Mutants with altered sensitivity to a calmodulin antagonist affect the circadian clock in Neurospora crassa

Two newly isolated mutant strains of Neurospora crassa, cpz-1 and cpz-2, were hypersensitive to chlorpromazine with respect to mycelial growth but responded differently to the drug with respect to the circadian conidiation rhythm. In the wild type, chlorpromazine caused shortening of the period length of the conidiation rhythm. Pulse treatment with the drug shifted the phase and inhibited light-induced phase shifting in Neurospora. By contrast to the wild type, the cpz-2 strain was resistant to these inhibitory effects of chlorpromazine. Inhibition of cpz-2 function by chlorpromazine affected three different parameters of circadian conidiation rhythm, namely, period length, phase and light-induced phase shifting. These results indicate that the cpz-2 gene must be involved in or related closely to the clock mechanism of Neurospora. By contrast, the cpz-1 strain was hypersensitive to chlorpromazine with respect to the circadian conidiation rhythm.

Molecular cloning of the acr-2 gene which controls acriflavine sensitivity in Neurospora crassa

The acr-2 gene of Neurospora crassa was cloned by complementation of the wild-type strain by DNA from an acriflavine-resistant strain, acr-2. The transcript of the acr-2 gene is 2.3 kb long and contains two leader open reading frames (ORFs) that precede the acr-2 coding region and, if translated, they would generate sequences of 23 and 43 amino acid residues, respectively. The predicted ACR-2 protein contains 595 amino acids that include a putative Zn(II)Cys6 binuclear domain that is followed by a rather long serine/threonine-rich region near the amino-terminus. The acr-2 mutation, which confers acriflavine resistance, substitutes the amino acid residue at position 303 of the encoded protein from asparagine to lysine. Progeny that were hypersensitive to acriflavine were obtained by disruption of the acr-2 gene by repeat induced point mutation (RIP). The level of expression of the acr-2 gene is significantly higher in the acr-2 strain than in the wild-type strain. These results indicate that the acr-2 gene controls acriflavine sensitivity in N. crassa.

Effect of IL-10 on collagen-induced arthritis in mice

In the present study we investigated the effect of a potent anti-inflammatory cytokine, interleukin (IL)-10, on the development of collagen-induced arthritis (CIA) in mice. Each DBA1/J mouse was immunized with 200 micrograms of native collagen and followed by booster injections at 3 weeks. rmIL-10 was injected i.p. daily at a dose of 100 ng/mouse. Mice were divided into four groups according to the administration period of rmIL-10. As a result, a 48-day course of IL-10 treatment significantly suppressed the severity of arthritis. Among the 4 groups, the most pronounced suppression was observed in the group in which IL-10 was given from day 0 to 21. On the other hand, there were no significant differences in the serum IgG anti-type II collagen (CII) titers between the four groups. Moreover, the production of cytokines (IL-6 and tumor necrosis factor-alpha (TNF-alpha)) and other mediators (prostaglandin E2 (PGE2) and nitric oxide (NO)) by peritoneal macrophages seemed to show no clear correlation with the severity of arthritis in mice. These results raise the possibility that IL-10 might be a useful agent for suppressing the progression and the development of CIA in mice.

Molecular cloning of thi-4, a gene necessary for the biosynthesis of thiamine in Neurospora crassa

The thiamine-4 (thi-4) gene was cloned by functional complementation of a thi-4 mutant of Neurospora crassa. The product of this gene is believed to be involved in the condensation of pyrimidine and thiazole precursors, which is necessary for the synthesis of thiamine. The thi-4 gene has ten introns which vary in length from 57 to 200 bp and the junction and internal (lariat) sequences are in good agreement with the consensus sequences for the splicing of introns in N. crassa. The thi-4 gene encodes a protein of 538 amino acids which is similar in terms of amino-acid sequence to proteins encoded by Saccharomyces cerevisiae whose function is unknown. The expression of the thi-4 gene in N. crassa was not repressed by thiamine.

