Local immune responses to Chlamydia pneumoniae in the lungs of BALB/c mice during primary infection and reinfection

Cell-mediated immune (CMI) responses play a major role in protection as well as pathogenesis of many intracellular bacterial infections. In this study, we evaluated the infection kinetics and assessed histologically the lymphoid reactions and local, in vitro-restimulated CMI responses in lungs of BALB/c mice, during both primary infection and reinfection with Chlamydia pneumoniae. The primary challenge resulted in a self-restricted infection with elimination of culturable bacteria by day 27 after challenge. A mild lymphoid reaction characterized the pathology in the lungs. In vitro CMI responses consisted of a weak proliferative response and no secretion of gamma interferon (IFN-gamma). The number of lung-derived mononuclear cells increased substantially during the primary infection; the largest relative increase was observed in B cells (B220(+)). After reinfection, the number of lung-derived mononuclear cells increased further, and the response consisted mainly of T cells. The reinfection was characterized in vivo by significant protection from infection (fewer cultivable bacteria in the lungs for a shorter period of time) but increased local lymphoid reaction at the infection site. In vitro, as opposed to the response in naive mice, acquired immunity was characterized by a strongly Th1-biased (IFN-gamma) CMI response. These results suggest that repeated infections with C. pneumoniae may induce Th1-type responses with similar associated tissue reactions, as shown in C. trachomatis infection models.     

Spread of murine cytomegalovirus to inner ocular structures following disruption of the blood-retina barrier in immunosuppressed BALB/c mice

PURPOSE: The aims of this study were to determine whether disruption of the blood-retina barrier (BRB) increases spread of murine cytomegalovirus (MCMV) to the eye after intraperitoneal inoculation and whether systemic immunosuppression influences the location of MCMV in the ocular compartment. METHODS: The BRB of the left eye of normal and immunosuppressed mice was disrupted by supraciliary inoculation of tissue culture medium followed 2 hours later by intraperitoneal injection of MCMV. Plaque assay of homogenized ocular tissue was used to determine the frequency of virus-positive eyes and the titer of virus in the eyes. Beta-galactosidase staining of frozen sections was used to locate virus in the eyes. RESULTS: In nonimmunosuppressed mice, the frequency of virus isolation, as well as the titer of virus, were significantly higher in eyes in which the BRB had been disrupted. Although the frequency of virus isolation was the same in both eyes of immunosuppressed mice, the titer of virus was significantly higher in the eye in which the BRB had been disrupted. The most striking result was that the location of virus was different in the nondisrupted eyes of immunosuppressed mice than it was in the disrupted eyes of immunosuppressed mice. In the former, virus was seen only in the outer ocular structures (conjunctiva, sclera, lacrimal gland), whereas in the latter, virus was observed in the retina and anterior segment (iris, ciliary body) as well as the outer ocular structures. CONCLUSIONS: The results of these studies suggest that ocular damage followed by increased spread of virus to and within the eye during systemic infection with CMV may be one mechanism by which development of CMV retinitis is facilitated in patients with acquired immune deficiency syndrome.     

Graves' disease: xenotransplantation model (athymic nude mice)

This study provides the first quantitative indication of the limits of sensitivity of a bone scan with technetium (99Tc-MDP) in detecting skeletal metastases and thereby also helps to explain the fact that bone scans may be negative when metastases are present in the bone marrow. Since 99Tc-MDP remains the least noxious and most widely used isotope for bone scanning, these results have direct clinical relevance in the evaluation of patients with solid tumors and possible metastatic spread.     

Neonatal stimulation and accelerated maturation in BALB/c mice.

Investigated the effects of neonatal stimulation on maturation rate using 24 litters of BALB/c mice as Ss. At birth litters were randomly assigned to 1 of 4 treatment conditions: (a) handled, (b) tactile, (c) handled control, or (d) undisturbed control. Continuous measurements were taken by 2 raters on a variety of physical maturation indexes. No significant treatment effects were obtained, but strong litter effects were found for each dependent variable. These results contradict previous reports in the literature and suggest that the genetic component attending physical maturation rate is not readily modulated by nonspecific neonatal stimulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Induction of B-cell lymphoma in BALB/c nude mice with an ecotropic, B-tropic helper virus present in the murine AIDS virus stock

