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Resistance to the induction of EAE in AO rats: its prevention by the pre-treatment with cyclophosphamide or low dose of irradiation.

Susceptibility to the induction of EAE was compared in AO, DA and Lewis strain of rats. As evaluated by clinical and histological criteria, AO rats exhibited significantly lower susceptibility to EAE induced with guinea-pig spinal cord (GPSC) tissue and complete resistance to the encephalitogenic challenge with rat myelin basic protein (BP) irrespective of antigen dose and adjuvant used. AO rats pre-treated with BP + Freund's incomplete adjuvant became completely unresponsive to the induction of EAE with GPSC + Freund's complete adjuvant (FCA) indicating that they do possess cells sensitive to some antigenic determinants of rat BP. In order to test whether the resistance to EAE is due to an active suppression, low dose of irradiation (300 rad) and cyclophosphamide (20 mg/kg) was applied prior to the induction of EAE. Selective depletion of radiosensitive cells facilitated the induction of EAE. Similarly, cyclophosphamide given 2 days prior to BP + FCA completely abrogated the resistance to EAE induction. Thus, it appears that the inability of BP + FCA to produce EAE in AO rats is due to the disproportionate activation of suppressor cells.

Animals↗

Autoimmune encephalomyelitis (EAE) mediated or prevented by T lymphocyte lines directed against diverse antigenic determinants of myelin basic protein. Vaccination is determinant specific.

Lines of T lymphocytes reactive against the basic protein of myelin (BP) were found in previous studies to mediate experimental autoimmune encephalomyelitis (EAE) in rats. Moreover, inoculation of rats with attenuated anti-BP line cells vaccinated them against subsequent attempts to induce active EAE by injection of BP in adjuvant. In the present study, we investigated the effects of T lymphocyte lines reactive to different antigenic determinants on the BP molecule, they are the major encephalitogenic peptide (EP) determinant present on guinea pig BP (G-BP), and minor, non-EP determinants present on bovine BP (B-BP). We found that both lines of T lymphocytes could mediate EAE. Resistance to active EAE acquired by spontaneous recovery from line mediated EAE or by vaccination with attenuated cells, however, was found to be specific for the particular BP determinant. Thus, EAE may be mediated by lines of T lymphocytes reactive to different determinants on the BP molecule, but the resistance to EAE acquired by exposure to line cells is determinant specific. This suggests that acquired resistance to EAE is directed by the receptor specificity of the autoimmune anti-BP T cells.

Animals↗

GFAP mRNA fluctuates in synchrony with chronic relapsing EAE symptoms in SJL/J mice.

Activation of astrocytes and hypertrophy of their processes is a result of a number of pathological conditions in the central nervous system. Astrocytic gliosis is especially prominent in multiple sclerosis (MS), where astrocytic fibers form a dense matrix around demyelinated axons. Experimental allergic encephalomyelitis (EAE), a laboratory model for MS, is also accompanied by astrocytic hyperactivity. We have previously shown the formation of plaque-like structures which stain heavily for glial fibrillary acidic protein (GFAP) in the brains and spinal cords of SJL/J mice after several episodes of chronic relapsing EAE (Smith and Eng: J Neurosci Res 18:203, 1987). To further investigate the mechanisms of this phenomenon, we have measured the levels of mRNA for GFAP throughout the course of three episodes and recoveries of EAE in the SJL/J mouse. Mice were immunized with spinal cord homogenate and subsequently developed EAE. After recovery they were again immunized at appropriate intervals, resulting in successive episodes of EAE, with partial or complete recovery between the paralytic stages. At appropriate times in the course of the different stages of EAE, spinal cords were dissected and RNA was prepared from each spinal cord. RNA was analyzed by Northern blots to determine the levels of mRNA for GFAP and, as a control for the 70 kDa neurofilament (NF-L). With the onset of the first EAE episode GFAP mRNA in spinal cords from animals with mild symptoms increased to sixfold the control level (P < 0.02) and to 20-fold in those with paralysis (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effects of cytokine deficiency on chemokine expression in CNS of mice with EAE.

