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.     

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.     

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)     

Murine cytomegalovirus replication in the lungs of athymic BALB/c nude mice

Uridine diphosphoglucose (UDPG) is a precursor of uridine that can be used as a rescuing agent from 5-fluorouracil (5FU) toxicity. Four doses of UDPG (2000 mg/kg i.p. or p.o. at 2, 6, 24, and 30 h after 5FU bolus) allowed the escalation of a weekly bolus of 5FU from 100 mg/kg (5FU100) to 150 mg/kg (5FU150) in healthy and tumor-bearing BALB/c, C57/BI, and CD8F1 (BALB/c x DBA/8) mice. 5FU150 without rescuing agents is not tolerated by the animals. When followed by UDPG, on the contrary, it is possible to increase the dose of 5FU even when it is modulated by leucovorin. Toxicity was the same for 5FU100 and 5FU150 + UDPG, and the nadir values (expressed as a percentage of pretreatment values) were 83 and 85% for weight, 45 and 45% for hematocrit, and 45 and 61% for leukocytes, respectively. Platelets were not affected by treatment. A protective effect was also shown for the gastrointestinal tract. The enzymes thymidine kinase, maltase, and sucrase were measured in the intestinal mucosa at different times after 5FU treatment with or without UDPG rescue. Even if the nadir values in enzyme activities were similar in mice receiving or not receiving UDPG, the pattern of recovery showed that cell repopulation was more rapid in the group treated with UDPG. 5FU150 + UDPG had enhanced antitumor activity against CD8F1 mammary carcinoma and against the resistant tumor Colon 26 (tumor doubling time 1.9 days for controls, 8.5 days for 5FU100, 13.7 days for 5FU150 + UDPG, and 15.9 days for 5FU150 + leucovorin + UDPG). We demonstrated that UDPG administered at 2, 24, and 30 h after 5FU100 does not reduce the antitumor activity of 5FU in two sensitive tumors (Colon 38 and Colon 26-10). In conclusion, UDPG is a promising rescuing agent for 5FU; it reduces the toxic side effects and increases the therapeutic index.     

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.     

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.     

Cloning, characterization and construction of htrA and htrA-like mutants of Brucella abortus and their survival in BALB/c mice

A genomic library of Brucella abortus S2308 was screened for expression of recombinant proteins recognized by sera from mice and from cattle infected with B. abortus. A positive clone, BA1, expressing a 50 kDa peptide was recognized by both sera. Plasmid pBA1, isolated from BA1, was shown by restriction enzyme digestion to possess a 1.9 kb insert. The nucleotide sequence of the pBA1 insert revealed an open reading frame with of 1539 bases with a coding capacity of 513 amino acids and a predicted molecular weight of 50,992. The predicted amino acid sequence showed 37% identity to E. coli HtrA, a temperature inducible serine protease. A second B. abortus htrA gene, designated htrA-like, was identified on a different cloned fragment that also encoded B. abortus recA. The nucleotide sequence of the htrA-like gene revealed an open reading frame of 1422 nucleotides with a coding capacity of 474 amino acids and a predicted molecular weight of 50,155. The deduced amino acid sequence of the htrA-like gene showed 42% and 36% identity with B. abortus and E. coli HtrAs respectively. Western blotting of E. coli lysate containing the htrA-like gene was not recognized by sera from B. abortus-infected cattle or mice. B. abortus htrA but not htrA-like relieved the temperature sensitive phenotype and permitted growth of an E. coli htrA mutant at 42 degrees C. B. abortus htrA and htrA-like mutants were constructed and their survival and growth in BALB/c mice was compared to the parental strain S2308.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of IL-4 deletion on cardiac allograft survival in the BALB/c to 129Sv x C57BL/6 strain combination

Calcified brain metastases are rare. They are unique or multiple. The primary site is lung, breast, gastro-intestinal tract, uterine cervix, bone or may be unidentified. It corresponds pathologically to an adenocarcinoma, a sarcoma or to a squamous cell carcinoma. We report a case of multiple calcified brain metastases discovered before primary tumour (bronchial adenocarcinoma), raising the problem of differential diagnosis resolved by stereotaxic brain biopsy.     