In vitro anti human immunodeficiency virus activity of mangrove plants

Mangrove plant extracts were screened in vitro against human immunodeficiency virus (HIV) on MT-4 cells. HIV infected MT-4 cells were cultured for five days in the presence of the extract, at various concentrations. Anti-HIV activity was evaluated by tetrazolium-based colorimetric assay. Seven extracts were found effective. Five of the active extracts completely inhibited the virus adsorption to the cells. Most of the active plants are from the family Rhizophoraceae.

Sulfated pentagalloyl glucose (Y-ART-3) inhibits HIV replication and cytopathic effects in vitro, and reduces HIV infection in hu-PBL-SCID mice

To evaluate the efficacy of Y-ART-3 as an antiviral drug for HIV infections, its anti-HIV activity was assessed in vitro in cell culture systems and in vivo in hu-PBL-SCID mice. The results indicated that Y-ART-3 invariably inhibited not only HIV-1, but also HIV-2 and SIV strains. Its mechanism of action is ascribed to inhibition of viral adsorption to CD4-positive cells. In an in vivo study, human Ig- and CD4-positive cells were detected at similar levels in Y-ART-3-treated hu-PBL-SCID mice that were infected with HIV, and in PBS-treated control hu-PBL SCID mice that were not infected with HIV. If HIV positivity was calculated using the number of tests in which HIV was detected (i.e. PCR, and p24 from co-cultures of spleen and peritoneal wash cells), a significant effect of Y-ART-3 at a dose of 4 mg/kg was noted. Therefore, Y-ART-3 may be considered to be a potent and effective anti-HIV compound.

Evaluation of the subacute pulmonary and testicular inhalation toxicity of diborane in rats

This study aimed to clarify the subacute pulmonary and testicular inhalation toxicity of diborane (B2H6, CAS: 19287-45-7) in rats. Male Wistar rats were exposed for 8 weeks to 0.11 or 0.96 ppm of diborane for 6 hr/day, 5 days/week. The control group was exposed to filtered air. Bronchoalveolar lavage fluid (BALF), hematological, biochemical, and histopathological examinations were conducted. Sperm counts and spermatic morphological changes were examined in epididymides, and histopathological examination was carries out in testes. BALF examinations revealed that the percentage of neutrophils increased in a dose-dependent manner and that of macrophages decreased in rats exposed to 0.96 ppm. Quantities of total and individual phospholipids in BALF increased in rats exposed to 0.96 ppm. The proportion of phosphatidylglycerol plus sphingomyelin decreased, and phosphatidylethanolamine and phosphatidylinositol increased in rats exposed to 0.96 ppm. LDH increased in rats exposed to 0.96 ppm, and ALP showed a dose-dependent increase. In serum, alpha 1-antitrypsin and superoxide dismutase activities increased in rats exposed to 0.11 or 0.96 ppm. These changes showed dose-dependent effects on the lung in rats exposed to diborane, possibly indicating that the hyperenergia of type II cells with proliferation and/or hypertrophy without histopathological changes occurred even in rats exposed to 0.11 ppm. Testicular examinations revealed no particular findings. The TLV-TWA of diborane (0.1 ppm) seems to be high and possibly unsafe, considering that the no-observed-effect level over 8 weeks for rat lung was under 0.11 ppm.

Expression of ornithine decarboxylase mRNA in gastric carcinoma

BACKGROUND

Ornithine decarboxylase (ODC) is a key rate-limiting enzyme in polyamine biosynthesis. Several studies using an enzyme assay revealed that the ODC activity was higher in tumor tissue than in normal tissue. However, there is little information on the mRNA status of ODC in surgical specimens. ODC is a transcriptional target gene of c-myc.

METHODS

cDNA was obtained by reverse transcription (RT) from fresh specimens of 56 surgical pairs of primary gastric carcinomas and corresponding normal tissue specimens. The ODC and c-myc mRNAs were subsequently detected by means of the polymerase chain reaction. The tumor/normal (T/N) ratio of ODC expression was calculated after correcting for glyceraldehyde-3-phosphate dehydrogenase as an internal control. The T/N ratio of ODC was plotted against that of c-myc.

