Biomedical subjects

C Lim

Publications and source records attributed to C Lim.

At least 37 records · Page 2Linked to original sources

PubMed2001

The role of the Fas/Fas ligand system in estrogen-induced thymic alteration.

PROBLEM: Estrogen induces atrophy in the thymus by an unknown mechanism. Since the Fas/FasL system is one of the main pathways in T cell apoptosis, we tested the hypothesis that estrogen-induced thymic atrophy is mediated by the Fas/FasL system. METHODS OF STUDY: In vivo experiments were done using ovariectomized female rats treated with estrogen or saline. In vitro experiments were performed using isolated thymocytes. Estrogen receptor (ER) alpha and beta expression was characterized using flow cytometry, RT-PCR and immunofluorescence. Fas and FasL mRNA and protein expression was evaluated using RT-PCR and Western blot analysis respectively. RESULTS: ERalpha and ERbeta are present in thymocytes and stromal cells. ER expression is mainly localized in the Double Positive CD4+CD8+ thymocytes. Estrogen treatment decreases thymus size and increase FasL expression. CONCLUSION: CD4+CD8+ thymocytes and thymic stroma cells express ERalpha and ERbeta. In vivo and in vitro we showed that estrogen treatment increases FasL expression while decreasing thymus cell number. These findings support the hypothesis that estrogen-induced thymic atrophy occurs as a result of apoptosis and is mediated by estrogen-induced FasL expression.

Animals↗

PubMed2001

A fast method for predicting amino acid mutations that lead to unfolding.

Amino acid mutation(s) that cause(s) partial or total unfolding of a protein can lead to disease states and failure to produce mutants. It is therefore very useful to be able to predict which mutations can retain the conformation of a wild-type protein and which mutations will lead to local or global unfolding of the protein. We have developed a fast and reasonably accurate method based on a backbone-dependent side-chain rotamer library to predict the (folded or unfolded) conformation of a protein upon mutation. This method has been tested on proteins whose wild-type 3D structures are known and whose mutant conformations have been experimentally characterized to be folded or unfolded. Furthermore, for the cases studied here, the predicted partially folded or denatured mutant conformation correlate with a decrease in the stability of the mutant relative to the wild-type protein. The key advantage of our method is that it is very fast and predicts locally or globally unfolded states fairly accurately. Hence, it may prove to be useful in designing site-directed mutagenesis, X-ray crystallography and drug design experiments as well as in free energy simulations by helping to ascertain whether a mutation will alter or retain the wild-type conformation.

Amino Acid Sequence↗

PubMed2001

Kaposi's sarcoma-associated herpesvirus open reading frame 50 represses p53-induced transcriptional activity and apoptosis.

Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 50 (ORF50) encodes a viral transcriptional activator which stimulates the transcription of viral early and late genes of KSHV. Here we show that ORF50 represses transcriptional activity of p53 and p53-induced apoptosis through interaction with CREB binding protein (CBP). This inhibitory effect of ORF50 on the transcriptional activity of p53 was relieved by the addition of CBP. ORF50 mutants, which are defective in interaction with CBP, lost the inhibitory effects on p53. Our data provide a framework for delineating the regulatory mechanisms used by KSHV to modulate cellular transcription and the cell cycle.

Apoptosis↗

PubMed2001

The Kaposi's sarcoma-associated herpesvirus K8 protein interacts with CREB-binding protein (CBP) and represses CBP-mediated transcription.

Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame K8 encodes a basic region-leucine zipper protein of 237 amino acids that homodimerizes with its bZIP domain. KSHV K8 shows significant homology to the Epstein-Barr virus (EBV) immediate-early protein Zta, a key regulator in the reactivation and replication of EBV. In this study, we report that K8, like its homolog EBV Zta, interacts with cellular CREB-binding protein (CBP) in vivo and in vitro. This interaction requires the C/H3 domain of CBP and the basic region of K8. K8 represses CBP-mediated transcription by competing with limited amounts of cellular CBP, exemplified by the reduced expression from the AP-1 and human immunodeficiency virus long terminal repeat promoters.

CREB-Binding Protein↗

PubMed2001

CREB-binding protein and histone deacetylase regulate the transcriptional activity of Kaposi's sarcoma-associated herpesvirus open reading frame 50.

