lolium, Festuca and Phleum. However, the available orchardgrass varieties have low summer survival rates and are susceptible to rust caused by Puccinia graminis Pers., resulting in lower yields and poor quality growth in subtropical regions of China. The summer survival rate, degree of rust resistant, and the correlation of rust resistance with summer survival rate of 242 germplasm resources of D. glomerata, from five continents of the world, were investigated in a field screening for 2 years (2011 and 2012) at the southern part of China. Results showed that 13 accessions were scored high disease resistance for the 2 years, and 36 were scored a summer survival rate of 100%. Thirteen accessions of orchardgrass were screened for disease resistance and high summer survival rate (≥80%), including two accessions named PI325293 and PI308794 with a high disease resistance and summer survival rate of 100% in the 2-year studies. The correlation between rust resistance and summer survival rate was low (r = 0.111 P = 0.295 in 2011, r = 0.112 P = 0.674 in 2012). These two accessions may serve as potential genetic materials to plant breeders for developing orchardgrass varieties that contain high rust resistance and summer survival rate. These results will also contribute to the conservation and utilization of orchardgrass germplasm.

As a group of disorders, autoimmunity ranks as the third most prevalent cause of morbidity and mortality in the Western World. However, the etiology of most autoimmune diseases remains unknown. Although genetic linkage studies support a critical underlying role for genetics, the geographic distribution of these disorders as well as the low concordance rates in monozygotic twins suggest that a combination of other factors including environmental ones are involved. Virus infection is a primary factor that has been implicated in the initiation of autoimmune disease. Infection triggers a robust and usually well-coordinated immune response that is critical for viral clearance. However, in some instances, immune regulatory mechanisms may falter, culminating in the breakdown of self-tolerance, resulting in immune-mediated attack directed against both viral and self-antigens. Traditionally, cross-reactive T-cell recognition, known as molecular mimicry, as well as bystander T-cell activation, culminating in epitope spreading, have been the predominant mechanisms elucidated through which infection may culminate in an T-cell-mediated autoimmune response. However, other hypotheses including virus-induced decoy of the immune system also warrant discussion in regard to their potential for triggering autoimmunity. In this review, we discuss the mechanisms by which virus infection and antiviral immunity contribute to the development of autoimmunity.

Cell-based therapies are attractive approaches to promote myelin repair. Recent studies demonstrated a reduction in disease burden in mice with experimental allergic encephalomyelitis (EAE) treated with mouse mesenchymal stem cells (MSCs). Here, we demonstrated human bone marrow-derived MSCs (BM-hMSCs) promote functional recovery in both chronic and relapsing-remitting models of mouse EAE, traced their migration into the injured CNS and assayed their ability to modulate disease progression and the host immune response. Injected BM-hMSCs accumulated in the CNS, reduced the extent of damage and increased oligodendrocyte lineage cells in lesion areas. The increase in oligodendrocytes in lesions may reflect BM-hMSC-induced changes in neural fate determination, since neurospheres from treated animals gave rise to more oligodendrocytes and less astrocytes than nontreated neurospheres. Host immune responses were also influenced by BM-hMSCs. Inflammatory T-cells including interferon gamma producing Th1 cells and IL-17 producing Th17 inflammatory cells and their associated cytokines were reduced along with concomitant increases in IL-4 producing Th2 cells and anti-inflammatory cytokines. Together, these data suggest that the BM-hMSCs represent a viable option for therapeutic approaches.

Pro-inflammatory CD4(+) T-cell-mediated autoimmune diseases, such as multiple sclerosis and type 1 diabetes, are hypothesized to be initiated and maintained by activated antigen-presenting cells presenting self antigen to self-reactive interferon-gamma and interleukin-17-producing CD4(+) T-helper (Th) type 1/Th17 cells. To date, the majority of Food and Drug Administration-approved therapies for autoimmune disease primarily focus on the global inhibition of immune inflammatory activity. The goal of ongoing research in this field is to develop both therapies that inhibit/eliminate activated autoreactive cells as well as antigen-specific treatments, which allow for the directed blockade of the deleterious effects of self-reactive immune cell function. According to the two-signal hypothesis, activation of a naive antigen-specific CD4(+) T cell requires both stimulation of the T-cell receptor (TCR) (signal 1) and stimulation of costimulatory molecules (signal 2). There also exists a balance between pro-inflammatory and anti-inflammatory immune cell activity, which is regulated by the type and strength of the activating signal as well as the local cytokine milieu in which the naive CD4(+) T cell is activated. To this end, the majority of ongoing research is focused on the delivery of suboptimal TCR stimulation in the absence of costimulatory molecule stimulation, or potential blockade of stimulatory accessory molecules. Therefore, the signaling pathways involved in the induction of CD4(+) T-cell anergy, as apposed to activation, are topics of intense interest.

