The refractory responses of the White Swiss strain of Mus musculus to infection with Taenia taeniaeformis

Penetration of intestinal mucosa by oncospheres of Taenia taeniaeformis occurred among three age groups of White Swiss Mus musculus. Highest frequency of penetration was demonstrated among the 10–30 day-old group with the other two older groups, 40–60 and 70–100 days, each having succeedingly less penetration. The invasion process was more cytolytic than ground substance lysis; no difference in this process, or the reaction of the villi to it, was detected among the various age groups. Liver reaction, displayed by the same three age groups against larvae of T. taeniaeformis, was age dependent. Disorganization, loss of larval tissue integrity, and formation of a non-cellular capsule were demonstrated within 48 h in the 10–30 day group, while a rapid cellular response of inflammation and walling-off of larvae was seen in the 40–60 day group. No larvae were observed in the 70–100 day group.     

Interactions between Taenia taeniaeformis and host cells in vitro: rapid adherence of peritoneal cells to strobilocerci

Engelkirk P. G., Williams J. F. and Signs M. M. 1981. Interactions between Taenia taeniaeformis and host cells in vitro: rapid adherence of peritoneal cells to strobilocerci. International Journal for Parasitology11: 463–474. Strobilocerci of Taenia taeniaeformis, incubated for l h in vitro with various combinations of serum and peritoneal cells from infected or non-infected rats, were examined at the ultrastructural level for evidence of cell adherence and tegumental damage. Maximal adherence and surface alterations occurred when larvae were incubated in the presence of cells and fresh serum. This was true regardless of whether the cells or the serum had been obtained from infected or non-infected donors. No tegumental damage was seen when parasites were incubated with or without cells in the absence of serum. Serum enhancement was either much reduced or abolished by heat treatment (56°C for 1 h). In the presence of EDTA, tegumental lesions still developed, but adherence of cells, especially those from non-infected rats, decreased markedly. The predominant cells interacting with the larval surface were eosinophils; these took up parasite material within phagosomes and appeared to strip microtriches from the tegumental free surface. Mast cells, some of which became degranulated, were also present in the adherent cell masses. The results indicate that potent non-specific effector mechanisms can rapidly damage the tegument of T. taeniaeformis, in vitro, in contrast to the failure of recognition and rejection by host defenses in vivo. Established strobilocerci are therefore not invulnerable but the balance of the host-parasite relationship in vivo must favor their survival.     

Susceptibility of different strains of mice to various levels of infection with the eggs of Taenia taeniaeformis

Susceptibility of different mouse strains to varying levels of Taenia taeniaeformis eggs has been studied. C3H are shown to be susceptible to any quantity of eggs. However C57 and NMRI are only susceptible to 1–2 eggs, while larvae from an infection of 30–50 eggs are precociously destroyed. Sometimes fertile larvae can also develop in resistant strains of mice infected with some hundred eggs. In C3H the challenge larvae are unable to survive even from an infection given 24–48 h post-first inoculum. The hypothesis is proposed that in resistant strains, infection with 30–50 eggs induces a more rapid immune response which becomes effective while the larva is still vulnerable; in massive infections, however, immune paralysis may occur. Although susceptible strains allow primary infections to develop, they show resistance to challenge infections because larvae are destroyed before they become insusceptible to host attack.     

Epiphytic microflora of poplar clones susceptible and resistant to infection by Dothichiza populea

One-year-old poplar shoots (nodes, internodes and lenticels) of clones susceptible to infection by the pathogenic fungus Dothichiza populea, viz. Populus nigra Italica and P. Robusta, resistant ones, viz. P. Grandis and P. Hybrida 275, as well as a hybrid of a susceptible and a resistant clone, viz. P. maximowiczii x P. nigra (P. Kórnik 42), were used. The plate method was employed to determine: 1. the abundance of the epiphytic microflora on a mineral medium with glucose; 2. the quantitative composition of epiphytic communities by determining the numbers of typical bacteria (including rod-shaped, spherical and sporulating forms), actinomycetes and yeasts in microscopic preparations from epiphyte colonies; 3. the abundance and level of activity of epiphytes antagonistic towards Dothichiza populea. In all poplar clones the epiphytic microflora was most abundant on nodes and least abundant on lenticels. In the resistant clones epiphytes were 7 (P. Grandis) to as many as 84 times (P. Hybrida 275) less numerous than in the susceptible ones. In the microflora communities of the susceptible poplars, rod-shaped bacteria were the most abundant, and in the resistant ones and the hybrid, yeasts, which made up from 60% to 70% of the strains tested. Spherical and sporulating bacteria as well as actinomycetes were found in numbers not exceeding 4% of the total number of epiphytes. The proportion of antagonistic microflora in whole epiphytic communities was higher in the resistant clones and the hybrid than in the susceptible clones, with the microflora having a more restrictive effect on the development of the pathogen.     