The pathogenicities of the murine AIDS (MAIDS) virus complex (LP-BM5) and ecotropic helper virus (BM5eco) isolated from the complex to BALB/c nude mice were studied to elucidate the possible role of replication-competent helper virus in inducing the monoclonal outgrowth of lymphoid cells. Neither LP-BM5 nor BM5eco was pathogenic in adult BALB/c nude mice. However, B-cell lymphoma developed with a very high frequency when either virus was inoculated into newborn BALB/c nude (nu/nu) mice. The cells from the B-cell lymphoma were easily transplanted into nude mice. These results suggested that ecotropic helper virus in the MAIDS virus complex plays an important role in inducing the monoclonal outgrowth of lymphoid cells under immunodeficient conditions caused by defective virus.     

Characterization of antihistamines using biphasic cutaneous reaction in BALB/c mice

Effects of 11 histamine H1 receptor antagonists on IgE-mediated biphasic cutaneous reaction in mice were examined. The immediate phase reaction (IPR) assessed at 1 hour after antigen application was significantly inhibited by all antihistamines examined. The inhibition of IPR by cetirizine and mequitazine were potent, but those by cyproheptadine and diphenhydramine were weak. The later phase reaction (LPR) assessed at 24 hours after antigen application was inhibited by chlorpheniramine, oxatomide, ketotifen, mequitazine, emedastine, terfenadine and azelastine. The inhibition of LPR by emedastine was potent, but those by ketotifen and terfenadine were only partial. Emedastine inhibited both IPR and LPR comparably. Present results indicate that H1 receptor activation is involved in the IPR of the biphasic cutaneous reaction, and that the blockade of H1 receptors at IPR does not contribute to the attenuation of following LPR. Histamine H1 receptor antagonists inhibiting the LPR have a property distinct from H1 receptor antagonism, which may have an additional benefit for the treatment of allergic diseases.     

Effect of prednisolone on IgE-dependent biphasic cutaneous reaction in BALB/c mice

We have examined a series of 24 Merkel cell carcinoma (MCC) DNAs for loss of heterozygosity (LOH) at eight loci on chromosome 13. All patients were heterozygous for at least one locus. Overall, 18 of 24 (75%) patients showed LOH, among whom 10 patients demonstrated LOH at all informative loci. A single common region of loss was identified in all cases and included the marker D13S233 (13q14.3), which maps close to the retinoblastoma susceptibility gene RB1. The RB1 protein was not detected by Western blot analysis in any of nine MCC cell lines tested. These data indicate that 13q losses are the most common chromosomal losses observed to date in MCC and the likely target of these deletions is the RB1 locus.     

Antiproliferative effect of methyl-beta-cyclodextrin in vitro and in human tumour xenografted athymic nude mice

A nondestructive leak detection method developed at Technical Research Centre of Finland (VTT) was tested for both gas-flushed and vacuum flexible packages. In the method, a gas package containing 0.5 to 5.0% (vol/vol) hydrogen in nitrogen was positioned in a test chamber, a controlled vacuum was pulled in the chamber through a pipe connected to a hydrogen sensor, and leaking packages were detected by the sensor as increased H2 concentration. The H2 tracer gas (0.5 to 5.0%) was introduced into leaking finished vacuum packages at 200 kPa pressure. Within 1 to 4 s the developed test method was able to detect leaks down to 10 to 15 microns and 20 to 30 microns in diameter in commercially manufactured gas-flushed packages filled with roasted meat balls and vacuum packages filled with ground coffee, respectively. Before leak testing, the vacuum packages were charged with H2 for 30 s. The sensitivity and leak detection time of the test method were improved when the H2 concentration in the package was increased and when the free space in the test chamber was decreased. The evaluated H2 concentrations did not affect the sensory or microbiological quality of the roasted meat balls. This study clearly demonstrated that the hydrogen tracer gas leak detection method has potential to be further developed as a fast, nondestructive, on-line leak testing apparatus for flexible packages with or without a headspace.     