Jointed goatgrass (Aegilops cylindrica Host) is an economically important weed in winter wheat (Triticum aestivum L.)-fallow production regions of the United States. Few options exist for man- agement of jointed goatgrass in winter wheat due to the close genetic relationship between the two species. This research evaluated use of imazamox herbicide (2-((RS)-4-isopropyl-4- methyl-5-oxo-2-imidazolin-2-yl)-5-methoxym- ethylnicotinic acid) in an imazamox-resistant (IR) winter wheat-fallow rotation over 6 yr when grown continuously or in rotation with a con- ventional winter wheat cultivar. The objectives of this study were to compare use patterns of IR technology in winter wheat with respect to jointed goatgrass density and wheat grain contamination over three crop years in a win- ter wheat-fallow system and to monitor jointed goatgrass and jointed goatgrass × wheat hybrid populations for resistance to imazamox. The IR treatment resulted in reduced jointed goatgrass density compared to conventional treatments in 5 out of 6 yr. Reductions in jointed goatgrass tiller density resulting from use of imazamox in IR winter wheat were evident in a subsequent crop year at each of two experimental sites. No IR jointed goatgrass plants nor viable jointed goatgrass × wheat hybrid plants were found. In a winter wheat-fallow rotation, IR technol- ogy can effectively manage jointed goatgrass populations and reduce jointed goatgrass con- tamination of grain. Use of the technology every other crop year, or two out of every three crop years, will provide management benefi ts in sub- sequent years.

Disease progression in experimental autoimmune encephalomyelitis (EAE) is regulated by programmed death receptor 1 (PD-1) and its ligands, B7-H1 (programmed death ligand 1 (PD-L1)) and B7-DC (PD-L2). B7-H1 and B7-DC have negative regulatory effects upon binding PD-1 on activated T cells and B7-H1 deficiency increases severity of both diabetes and EAE. However, the role of PD-L expression on different APC in the CNS in regulating local T-cell function during relapsing EAE has not been examined. Our data show that the majority of CNS CD4+ T cells isolated during acute EAE are PD-1+, and T cells specific for relapse-associated epitopes express PD-1 upon antigen stimulation in the CNS. B7-H1 and B7-DC are differentially expressed on discrete APC populations in the inflamed CNS. B7-H1 and PD-1 have mainly inhibitory functions on CNS T cells. B7-H1 negatively regulates the stimulation of activated PD-1+ T(H) cells, in co-cultures with microglia and different CNS-infiltrating APC presenting endogenously processed peptides. The preponderance of IFN-gamma+ versus IL-17+ T cells in the CNS of B7-H1(-/-) mice suggests that B7-H1 more selectively suppresses T(H)-1 than T(H)-17 responses in vivo. In contrast, blockade of B7-DC has less pronounced regulatory effects. Overall, the results demonstrate that B7-H1 expressed by CNS myeloid APC negatively regulates T-cell activation during acute relapsing EAE.

The National Science Foundation's Extensible Terascale Facility (ETF), or TeraGrid (http://www.teragrid.org/), is entering its operational phase. An example of an ETF science gateway effort is the Neutron Science TeraGrid Gateway (NSTG). The Oak Ridge National Laboratory (ORNL) resource provider effort (ORNL-RP) now in operation is bridging the gap between a large-scale experimental community and the TeraGrid as a large-scale national cyberinfrastructure. Of particular importance here is the collaboration with the Spallation Neutron Source (SNS) at ORNL. The U.S. Department of Energy's SNS (http://www.sns.gov/) at ORNL will be commissioned in the spring of 2006 as the world's brightest source of neutrons. Neutron science users can run experiments, generate datasets, perform data reduction, analysis, visualize results, collaborate with remotes users, and archive long-term data in repositories with curation services. The ORNL-RP and the SNS data analysis group have spent 18 months developing and exploring user requirements, including the creation of prototypical services such as a facility portal, data, and application execution services. We describe results from these efforts and discuss implications for science gateway creation. Finally, we show incorporation into implementation planning for the NSTG and SNS architectures. The plan is for a primarily portal-based user interaction supported by a service-oriented architecture for functional implementation. Published in 2006 by John Wiley & Sons, Ltd.