RESULTS

The corrected expression levels of ODC mRNA in the tumor were greater than those of the normal mucosa in 36 of 56 cases (64%). The cases of tumor with vascular vessel invasion showed a higher T/N ratio than those without vascular invasion (P < 0.01). Similarly, female patients showed a higher T/N ratio than male patients (P < 0.01). There was a significant correlation between the expressions of both ODC and c-myc genes (P < 0.05).

CONCLUSIONS

The findings imply that (1) overexpression of ODC mRNA in tumor tissue may correlate with aggressive biologic behavior, such as vascular vessel invasion, and (2) there is an intimate correlation between ODC and c-myc genes.

Phase I and pharmacologic study of 9-aminocamptothecin given by 72-hour infusion in adult cancer patients

PURPOSE

To conduct a phase I and pharmacologic study of the new topoisomerase I inhibitor, 9-aminocamptothecin (9-AC).

PATIENTS AND MATERIALS

A 72-hour infusion of 9-AC was administered every 14 days to 48 solid-tumor patients at doses of 5 to 59 microg/m2/h without granulocyte colony-stimulating factor (G-CSF) and 47 to 74 microg/m2/h with G-CSF.

RESULTS

Without G-CSF, two of eight patients who received 47 microg/m2/h had dose-limiting neutropenia in their initial cycle, as did both patients who received 59 microg/m2/h (with a platelet count < 25,000/microL in one). With G-CSF, zero of seven patients treated with 47 microg/m2/h had dose-limiting neutropenia in their first cycle, while dose-limiting neutropenia occurred in six of 14 patients (with platelet count < 25,000/microL in five) entered at 59 microg/m2/h. Among 39 patients entered at > or = 25 microg/m2/h 9-AC with or without G-CSF, fatigue, diarrhea, and nausea/vomiting of grade 2 severity ultimately occurred in 54%, 30%, and 38%, respectively, while grade 3 toxicities of each type occurred in 8% of patients. Steady-state 9-AC lactone concentration (Css) increased linearly from 0.89 to 10.6 nmol/L, and correlated strongly with leukopenia ( r = .85).

CONCLUSION

The recommended phase II dose of 9-AC given by 72-hour infusion every 2 weeks is 35 microg/m2/h without G-CSF or 47 microg/m2/h with G-CSF support. Dose escalation in individual patients may be possible according to their tolerance.

Relationship between gelation rate of controlled-release acetaminophen tablets containing polyethylene oxide and colonic drug release in dogs

PURPOSE

We hypothesized that sufficient gelation of orally administered hydrophilic matrix tablets before they reach the colon could, as a result of continuous erosion of the gelated matrix, prevent the decrease in colonic drug release which normally occurs here. The purpose of this study was to elucidate the effect of gelation of hydrophilic matrices containing polyethylene oxide on colonic drug release in dogs using controlled-release (CR) acetaminophen tablets.

METHODS

Two types of CR tablets were prepared, a slow gelling tablet (SG) and a rapid gelling tablet (RG) containing an extra highly water soluble filler. In vitro and in vivo performance were examined.

RESULTS

SG and RG showed similar drug release behavior in vitro. In oral administration to dogs, the two formulations showed similar gastrointestinal transit, reaching the colon within 2-4 h after oral dosing. Further, they showed similar maximum plasma levels (Cmax) and time to Cmax (Tmax). In contrast, however, the two tablets produced different plasma levels from 2 h post-dosing, with plasma levels of RG higher than those of SG and with smaller individual variation. Directly observed colonic drug release behavior of RG was similar to in vitro drug release, whereas that from SG was suppressed.

CONCLUSIONS

Colonic drug release is closely related to the gelation of hydrophilic matrix, and rapid gelation provides continuous in vivo drug release.

