Immunologic Control of Mus musculus Papillomavirus Type 1

Persistent papillomas developed in ~10% of out-bred immune-competent SKH-1 mice following MusPV1 challenge of their tail, and in a similar fraction the papillomas were transient, suggesting potential as a model. However, papillomas only occurred in BALB/c or C57BL/6 mice depleted of T cells with anti-CD3 antibody, and they completely regressed within 8 weeks after depletion was stopped. Neither CD4+ nor CD8+ T cell depletion alone in BALB/c or C57BL/6 mice was sufficient to permit visible papilloma formation. However, low levels of MusPV1 were sporadically detected by either genomic DNA-specific PCR analysis of local skin swabs or in situ hybridization of the challenge site with an E6/E7 probe. After switching to CD3+ T cell depletion, papillomas appeared upon 14/15 of mice that had been CD4+ T cell depleted throughout the challenge phase, 1/15 of CD8+ T cell depleted mice, and none in mice without any prior T cell depletion. Both control animals and those depleted with CD8-specific antibody generated MusPV1 L1 capsid-specific antibodies, but not those depleted with CD4-specific antibody prior to T cell depletion with CD3 antibody. Thus, normal BALB/c or C57BL/6 mice eliminate the challenge dose, whereas infection is suppressed but not completely cleared if their CD4 or CD8 T cells are depleted, and recrudescence of MusPV1 is much greater in the former following treatment with CD3 antibody, possibly reflecting their failure to generate capsid antibody. Systemic vaccination of C57BL/6 mice with DNA vectors expressing MusPV1 E6 or E7 fused to calreticulin elicits potent CD8 T cell responses and these immunodominant CD8 T cell epitopes were mapped. Adoptive transfer of a MusPV1 E6-specific CD8+ T cell line controlled established MusPV1 infection and papilloma in RAG1-knockout mice. These findings suggest the potential of immunotherapy for HPV-related disease and the importance of host immunogenetics in the outcome of infection.     

Genetic analysis of the hybridization zone between two subspecies Mus musculus domesticus and Mus musculus musculus in Bulgaria

The hybrid zone between the two subspecies of mice Mus musculus domesticus and Mus musculus musculus, which has been studied extensively in Denmark, crosses Europe to the Black Sea through the Alps and the Balkans. Two hundred and seventy-nine animals were captured in 22 localities along a transect across the Balkans. The animals were characterized for seven diagnostic nuclear loci by protein electrophoresis and by restriction pattern analysis of their mitochondrial DNA. The nuclear data show a sharp transition between the two subspecies, most of the variations in allele frequencies (from 0.9 to 0.1) occurring within a 36-km section of the transect. The introgression varies from one locus to the other and is more pronounced, in terms of distance, in M. m. musculus territory. Mitochondrial DNA introgression is important but occurs in one direction only, i.e. from M. m. musculus to M. m. domesticus, while a cytoplasmic transfer from M. m. domesticus to M. m. musculus has been reported. A previous study showed that no Y chromosome introgression occurs. The different behaviour of these three types of markers could be due to the interaction between selection against hybrid genomes and meiotic recombination. Objectively, it would appear that the genes that can introgress are neutral or nearly so and have been separated from deleterious genes they were linked to by recombination. This could explain the differential introgression between autosomal loci. The mitochondrial and Y chromosomes undergo no or very little recombination and each is transmitted as a whole. Their degree of introgression is thus indicative of the intensity of selection resulting from the amount of functional differentiation between the two taxa, which seems to be strong for the Y chromosome and weak for mitochondrial DNA. We propose that the asymmetry of nuclear introgression is due to different population structures. As M. m. musculus is relatively less structured, the rapid spreading of introgressed genes would be favoured. Such a scheme, however, can hardly account for the unidirectionality of the mitochondrial flow, which could be due to sex-dependent behaviour.     