Cuprizone-induced demyelination is a mouse model of multiple sclerosis (MS) as cuprizone-fed mice exhibit neuroin-flammation and demyelination in the brain. Upon removal of cuprizone from the diet, inflammation is resolved and reparative remyelination occurs. In an Affymetrix Gene-Chip analysis, the stress-associated gene p8 was strongly upregulated (>10×) during cuprizone-induced demyelination but not remyelination. We verified this upregulation (>15×) of p8 in the CNS during demyelination by real-time polymerase chain reaction (PCR). This upregulation is brain-specific, as p8 is not elevated in the liver, lung, kidney, spleen, and heart of cuprizone-treated mice. We also localized the cellular source of p8 during cuprizone treatment, and further found elevated expression during embryogenesis but not in normal adult brain. Compared with wild-type controls, the death of oligodendrocytes in p8−/− mice is delayed, as is microglial recruitment to areas of demyelination. The corpus callosum of p8−/− mice demyelinates at a slower rate than wild-type mice, suggesting that p8 exacerbates CNS inflammation and demyelination. Enhanced expression of p8 is also observed in the spinal cords of mice with acute experimental autoimmune encephalomyelitis (EAE) induced by PLP139–151 peptide (10×). Increased expression is detected during disease onset and expression wanes during the remission phase. Finally, p8 is found upregulated (8×) in post-mortem tissue from MS patients and is higher in the plaque tissue compared with adjacent normal-appearing white and gray matter. Thus, p8 is an excellent candidate as a novel biomarker of demyelination.

Theiler's murine encephalomyelitis virus (TMEV), a natural mouse pathogen, is a neurotropic picornavirus that induces a chronic, CD4+ T cell-mediated demyelinating disease with a clinical course and histopathology similar to those of chronic-progressive multiple sclerosis. Upon infection, TMEV-specific CD4+ T cells target persistent viral antigens in the CNS and initiate myelin damage. Later in the disease, myelin-specific CD4+ T cells are primed by epitope spreading, and these autoimmune T cells contribute to the pathogenesis of the chronic-progressive disease. This review focuses upon aspects of the initiation of a virally induced CD4+ T cell-mediated autoimmune response. First, the steps involved in the hierarchical activation of non-cross-reactive myelin-specific T cells in the SJL/J mouse after CNS infection with TMEV and the role of these autoreactive T cells in chronic myelin damage are discussed. Second, the process of epitope spreading and the role of CNS antigen presenting cells in the temporal presentation of self-antigens is considered. Finally, we will discuss aspects of T cell activation and antigen presentation, and how they can impact autoimmune disease.

Many farmers in the central High Plains graze corn (Zea mays L.) aftermath and are looking at ways to improve the quality and amount of this fall pasture resource. However, no information is available on intercropping annual legumes with irrigated corn in the region. Our objective was to determine the most appropriate pasture legume species that could be used for an irrigated corn-legume system. To accomplish this, field experiments were conducted under irrigation at four sites in Wyoming. Eight legume spedes planted with corn were compared with monoculture corn under weed-free and weedy conditions. Under weed-free conditions, corn grain yields were reduced by the presence of legume in some treatments while others were comparable to the check yields. Black medic (Medicago lupulina L.) did not reduce corn yields, but barrel medic (M. truncatula Gaertn.) and sphere medic (M. sphaerocarpus L.) reduced corn yields by 17%. Corn yields were reduced 62% by the presence of weeds regardless of legume spedes. Legumes did not suppress weed growth. Barrel medic produced the most forage in July; however, there was little difference among species by November. In November, when corn stalks would be grazed, black medic and yellow sweetclover (Melitotus officinalis Lam.) produced the highest quality forage. These results indicate that a mostly weed-free field is required to maximize corn and legume production. Of the legume species evaluated, black medic appears to offer the greatest potential for intercropping with irrigated corn in the central High Plains.