Although both cytokines and chemokines have been implicated in the pathogenesis of clinical and histological EAE, their interactions in vivo have not yet been clearly established. To address this issue, we evaluated expression of chemokines and receptors in the CNS of wild-type control and cytokine deficient mice at the peak of EAE induced with MOG-35-55 peptide in CFA. Our results demonstrate that: 1) expression of most chemokines/receptors was drastically inhibited in TNF-alpha deficient mice, and was reflective of delayed onset and reduced severity of EAE; 2) distinct patterns of chemokine expression occurred in various other cytokine knockout mice that did not significantly affect expression of clinical EAE; 3) there was a strong association between expression of MIP-1alpha, MIP-2 and MCP-1 in CNS and overall severity of EAE in wild-type and cytokine knockout mice; and 4) among CNS infiltrating cells at the peak of EAE, macrophages and CD8+ T cells were the primary cellular source of most of the chemokines. Of note, we present evidence that TNF-alpha may be involved in regulating RANTES and MIP-1alpha, and that IL-4 may be involved in regulating MCP-1. Our results not only identify the cellular source of chemokines in CNS, but also implicate MIP-1alpha, MIP-2, and MCP-1 in controlling CNS inflammation and severity of EAE.

Animals↗

Presence of the LEE (locus of enterocyte effacement) in pig attaching and effacing Escherichia coli and characterization of eae, espA, espB and espD genes of PEPEC (pig EPEC) strain 1390.

In the present study, attaching and effacing Escherichia coli (AEEC) O45 isolates from post-weaning pigs with diarrhoea were examined for the presence of the LEE (locus of enterocyte effacement) using various DNA probes derived from the LEE of human enteropathogenic E. coli (EPEC) strain E2348/69. The LEE fragment was conserved among the eae -positive pig isolates. The attaching and effacing activity of PEPEC (pig EPEC) O45 isolates is highly correlated with the presence of the LEE. Nevertheless, for some PEPEC isolates, the insertion site of the LEE is different or has diverged during evolution. The presence of the LEE fragment in PEPEC isolates provides further evidence that the LEE region is conserved among AEEC of different animal origins. In addition, the nucleotide sequence of the region containing the eae gene and esp genes of a pig AEEC isolate, strain 1390, was determined. Among examined Eae proteins, Eae of strain 1390 showed the highest similarity with Eae belonging to the beta intimin group such as the Eae of rabbit AEEC. Moreover, all pig strains that produced attaching and effacing lesions in piglets and pig ileal explants belonged to the beta intimin group. The deduced amino acid sequences of the EspA, EspB and EspD proteins of strain 1390 showed particularly strong homology to those of AEEC strains presenting a beta intimin allele. Thus, pig AEEC possess the LEE sequences, and for the strain 1390, sequences of the eae and esp regions are related to those of other AEEC, in particular, strains presenting a beta intimin allele, such as the rabbit AEEC.

Adhesins, Bacterial↗

Monoclonal antibody-induced inhibition of relapsing EAE in SJL/J mice correlates with inhibition of neuroantigen-specific cell-mediated immune responses.