[Clinical efficacy of fluconazole against fungal infections in hematological diseases]

Clinical efficacy of fluconazole was evaluated against fungal infections complicated with hematological diseases. Fluconazole 200 approximately 400 mg was administered intravenously to 20 suspected fungal infections occurring in patients with hematological diseases (acute leukemia 6, malignant lymphoma 11, adult T cell leukemia 2, chronic myelogenous leukemia blastic crisis 1). These mycoses included 8 cases of suspected pulmonary fungal infection, 10 cases suspected fungemia, and two cases of suspected hepatic fungal abscess. The clinical response rate was 60.0%. Side effects were observed in two cases, one with transient liver function test abnormality and the other with nausea. Fluconazole is considered to be a potent, safe antifungal agent for the treatment of suspected fungal infections associated with hematological diseases.

[Clinical significance of genetic instability in gastrointestinal cancers]

We reviewed the clinical significance of genetic instability or replication error (RER) in human gastrointestinal carcinomas. The RER positive tumors are seen in about 10-30% of these carcinomas. The RER positive esophageal carcinomas tend to show unusual histologic subtypes such as adenocarcinoma or small cell carcinoma. The RER positive gastric carcinomas show no specific characteristics in our study while several investigators describe the high frequency of poorly differentiated adenocarcinomas of the higher frequency of advanced carcinomas. The RER positive colorectal carcinomas show a tendency to show poorly differentiation to occur in the proximal colon, to have no lymph node metastasis and to show good prognosis. Several candidate genes that may correlate with RER are shown.

5'-linked lipid-oligodeoxyridonucleotide derivatives as inhibitors of human immunodeficiency virus replication

The covalent attachment of a phospholipid moiety, bound to the 5'-ends of phosphodiester and phosphorothioate oligonucleotides (L-ODNs and LS-ODNs), was achieved using H-phosphonate chemistry, and the lipid-oligonucleotides were assayed for the inhibition of virus replication in HIV-1 infected MT-4 cells. In the anti-HIV activity test, lipid-phosphorothioate oligonucleotides showed higher anti-HIV activities than non-lipid-phosphorothioate oligonucleotides, at the low concentration of 0.04 microM. LS-ODNs can inhibit HIV-1 reverse transcriptase activity through interactions with the enzyme. We found that the covalent attachment of a phospholipid group to the 5'-end of the phosphorothioate oligonucleotide enhances its nonsequence specific anti-HIV activity.

[Presurgical evaluation of cerebral perfusion reserve in patients for cardiovascular surgery using 99mTc-ECD SPECT with diamox enhancement]

Cerebrovascular stroke is one of the major complications in cardiovascular surgery with cardiopulmonary bypass. The purpose of this study was to evaluate the usefulness of preoperative 99mTc-ethyl cysteinate dimer (ECD) SPECT and acetazolamide (diamox) enhancement to predict neurological complications in cardiovascular surgery. Eighteen patients with coronary disease, valvular disease or aortic aneurysm were studied before the operations. Regional cerebral blood flow and perfusion reserve were evaluated using ECD SPECT before and after the intravenous administration of diamox (1 g). Three cases with moderate to severe baseline abnormalities and poor perfusion reserve had cerebral infarction postoperatively. Twelve cases with good to fair perfusion reserve had no neurological complication. Three cases having poor perfusion reserve had the operations with more intensive brain protection, in which higher perfusion pressure to the brain was maintained during cardiopulmonary bypass, and no neurological complication was observed. In conclusion, patients who have moderately or markedly abnormal baseline flow with poor perfusion reserve may have some risk of neurological complications in cardiovascular surgery. ECD SPECT with diamox enhancement may give information useful for selection of operation procedures.