T cell receptor engagement and the B7-CD28 / CTLA-4 signaling pathways play critical roles in T cell activation and regulation. CD28 engagement results in T cell activation, differentiation and survival while CTLA-4 signals block IL-2 production, cell cycle progression and T cell differentiation. We explored the role of CTLA-4 in peripheral tolerance induced by intravenous administration of ethylene carbodiimide-fixed, antigen-coupled splenocytes in the PLP139 - 151-induced relapsing experimental autoimmune encephalomyelitis system. Tolerance induction with PLP139 - 151-coupled splenocytes correlates with low B7 expression on the fixed antigen-presenting cells, conditions that would favor CTLA-4-mediated inhibition. Administration of CTLA-4Ig or anti-CTLA-4 concomitant with the 'tolerogenic' stimulus, however, failed to reverse tolerance induction. In contrast, blocking CTLA-4 at the time of secondary 'immunogenic' encounter with antigen reversed the tolerant state. These findings indicate that CTLA-4 is required to maintain the unresponsive state of the tolerized T cells upon antigenic stimulation under inflammatory conditions and, therefore, have important implications for therapeutic regulation of autoimmune disease.

Background: Ethanol consumption impairs cell-mediated immunity and enhances humoral immunity. Among cell-mediated immune reactions, little is known of the effect of ethanol on chronic graft rejection. Allograft responses against the male-specific minor histocompatibility antigen, Hya, are widely used to study chronic graft rejection. Methods: Female C57BL/6 (B6) mice were fed ethanol-containing liquid diets, were pair-fed an isocaloric liquid control diet, or were fed solid diet and water ad libitum. One week after diet initiation, the mice were grafted with split thickness, orthotopic male tail skin grafts, and the integrity of the grafts was monitored as the diet continued. Delayed hypersensitivity (DTH) was also determined in these same mice. In addition, Hya-cytolytic T-cell–deficient syngeneic major histocompatibility complex mutant B6.C-H2bm13 (bm13) and B6.C-H2bm14 (bm14) mice were assessed for skin graft rejection, DTH, and cytotoxic T-lymphocyte (CTL) activity. Results: Ethanol-consuming female B6 mice are impaired in their ability to reject syngeneic male skin grafts and to develop Hya-specific DTH responses. To address the underlying mechanism, we show that Hya graft rejection correlates with DTH and not with CTL activity. Female B6 mice clearly differ from female bm13 and bm14 mice in their ability to generate CTLs against Hya antigen. Despite their inability to make Hya-specific CTL responses, bm13 and bm14 female mice, nevertheless, make Hya-specific DTH responses and ultimately reject Hya-disparate skin grafts, indicating that Hya-specific graft rejection results from DTH. Ethanol, by impairing Hya-specific DTH, inhibits Hya-specific skin graft rejection. Conclusions: We demonstrate that ethanol consumption impairs Hya-specific graft rejection. In addition, experiments with mice unable to generate anti-Hya CTLs support previous observations suggesting that DTH responses are sufficient to cause rejection of Hya-incompatible grafts.

Sugarbeet (Beta vulgaris L.) is a major cash crop in Wyoming where overuse of water and agrochemicals is a concern in furrowirrigated areas. Drip irrigation, an alternative technology, is not well developed for row crops within the state. Therefore, our objective was to evaluate the economic feasibility of implementing drip irrigation practice for sugarbeet production. Capital budgeting analyses, including net present value (NPV) and rate of return (ROR), were used for 10 to 40 ha. Sensitivity analyses were conducted with drip system size and life span, interest rate, water price, and weed control cost. Sugarbeet and sugar yields were higher under drip irrigation than furrow irrigation at P = 0.05. The drip system investment cost decreased with increasing size. Total variable costs for drip irrigation were lower than those for furrow irrigation. Sugarbeet returns were $2080 and $2310 ha -1 for furrow and drip irrigation practices, respectively. Higher returns and shorter payback time were observed for large conversion areas. The sensitivity was more pronounced with small-scale farming. Increasing interest rates caused delays in positive return and profit and contributed to larger differences in payback time between drip system sizes. For all conversion sizes, ROR increased with system lifetime. Higher profitability was observed for areas with increased water prices and weed control costs. The overall findings indicated that sugarbeet production under drip irrigation would be most profitable for a 40-ha area with payback periods ranging from 7 to 10 yr.