Relapsing experimental allergic encephalomyelitis (R-EAE) in SJL/J mice was examined in relation to the development of neuroantigen-specific T cell proliferative (Tprlf) and delayed-type hypersensitivity (DTH) responses. R-EAE was induced by injecting syngeneic mouse spinal cord homogenate in CFA on days 0 and 7 over the shaved flanks of female SJL/J mice. Mice primed in this manner exhibited significant Tprlf and DTH responses specific for both major myelin proteins, myelin basic protein (MBP) and proteolipid protein (PLP). A time course comparison between the induction of R-EAE and the development of neuroantigen-specific cell-mediated immune (CMI) responses (Tprlf and DTH) revealed that the MBP- and PLP-specific Tprlf and DTH responses peaked prior to the onset of initial clinical symptoms and the DTH responses remained at significant levels throughout the relapsing course of the disease. Monoclonal antibodies were used to determine whether in vivo inhibition of class II-restricted Tprlf and DTH responses correlated with inhibition of R-EAE. In vivo administration of a total of 100 micrograms anti-L3T4 antibody, but not anti-Lyt-2 antibody, resulted in delayed onset and reduced severity of clinical signs of R-EAE concomitant with significantly reduced levels of MBP- and PLP-specific Tprlf and DTH responses. Treatment with a total of 300 micrograms of purified anti-L3T4 resulted in total abrogation of R-EAE induction and neuroantigen-specific CMI. Thus, clinical signs of R-EAE were found to correlate with the activity of neuroantigen-specific, class II-restricted T cells.

Animals↗

Presence of nerve growth factor and TrkA expression in the SVZ of EAE rats: evidence for a possible functional significance.

Nerve growth factor (NGF) is a well-characterized neurotrophic factor that plays a crucial role during development in the growth, differentiation, and maintenance of brain neurons as well as in the reparative response of the adult brain to neuronal damage. Recent studies have shown that acute axonal loss occurs in multiple sclerosis (MS) and its animal model, experimental allergic encephalomyelitis (EAE), and that NGF suppresses clinical symptoms of EAE in nonhuman primates. Aim of the present study was to investigate the role of NGF in the regenerative response of the adult brain to neuronal damage occurring in EAE. Using EAE rats, we have found that exogenous NGF injection and NGF deprivation (NGF autoimmunization) can act on growth and differentiation of brain precursor cells in the subventricular zone (SVZ) of EAE rats. Moreover, NGF administration in brain of EAE rats stimulates the expression of early neuronal markers on proliferating precursor cells of the SVZ. The data obtained demonstrated that NGF and its antibody affect bromodeoxyuridine (BrdU) incorporation and NGF receptor expression by SVZ progenitor cells in the brain of EAE rats.

Animals↗

Real-time reverse transcription-multiplex PCR for simultaneous and specific detection of rfbE and eae genes of Escherichia coli O157:H7.

A real-time reverse transcription multiplex polymerase chain reaction (rRT-MPCR) was developed for detection of mRNA encoded by rfbE and eae genes of enterohemorrhagic Escherichia coli (EHEC) O157:H7. A 129-bp and a 106-bp sequence specific to rfbE and eae, respectively, were targeted for reverse transcription, amplification, and real-time detection. A single-step RT-PCR kit containing a mixture of reverse transcriptases converted mRNA into cDNA, which was subsequently amplified by Taq polymerase included in the same kit. The real-time detection of amplification products was achieved by incorporating rfbE(O157)- and eae(O157:H7)-specific TaqMan probes in rRT-MPCR. The ability of two sets of primers and probes for specific detection of rfbE(O157) and eae(O157:H7) was initially verified by screening RNA of eight E. coli serotypes possessing different O antigens and eae alleles. These two sets of primers and probes were also tested in a standard real-time PCR (rPCR) using DNA prepared from several E. coli and non-E. coli strains to verify that only rfbE(O157)- and eae(O157:H7)-specific sequences were amplified and detected. The rRT-MPCR was then evaluated for detecting low-level contamination of EHEC O157:H7 in feces. When RNA prepared from bovine feces, which were artificially seeded with EHEC O157:H7 cells and cultured for five hours, was tested in rRT-MPCR as low as 1cfu/g of feces could be detected. The detection range for the two genes in fecal cultures was 5.1 x 10(-1)-5.1 x 10(4) cfu/g of feces. Thus, the described procedure could be applied to rapid detection of very low levels of EHEC O157:H7 using total RNA as a template. Since the presence of rfbE(O157)- and eae(O157:H7)-specific mRNA is dependent on replicating cells, rRT-MPCR could provide important information about the viability of EHEC O157:H7 in feces.