Differential expression of VGLUT3 in laboratory mouse strains: Impact on drug‐induced hyperlocomotion and anxiety‐related behaviors

The atypical vesicular glutamate transporter VGLUT3 is present in subpopulations of GABAergic interneurons in the cortex and the hippocampus, in subgroups of serotoninergic neurons in raphe nuclei, and in cholinergic interneurons in the striatum. C56BL/6N mice that no longer express VGLUT3 (VGLUT3^?/?) display anxiety‐associated phenotype, increased spontaneous and cocaine‐induced locomotor activity and decreased haloperidol‐induced catalepsy. Inbred mouse strains differ markedly in their sensitivity to anxiety and behavioral responses elicited by drugs. The purpose of this study was to investigate strain differences in VGLUT3 expression levels and its potential correlates with anxiety and reward‐guided behaviors. Five inbred mouse lines were chosen according to their contrasted anxiety and drugs sensitivity: C57BL/6N, C3H/HeN, DBA/2J, 129/Sv, and BALB/c. VGLUT3 protein expression was measured in different brain areas involved in reward or mood regulation (such as the striatum, the hippocampus, and raphe nuclei) and genetic variations in Slc17a8, the gene encoding for VGLUT3, have been explored. These five inbred mouse strains express very different levels of VGLUT3, which cannot be attributed to the genetic variation of the Slc17a8 locus. Furthermore, mice behavior in the open field, elevated plus maze, spontaneous‐ and cocaine‐induced locomotor was highly heterogeneous and only partially correlated to VGLUT3 levels. These data highlight the fact that one single gene polymorphism could not account for VGLUT3 expression variations, and that region specific VGLUT3 expression level variations might play a key role in the modulation of discrete behaviors.     

T-cell dependent collagenous encapsulating response in the mouse liver to Mesocestoides corti (Cestoda)

Pollacco S., Nicholas W.L., Mitchell G.F. and Chaicharn Stewart A. 1978. T-cell dependent collagenous encapsulating response in the mouse liver to Mesocestoides corti (Cestoda). International Journal for Parasitology8: 457–462. Experiments with genetically hypothymic mice show that the tetrathyridial larvae of Mesocestoides corti (Cestoda) multiply much more rapidly in the liver than in normal mice. In the hypothymic mouse, collagen fibres are not laid down and the parasite is not encapsulated as it is in the normal mouse. Encapsulation probably restricts the parasite's multiplication, and it is suggested that the failure to encapsulate the parasite accounts for its more rapid multiplication in the hypothymic mouse. Fibrogenesis and encapsulation is restored to hypothymic mice by transferring syngeneic thymus cells, spleen cells or peritoneal exudate cells. It is concluded that the encapsulation of M. corti is a T-cell dependent process.     

Influence of serial passage on the infectivity and immunogenicity of Nematospiroides dubius in mice

Dobson C. and Owen M. E. 1977. Influence of serial passage on the infectivity and immunogenicity of Nematospiroides dubius in mice. International Journal for Parasitology7: 463–466. The infectivity of Nematospiroides dubius was increased for Quackenbush (Q) mice by ten serial passages through this host. At the same time C(In3)H mice became more refractory to infection with successive Q generations of the parasite. Both strains of mice rejected the most highly selected parasites more readily than parasites from the earlier generations. These responses were shown to be immunological in nature by infections in hypothymic Balb/c CBA nu/nu and nu/+ mice and to be dose dependent. The selection of N. dubius for increased infectivity in Q mice enhanced its immunogenicity in this and other mouse strains possibly because of increased genetic homogenicity in the selected populations. N. dubius selected for Q mice showed a degree of immunologieal adaptation to Q but not to C₃H mice.     