Uncovering subdominant cytotoxic T-lymphocyte responses in lymphocytic choriomeningitis virus-infected BALB/c mice

The cytotoxic T-lymphocyte response against lymphocytic choriomeningitis virus (LCMV) in BALB/c mice is predominantly directed against a single, Ld-restricted epitope in the viral nucleoprotein (residues 118 to 126). To investigate whether any Kd/Dd-restricted responses were activated but did not expand during the primary response, we used a BALB/c mutant, BALB/c-H-2dm2, which does not express the Ld molecule. Splenocytes from LCMV-infected BALB/c mice were transferred into irradiated BALB/c-H-2dm2 mice and rechallenged with LCMV. Thus, they were exposed to an antigenic stimulus without the involvement of the immunodominant Ld-restricted epitope. In this adoptive transfer model, the donor splenocytes protected the recipient mice against chronic LCMV infection by mounting a potent Kd- and/or Dd-restricted secondary antiviral response. Analysis of a panel of Kd binding LCMV peptides revealed that residues 283 to 291 from the viral glycoprotein (GP(283-291)) comprise a major new epitope in the adoptive transfer model. Because the donor splenocytes were first activated during the primary infection in BALB/c mice, the GP(283-291) epitope is a subdominant epitope in BALB/c mice that becomes dominant after rechallenge in BALB/c-H-2dm2 mice. This study makes two points. First, it shows that subdominant CTL responses can be protective, and second, it provides a general experimental approach for uncovering subdominant CTL responses in vivo. This strategy can be used to identify subdominant T-cell responses in other systems.     

Herpes simplex virus type 2 induced retinal necrosis in BALB/c mice

We injected herpes simplex virus type 2 of MS- or G-strain into the anterior chamber of BALB/c mice. In the contralateral eye inflammatory cell infiltration began in the ciliary body; focal retinitis, detected by day 8, led to total destruction of the retina by day 10. Contralateral disease was observed in 75% of mice inoculated with 8 x 10(3) pfu herpes simplex virus type 2, but in only 20% of mice receiving 80 pfu herpes simplex virus type 2. Still this low concentration, however, produced a suppressed delayed-type hypersensitivity response. Anti-herpes simplex virus type 2 antibody, first detected on day 8, reached high titers on day 10; by then, most of the mice had died of encephalitis. The G-strain of herpes simplex virus type 2 was more neurotoxic than the MS-strain, but produced the same incidence of contralateral retinitis. Herpes simplex virus type 2 products contralateral necrotizing retinitis comparable to that produced by herpes simplex virus type 1. These findings, like those of other authors, suggest a role for herpes simplex virus type 2 in some cases of acute retinal necrosis in humans.     

Generation of a nude mouse tumor model for in vivo replication of human cytomegalovirus

PURPOSE: Our purpose was to report the patterns of injury observed in five patients who suffered brain damage consequent to neonatal hypoglycemia. METHODS: The imaging studies and clinical records of five patients with brain damage caused by neonatal hypoglycemia were reviewed retrospectively. Patterns of injury were compared with those described in the literature and those seen in neonatal hypoxic-ischemic injury. RESULTS: Diffuse cortical and subcortical white matter damage was seen, with the parietal and occipital lobes affected most severely. Globus pallidus injury was present in one patient who had the most severe cortical injury. CONCLUSION: We found a specific pattern of injury that correlates well with the sparse pathologic and imaging reports on neonatal hypoglycemia. We speculate that the patterns of damage are the result of regional hypoperfusion and excitatory toxicity with cell-type-specific injury.     

Induction of lupus-associated autoantibodies in BALB/c mice by intraperitoneal injection of pristane

Intraperitoneal injection of pristane (2,6,10,14 tetramethylpentadecane) is a standard technique for obtaining monoclonal antibody-enriched ascitic fluid. However, pristane also induces plasmacytomas and an erosive arthritis resembling rheumatoid arthritis in BALB/c mice, probably as a consequence of enhanced interleukin 6 production. We report here that the production of autoantibodies characteristic of systemic lupus erythematosus (SLE) is a further consequence of injecting pristane in BALB/c mice. Anti-Su antibodies appeared as early as 1-2 mo after a single injection of 0.5 ml pristane, followed by anti-U1RNP and anti-Sm antibodies after 2-4 mo. Within 6 mo of pristane injection, 9 of 11 BALB/c mice had developed anti-Su, anti-U1RNP, anti-U2RNP, anti-Sm, and possibly anti-U5RNP antibodies. Autoantibodies were not produced by 20 BALB/c mice of the same age and sex that were not injected with pristane. Thus, autoantibodies characteristic of lupus were induced in mice that are not usually considered to be genetically susceptible to the disease. The induction of autoantibodies associated with SLE by pristane may be relevant to understanding the role of abnormal cytokine production in autoantibody production and the pathogenesis of autoimmune disease. Furthermore, the induction of high titer autoantibodies by pristane dictates caution in the use of ascitic fluid as a source of monoclonal antibodies, since the polyclonal antibodies induced by pristane may copurify with the monoclonal antibody secreted by an injected hybridoma.     