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.     

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.     

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.     

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.     

Dose-dependent promoting effects of catechol on glandular stomach carcinogenesis in BALB/c mice initiated with N-methyl-N-nitrosourea

The effects of catechol administration in the diet on stomach carcinogenesis in mice after initiation with N-methyl-N-nitrosourea (MNU) in the drinking water were investigated in a development trial for a new experimental protocol. Male 6-week-old BALB/c mice were given MNU in the drinking water intermittently for a total of three one-week periods, with one-week intervals, at the concentration of 120 ppm (groups 1 and 2). Groups 3 and 4 served as non initiated controls. From week 7, groups 1 and 3 were divided into three subgroups and the mice were fed on diet containing 0.05% (groups 1a and 3a), 0.2% (groups 1b and 3b), 08% (groups 1c and 3c) or 0% (groups 2 and 4) catechol for 29 weeks. At week 20, appreciably enhanced development of pepsinogen 1-altered pyloric glands was noted in all catechol-treated groups, in a partially dose-dependent manner (12.8 +/- 12.5, 13.8 +/- 11.7, and 24.0 +/- 12.7/100 pyloric glands respectively, for groups 1, 2 and 3). The incidences of adenomas (groups 1, 2 and 3) were also increased. At week 35, dose-dependent induction of adenocarcinomas in groups 1 (3/19), 2 (3/19) and 3 (14/20) was evident. In addition, the depth of invasion of the adenocarcinomas was enhanced by catechol in a dose-dependent manner, though the histological type was not influenced. Thus, the administration of catechol in the diet strongly enhanced the preneoplastic and neoplastic lesions in mouse glandular stomach induced by MNU in the drinking water, in a dose-dependent manner.     

Induction of mammary tumors in virgin female BALB/c mice by single low doses of 7,12-dimethylbenz[a]anthracene

The induction of mammary tumors in virgin female inbred BALB/c mice after administration of 7,12-dimethylbenz[a]anthracene (DMBA) over a wide range of doses was studied. Mice were exposed at 12 weeks of age to single or multiple doses of DMBA ranging from 0.0025 to 12.0 mg by gastric intubation and were checked regularly for mammary tumors. The experiment was terminated when the mice were 800 days of age. In the dose range of 0.0025--0.125 mg DMBA, the incidence of mammary tumors was dose-dependent. At higher doses, the mammary tumor incidence became less dose-dependent and was nearly independent of doses above the 0.25-mg level. Analysis of the data for the rate of appearance of mammary tumors with age of the animals and for the age at death of non-mammary tumor-bearing animals indicated that in the low dose range induction of mammary tumors was the predominant effect of DMBA exposure, whereas at moderate to high doses the toxic and carcinogenic effects of DMBA on other tissues significantly influenced the final incidence of mammary tumors. Greater than 90% of the tumors that resulted from administration of low doses of DMBA were adenocarcinomas. In contrast, adenocarcinomas and adenoacanthomas were found in approximately equal proportions following administration of high doses of DMBA.     

In vivo blocking of L-selectin rescues BALB/c mice from fatal Leishmania major infection

Susceptibility and resistance to experimental Leishmania major (L. major) infection in mice are associated with a Th2- or Th1-type response, respectively. We have previously shown that immunological events occurring within the first 24 h after infection in the lymph node (LN) draining the site of parasite challenge are critical for the development of either type of T-cell responses. In the present study we manipulated these events by preventing the entry of naive lymphocytes into the draining LN by injecting BALB/c mice with a single dose of the anti-L-selectin mAb MEL-14 one day prior to infection with L. major. In contrast to control BALB/c mice, in MEL-14 treated animals the primary lesion healed 12 weeks after infection. The parasite load in the spleen and lymph nodes of MEL-14 treated mice was significantly reduced. The healing was found to be associated with an increased production of IFN-gamma and with a decrease in IL-4 production by LN cells. We observed a dramatic decrease in cellularity in the draining LN in Mel-14 treated L. major-infected mice within the first week of infection. Moreover, the cells in the LN of MEL-14 treated mice were highly enriched in activated cells as well as in cell influx in the draining LN after local L. major infection of BALB/c mice prevents fatal disease. The data suggest the MEL-14-induced enrichment of the draining LN in memory and activated cells is fundamental for the initiation of a protective Th1-type response.     