Strain-Specific Differences in LFA-1 Induction on Measles Virus-Infected Monocytes and Adhesion and Viral Transmission to Endothelial Cells

Measles virus (MV) infection of monocytes induces leukocyte function-associated antigen-1 (LFA-1), an integrin that mediates intercellular adhesion to the endothelium. Thus, an increase in LFA-1 expression could lead to enhanced monocyte adherence and virus dissemination to endothelial cells (ECs) and potentially be an important means of distinction between MV strains. We identified both vaccine and wild-type strains that induced LFA-1 and others that failed to induce. Although adhesion of MV-infected monocytes and viral transmission to ECs was demonstrated, strain-specific differences were not correlated with LFA-1 induction. MV infection of ECs was dramatically reduced in the absence of cell contact, suggesting virus dissemination by cell-cell transmission.     

Mitochondrial DNA in the hybrid zone between Mus musculus musculus and Mus musculus domesticus: a comparison of two transects

We studied mtDNA introgression across the contact zone between Mus musculus musculus and M. m. domesticus in two independent transects in the Czech Republic and Bavaria, Germany. A total of 1270 mice from 98 localities in the Czech transect and 456 mice from 41 localities in the Bavarian transect were examined for presence or absence of a Bam HI restriction site in the mt-Nd1 gene. Using this simple mtDNA marker, variants that belonged to the M. m. domesticus lineage (presence of restriction site) could be unequivocally distinguished from those belonging to the M. m. musculus lineage (absence of restriction site). The extent of introgression of mtDNA, three autosomal allozymes and the X chromosome was compared. The introgression of X markers was more limited than was that of the allozymes and mtDNA. In the Czech transect, the centre for the mtDNA cline was shifted about 3.6 km to the west relative to the X chromosome cline, with asymmetric introgression from M. m. musculus to M. m. domesticus . Interestingly, in the Bavarian transect, the centre of the mtDNA cline was shifted about 10.9 km to the east relative to the X chromosome cline, with asymmetric introgression from M. m. domesticus to M. m. musculus, opposite in direction to that observed in the Czech transect.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 84 , 363–378.     

Characterization of Mus musculus Papillomavirus 1 Infection In Situ Reveals an Unusual Pattern of Late Gene Expression and Capsid Protein Localization

Full-length genomic DNA of the recently identified laboratory mouse papillomavirus 1 (MusPV1) was synthesized in vitro and was used to establish and characterize a mouse model of papillomavirus pathobiology. MusPV1 DNA, whether naked or encapsidated by MusPV1 or human papillomavirus 16 (HPV 16) capsids, efficiently induced the outgrowth of papillomas as early as 3 weeks after application to abraded skin on the muzzles and tails of athymic NCr nude mice. High concentrations of virions were extracted from homogenized papillomatous tissues and were serially passaged for >10 generations. Neutralization by L1 antisera confirmed that infectious transmission was capsid mediated. Unexpectedly, the skin of the murine back was much less susceptible to virion-induced papillomas than the muzzle or tail. Although reporter pseudovirions readily transduced the skin of the back, infection with native MusPV1 resulted in less viral genome amplification and gene expression on the back, including reduced expression of the L1 protein and very low expression of the L2 protein, results that imply skin region-specific control of postentry aspects of the viral life cycle. Unexpectedly, L1 protein on the back was predominantly cytoplasmic, while on the tail the abundant L1 was cytoplasmic in the lower epithelial layers and nuclear in the upper layers. Nuclear localization of L1 occurred only in cells that coexpressed the minor capsid protein, L2. The pattern of L1 protein staining in the infected epithelium suggests that L1 expression occurs earlier in the MusPV1 life cycle than in the life cycle of high-risk HPV and that virion assembly is regulated by a previously undescribed mechanism.     

Solution structure of the pro-hormone convertase 1 pro-domain from Mus musculus

The solution structure of the mouse pro-hormone convertase (PC) 1 pro-domain was determined using heteronuclear NMR spectroscopy and is the first structure to be obtained for any of the domains in the convertase family. The ensemble of NMR-derived structures shows a well-ordered core consisting of a four-stranded antiparallel beta-sheet with two alpha-helices packed against one side of this sheet. Sequence homology suggests that the other eukaryotic PC pro-domains will have the same overall fold and most of the residues forming the hydrophobic core of PC1 are highly conserved within the PC family. However, some of the core residues are predicted by homology to be replaced by polar amino acid residues in other PC pro-domains and this may help to explain their marginal stability. Interestingly, the folding topology observed here is also seen for the pro-domain of bacterial subtilisin despite little or no sequence homology. Both the prokaryotic and eukaryotic structures have hydrophobic residues clustered on the solvent-accessible surface of their beta-sheets although the individual residue types differ. In the bacterial case this region is buried at the binding interface with the catalytic domain and, in the eukaryotic PC family, these surface residues are conserved. We therefore propose that the hydrophobic patch in the PC1 pro-domain is involved in the binding interface with its cognate catalytic domain in a similar manner to that seen for the bacterial system. The PC1 pro-domain structure also reveals potential mechanisms for the acid-induced dissociation of the complex between pro- and catalytic domains.     