Effect of treatment with BCG on the course of visceral leishmaniasis in BALB/c mice

Intravenous inoculation of BCG was found to be both prophylactic and therapeutic in BALB/c mice against challenge with amastigotes of Leishmania donovani. Spleens and livers of mice inoculated with BCG maintained total parasite burdens at significantly lower levels when compared to controls. BCG administered intravenously 14 days prior to and on the same day of protozoan challenge was more protective than vaccine given 30 and 14 days prior to challenge. A level of 10(7) viable units of BCG provided more protection against challenge with parasites than did 10(6) viable units. BCG given the same route as the challenge dose of amastigotes provided more protection than if administered via some other route. BCG given to mice with an already established infection was shown to significantly reduce their parasite burdens.     

Topical application of T-2 toxin inhibits the contact hypersensitivity response in BALB/c mice

T-2 toxin, a trichothecene mycotoxin, has previously been shown to alter immune functions and promote skin tumors. We demonstrate that topically applied T-2 toxin reduces the ear swelling response to oxazolone challenge in BALB/c mice. For this reduction in ear swelling to occur, toxin application must be at, or within, 1 h after challenge. Dose-response studies showed a 44% reduction in ear swelling with 30 ng of T-2 toxin as compared with a similar reduction with 300 ng of dexamethasone. T-2 toxin did not affect Ag transport from the challenge site to the draining lymph nodes as measured by FITC transport. However, T-2 toxin significantly reduced both MHC class II (Ia) expression and Ag presentation at the same concentrations. Because T-2 toxin, a known protein synthesis inhibitor, was found to inhibit protein synthesis in epidermal cell cultures as measured by [3H]-leucine incorporation, cycloheximide was also examined. Cycloheximide reduced both oxazolone-induced ear swelling and Ag presentation in a similar manner to T-2 toxin. One mechanism of action for T-2 toxin in reducing the contact hypersensitivity response is via inhibition of protein synthesis and effective Ag presentation by epidermal Langerhans cells. This may involve alterations in Ia Ag expression, although a role for class II in the induction phase of the contact hypersensitivity response has not been established definitively.     

Psychosocial influences on immune responses to HSV-1 infection in BALB/c mice

The effects of differential housing (one or four mice/cage) on T-helper (Th) cell markers of cellular and humoral immune responses were examined. Differentially housed male BALB/cJ mice were infected with herpes simplex virus (HSV)-1 (Patton strain), and in vitro cytokine production [interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-gamma] by splenocytes and popliteal lymph node cells and serum antibody titers (IgM and IgG) were evaluated. Differential housing of male BALB/c mice influenced the magnitude, but not the kinetics, of some, but not all, immune responses to HSV-1. Splenocytes from individually housed mice produced more IL-2, IFN-gamma, IL-4, and IL-10 than splenocytes from group-housed mice; in popliteal lymph node cells, only IFN-gamma and IL-10 production was influenced by housing. Although the social environment influenced cytokine production, there were no concomitant changes in circulating IgM or IgG antibody titers. These results do not support the hypothesis that dominant Th cell responses are the primary targets of this psychosocial manipulation, or that a reciprocal relationship exists between Th1 and Th2 cell-derived cytokines.     