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) open reading frame 50 (ORF50) encodes a viral transcriptional activator, which binds to the KSHV promoter and stimulates the transcription of viral early and late genes, thus activating the lytic cycle of KSHV. We report here that KSHV ORF50 binds to the cellular proteins CREB-binding protein (CBP) and histone deacetylase (HDAC) and these binding events modulate ORF50-activated viral transcription. Binding of ORF50 to CBP and HDAC activates and represses, respectively, ORF50-mediated viral transcription. KSHV ORF50 was shown to bind to the C/H3 domain and the C-terminal transcriptional activation domain of CBP, while CBP bound to the amino-terminal basic domain and the carboxyl-terminal transactivation domain of ORF50. The LXXLL motif within the transcriptional activation domain of ORF50 is reminiscent of the CBP-binding sequence found in nuclear receptor proteins. The adenovirus E1A protein, which also binds to the C/H3 domain of CBP, repressed the transcriptional activation activity of ORF50. The cellular protein c-Jun, which binds to the kinase-induced activation domain of ORF50, stimulated ORF50-mediated viral transcription. The HDAC1-interacting domain of ORF50 was shown to be a central proline-rich sequence. Our data provide a framework for delineating the regulatory mechanisms used by KSHV to modulate its transcription and replication through interaction with both histone acetyltransferases and HDACs.

CREB-Binding Protein↗

PubMed2001

The glucocorticoid receptor interacting protein 1 (GRIP1) localizes in discrete nuclear foci that associate with ND10 bodies and are enriched in components of the 26S proteasome.

The glucocorticoid receptor interacting protein-1 (GRIP1) is a member of the steroid receptor coactivator (SRC) family of transcriptional regulators. Green fluorescent protein (GFP) fusions were made to full-length GRIP1, and a series of GRIP1 mutants lacking the defined regulatory regions and the intracellular distribution of these proteins was studied in HeLa cells. The distribution of GRIP1 was complex, ranging from diffuse nucleoplasmic to discrete intranuclear foci. Formation of these foci was dependent on the C-terminal region of GRIP1, which contains the two characterized transcriptional activation domains, AD1 and AD2. A subpopulation of GRIP1 foci associate with ND10s, small nuclear bodies that contain several proteins including PML, SP100, DAXX, and CREB-binding protein (CBP). Association with the ND10s is dependent on the AD1 of GRIP1, a region of the protein previously described as a CBP-interacting domain. The GRIP1 foci are enriched in components of the 26S proteasome, including the core 20S proteasome, PA28alpha, and ubiquitin. In addition, the irreversible proteasome inhibitor lactacystin induced an increase in the total fluorescence intensity of the GFP-GRIP1 expressing cells, demonstrating that GRIP1 is degraded by the proteasome. These findings suggest the intriguing possibility that degradation of GRIP1 by the 26S proteasome may be a key component of its regulation.

Acetylcysteine↗

PubMed2000

Design, synthesis, and SAR of novel carbapenem antibiotics with high stability to Xanthomonas maltophilia oxyiminocephalosporinase type II.

Racemic cis-6-(phenylacetamido)carbapenem (21), 2-hydroxycarbonyl-cis-6-(phenylacetamido)carbapenem (22), 2-methoxycarbonyl-cis-6-(phenylacetamido)carbapenem (30), 2-methoxycarbomethyl-cis-6-(phenylacetamido)carbapenem (33), 2-hydroxyethyl-cis-6-(phenylacetamido)carbapenem (34), and 2-acetoxyethyl-cis-6-(phenylacetamido)carbapenem (35) were synthesized. Formation of the carbapenem nuclei in 21, 22, and 30 involved dehydrophosphonation of the corresponding 2-diphenylphosphono-6-(phenylacetamido)carbapenam precursors 14, 15, and 28 using trimethylsilyl triflate and 1,8-diazabicyclo[5.4.0]undec-7-ene in THF. Syntheses of carbapenems 33-35 involved a Wittig reaction of carbapenam 14 with methyl glyoxylate in the presence of lithium 2,2,6,6-tetramethylpiperidine in THF. For the antibacterial activities against Staphylococcus aureus FDA 209P, S. aureus 95, Escherichia coli ATCC 39188, Klebsiellapneumoniae NCTC 418, Pseudomonas aeruginosa 1101-75, and P. aeruginosa 18S-H, carbapenems (+/-)-21, (+/-)-22, (+/-)-30, and (+/-)-33-35 were found comparable with imipenem ((+)-3), yet they were notably more potent than (+)-3 against Xanthomonas maltophilia GN 12873. On the other hand, unlike (+)-3, carbapenems (+/-)-21, (+/-)-22, (+/-)-30, and (+/-)-33-35 were stable to X. maltophilia oxyiminocephalosporinase type II. Their beta-lactamase inhibitory properties, however, were found to be more comparable with those of penicillin G ((+)-4) than to those of imipenem ((+)-3). A combination of imipenem ((+)-3) with (+/-)-21, (+/-)-22, (+/-)-30, and (+/-)-33-35 resulted in synergistic antibacterial activity against X. maltophilia GN 12873. Results from the biological tests were correlated with the distribution of the electron density at C(2)=C(3) of carbapenems upon reaction with transpeptidases or beta-lactamases.