Influence of serum donor and recipient mouse genotype on the passive transfer of protective immunity with serum against Nematospiroides dubius

Dobson C., Brindley P. J. and Sitepu P. 1982. Influence of serum donor and recipient mouse genotype on the passive transfer of protective immunity with serum against Nematospiroides dubius. International Journal for Parasitology12: 567–572. Different strains of serum donor mice showed variations in innate immunity to primary infections with Nematospiroides dubius. Different levels of anti-N, dubius antibodies were detected in sera from these mouse strains; there was no correlation between antibody titre and numbers of worms recovered. Serum from donor wild and six laboratory strains of mice protected female Quackenbush (Q) recipients against N. dubius infections; donor mouse strain influenced the degree of protection conferred and donor serum antibody titre related to the degree of stunting of worm growth in recipient mice. Five laboratory strains of mice developed different levels of protective immunity following multiple experimental infections with N. dubius. Antibody titres in these mice were strongly correlated with the percentage protection observed after 1–4 infections: Q and CBA mice produced more anti-N. dubius antibody and were better protected than DBA/2, BALB/c and C3H mice. However BALB/c, C3H and CBA mice attained similar anti-N. dubius antibody titres after a single infection with N. dubius but serum from BALB/c gave better protection when transferred to female Q recipients than that from the other two strains. This suggested qualitative differences in the protective antibodies in sera between mouse strains. Five mouse strains were passively immunized with a uniform dose of serum from female Q donors: DBA/2 female recipients showed the least, BALB/c and C3H females were intermediate, and Q and CBA female mice attained the greatest level of passive protection against N. dubius. A close positive correlation existed between the degree of actively acquired and the level of passively acquired protection between the five strains of mice.     

Taenia crassiceps: Immunity to metacestodes in BALB/c and BDF1 mice

The kinetics of primary and secondary infections with Taenia crassiceps larvae and the effects of immune serum on T. crassiceps larvae were studied in BALB/c and BDF1 mice. In both strains of mice a substantial degree of resistance to reinfection comparable to that previously reported in C3H mice can be induced by subcutaneous injection of three larvae 3 weeks prior to intraperitoneal challenge infection. Both early immune damage in the absence of adherent host cells and encapsulation by host cells are involved in rejection of larvae by BALB/c and BDF1 mice, but in both of these strains early immune damage is less pronounced and the cellular encapsulation response considerably more prominent than in the C3H mice studied previously. This difference is also reflected in the effect of immune serum on T. crassiceps metacestodes in vitro: immune serum from BALB/c and BDF1 mice is less effective than immune serum taken from C3H mice at comparable times after challenge infection in mediating damage to T. crassiceps larvae in vitro in the absence of host cells. These results suggest that genetically determined differences in immune capability can alter the state of equilibrium existing among different immune effector mechanisms without producing measurable effects upon overall host resistance to reinfection.     

Plasmodium yoelii: Assessment of production and role of nitric oxide during the early stages of infection in susceptible and resistant mice

There is conflicting evidence regarding the role of nitric oxide (NO) in the process of resistance against blood-stage malaria parasites. In this study, we used two strains of mice infected with Plasmodium yoelii 17XL in order to assess the NO production profile and its possible role during the early stage of malaria infection. We found a greater elevation of NO production associated with a sharp increase in the levels of IFN-γ in infected DBA/2 mice, compared with infected BALB/c mice. This difference was associated with relatively lower parasitemia, a higher constituent ratio of infected reticulocytes, and greater survival in DBA/2 mice. Endogenous IFN-γ driving Th1 immunity was responsible for NO production. Moreover, schizonts treated in vitro with NO donors caused a delayed infection to BALB/c mice in a dose and time-dependent manner. These data, thus, suggest that NO may play an inhibitory role in Plasmodium infection.     

Expression of the intercellular adhesion molecule-1 on high endothelial venules and on non-lymphoid antigen handling cells: interdigitating cells,antigen transporting cells and follicular dendritic cells