Relationship between acetone exposure concentration and health effects in acetate fiber plant workers

In order to clarify the effects of acetone (AC) exposure on health, a cross-sectional study was carried out in 110 male AC-exposed and 67 male nonexposed shift workers. The AC workers ranged in age from 18.7 to 56.8 years (mean: 37.6 years) and in length of AC exposure from 0.5 to 34.3 years (mean: 14.9 years). The nonexposed workers ranged in age from 20.7 to 57.5 years (mean: 41.9 years). AC exposure levels assessed by personal passive monitors and biological monitoring indices measured at the end of the workshift were 19.6-1018 ppm in the breathing zone (AC-E, mean: 364 ppm), 2.5-422 ppm in alveolar air (AC-A, mean: 97.3 ppm) 4-220 mg/l in blood (AC-B, mean 66.0 ppm), and 0.75-170 mg/l in urine (AC-U, mean: 37.8 mg/l). Symptoms at the end of the workshift with good exposure-response relationships were eye irritation, tearing, and acetone odor, and symptoms within the previous 6 months with good exposure-response relationships were heavy, vague, or faint feeling in the head, nausea, loss of weight, and slow healing of an external wound. In the 30-44 year age range, simple reaction time and digit span scores in a short computerized neuro-behavioral test battery were significantly lower in AC workers, but exposure-response relationships were not clear. Manifest Anxiety Scale scores, Self-rating Depression Scale scores, R-R interval variation on the ECG, hematological examinations, serum biochemistry examinations for liver function, and phagocytic activity of peripheral neutrophils did not show any AC-related differences between the two groups. In view of the reported findings, the current occupational exposure limit of 750 ppm recommended by many governmental and academic associations seems to be too high to prevent the health effects of AC observed in this study.

FR901724, a novel anti-human immunodeficiency virus (HIV) peptide produced by Streptomyces, shows synergistic antiviral activities with HIV protease inhibitor and 2',3'-dideoxynucleosides

A novel tricyclic 21-amino-acid peptide, FR901724, was isolated from the cultured broth of Streptomyces sp. No. 73264. This peptide appears to possess potent anti-human immunodeficiency virus (HIV) activity in vitro and might represent a lead to a new class of anti-HIV agents; it qualifies as an HIV-cell fusion inhibitor because of its weak inhibition of virus-cell binding and strong inhibition of syncytium formation. From the time-of-addition experiments, the mode of action of FR901724 was found to definitely differ from that of KNI-272, a peptide mimetic allophenylnorstatine-derivative HIV protease inhibitor. FR901724 appears to interact with a stage of the virus replicative cycle that may well correspond to virus-cell fusion. We also found that FR901724 was synergistic or had a strong tendency toward synergism when combined with other antiviral drugs, such as KNI-272, AZT, ddI and dextran sulfate.

A case of alpha-fetoprotein-producing gastric cancer showing an exogastric growth pattern

A case of alpha-fetoprotein (AFP)-producing gastric cancer, which showed a huge abdominal mass due to an exogastric growth, is here described. A 69-year-old Japanese woman with a huge abdominal mass, measuring 22 x 15 cm in size, had a serum AFP level that was exceptionally high (155 x 10(3) ng/ml). CT, barium meal studies, and gastrointestinal fiberoscopy revealed a gastric tumor with an exogastric growth pattern. The patient underwent a partial gastrectomy. The histological examination revealed that the tumor consisted of anaplastic carcinoma with positive staining for AFP. Although no liver metastasis was observed at operation, she died of multiple liver metastases 8 weeks after the operation. A gastric cancer that shows both AFP production and an exogastric growth pattern is quite rare and may be virulent.

Synthesis of sulfated octadecyl ribo-oligosaccharides with potent anti-AIDS virus activity by ring-opening polymerization of a 1,4-anhydroribose derivative