Epitope spreading is a process whereby epitopes distinct from and non-cross-reactive with an inducing epitope become major targets of an ongoing immune response. This phenomenon has been defined in experimental and natural situations as a consequence of acute or persistent infection and secondary to chronic tissue destruction that occurs during progressive autoimmune disease. We have investigated the functional significance of this process in the chronic stages of both autoimmune and virus-induced central nervous system (CNS) demyelinating disease models in the SJL/J mouse. During the relapsing-remitting course of experimental autoimmune encephalomyelitis (R-EAE) induced with defined encephalitogenic myelin peptides, CD4+ T cells specific for endogenous epitopes on both the initiating myelin protein (intramolecular epitope spreading) and distinct myelin proteins (intermolecular epitope spreading) are primed secondary to myelin destruction during acute disease and play a major functional role in mediating disease relapses. Similarly, epitope spreading to endogenous myelin epitopes appears to play a major functional role in the chronic-progressive course of Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD), a virus-induced CD4+ T-cell-mediated immunopathology. In TMEV-IDD, myelin destruction is initiated by virus-specific CD4+ T cells which target virus epitopes persisting in CNS-derived antigen-presenting cells. However, the chronic stage of this progressive disease is associated with the activation of CD4+ T cells specific for multiple myelin epitopes. In both models, the temporal course of T-cell activation occurs in a hierarchical order of epitope dominance, spreading first to the most immunodominant epitope and progressing to lesser immunodominant epitopes. In addition, epitope spreading in R-EAE is regulated predominantly by CD28/B7-1 co-stimulatory interactions, as antagonism of B7-1-mediated co-stimulation using anti-B7-1 F(ab) fragments is an effective ameliorative therapy for ongoing disease. The process of epitope spreading has obvious important implications for the design of antigen-specific therapies for the treatment of autoimmune disease since these therapies will have to identify and target endogenous self epitopes associated with chronic tissue destruction.

Injection of antigen cross-linked accessory cells has proven to be an efficient and highly selective approach for inducing epitope-specific peripheral tolerance. This approach has been used successfully to inhibit induction of experimental autoimmune encephalomyelitis (EAE) and to dissect the relative dominance of component encephalitogenic determinants that contribute to both acute and relapsing EAE. In this study, we evaluated the tolerogenic effect of the dominant encephalitogenic epitope for SJL/J mice, residues 139-151 of myelin proteolipid protein (PLP), on the induction and relapses of EAE induced actively with PLP139-151/CFA. Our results demonstrate the powerful protective effect of treating mice before induction of EASE with PLP139-151-conjugated splenocytes (SPL) on the incidence and severity of both the initial episode and the first relapse of EAE. Moreover, treatment of mice on the first day of onset of clinical signs of EAE reduced the severity of the first relapse, apparently by reducing T cell recognition of PLP139-151, although no significant therapeutic effect was observed during the initial treated clinical episode. These data demonstrate the utility of using neuroantigen-coupled accessory cells to prevent and treat relapsing EAE.

Peripheral antigen-specific tolerance can be induced by feeding protein antigens. The mechanism has been described as either clonal anergy/deletion or induction of antigen-specific regulatory cells that produce transforming growth factor-beta (TGF-beta). These two mechanisms have been linked to the magnitude and frequency of the dose of antigen fed; a single high dose induces anergy/deletion, whereas multiple low doses of antigen induce TGF-beta-secreting regulatory cells. In the present study, we investigated the mechanisms of feeding soluble peptides of proteolipid protein (PLP) for prevention of experimental autoimmune encephalomyelitis (EAE) induced by either intact PLP or the immunodominant PLP139-151 peptide. Feeding PLP139-151 prevented acute and relapsing EAE induced by either PLP139-151 or intact PLP. PLP139-151 feeding induced anergy in the T helper 1 (Th1) population as measured by an inhibition of both proliferation and interferon-gamma (IFN-gamma) production. Interleukin-4 (IL-4) production was increased, but increased TGF-beta production was not observed. Importantly, PLP139-151 feeding induced anergy in peripheral and central nervous system (CNS)-in-filtrating T cells. Feeding of the subdominant PLP epitope (PLP178-191) failed to inhibit EAE induced by PLP139-151; therefore, oral tolerance was not due to induction of bystander suppression. These results demonstrate that both acute and relapsing paralysis in EAE can be prevented by feeding the immunodominant peptide of PLP.