Adhesins, Bacterial↗

The role of regulatory T cells in Lewis rats resistant to EAE.

Adult Lewis (LEW) rats are highly susceptible to experimental autoimmune encephalomyelitis (EAE), induced actively by immunization with guinea pig (GP) myelin basic protein (MBP) in complete Freund's adjuvant or adoptively transferred with activated T lymphocytes reactive to GP MBP peptide 68-88. Once LEW rats recover from active EAE or when given MBP in incomplete Freund's adjuvant (IFA), they become resistant to further attempts to induce active or passive EAE. In this study, we examined whether such EAE-resistant rats after MBP-IFA immunization have reduced frequencies of MBP-reactive T cells, whether these T cells are anergized, and whether the activity of regulatory T cells is increased to the event that they prevent activation of MBP-specific T cell subpopulations. By limiting dilution analyses (LDA) of unfractionated splenic T cells, the levels of MBP-reactive T cells in EAE-resistant rats appeared to be approximately 5% of the levels in EAE-susceptible rats. However, a subsequent analysis of CD4+ enriched T cell populations, depleted of the CD8 subset, showed similar frequencies of MBP-reactive cells in susceptible and resistant LEW rats. Not only were the frequencies on LDA altered by suppressor cells, but also LDA comparisons based on cell proliferation and cytokine production as indicators of MBP reactive cell frequencies gave markedly different results. We conclude that MBP-reactive T cells in this model of EAE-resistant LEW rats are hyporeactive to MBP as the result of an increased activity of a regulatory subset of CD8+ T cells. These results also demonstrate that the quantitation of MBP-reactive CD4+ T cells by LDA is strongly influenced by the presence of functionally antagonistic CD8+ T cells, which cause an underestimation of responder T cell frequencies, and by the method of detecting T cell reactivity.

Animals↗

Genetic and epigenetic influence on EAE phenotypes induced with different encephalitogenic peptides.

Different encephalitogenic peptides can induce two distinct experimental autoimmune encephalomyelitis (EAE) phenotypes in different mouse strains. To determine whether different peptides induce distinct phenotypes in genetically identical mice, parental strain and (SJLXC3H/HeJ)F1 mice were sensitized with myelin proteolipid protein peptide p139-151 or p215-232. p139-151 was non-encephalitogenic in C3H/HeJ mice and p215-232 was non-encephalitogenic in SJL mice. p139-151 induced typical acute EAE in SJL and F1 mice with most CNS inflammatory/demyelinating lesions located in the spinal cord. p215-232 induced mild clinical disease in only two of 10 C3H/HeJ mice; in 11 of 13 F1 mice (85%) it induced a disease spectrum that included typical paralytic acute EAE with a predominance of spinal cord lesions and later-onset mild EAE with predominance of brain stem/cerebellar lesions. Thus, the EAE phenotype induced in F1 mice by one encephalitogen, e.g. p139-151, can be the same as that induced in the susceptible parent. However, other encephalitogenic peptides, e.g. p215-232, may induce a broad range of heterogeneous EAE phenotypes in syngeneic mice. These data indicate that in some encephalitogenic responses, epigenetic factors influence EAE incidence, time of onset, severity, neurological signs and CNS lesion distribution.

Acute Disease↗

Verotoxin-producing Escherichia coli (VTEC) and eae-positive non-VTEC in 1-30-days-old diarrhoeic dairy calves.