Intercellular adhesion molecule-1 (ICAM-1)¹ has been implicated in the development of germinal center reactions in vitro, and the present study was undertaken to determine the distribution of ICAM-1 in active germinal centers in vivo and in murine secondary lymphoid tissues in general. Anti-ICAM-1-specific monoclonal antibodies were used in conjunction with immunohistochemistry at both the light and ultrastructural levels of resolution. Examination of cryostat sections of lymph nodes, spleens, and Peyer's patches revealed that anti-ICAM-1 distinctly labeled cells in the light zones of germinal centers, a few cells in the T cell zones (e.g. paracortex of lymph nodes), cells in the sinus floor of the subcapsular sinuses of lymph nodes, and high endothelial venules (HEV). Ultrastructural studies revealed that the cells labeling with anti-ICAM-1 in germinal centers were follicular dendritic cells (FDC) which appeared to have more ICAM-1 than any other cell type. The surfaces of well-developed, intricate, convoluted FDC processes were intensely labeled even under conditions where B cells appeared negative. Interdigitating cells (IDC) were also labeled as were certain endothelial cells in the HEV. The cells in the subcapsular sinus floor labeling with anti-ICAM-1 were the antigen transporting cells (ATC) that carry antigen-antibody complexes into lymph node follicles. We suspect ATC are FDC precursors which mature into FDC in the follicles. Interestingly, FDC, IDC, and ATC are 3 important accessory cells known to handle antigens in specific compartments of lymphoid tissues. The marked localization of this adhesion molecule on these critical antigen handling cells supports the concept that ICAM-1 is important in providing the intercellular adhesion necessary for optimal initiation of immune responses in vivo.Abbreviations ICAM-1 Intercellular adhesion molecule-1 - LFA-1 leukocyte functional antigen-1 - IDC interdigitating cells - ATC antigen transporting cells - FDC follicular dendritic cells - HEV high endothelial venules - DC dendritic cells - PBS phosphate-buffered saline - PLP periodate-lysine-4% paraformaldehyde - GPLP periodate-lysine-0.1% glutaraldehyde-2% paraformaldehyde - EM electron microscopy - HRP horseradish peroxidase - DAB diaminobenzidine tetrahydrochloride - HSA human serum albumin     

Oviposition and chemosensory stimulation of the root flies Delia radicum and D. floralis in response to plants and leaf surface extracts from resistant and susceptible Brassica genotypes

In Brassica crops differences in susceptibility to root fly attack can be largely attributed to antixenotic resistance. Plants of four genotypes (two swedes and two kales) with widely differing resistance in field trials, were compared in laboratory choice assays for their susceptibility to oviposition by the root flies Delia radicum (L.) and D. floralis (Fallen) (Diptera, Anthomyiidae). For both species the preference among the genotypes corresponded to the susceptibility of the genotypes in the field. The preference ranking in response to surrogate leaves treated with methanolic surface extracts of the four genotypes was identical to the preference among potted plants, demonstrating that chemical factors on the leaf surface mediate host preference for oviposition in these species.For both species of fly, glucosinolates are major oviposition stimulants and for D. radicum an additional, nonglucosinolate oviposition stimulant, presently called CIF, is known. We describe a procedure for chromatographic separation of glucosinolates from CIF in leaf surface extracts. In oviposition-choice assays with D. radicum, the CIF-fractions of the two swede genotypes applied to surrogate leaves received a 1.8 and 4.6 times higher proportion of eggs than the respective glucosinolate-fractions, confirming the major importance of CIF as an oviposition stimulant. The genotype of swede that was preferred by both fly species in tests with plants and methanolic leaf surface extracts, also stimulated oviposition more in tests with the glucosinolate-fractions or the CIF-fractions derived from the surface extracts, respectively. Thus, glucosinolates and CIF together account for the observed preference among the genotypes and may also be responsible for their susceptibility under field conditions. In the two kale genotypes the preference for plants or surface extracts differed from the preference among the corresponding glucosinolate- and CIF-fractions, indicating that additional, as yet unknown chemical factors may also be involved.For both groups of stimulants tarsal chemoreceptors allow electrophysiological monitoring of glucosinolate- and CIF-activity in fractionated surface extracts. For D. radicum the chemosensory activity of both glucosinolate- and CIF-fractions corresponded to the respective behavioural activity in the oviposition preference tests, suggesting that preference for oviposition among genotypes can be predicted from the electrophysiological activity of their fractions. The chemosensory response of D. floralis, in particular to the CIF-fractions, was less pronounced than the response of D. radicum, indicating interspecific differences in the perception of the major oviposition stimulants. We discuss the potential application of electrophysiological techniques in support of other screening methods used in breeding for root fly resistance in Brassica crops.     

Immunization with killed Escherichia coli increases resistance of lipopolysaccharide-hyporesponsive C3H/HeJ mice to experimental urinary tract infection

Abstract C3H/HeJ mice are highly susceptible to experimental ascending urinary tract infection. After a 4-week intraperitoneal immunization regimen with killed Escherichia coli , these mice became more resistant to urinary tract infection. The level of resistance induced by this regimen in this strain was similar to that of the normally more resistant C3HeB/FeJ strain of mouse and was evident from 3 to 14 days after transurethral challenge with E. coli . Increased resistance also developed after a 2- or 3-week immunization regimen, but this resistance was not apparent until 14 days after challenge.     