苦参碱的提取分离及对小鼠的毒性研究

采用酸性乙醇提取、乙醚萃取、硅胶柱层析分离等方法从苦参中分离到苦参碱单体.以小鼠为实验动物进行毒性测定,小鼠的死亡主要集中在48h内,48h后无小鼠的死亡现象.小鼠对苦参碱的耐受量大于30mg.k-g1,小于140mg.k-g1,致死中量LD50为64.01mg.kg-1,回归方程Y=-3.2370+4.5602X,LD50标准误差SE=6.14.适口性的测定表明,苦参碱对小鼠有较好的适口性,可以作为杀鼠剂使用.     

Mus musculus and Mus spretus homologues of the human telomere-associated protein TIN2

Telomere length is regulated by TRF1, which binds telomeric DNA, and TIN2, which binds TRF1. Laboratory mice (Mus musculus) have long telomeres, although a related mouse species, Mus spretus, has human-sized telomeres. Because differences in TIN2 might explain these differences in telomere length, we cloned cDNAs encoding murine TIN2s and compared their sequence to that of human TIN2. M. musculus (Mm) and M. spretus TIN2s were >95% identical, but shared only 67% identity with human TIN2. An N-terminal truncation, or N-terminal fragment, of MmTIN2 elongated M. spretus telomeres. These findings suggest that mouse TIN2, like human TIN2, negatively regulates telomere length, and that N-terminal perturbations have dominant-negative effects. Our findings suggest that differences in TIN2 cannot explain the telomere length differences among Homo sapiens, M. musculus, and M. spretus. Nonetheless, M. spretus cells appear be a good system for studying the function of mouse telomere-associated proteins.     

ELISPOT检测人乳头瘤病毒特异性的记忆T细胞

应用ELISPOT方法检测人乳头瘤病毒感染后自发清除者外周血中抗原特异性的记忆T细胞。收集人乳头瘤病毒（HPV）感染后自发清除者外周血（病毒清除后74个月）,分离外周血单个核细胞（peripheralblood mononuclear cells,PBMC）。体外应用已鉴定的表位肽刺激PBMC,10 d后计数细胞,去除表位肽,继续培养。第11天,ELISPOT方法检测PBMC中HPV抗原特异性的记忆T细胞。PBMC经表位肽刺激10 d后,细胞数量有明显增加,由最初的4.1×105增加为4.2×106。第11天,细胞数量增加为4.65×106,为抗原刺激前细胞数的11.3倍。ELISPOT结果显示,PBMC中的记忆T细胞活化后,能够识别抗原递呈细胞递呈的抗原肽,并分泌IFN-γ。此HPV自发清除者外周血中抗原特异性的记忆T细胞的频数为0.007%。人乳头瘤病毒（HPV）感染后自发清除者外周血存在抗原特异性记忆T细胞,抗原肽可激活记忆T细胞,使之数量增加,分泌IFN-γ。ELISPOT可用于检测外周血中HPV特异性的记忆T细胞。     

氧化苦参碱的提取分离及对小鼠的毒性研究

采用酸性乙醇提取、硅胶柱层析分离、乙醚分级沉淀、丙酮重结晶的方法从苦参中分离到氧化苦参碱单体。对小鼠的毒性测定表明,试鼠的死亡主要集中在48 h内,48 h后无试鼠的死亡现象。小鼠对氧化苦参碱的耐受量大于50 mg/kg,小于20 mg/kg,致死中量LD50为85.95 mg/kg,回归方程Y=-3.2664 4.2737X,LD50标准误差s=8.77。氧化苦参碱毒性较低,致死中量适宜,对试鼠有较好的适口性,可以作为杀鼠剂使用。     

Secondary Infections,Expanded Tissue Tropism,and Evidence for Malignant Potential in Immunocompromised Mice Infected with Mus musculus Papillomavirus 1 DNA and Virus

Papillomavirus disease poses a special challenge to people with compromised immune systems. Appropriate models to study infections in these individuals are lacking. We report here the development of a model that will help to address these deficiencies. The MmuPV1 genome was synthesized and used successfully to produce virus from DNA infections in immunocompromised mice. In these early studies, we have demonstrated both primary and secondary infections, expanded tissue tropism, and extensive dysplasia.     

