Androgenic response of genotypes selected from Capsicum annuum L.?×?C. chinense Jacq. hybrids

In research on androhaploids in the progeny of interspecific hybrids within the Capsicum genus, three genetically stable lines of F₇ generation, selected from the C. annuum L. × C. chinense Jacq. hybrid, were used. In the first line, only callus tissue was formed as a reaction to the conditions of culture. Cytometric analysis of this tissue revealed the presence of cells with DNA content in nuclei at the level of 1C to 16C. The tissue was mixoploid and non-embryogenic. Anthers of the other line did not respond. In the third one, nine embryos were obtained, and they developed into plants. By means of cytometric analysis, the 1C DNA level was found in eight of them and these were androgenic plants. The origin of one of the diploid plant was not established due to the homozygous character of the donor plants. The experiment results confirm the already known diversity of genotype reaction to the conditions of culture. It moreover point to the possibility of selection of the forms with an androgenic potency from interspecific hybrids.     

Reevaluating the CD8 T-Cell Response to Herpes Simplex Virus Type 1: Involvement of CD8 T Cells Reactive to Subdominant Epitopes

In C57BL/6 (B6) mice, most herpes simplex virus (HSV)-specific CD8 T cells recognize a strongly immunodominant epitope on glycoprotein B (gB₄₉₈) and can inhibit HSV type 1 (HSV-1) reactivation from latency in trigeminal ganglia (TG). However, half of the CD8 T cells retained in latently infected TG of B6 mice are not gB₄₉₈ specific and have been largely ignored. The following observations from our current study indicate that these gB₄₉₈-nonspecific CD8 T cells are HSV specific and may contribute to the control of HSV-1 latency. First, following corneal infection, OVA₂₅₇-specific OT-1 CD8 T cells do not infiltrate the infected TG unless mice are simultaneously immunized with OVA₂₅₇ peptide, and then they are not retained. Second, 30% of CD8 T cells in acutely infected TG that produce gamma interferon in response to HSV-1 stimulation directly ex vivo are gB₄₉₈ nonspecific, and these cells maintain an activation phenotype during viral latency. Finally, gB₄₉₈-nonspecific CD8 T cells are expanded in ex vivo cultures of latently infected TG and inhibit HSV-1 reactivation from latency in the absence of gB₄₉₈-specific CD8 T cells. We conclude that many of the CD8 T cells that infiltrate and are retained in infected TG are HSV specific and potentially contribute to maintenance of HSV-1 latency. Identification of the viral proteins recognized by these cells will contribute to a better understanding of the dynamics of HSV-1 latency.The generation and maintenance of a CD8 T-cell response represent an important line of defense against many viral pathogens. Such responses are typically initiated when host antigen-presenting cells at the site of infection capture and process viral proteins and transport them to local draining lymph nodes (DLN). There the antigen-presenting cells either directly present viral antigens to naïve CD8 T cells or pass them to a distinct LN-resident dendritic cell (DC) subset for antigen presentation in the context of major histocompatibility complex class I (1). Antigen-specific CD8 T cells then undergo robust division and differentiation into effector populations armed to infiltrate infected tissue and eliminate the invading pathogen. The magnitude of the CD8 T-cell response against different viral epitopes is typically aligned within a defined hierarchy. Those epitopes recognized by the largest portion of the pathogen-specific CD8 T-cell population are referred to as immunodominant, while those inciting lesser responses are referred to as subdominant (17). Manipulation of this hierarchal system by the elimination of an immunodominant epitope often results in the expansion of a normally silent or “cryptic” determinant (2, 17, 21).Although the HSV-1 genome contains at least 84 open reading frames (13), it is estimated that 70 to 95% of the acute CD8 T-cell response in lymphoid organs of B6 mice is directed against the single immunodominant gB₄₉₈ epitope (11, 21, 24, 26, 27). The remaining HSV-specific CD8 T cells are thought to be directed against a subdominant epitope on the viral ribonucleotide reductase (RR1₈₂₂) (16). These conclusions are derived from studies characterizing the specificity of CD8 T cells at the peak of the effector response in lymphoid tissue. Interestingly, a recombinant HSV-1 lacking the immunodominant gB₄₉₈ epitope induced an HSV-specific CD8 T-cell response of normal magnitude, while the RR1₈₂₂ epitope remained subdominant (21), suggesting the emergence of previously unrecognized or cryptic epitopes.Following HSV-1 corneal infection of B6 mice, virus is transmitted to the trigeminal ganglia (TG), where it replicates briefly (up to 6 days postinfection [dpi]) and then establishes a latent infection. CD8 effector T cells accumulate to peak levels in the TG by 8 dpi and then undergo contraction, and then a memory population of constant size is maintained for the life of the animal. While 50% of both the effector and memory CD8 T-cell populations are specific for the immunodominant gB₄₉₈ epitope (11, 18), the remaining TG-resident CD8 T cells are specific for neither the dominant gB₄₉₈ nor the subdominant RR1₈₂₂ epitope. Although the phenotype and function of the gB₄₉₈-specific CD8 T cells in sensory ganglia and their role in maintaining HSV-1 latency have been well characterized (3, 5, 9, 11, 12, 14, 18, 19, 22, 24, 25, 27), the properties of the gB₄₉₈-nonspecific TG-resident CD8 T-cell population and their role in maintaining viral latency remain unexplored. Here we demonstrate that many of the gB₄₉₈-nonspecific CD8 T cells in latently infected TG proliferate and some produce gamma interferon (IFN-γ) when stimulated with HSV-1 antigens directly ex vivo. These cells also persistently exhibit an activation phenotype within latently infected TG, are expanded in ex vivo cultures of latently infected TG, and can block HSV-1 reactivation in TG neurons in the absence of gB₄₉₈-specific CD8 T cells.     