Dietary lutein from marigold extract inhibits mammary tumor development in BALB/c mice

Even though lutein can stimulate immunity and decrease cancer growth, no systematic studies are available on the uptake of lutein in mice. We studied the uptake of lutein in 8-wk-old female BALB/c mice fed a diet containing 0, 0.05, 0.1, 0.2 or 0.4% lutein. Mice were killed on d 0, 3, 7, 14, 21 and 28 (n = 6/period), and blood, spleen and liver were collected. Food intake and body, liver and spleen weights did not differ among treatment groups. Lutein + zeaxanthin were not detectable in the plasma, liver and spleen of unsupplemented mice. Mice fed lutein showed very rapid lutein + zeaxanthin absorption. On d 3, concentrations of plasma lutein + zeaxanthin had rapidly increased (P < 0.05) in lutein-fed mice and no further increases were observed. Plasma lutein + zeaxanthin concentrations did not differ among lutein-fed mice by d 7 (2.58 +/- 0.2 micromol/L). Even though maximal uptake of plasma lutein + zeaxanthin was observed by d 3, uptake of lutein + zeaxanthin by the liver and especially by the spleen generally continued to increase (P < 0.05) through d 28 to reach concentrations of 0.11 +/- 0.001 (spleen) and 0.71 +/- 0. 0002 (liver) nmol/g. Therefore, dietary lutein is readily absorbed into the plasma and taken up by liver and spleen of mice. Plasma lutein + zeaxanthin concentrations were higher than in human studies; however, mice were fed lutein at a level several hundredfold greater than in humans. The liver is a major storage organ for lutein + zeaxanthin in mice. Uptake of lutein + zeaxanthin by the spleen suggests a role for lutein in modulating immunity.     

The role of BALB/c donor CD8+ lymphocytes in graft-versus-host disease in (BALB/c x A/J)F1 (CAF1) mice

To investigate the role of donor T lymphocyte subsets in the development of chronic graft-vs-host disease (GVHD) induced in (BALB/c x A/J)F1 (CAF1) mice by injecting BALB/c lymphoid cells, we analyzed the effect that CD8+ cell removal from donor inoculum has on the manifestation of the disease. Compared with age- and sex-matched CAF1 mice injected with whole lymphocyte inoculum, CAF1 mice injected with CD8(+)-depleted inoculum exhibited: 1) a higher incidence and exacerbation of nephritis by immunocomplexes; 2) higher (five- to sevenfold) spontaneous IL-4 production; 3) higher frequency titer and precocity of anti-dsDNA, anti-histone, and IgM and IgG rheumatoid factors; 4) a dramatic change in the frequency and titer of anti-U1 small nuclear ribonucleoprotein Abs; and 5) a markedly decreased engraftment (10- to 15-fold) on BALB/c donor lymphocytes. In contrast, rheumatoid arthritis-like disease, a later clinical manifestation of the GVHD in CAF1 + BALB/c model, is not present in the CD8(+)-depleted model (CAF1 + CD8-BALB/c). Considered together, these data suggest that CD8+ donor T lymphocytes play an important role in the degree of chimerism, modulation of the response to autoantigens, and clinical aspects developed in the GVHD model presented here.     

Antisense oligonucleotide intralesional therapy for human PC-3 prostate tumors carried in athymic nude mice

To address the question whether calretinin (CR) may protect cells against Ca2+ overload or trophic factor deprivation, PC12 cells were transfected with plasmids containing a CR coding region under control of a cytomegalovirus promoter. Nerve growth factor (NGF) treatment induced differentiation, increased transfection efficiency (at least 10-fold) and activated the CR gene (as found by RNase protection method and immunohistochemistry). Exogenous CR expression was identified either in living cells by fluorescence of green fluorescent protein (when the CR coding region was fused to this protein) or in fixed cells by CR immunoreactivity. Undifferentiated and NGF-differentiated populations of transfected cells were incubated in the presence of a Ca(2+)-ionophore or in media deprived of serum or NGF. Expression of exogenous CR in undifferentiated or NGF-treated cells (due to transfection) or endogenous CR (due to gene activation by NGF) did not render PC12 cells more resistant to insults such as Ca(2+)-overload and trophic factor deprivation.     

Effect of the dietary vitamin concentrate Ammivit on survival of irradiated BALB/c mice]

Hemorrhage from duodenal varices may be severe and life threatening. We report a patient with portal hypertension and bleeding duodenal varices caused by cirrhosis of the liver. Endoscopic sclerotherapy and intravenous vasopressin failed to control bleeding in this patient. Hemorrhage was subsequently controlled by placement of a transjugular intrahepatic portosystemic shunt. We recommend that in patients with life-threatening hemorrhage from duodenal varices caused by cirrhosis of the liver, transjugular intrahepatic portosystemic shunt be considered in the management.