Carbapenems↗

PubMed2000

Racial differences in tamoxifen metabolism.

PURPOSE: A recent study indicates that black women may have a higher risk/benefit ratio from tamoxifen than white women. Several reports in the literature indicate that racial differences in the risks/benefits from other pharmaceutical agents may be partially due to racial differences in drug metabolism. Thus, we explore the hypothesis that the racial difference in the tamoxifen risk/benefit ratio may be due, in part, to racial differences in tamoxifen metabolism.METHODS: We conducted a pilot study in which we recruited 6 white and 4 black breast cancer patients from the Baltimore, Maryland area. All patients were taking tamoxifen for at least 30 days. Each provided a blood sample that was used to measure tamoxifen metabolites by high performance liquid chromatography.RESULTS: Our results indicate that the black women had significantly higher levels of the tamoxifen metabolite, N-desmethyltamoxifen (N-DMT) than the white women (0.585 µg/ml vs 0.199 µg/ml, p < 0.05). There were no differences in the serum levels of tamoxifen in black and white women (0.809 vs 0.699, p > 0.1).CONCLUSIONS: These data suggest that both black and white breast cancer patients reach steady state tamoxifen levels, but that black women are more likely to metabolize tamoxifen to N-DMT or to maintain higher levels of N-DMT (i.e., less excretion of N-DMT) than white women. N-DMT is thought to be less effective in breast cancer treatment than tamoxifen. N-DMT also has been associated with excess proliferation in breast cancer cells. Thus, it is possible that the relatively high tamoxifen risk/benefit in black women occurs because tamoxifen is readily converted to N-DMT in black women, but not in white women. Although the data reported here are from a pilot study, it is important to note that significant racial differences in tamoxifen metabolism were observed with only a few participants. We urge other investigators to confirm these findings using a large population of breast cancer patients.

Journal Article↗

PubMed2000

Conformational analysis of long spacers in PROSITE patterns.

To determine if variable sequences (spacers) between conserved positions in a sequence motif or pattern share a consensus structure, three-dimensional structures containing PROSITE patterns with spacers of fixed length greater than three residues were analyzed. Structural similarities of a given pattern were evaluated by computing the backbone phi, psi and side-chain chi1 dihedral order parameters. The exact bias information in analyzing the conformational variability of the patterns was taken into account by introducing a new parameter, the bias coefficient, which describes the number and distribution of residue types found at each position of a pattern in the structures. The results of the analyses show that backbone conformational heterogeneity at a given position in a sequence motif does not necessarily correlate with the residue-type variability at that position, and the long spacer region can adopt a well-defined backbone conformation, in addition to the conserved residues. Furthermore, a PROSITE pattern may be redefined to yield two or more "refined" regular expressions, each corresponding to a distinct backbone conformation. A way in which the observed structural consensus in a pattern may be employed to improve the accuracy of function prediction from sequence is suggested.

Amino Acid Motifs↗

PubMed2000

Expression of SAG-1 of Toxoplasma gondii in transgenic mice.

We describe the expression of SAG-1 cDNA in B6C3F1 mice by microinjecting a 3.3 kbp DNA fragment, consisting of the cytomegalovirus enhancer-chicken beta-actin hybrid promoter and SAG-1 into the pronucleus of a fertilized egg at the one-cell stage. Offspring derived from this microinjection were analyzed for the integration and functional expression of the SAG-1 transgene. Steady-state expressions of both the mRNA for SAG-1 and SAG-1 protein product were detected in the brain, thymus, spleen and liver. Approximately 50% of F1 and F2 progeny inherited the SAG-1 transgene from SAG-1 transgenic mice in Mendelian fashion. These results indicated that SAG-1 transgenic lines were established. Transgenic mice harboring the SAG-1 gene will contribute a critical tool of defining the molecular mechanisms of SAG-1 in pathogenesis and host immune response.