Theiler's murine encephalomyelitis virus (TMEV) infection and experimental allergic encephalomyelitis (EAE) are considered among the best models of human multiple sclerosis (MS). In both models, clinical disease is characterized by paralysis, while pathological changes consist of inflammatory demyelination. In both models there is a genetic influence on susceptibility/resistance to the development of disease. This has been thoroughly studied in TMEV infection, and it has been found to depend on both major histocompatibility complex (MHC) and non‐MHC genes. At least four genes have been so far identified. Because of this genetic influence, some strains of mice are more susceptible to both clinical and pathological changes than others, and susceptibility appears to best correlate with the ability of a certain murine strain to develop a delayed‐type hypersensitivity (DTH) response to viral antigens. We have also observed that even among mice which are equally susceptible clinically, striking differences may be seen under pathological examination. These consist of different gradients of severity of inflammation, particularly in regards to the macrophage component. There is an inverse relationship between the number of macrophages, and their length of stay in the CNS, and the ability of mice to remyelinate their lesions. The most severe lesions are in SJL/J mice, and remyelination in this strain is extremely poor. The least severe lesions in terms of macrophage invasion are in strains such as NZW and RIIIS/J, and these are able to remyelinate lesions very successfully. Murine chronic relapsing EAE (CR‐EAE) shows pathological changes in many ways similar to those in TMEV‐infected SJL/J mice, although less severe in terms of degrees of macrophage infiltration and tissue destruction. Mice with CR‐EAE have a correspondingly limited ability to remyelinate their lesions. In both models the pathology appears to be mediated through a DTH response. However, while in EAE the DTH response is clearly against neuroantigens, the response in TMEV infection is against the virus itself. The end result in both models would be that of myelin destruction through a lymphotoxincytokine‐mediated mechanism. The importance of the DTH response in both models is well illustrated by the effects of tolerance induction in EAE and TMEV infection to neuroantigens and virus, respectively. These are important models of human MS, since the current hypothesis is that a viral infection early in life, on the appropriate genetic background, may trigger a secondary misdirected immune response which could be directed either against myelin antigens and/or possible persistent virus(es). © 1995 Wiley‐Liss, Inc.

Fig. 6 depicts a model for epitope spreading in T cell-mediated demyelination. The acute phase of disease is due to T cells specific for the initiating epitope, which can be either a determinant on the CNS target organ of the autoimmune response or a determinant on a persisting, CNS-tropic virus. The primary T cell response is responsible for the initial tissue damage by the production of proinflammatory Th1 cytokines which can affect myelination directly (Selmaj et al. 1991) and indirectly by their ability to recruit and activate macrophages to phagocytize myelin (Cammer et al. 1978). As a result of myelin damage and opening of the blood-brain-barrier during acute disease, T cells specific for endogenous epitopes on the same and/or different myelin proteins are primed and expand either in the periphery or locally in the CNS. These secondary T cells initiate an additional round of myelin destruction, leading to a clinical relapse by production of additional pro-inflammatory cytokines, similar to the bystander demyelination operative during acute disease. It will be of great interest to determine the relative contributions of local and systemic immune responses to these endogenous neuroepitopes. It is possible that local CNS presentation of endogenous neuroepitopes following acute CNS damage could be mediated by infiltrating inflammatory macrophages, activated microglial cells, endothelial cells and/or astrocytes. These tissue resident antigen presenting cells have been shown to upregulate expression of MHC class II (Sakai et al. 1986, Traugott & Lebon 1988), certain adhesion molecules (Cannella et al. 1990), and B7 costimulatory molecules (K. M. Nikcevich, J. A. Bluestone, and S. D. Miller, in preparation) in response to pro-inflammatory cytokines. The data on epitope spreading provided by the murine demyelinating disease models clearly illustrate the dynamic nature of the T cell repertoire during chronic inflammation in a specific target organ. The contribution of epitope spreading to chronic CNS demyelination could be considered to be a special case since tolerance to myelin epitopes would be expected to be inefficient due to their sequestration behind the blood-brain-barrier. However, the recent description of epitope spreading in response to pancreatic antigens in spontaneous diabetes in the NOD mouse may indicate that this phenomenon is operative in a variety of organ-specific experimental and spontaneous autoimmune diseases.(ABSTRACT TRUNCATED AT 400 WORDS)