Ultrastructural changes and location of beta-1, 3-glucanase in resistant and susceptible cotton callus cells in response to treatment with toxin of Verticillium dahliae and salicylic acid

Calli from two cotton cultivars susceptible and resistant to Verticillium wilt, were treated with a crude toxin of Verticillium dahliae (VD-toxin) plus salicylic acid (SA). Cells treated with VD-toxin showed distinct ultrastructural changes. Cells from the susceptible cultivar displayed damage to plasma membrane and cytoplasm. The deleterious effect on cells of the resistant cultivar, with an accumulation of electron-dense precipitate in the vacuoles, was less noticeable. Exogenous SA protected callus cells from VD-toxin. We also report the localization of β-1,3-glucanase in callus cells with immunofluorescence labeling. Stronger fluorescence was observed in the extra-cellular space in resistant than in susceptible cotton; strongest in resistant cotton after 5 days of treatment with VD-toxin plus SA. The findings reported here indicate an important role of exogenous salicylic acid in the induction of resistance to VD-toxin in cotton. Coupled with an increase in β-1,3-glucanase, cellular integrity is maintained and damage to cell wall and plasma membrane is avoided.     

Toxoplasma gondii: The severity of toxoplasmic encephalitis in C57BL/6 mice is associated with increased ALCAM and VCAM-1 expression in the central nervous system and higher blood-brain barrier permeability

In order to investigate the differential ALCAM, ICAM-1 and VCAM-1 adhesion molecules mRNA expression and the blood-brain barrier (BBB) permeability in C57BL/6 and BALB/c mice in Toxoplasma gondii infection, animals were infected with ME-49 strain. It was observed higher ALCAM on day 9 and VCAM-1 expression on days 9 and 14 of infection in the central nervous system (CNS) of C57BL/6 compared to BALB/c mice. The expression of ICAM-1 was high and similar in the CNS of both lineages of infected mice. In addition, C57BL/6 presented higher BBB permeability and higher IFN-γ and iNOS expression in the CNS compared to BALB/c mice. The CNS of C57BL/6 mice presented elevated tissue pathology and parasitism. In conclusion, our data suggest that the higher adhesion molecules expression and higher BBB permeability contributed to the major inflammatory cell infiltration into the CNS of C57BL/6 mice that was not efficient to control the parasite.     

基于JAK2/STAT3信号通路探讨头针结合艾灸对缺血缺氧脑瘫幼鼠模型的影响及作用机制

摘要 目的：基于JAK2/STAT3信号通路探讨头针结合艾灸对缺血缺氧脑瘫幼鼠模型的影响及作用机制。方法：选取40只7 d龄的清洁级SD幼鼠,按随机数字表法分为A组、B组、C组、D组、E组,每组8只。E组不予以任何处理,其余各组幼鼠均以改良的缺氧缺血性脑病造模方法构建缺血缺氧脑瘫模型。造模成功后A组、B组、C组分别给予头针结合艾灸治疗、头针治疗、艾灸治疗,D组、E组均给予50 ?滋L生理盐水。对比各组幼鼠脑组织Janus蛋白酪氨酸激酶2（JAK2）及转录活化因子3（STAT3）蛋白表达量、血清炎症因子[白介素-6（IL-6）、肿瘤坏死因子--α（TNF-α）、白介素-1（IL-1）]水平、神经递质[去甲肾上腺素（NE）、5-羟色胺（5-HT）]水平、记忆功能。结果：A组脑组织JAK2、STAT3 蛋白表达量低于B、C、D组,但高于E组（P<0.05）;A组血清IL-6、IL-1和TNF-α水平低于B、C、D组,但高于E组（P<0.05）;A组血清NE、5-HT水平低于B、C、D组,但高于E组（P<0.05）;A组Y迷宫实验正确次数多于B、C、D组（P<0.05）,而少于E组（P<0.05）。结论：头针结合艾灸可通过靶向抑制JAK2/STAT3信号通路相关蛋白的表达下调机体炎症反应水平,从而降低缺血缺氧脑瘫幼鼠脑组织损伤,促进其记忆功能恢复。