3T3 Cells↗

PubMed2000

Metastatic extragonadal seminoma associated with cardiac transplantation.

A 37-year-old man who had successfully undergone cardiac transplantation for dilated cardiomyopathy presented with a history of severe pain over his left shoulder, rib cage and thoracic spine. Clinical examination revealed the presence of bony tenderness over these sites, but there was no other clinical evidence of malignancy. Further investigations suggested the presence of multiple bony metastases. Bone biopsy revealed extensive bone marrow infiltration by large undifferentiated cells showing pronounced cytoplasmic vacuolation with a striking granulomatous reaction. Immunocytochemistry revealed these anaplastic cells to be cytokeratin and placenta-like alkaline phosphatase positive but S100, CD30 and lymphoid marker negative. Analyses by in situ hybridisation of these cells revealed no evidence of Epstein-Barr virus infection. Overall the pathology suggested a diagnosis of metastatic seminoma. Confirmation of this diagnosis was obtained by the analysis of serum human chorionic gonadotrophin which was elevated at 90 IU/l. In the absence of testicular or retroperitoneal disease, it is very likely that this unusual case of metastatic seminoma was related to the patient's immunosuppressive therapy, which at diagnosis included cyclosporin and prednisolone. The patient was successfully treated with cisplatin based chemotherapy and decreased immunosuppression and remains in complete remission one year after completion of chemotherapy. Seminoma is an uncommon complication of prolonged immunosuppression with very few cases being described in the literature post-organ transplantation. This case shows that the clinical presentation of this treatable tumour in this patient population can be unusual and difficult to diagnose.

Adult↗

PubMed2000

Interleukin-8 and SDF1-alpha mRNA expression in colonic biopsies from patients with inflammatory bowel disease.

OBJECTIVES: Interleukin-8 (IL-8) as an alpha-chemokine recruits and activates neutrophils, which are abundant in the intestinal lesions of ulcerative colitis (UC) and Crohn's disease (CD). Stromal cell-derived factor 1 (SDF1-alpha) is a new chemokine that is chemotactic to neutrophils. The aims of this study were to assess the relative expression of SDF1-alpha and IL-8 mRNA in different colonic regions and patients with inflammatory bowel disease with varied degrees of inflammation in the colon. METHODS: Colon biopsy samples were obtained from 19 patients with UC, 12 with CD, and 5 with irritable bowel syndrome (IBS) who underwent colonoscopy. Levels of IL-8 and SDF1-alpha mRNA expression were measured semiquantitatively by reverse-transcription and polymerase chain reaction amplification. The cytokine mRNA levels were corrected for glyceraldelyde-3-phosphate dehydrogenase mRNA expression. RESULTS: IL-8 mRNA expression was significantly correlated with SDF1-alpha expression in normal biopsies from IBS patients (r = 0.58, p < 0.01). There was no significant difference in cytokine mRNA expression (IL-8 or SDF1-alpha) across different regions of the colon or rectum in uninflamed normal biopsies. The IL-8 mRNA expression ratios in UC (mean +/- SD, 1.03 +/- 0.52) and CD (0.90 +/- 0.38) patients were significantly higher than in IBS (0.52 +/- 0.17) (p < 0.01, p < 0.05, respectively). The SDF1-alpha mRNA expression ratio in UC (0.30 +/- 0.52) was higher than in both CD (0.21 +/- 0.10) and IBS patients (0.22 +/- 0.11) (p < 0.01, <0.05, respectively). A statistically significant correlation was found between the IL-8 mRNA expression and the colonic inflammation in UC patients (r = 0.44, p < 0.05) but not for SDF1-alpha expression in UC patients. CONCLUSIONS: IL-8 but not SDF1-alpha mRNA expression was associated with inflammation in UC. This suggests that IL-8 may play a more important role in inflammatory bowel disease than does SDF1-alpha.

Adult↗

PubMed2000

The ribavirin analog ICN 17261 demonstrates reduced toxicity and antiviral effects with retention of both immunomodulatory activity and reduction of hepatitis-induced serum alanine aminotransferase levels.