Faecal samples from 221, 1-30-days-old, diarrhoeic dairy calves were screened for the presence of verotoxin-producing Escherichia coli (VTEC) and eae-positive non-VTEC. Calves were grouped according to their age (1-7, 8-14, 15-21 and 22-30 days) and analyses of prevalences were done by Mantel-Haenzsel chi 2-test for trend. VTEC and eae-positive non-VTEC were detected in 20 (9.0%) and 18 (8.1%) of the diarrhoeic calves, respectively. A significant age-associated increase in the prevalence of VTEC (p = 0.0001), but not in the prevalence of eae-positive non-VTEC (p = 0.381), was found. Significant differences in VTEC prevalence were found between the age-group 22-30 days and in all other age-groups. 43 (5.0%) of the 861 E. coli isolates from the 221 diarrhoeic calves were VTEC, and 30 (69.8%) of these strains produced VT1 only. More than one-half of the VTEC strains (55.8%) were positive for the eae gene and all these eae-positive VTEC strains produced VT1 only. A high percentage (76.7%) of VTEC strains belonged to E. coli serogroups (O4, O26, O39, O91, O113, O128 and O145) associated with haemorrhagic colitis and haemolytic uraemic syndrome in humans. 51 (5.9%) of the E. coli strains studied were eae-positive non-VTEC and the serogroups most prevalent among these strains were O4, O14, O26 and O123. Only four of the eae-positive strains were also espB-positive by hybridization with a probe from a human EPEC isolate and none of these strains produced VT.

Adhesins, Bacterial↗

Treatment of experimental allergic encephalomyelitis (EAE) induced by guinea pig myelin basic protein epitope 72-85 with a human MBP(87-99) analogue and effects of cyclic peptides.

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory and demyelinating disease of the central nervous system and is an animal model of multiple sclerosis (MS). In the present report, a linear analogue and a series of cyclic semi-mimetic peptides were designed and synthesized based on the human myelin basic protein (MBP(87-99)) epitope (Val87-His-Phe-Phe-Lys-Asn-Ile-Val-Thr-Pro-Arg-Thr-Pro90) and on Copolymer I (a mixture of random polymers of Ala, Gln, Lys and Tyr used to treat MS). These analogues were designed looking for suppressors of EAE induced by guinea pig MBP(72-85) epitope (Gln-Lys-Ser-Gln-Arg-Ser-Gln-Asp-Glu-Asn-Pro-Val) in Lewis rats. The linear analogue [Arg91,Ala96]MBP(87-99), in which Arg substitutes Lys91 and Ala substitutes Pro96, was found to be a strong inhibitor which when administered to Lewis rats together with the encephalitogenic agonist MBP(72-85) completely prevented the induction of EAE. In contrast, three N- and C-termini amide-linked cyclic semi-mimetic peptides, [cyclo-Phe-Arg-Asn-Ile-Val-Thr-Ala-Acp (1), cyclo-Phe-Ala-Arg-Gln-Acp (2), cyclo-Tyr-Ala-Lys-Gln-Acp (3)] as well as a Lys side chain and C-terminous cyclic semi mimetic peptide cyclo(Lys, Acp)-Phe-Lys-Asn-Ile-Val-Thr-Ala-Acp (4) which contain segments of MBP(87-99) or are constituted from immunophoric residues of copolymer 1, were ineffective in inducing or inhibiting EAE in Lewis rats. However co-injection of cyclic analogues with MBP(72-85) delayed the onset of EAE indicating a modulatory effect on the EAE activity of MBP(72-85). These findings suggest that molecule length, size of cyclic moiety and backbone conformation are important elements for immunogenic activity. Moreover blockade of MBP(72-85) induced EAE by the unrelated peptide [Arg91,Ala56]MBP(87-99) could indicate that the mechanism of inhibition is not due to binding competition but rather due to the delivery of a negative signal by the antagonist which overcomes the agonist response possibly through the activation of antigen specific regulatory T cells.

Animals↗

Complexities of applying nasal tolerance induction as a therapy for ongoing relapsing experimental autoimmune encephalomyelitis (EAE) in DA rats.