A change from conventional tillage to a conservation tillage system can lead to shifts in weed species composition. A weed species shift can result in the emergence of weeds tolerant of existing weed management practices. An understanding of crop production effects on weed species shifts can lead to development of improved weed management strategies. Research evaluated the effects of primary tillage (moldboard and chisel plowing), row cultivation, and herbicide input level on weed species changes over a 5-yr period in three irrigated cropping sequences. The cropping sequences consisted of continuous corn (Zea mays L.) for 5 yr (CN), pinto bean (Phaseolus vulgaris L.) for 3 yr followed by corn for 2 yr (PB), and sugar beet (Beta vulgaris L.) for 2 yr followed by corn for 3 yr (SB). Over the course of the 5-yr study, total weed density increased from 1 to 245 weeds m⁻² in PB, from 100 to 209 in SB, and from 2 to 190 in CN cropping sequences in chisel-plowed treatments, while weed density increases in moldboard-plowed treatments were negligible. General observation of each cropping sequence indicated that during the final year, green foxtail [Setaria viridus (L.) P. Beauv.] was most prevalent in the CN sequence, redroot pigweed (Amaranthus retroflexus L.) and hairy nightshade (Solanum sarrachoides Sendtner) in the PB sequence, and redroot pigweed and green foxtail in the SB sequence. However, weed species differences due to cropping sequences were evident only in treatments receiving chisel plow primary tillage. Further, the increase in redroot pigweed density due to cropping sequence and chisel plowing was diminished by high herbicide input levels. Row cultivation also had an influence on the weed species composition when compared to uncultivated plots. Wyoming Agric. Exp. Stn. JA 1691.

Theiler's murine encephalomyelitis virus (TMEV) produces a chronic, inflammatory demyelinating disease in susceptible mouse strains that is used as a model for multiple sclerosis. Because disease susceptibility correlates temporally with the development of virus-specific delayed-type hypersensitivity (DTH) responses, we studied methods and mechanisms by which virus-specific DTH could be specifically inhibited. The intravenous injection of UV-inactivated TMEV coupled to syngeneic splenocytes via a carbodiimide linkage (TMEV-SP), prior to immunization, induced a significant degree of tolerance in virus-specific helper (Th) cells as determined by decreased DTH and T cell proliferative responses, and decreased interleukin (IL)-2 and interferon (IFN)-gamma protein and mRNA levels. In contrast to the reduced levels of Th1-specific lymphokine mRNA levels, IL-4-specific mRNA levels in response to virus stimulation were not affected in tolerant mice. Surprisingly, the total anti-TMEV antibody response in DTH tolerant mice was enhanced 20-100-fold over sham-tolerized controls and was composed of reduced levels of anti-virus IgG2a, but dramatically increased levels of anti-virus IgG1. The "split-tolerance" was antigen specific, dependent on the concentrations of TMEV and carbodiimide used in the coupling procedure, and varied with the number of coupled syngeneic splenocytes administered. The fixative effects of carbodiimide on antigen-presenting function were necessary for the induction of DTH tolerance with TMEV-SP, since intravenous administration of virus coupled to splenocytes via a biotin-avidin linkage led to enhanced virus-specific antibody responses, but was unable to inhibit DTH unless concomitantly fixed with carbodiimide. Collectively, the data indicate that Th1 cells (mediating DTH, IL-2 and IFN-gamma production, and helper function for IgG2a production) were specifically anergized, with concomitant stimulation of Th2 cells (producing IL-4 and mediating helper function for IgG1 antibody production).

This unit details the materials and methods required for both active induction and adoptive transfer of experimental autoimmune encephalomyelitis (EAE) in the SJL mouse strain using intact proteins or peptides from the two major myelin proteins: proteolipid protein (PLP) and myelin basic protein (MBP). Detailed materials and methods required for the purification of both PLP and MBP are also described. A protocol for isolating CNS-infiltrating lymphocytes in EAE mice is included. Modifications of the specified protocols may be necessary for efficient induction of active or adoptive EAE in other mouse strains.

(...) Field studies were conducted at Torrington, WY on a Bayard fine sandy loam (coarse loamy, mixed, mesic Torriothentic Haplustoll) in 1984 and 1985 to evaluate the response of «Oslo» spring wheat to 10 broadleaf herbicide treatments applied at three growth stages (...)