The demonstrated utility of the nucleoside analog ribavirin in the treatment of certain viral diseases can be ascribed to its multiple distinct properties. These properties may vary in relative importance in differing viral disease conditions and include the direct inhibition of viral replication, the promotion of T-cell-mediated immune responses via an enhanced type 1 cytokine response, and a reduction of circulating alanine aminotransferase (ALT) levels associated with hepatic injury. Ribavirin also has certain known toxicities, including the induction of anemia upon chronic administration. To determine if all these properties are linked, we compared the D-nucleoside ribavirin to its L-enantiomer (ICN 17261) with regard to these properties. Strong similarities were seen for these two compounds with respect to induction of type 1 cytokine bias in vitro, enhancement of type 1 cytokine responses in vivo, and the reduction of serum ALT levels in a murine hepatitis model. In contrast, ICN 17261 had no in vitro antiviral activity against a panel of RNA and DNA viruses, while ribavirin exhibited its characteristic activity profile. Importantly, the preliminary in vivo toxicology profile of ICN 17261 is significantly more favorable than that of ribavirin. Administration of 180 mg of ICN 17261 per kg of body weight to rats by oral gavage for 4 weeks generated substantial serum levels of drug but no observable clinical pathology, whereas equivalent doses of ribavirin induced a significant anemia and leukopenia. Thus, structural modification of ribavirin can dissociate its immunomodulatory properties from its antiviral and toxicologic properties, resulting in a compound (ICN 17261) with interesting therapeutic potential.

Alanine Transaminase↗

PubMed2000

Ten years of presymptomatic testing for Huntington's disease: the experience of the UK Huntington's Disease Prediction Consortium.

Data on all presymptomatic genetic tests for Huntington's disease (HD) in the UK have been collected over the 10 year period since testing became available as a service. A total of 2937 completed tests have been performed up to the end of 1997, 2502 based on specific mutation testing, feasible since late 1993.A total of 93.1% of these were at 50% prior risk, with a significant excess of females (58.3%); 41.4% of results were abnormal or high risk, including 29.4% in subjects aged 60 or over. The trend in test numbers has currently levelled out at around 500 per year. Almost all presymptomatic tests are carried out in National Health Service genetics centres, with a defined genetic counselling protocol and with availability now in all regions of the UK. The introduction and establishment of HD presymptomatic testing shows that this form of predictive medicine for Mendelian disorders can be successfully incorporated into National Health Service structures. The comprehensive collection of simple data allows trends in demand and outcomes to be monitored and has also been the foundation for more detailed specific studies. A comparable approach to data collection in other genetic disorders will be important as presymptomatic testing becomes more generally feasible.

Female↗

PubMed2000

Formation of a Novel Cage Compound with a Pentacyclo

Abnormally long C-C single bonds are found in the polycyclic caged diol with a pentacyclo[6.3.0.1(4,11).0(2,6).0(5,10)]dodecane skeleton formed by photolysis (see scheme). This skeleton resembles the structure of diamantane, but instead of having six cyclohexane rings in a chair conformation it contains only two cyclohexane rings in a distorted chair conformation and four cyclopentane rings, which makes it more highly strained than diamantane.

Journal Article↗

PubMed2000

Comparative analysis of alpha-stat and pH-stat strategies with a membrane oxygenator during deep hypothermic circulatory arrest in young pigs.

Using young pigs, this study compared the strategies of alpha-stat and pH-stat during deep hypothermic circulatory arrest (DHCA) for the cooling time of brains during the induction of hypothermia and rewarming time with cardiopulmonary bypass (CPB); the cerebral perfusion rate and metabolism rate, and the ratio of these 2 rates; and the extent of the cerebral edema development after circulatory arrest. Fourteen young pigs were assigned to 1 of 2 strategies of gas management. Cerebral blood flow was measured with a cerebral venous outflow technique. With CPB, core cooling was initiated and continued until the nasopharyngeal temperature fell below 20 degrees C. The flow rate was set at 2,500 ml/min. Once the temperature reached below 20 degrees C, the animals were subjected to DHCA for 40 min. During the cooling period, the acid-base balance was maintained using either alpha-stat or pH-stat strategy. After DHCA, the body was rewarmed to the normal body temperature. The animals then were sacrificed, and we measured the brain water content. The cerebral perfusion and metabolism rates were measured before the onset of CPB, before cooling, before DHCA, 15 min after rewarming, and upon the completion of rewarming. The cooling time was significantly shorter with alpha-stat than with pH-stat strategy while no significant differences were observed in the rewarming time between groups. Also, no significant differences were found in cerebral blood flow volume, metabolic rate, or flow/metabolic rate ratio between groups. In each group, the cerebral blood flow volume, metabolic rate, and flow/metabolic rate ratio showed significant differences in body temperature. Brain water content showed no significant differences between the 2 groups. In summary, this study found no significant differences between alpha-stat and pH-stat strategies, except in the cooling time. The cooling time was rather shorter with the alpha-stat than with the pH-stat strategy.