EAE is an autoimmune disease of the central nervous system (CNS) that serves as an experimental model for the human inflammatory demyelinating disease multiple sclerosis (MS). Antigen-based immunotherapy including soluble antigen administration via feeding has been shown to be successful in treating EAE in rodents. In the present study, we explore nasal administration of small amounts of myelin basic protein (MBP) as a potential means of treatment of protracted, relapsing EAE (PR-EAE) in a novel DA rat system. We found that nasal administration of MBP prevented EAE induced with whole spinal cord homogenate + Freund's incomplete adjuvant (FIA), and strongly down-regulated levels of MBP-reactive interferon-gamma (IFN-gamma)-secreting Th1-like cells. However, in rats with ongoing PR-EAE receiving the same regimen of MBP, a trend of aggravated disease was recorded, in conjunction with augmented levels of MBP-reactive IFN-gamma-secreting Th1-like splenocytes during the acute phase of EAE. These data have implications for the clinical application of nasal tolerance to autoimmune diseases.

Administration, Inhalation↗

Suppression of ongoing experimental allergic encephalomyelitis (EAE) in Lewis rats: synergistic effects of myelin basic protein (MBP) peptide 68-86 and IL-4.

Mucosal myelin autoantigen administration effectively prevented EAE, but mostly failed to treat ongoing EAE. Patients with multiple sclerosis (MS), for which EAE is considered an animal model, did not benefit from oral treatment with bovine myelin. We anticipated that autoantigen, administered together with a cytokine that counteracts Th1 cell responses, might ameliorate Th1-driven autoimmune disease, and that nasal administration might considerably reduce the amounts of antigen + cytokine needed for treatment purposes. Lewis rats with EAE actively induced with myelin basic protein peptide (MBP 68-86) and Freund's complete adjuvant (FCA), received from day 7 post-immunization, i.e. after T cell priming had occurred, 120 microg MBP 68-86 + 100 ng IL-4 per rat per day for 5 consecutive days. These rats showed later onset, lower clinical scores, less body weight loss and shorter EAE duration compared with rats receiving MBP 68-86 or IL-4 only, or PBS. EAE amelioration was associated with decreased infiltration of ED1+ macrophages and CD4+ T cells within the central nervous system, and with decreased interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) and enhanced IL-4, IL-10 and transforming growth factor-beta (TGF-beta) responses by lymph node cells. Simultaneous administration of encephalitogenic peptide + IL-4 by the nasal route thus suppressed ongoing EAE and induced IL-4, IL-10 and TGF-beta-related regulatory elements.

Administration, Intranasal↗

The protective effects of omega-6 fatty acids in experimental autoimmune encephalomyelitis (EAE) in relation to transforming growth factor-beta 1 (TGF-beta1) up-regulation and increased prostaglandin E2 (PGE2) production.

Polyunsaturated fatty acids are known to affect the immune response and administration of the omega-6 fatty acid linoleic acid has been reported to be beneficial in multiple sclerosis (MS) and EAE. In this study we have investigated the effects of oral feeding of plant lipid rich in the omega-6 fatty acid gamma-linolenic acid from Borago officinalis on acute and relapse disease and the immune response in EAE using SJL mice. EAE was induced by an encephalitogenic peptide (92-106) of myelin oligodendrocyte glycoprotein (MOG), and mice were fed the plant lipid daily from 7 days after EAE induction to assess the effects on acute disease and from day 25 to assess the effects on disease relapse. The clinical incidence and histological manifestations of acute EAE, and the clinical relapse phase of chronic relapsing EAE (CREAE) were markedly inhibited by omega-6 fatty acid feeding. A significant increase in the production of TGF-beta1 in response to concanavalin A (Con A) at day 13 and a significant increase in TGF-beta1 and PGE2 to Con A, PPD and MOG peptide (92-106) at day 21 were detected in spleen mononuclear cells from fatty acid-fed mice. There was no difference in interferon-gamma, IL-4 and IL-2 production between the fatty acid-fed and control groups. Significantly higher TGF-beta mRNA expression was found in the spleens of omega-6 fatty acid-fed mice at day 21. There were no differences in spleen cell proliferative response to Con A, PPD and MOG peptide (92-106). Biochemical analysis of spleen cell membrane fatty acids revealed significant increases in the eicosanoid precursor fatty acids dihomo-gamma-linolenic acid and arachidonic acid in response to gamma-linolenic acid feeding, indicating rapid metabolism to longer chain omega-6 fatty acids. These results show that oral feeding of gamma-linolenic acid-rich plant lipid markedly affects the disease course of acute EAE and CREAE and is associated with an increase in cell membrane long chain omega-6 fatty acids, production of PGE2 and gene transcription and, on activation, secretion of TGF-beta1.