Response to cecropia cocoons of Mus musculus and two species of Peromyscus

Summary In rural areas cocoons of overwintering Hyalophora cecropia spum close to the ground are opened and the pupae eaten by small mammals, but in urban areas, where cecropia populations are much larger, the cocoons are almost never opened by mammals. Peromyscus leucopus noveboracensis and P. maniculatus bairdii are abundant in rural areas, but are largely replaced by Mus musculus in urban areas. In laboratory experiments P. l. noveboracensis invariably opened cecropia cocoons and ate the pupae. P. m. bairdii were slower to open cecropia cocoons and two of twelve did not open one at all. M. musculus, on the other hand, never opened cecropia cocoons although they gnawed the silk and ate uncovered pupae. Cocoons opened in the laboratory by the two species of Peromyscus cannot be distinguished from each other or from cocoons opened in the field.Part of the Ph. D. dissertation presented by the first author to the Department of Entomology, University of Illinois. This investigation was supported in part by PHS Training Grant no. 2-T01-GM 01076 from General Medical Sciences.     

Assignment of the gene for dipeptidase 2 to Mus musculus chromosome 18 by somatic cell hybridization

Evidence is presented for the assignment of the gene for dipeptidase 2 to Mus musculus chromosome 18 by synteny testing and karyotypic analysis of Chinese hamster × mouse somatic cell hybrid clones. DIP-2 and chromosome 18 were expressed concordantly in 24/24 clones examined (ten primary clones and 14 secondary clones). Synteny testing indicated that DIP-2 was not expressed concordantly with the expression of any marker enzymes.This work was supported by NIH grant USPHS GM 09966.     

Genotoxicity and repair capability of Mus musculus DNA following the oral exposure to Tramadol

Tramadol is an analgesic and psychoactive drug that acts primarily upon the central nervous system where it alters brain function, resulting in temporary changes in perception, mood, consciousness and behavior. The aim of present study was to analyze the genotoxicity and repair capability of DNA after Tramadol exposure in albino mice (Mus musculus). For this purpose, forty mice were divided equally into four groups as; a control group (without drug) and three treatment groups that were treated with three doses of Tramadol as minimum dose group, Intermediate dose group and maximum dose group, corresponding to 25 mg/kg, 50 mg/kg and 75 mg/kg of body weight respectively. The dose was given orally for 15 days. After 15 days peripheral blood was drawn from half mice of each group and subjected to comet assay. While the remaining half mice were given a recovery period of 15 days and same procedure was used for blood collection and comet assay. Significant difference in various comet parameters was observed among control and exposed groups. Maximum damage was observed at highest concentration 75 mg/kg of Tramadol and minimum damage was observed at dose 25 mg/kg of Tramadol, while results of repaired mice group showed that repair capability of Tramadol was minor and recovery of Tramadol required a lot of time. It can be concluded that Tramadol cause genotoxicity that is dose dependent and has low repair capability.     

Assignment of the genes for triose phosphate isomerase to chromosome 6 and tripeptidase-1 to chromosome 10 in Mus musculus by somatic cell hybridization

Evidence is presented for the assignment of the gene for triose phosphate isomerase to Mus musculus chromosome 6 and tripeptidase-1 to chromosome 10 by synteny testing and chromosome assignment in Chinese hamster X mouse somatic cell hybrid clones. Neither TPI nor TRIP-1 were expressed concordantly with any known isozyme markers in 45 hybrid clones (13 primary and 32 secondary). Karyotypic analysis of 21 clones showed that the expression of TPI and chromosome 6 were concordant in all cases as was expressed of TRIP-1 and chromosome 10. Both chromosomes were previously unmarked by isozymes.