Receptor independent and receptor dependent CoMSA modeling with IVE-PLS: application to CBG benchmark steroids and reductase activators

Comparative molecular surface analysis (CoMSA) with robust IVE-PLS variable elimination if tested for the benchmark CBG steroid series provides highly predictive RI 3D QSAR models, but failed however to model the activity of sulforaphane (SP) activators of quinone reductase. The application of the SP poses obtained from multipose molecular docking to model the RD IVE-PLS CoMSA resulted in a predictive form. This model indicated lipophilic potential as the activity determinant. The individual molecular surface areas of the highest contribution to the SP activity was identified and visualized by CoMSA contour plots.     

The High Throughput Sequence Annotation Service (HT-SAS) – the shortcut from sequence to true Medline words

Background  

Advances in high-throughput technologies available to modern biology have created an increasing flood of experimentally determined facts. Ordering, managing and describing these raw results is the first step which allows facts to become knowledge. Currently there are limited ways to automatically annotate such data, especially utilizing information deposited in published literature.     

Targeted deletion of the genes encoding NTH1 and NEIL1 DNA N-glycosylases reveals the existence of novel carcinogenic oxidative damage to DNA

We have generated a strain of mice lacking two DNA N-glycosylases of base excision repair (BER), NTH1 and NEIL1, homologs of bacterial Nth (endonuclease three) and Nei (endonuclease eight). Although these enzymes remove several oxidized bases from DNA, they do not remove the well-known carcinogenic oxidation product of guanine: 7,8-dihydro-8-oxoguanine (8-OH-Gua), which is removed by another DNA N-glycosylase, OGG1. The Nth1^?/?Neil1^?/? mice developed pulmonary and hepatocellular tumors in much higher incidence than either of the single knockouts, Nth1^?/? and Neil1^?/?. The pulmonary tumors contained, exclusively, activating GGT → GAT transitions in codon 12 of K-ras of their DNA. Such transitions contrast sharply with the activating GGT → GTT transversions in codon 12 of K-ras of the pathologically similar pulmonary tumors, which arose in mice lacking OGG1 and a second DNA N-glycosylase, MUTY. To characterize the biochemical phenotype of the knockout mice, the content of oxidative DNA base damage was analyzed from three tissues isolated from control, single and double knockout mice. The content of 8-OH-Gua was indistinguishable among all genotypes. In contrast, the content of 4,6-diamino-5-formamidopyrimidine (FapyAde) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua) derived from adenine and guanine, respectively, were increased in some but not all tissues of Neil1^?/? and Neil1^?/?Nth1^?/? mice. The high incidence of tumors in our Nth1^?/?Neil1^?/? mice together with the nature of the activating mutation in the K-ras gene of their pulmonary tumors, reveal for the first time, the existence of mutagenic and carcinogenic oxidative damage to DNA which is not 8-OH-Gua.     

Strain fidelity of chronic wasting disease upon murine adaptation

Chronic wasting disease (CWD), a prion disease of deer and elk, is highly prevalent in some regions of North America. The establishment of mouse-adapted CWD prions has proven difficult due to the strong species barrier between mice and deer. Here we report the efficient transmission of CWD to transgenic mice overexpressing murine PrP. All mice developed disease 500 +/- 62 days after intracerebral CWD challenge. The incubation period decreased to 228 +/- 103 days on secondary passage and to 162 +/- 6 days on tertiary passage. Mice developed very large, radially structured cerebral amyloid plaques similar to those of CWD-infected deer and elk. PrP(Sc) was detected in spleen, indicating that murine CWD was lymphotropic. PrP(Sc) glycoform profiles maintained a predominantly diglycosylated PrP pattern, as seen with CWD in deer and elk, across all passages. Therefore, all pathological, biochemical, and histological strain characteristics of CWD appear to persist upon repetitive serial passage through mice. These findings indicate that the salient strain-specific properties of CWD are encoded by agent-intrinsic components rather than by host factors.