Acid-Base Equilibrium↗

PubMed1999

Inhibition of CD28 expression by oligonucleotide decoys to the regulatory element in exon 1 of the CD28 gene.

Ligation of CD28 provides a costimulatory signal essential for Ag-mediated T cell activation via the TCR. Previously we demonstrated that inhibition of human and murine CD28 expression by a guanosine (G)-rich oligonucleotide (ODN), GR1, led to immunosuppression in vitro and in vivo. The bioactivity of GR1 was dependent on a G-rich DNA sequence motif consisting of two G tetrads separated by four nucleotides, (G4N4G4). We have shown recently that a G-rich region, designated CD28GR, in exon 1 of the CD28 gene is such a motif and is a positive regulatory element that binds the transcription factors Sp1 and EGR-1. Here we showed that the bioactivity of GR1 and the related GR2 correlated with the sequence-specific formation of distinct nuclear protein complexes and a high degree of ODN secondary structure. In addition, these ODN blocked transcription factor binding to CD28GR (also in a sequence-specific manner) and prevented CD28GR from driving transcription of a reporter gene. Interestingly, GR1 potently inhibited CD28, but not the expression of other Sp1- and EGR-1-regulated genes, an effect associated with lower Sp1 protein binding affinity of GR1 and GR2 compared with that of canonical Sp1 sites. These data show that DNA sequences that contain the G-rich sequence motif, G4N4G4, such as GR1 and GR2, can functionally mimic the regulatory protein binding ability of CD28GR. Thus, GR1 and GR2 act as molecular decoys to selectively interfere with transcriptional regulation of the CD28 gene.

Antigens, CD↗

PubMed1999

Contact hypersensitivity responses following ribavirin treatment in vivo are influenced by type 1 cytokine polarization, regulation of IL-10 expression, and costimulatory signaling.

We previously described the promotion of type 1 cytokine responses by the nucleoside analogue, ribavirin, in human T cells in vitro. In this study, we examined whether type 1 cytokine polarization by ribavirin in vivo could promote contact hypersensitivity (CHS) responses to dinitrofluorobenzene, a type 1 cytokine-mediated immune response. Unexpectedly, although type 1 cytokine responses were enhanced following ribavirin treatment in vitro and in vivo, the magnitude of CHS responses in BALB/c and C57BL/6 mice was influenced more by a second ribavirin-regulated pathway. The key regulatory molecule in this pathway was IL-10. Ribavirin-mediated suppression of IL-10 in BALB/c mice was associated with increased B7-2 expression and enhanced CHS responses, whereas enhanced IL-10 levels, following ribavirin administration, led to increased B7-1 expression and impaired CHS responses in C57BL/6 mice. The effect of ribavirin on the expression of B7 molecules and on CHS responses was neutralized by IL-10 administration in BALB/c and by anti-IL-10 Ab in C57BL/6. Thus, ribavirin controlled CHS responses directly through the modulation of IL-10 expression, and in vivo outcome was dictated by the preferential expression of either B7-1, an inappropriate costimulatory molecule in CHS, or B7-2, the predominant costimulatory molecule in CHS. Replacing dinitrofluorobenzene priming with IFN-alpha stimulation, we showed that the ribavirin-regulated pathway could function independent of Ag priming. Altogether, these data showed that, although ribavirin treatment induced a type 1 cytokine bias in contact allergen-primed BALB/c and C57BL/6 mice, in vivo CHS responses were dependent on ribavirin-mediated regulation of both IL-10 and preferential costimulatory signaling.

Adjuvants, Immunologic↗