Previous studies of pig-to-non-human primate (NHP) islet xenotransplantation have provided important insights into the immune recognition and effector pathways operative in this relevant preclinical model. The specifics of the xenograft product, microenvironment at the implantation site, and the immunosuppressive regimen significantly influence the mechanisms underlying the rejection of xenogeneic islets. Our current understanding of the immunological barriers to survival of pig islets in NHPs is largely based on studies on intraportal islet xenografts and on comparisons with islet allografts. The demonstration of cell-mediated rejection of intraportal porcine islet xenografts at about 1 month posttransplant in monkeys immunosuppressed with the same protocols that prevent monkey islet allograft rejection indicates that islet xenograft rejection involves cellular mechanisms that are not present in acute islet allograft rejection. While these mechanisms remain poorly defined the demonstration of long-term diabetes reversal after intraportal islet xenotransplantation in non-human primates immunosuppressed with anti-CD40L but not with anti-CD40 antibody-based protocols suggests that the therapeutic efficacy of anti-CD40L in this transplantation setting likely involves the depletion of donor-reactive, activated T cells besides CD40:CD40L costimulation blockade. Rejection of intraportal islet xenografts in NHPs immunosuppressed with CTLA4-Ig and rapamycin was mediated largely by IL-15-primed, CXCR3+CD8+ memory T cells recruited by IP-10 (CXCL10) positive pig islets and macrophages that showed staining for IL-12 and iNOS. Adding basiliximab induction and tacrolimus maintenance therapy to this protocol prevented rejection in 24 of 26 recipients followed for up to 275 days. Comparison of both groups suggests, though by no means conclusive, that prolongation of graft survival in this large cohort was associated with reduced direct T cell responses to xenoantigens, reduced proportion of intrahepatic (intragraft) B cells and IFN-γ+ and IL-17+ CD4 and CD8 T cells, and increased local production of immunoregulatory molecules linked with Tregs, including TGF-β, Foxp3, HO-1, and IL-10. Anti-pig non-Gal IgG antibody elicitation was suppressed in both groups. We are currently exploring the concept of negative vaccination to markedly minimize the need for immunosuppression in islet xenotransplantation. Peritransplant administration of donor apoptotic cells extended pig-to-mouse islet xenograft survival to >250 days when combined with peritransplant B cell-depletion and rapamycin. This costimulation blockade-sparing, antigen-specific immunotherapy is expected to cause rapid pretransplant clonal deletion of indirect and anergy of direct xenospecific T cells while inducing regulatory T cells. As anti-CD40L antibodies, B cell depleting antibodies are expected to interfere with indirect antigen presentation, costimulation, and cytokine production required for optimal T cell proliferation, memory formation, and intragraft CD8+ effector function. It is conceivable that additional strategies must be employed in NHPs and eventually in diabetic patients to achieve – as previously with anti-CD40L antibodies – more complete, yet selective depletion of donor-reactive, activated T-cells for the purpose of stable xenograft acceptance.

This unit details the materials and methods required for both active induction and adoptive transfer of experimental autoimmune encephalomyelitis (EAE) in the SJL mouse strain using intact proteins or peptides from the two major myelin proteins: proteolipid protein (PLP) and myelin basic protein (MBP). Detailed materials and methods required for the purification of both PLP and MBP are also described. A protocol for isolating CNS-infiltrating lymphocytes in EAE mice is included. Modifications of the specified protocols may be necessary for efficient induction of active or adoptive EAE in other mouse strains. Curr. Protoc. Immunol. 88:15.1.1-15.1.20. © 2010 by John Wiley & Sons, Inc. Keywords: CFA; complete Freund's adjuvant; CNS; central nervous system; EAE; experimental autoimmune encephalomyelitis; MBP; myelin basic protein; MOG; myelin oligodendrocyte glycoprotein; PLP; proteolipid protein

Field studies using glyphosate-resistant corn (Zea mays L.), sugarbeet (Beta vulgaris L.), and spring wheat (Triticum aestivum L.) were conducted at Scottsbluff, NE, Torrington, WY, and Fort Collins, CO, over 6 yr to evaluate weed population dynamics under glyphosate- and conventional herbicide–based weed control strategies. We report the response of common lambsquarters (Chenopodium album L.), wild buckwheat (Polygonum convolvulus L.), and all grasses combined to four management strategies imbedded in two crop rotations. There were no consistent or highly signifi cant benefi ts from a diverse crop rotation versus continuous corn when weed control was considered. Rotating herbicide mode of action for general weed control provided no benefi t above that provided by glyphosate at 0.8 kg acid equivalent (ae) ha –1 applied twice each year. There was no evidence that any weed species developed resistance to glyphosate. The most striking fi nding of these studies was the buildup of common lambsquarters and wild buckwheat that occurs when glyphosate is applied at 0.4 kg ae ha –1 twice each year. Such a low-use-rate approach is to be completely discouraged since it appears to enrich the gene pool for individuals that survive low rates of glyphosate. The continuing decline in the real cost of glyphosate should eliminate any legitimate reason for growers to consider using less than the full labeled rate of glyphosate. All treatments that included glyphosate at all three locations over 6 yr provided signifi cantly better grass control than the nonglyphosate conventional treatments.