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.     

T cell responses to myelin basic protein in experimental autoimmune encephalomyelitis-resistant BALB/c mice

In strains of mice that are susceptible to experimental autoimmune encephalomyelitis (EAE), cloned CD4+ T cells reactive with autologous myelin basic protein (MBP) have been shown to cause disease when transferred to naive syngeneic recipients. Recent reports indicate that under particular experimental conditions, 'resistant' strains of mice can also develop EAE, although cloned cells have not been isolated and characterized. An analysis of the characteristics of a panel of MBP-specific T cells and the antigen presenting capability of CNS-derived cells obtained from the resistant strain BALB/c is presented here. The data demonstrate that immunization of EAE-resistant BALB/c mice results in the activation of a heterogeneous group of T cells reactive with autologous MBP. Both peripheral antigen presenting cells, as well as microglia isolated from brains of BALB/c mice, are capable of stimulating these cloned MBP-specific T cells to proliferate. When optimally activated in vitro and then injected in vivo into syngeneic BALB/c recipients, three clones studied induced severe cachexia, resulting in loss of up to 35% of body weight before death. Two of the clones also induced clinical and histological EAE, while the third induced only occasional histological evidence of disease. Differences in epitope recognition, T cell receptor usage, cytokine profiles or regulatory mechanisms of self tolerance, may play important roles in preventing potentially destructive autoimmune reactions by these T cells capable of recognizing autologous myelin in the central nervous system.     

Human anticardiolipin monoclonal autoantibodies cause placental necrosis and fetal loss in BALB/c mice

OBJECTIVE: To analyze the structure, specificity, and in vivo pathogenetic potential of 2 human anticardiolipin (aCL) monoclonal antibodies (MAb). METHODS: Human aCL IgG MAb were generated from hybridized Epstein-Barr virus-induced B cell lines from a healthy subject (MAb 519) and from a patient with primary antiphospholipid syndrome (MAb 516). Studies of antigen-binding specificity and analysis of Ig V-gene mutations were carried out. The MAb were independently injected into mated female BALB/c mice, and their effect on pregnancy outcome was compared with that of MAb 57, a highly mutated and antigen-selected human IgG1lambda rabies virus antibody. RESULTS: Both MAb 519 and MAb 516 utilized minimally mutated V(H)DJ(H) and VkappaJkappa gene segments and bound cardiolipin and other anionic phospholipids in the absence of beta2-glycoprotein I (beta2-GPI). The mice injected with aCL MAb displayed a significantly higher rate of fetal resorption and a significant reduction in fetal and placental weight as compared with those injected with MAb 57. These findings were accompanied by a finding of placental human IgG deposition and necrosis in the aCL MAb-treated animals. CONCLUSION: The results of this study indicate that human aCL IgG that are beta2-GPI independent can induce pathology.     

Pathogenic autoimmunity to affinity-purified mouse acetylcholine receptor induced without adjuvant in BALB/c mice

Myasthenia gravis (MG) and experimental autoimmune myasthenia gravis (EAMG) are antibody-mediated disorders in which anti-acetylcholine receptor (anti-AChR) antibodies cause loss of muscle AChR and subsequent weakness. Many species are susceptible to induction of EAMG with purified xenogeneic AChR in adjuvant, but injection of Torpedo AChR without adjuvants can also induce evidence of EAMG. To see whether pathogenic autoimmunity could be induced in mice by isolated mouse AChR we injected BALB/c mice with several doses (1 pmole; about 0.1 microgram) of affinity-purified AChR (from the BC3H1 cell line but thought to be identical with denervated mouse muscle) intraperitoneally, without adjuvant, over a period of 10-22 weeks. Some of the mice became ill and died. High levels of serum anti-mouse AChR, directed mainly towards the main immunogenic region, were found and, in the survivors, correlated with loss of muscle AChR. Thus BALB/c mice can mount an autoimmune response to minute amounts of mouse AChR, without the use of adjuvants, and this response is very similar to that found in MG. This novel finding has implications regarding the etiology of the human disease.