Amino Acid Sequence↗

Characterization of Shiga toxin gene (stx)-positive and intimin gene (eae)-positive Escherichia coli isolates from wastewater of slaughterhouses in France.

Wastewater samples from 12 slaughterhouses located in different regions in France were tested for the presence of stx-positive and eae-positive Escherichia coli isolates, and characteristics of the isolates obtained were determined. A total of 224 wastewater samples were collected in wastewater treatment plants at different stages of wastewater processing. Altogether, 5,001 E. coli isolates were obtained by colony counting and screened for the presence of stx and eae genes by multiplex PCR. stx-positive and eae-positive E. coli isolates were detected in 25% of the samples collected; they were found in 13% and 3% of the samples obtained from treated effluent and sludge, respectively, suggesting that they could be spread into the environment. Screening of the samples collected by immunomagnetic separation allowed us to isolate 31 additional E. coli serogroup O157 isolates. Four of these isolates harbored stx and eae genes. All stx-positive and eae-positive E. coli isolates were analyzed for eae and stx genetic variants, as well as for additional virulence factors and serotypes. Our results suggest that the majority of the stx- and eae-positive E. coli isolates from wastewater have low virulence for humans. However, the diversity of the enterohemorrhagic E. coli-associated virulence factors in the strains indicates that the environment may play an important role in the emergence of new pathogenic enterohemorrhagic E. coli strains.

Abattoirs↗

Polymerase chain reaction analysis of eae gene subtypes present in attaching and effacing Escherichia coli isolated from pigs with diarrhea.

In this study the subtype of eae gene was determined by polymerase chain reaction for a total of 59 attaching and effacing Escherichia coli isolated from preweaned (38 isolates) and postweaned (21 isolates) pigs. The eae(beta) gene detected in 19 E. coli from preweaned pigs and 10 E. coli from postweaned pigs was found to be the most common subtype, followed by eae(gamma), eae(epsilon), and eae(zeta) genes. Subtypes were not determined for 7 E. coli isolates. No other subtype of the eae gene was detected in eae+ E. coli evaluated in this study.

Adhesins, Bacterial↗

[Fibronectin (FN) concentrations in plasma and cerebrospinal fluid (CSF) from guinea pigs with experimental allergic encephalomyelitis (EAE) induced by myelin basic proteins].

The aim of this study was to ascertain whether the FN concentrations in plasma and in CSF are related to the symptomatic status of EAE induced in guinea pigs by myelin basic protein. Guinea pigs were immunized with myelin basic proteins in Freund's complete adjuvant, and after the appearance of neurological symptoms, the plasmas and CSFs from these animals were individually collected. The FN concentrations in these specimens were determined by a solid-phase inhibitory radioimmunoassay using a rabbit antibody specific for guinea pig FN. In plasmas from EAE induced animals, the average value of FN concentrations was lower than that from control animals, but in CSFs from EAE induced animals the average value was slightly higher than that from control animals. The FN concentration in plasma from individual animals with or without EAE was not related to that in the respective CSF, and no direct correlation between the symptomatic severity of EAE and the FN concentration in CSF from the respective animals was observed. These results indicate that the FN concentrations in CSFs probably increase in association with the induction of EAE in guinea pigs, but the levels are highly variable in individual cases, and that the FN concentration in CSF is not available to use as a consistent indicator for EAE in guinea pigs.

Animals↗