The synthesis and anti-AIDS virus activity of sulfated octadecyl ribofuranans with medium-range molecular weights have been investigated. Selective ring-opening polymerization of 1,4-anhydro-2,3-di-O-benzyl-alpha-D-ribopyranose with 10-20 mol% of boron triflouride etherate as a catalyst in a large amount of dichloromethane gave 2,3-di-O-benzyl-(1-->5)-alpha-D-ribofuranan in good yield. The molecular weight of the benzylated ribofuranan was in the range of 9 x 10(3) to 10 x 10(3). Debenzylation of the polymer followed by acetylation gave peracetylated (1-->5)-alpha-D-ribofuranans. The peracetylated ribofuranans were treated with octadecyl alcohol and a stannic chloride catalyst to afford acetylated ribofuranans having octadecyl groups at the reducing terminal. The molecular weights of the resulting acetylated octadecyl ribofuranans were below 9 x 10(3). Sulfation of the deacetylated octadecyl ribofuranans by piperidine-N-sulfonic acid in dry Me2SO gave sulfated octadecyl ribofuranans with molecular weights of 3 x 10(3) to 9 x 10(3) and sulfur contents of 13.0-16.2%. The sulfated octadecyl ribofuranans had potent anti-AIDS virus activity, EC50 = 0.6-2.5 micrograms/mL (a standard curdlan sulfate showed EC50 = 0.43 micrograms/mL), and low anticoagulant activity, 4-17 units/mg (a standard dextran sulfate, 22.7 unit/mg). Structural analysis of the ribofuranans was performed by NMR at 400 and 600 MHz.

Acute and subacute inhalation toxicity of dichlorosilane in male ICR mice

Using male ICR mice, the LC50 and acute and subacute inhalation toxicity of dichlorosilane (SiH2Cl2, DCS) and the fate of DCS released into the air were investigated. DCS resolved and minute particles including silicon and chloride were observed, when DCS was released into the air. Most particles were under 1 micron in diameter. The LC50 of DCS at 4-h exposure was 144 ppm (nominal concentration). In the acute inhalation study, ten mice in each group were exposed to 64 ppm (nominal concentration) DCS for 1, 2, 4 or 8 h. Body weight loss, wheezing and piloerection were observed in mice exposed for 2 h or more. Histopathologically, injury to the nasal mucosa and trachea were observed in all exposed mice. Mice exposed to 32 ppm (nominal concentration) DCS for 2 or 4 weeks also exhibited depression of body weight gain, wheezing and piloerection. Squamous metaplasia of the nasal mucosa and tracheal epithelium was observed in both 2- and 4-week exposure groups. Exposure to DCS was irritant or corrosive to the respiratory tract with both acute and subacute inhalation. Apart from silane (SiH4), toxic effects of DCS seem to be characterized by chloride compounds derived from DCS.

Suppression of HIV-1 reverse transcriptase activity by culture supernatants of mycoplasmas

Coinfection with mycoplasmas has been shown to enhance cytopathic changes in T lymphocytes in culture brought about by human immunodeficiency virus type-1 (HIV-1), accelerate disease progression, and suppress reverse transcriptase (RT) activity simultaneously. We attempted to identify the components in culture supernatants of mycoplasmas which suppress RT activity. The marked inhibitory effect on RT by culture supernatants was dependent upon Mg2+. The culture supernatants exhibited the activities of DNase and RNase, which degraded the products and substrates in RT assay, respectively. Gel filtration studies revealed that two major protein peaks, peak 1 (MW 67-100 kDa) and peak 2 (MW 10-25 kDa), exhibited DNase and/or RNase activities, and that both peaks contained a significant degree of inhibitory activity on RT. These results indicate that suppression of RT activity by the culture supernatants of mycoplasmas is due to DNase and RNase activities in the culture supernatants. The results of the present investigation suggest that RT assay of certain biological materials that are contaminated with mycoplasmas must be conducted carefully.

Human esophageal carcinomas frequently express the tumor-rejection antigens of MAGE genes

The human genes MAGE-1 and -3 encode melanoma peptide antigens that are recognized by autologous cytotoxic T lymphocytes. Tumors expressing MAGE genes are potential targets for cancer immunotherapy, because MAGE genes are expressed only in tumor tissue and not in any normal tissue except testis and placenta. However, little is known about MAGE gene expression in human esophageal carcinoma. The purpose of this study was therefore to analyze MAGE gene status in human esophageal carcinoma. We studied the expression status of these genes in 42 surgical samples and in 12 cell lines of human esophageal carcinoma using the reverse transcription polymerase chain reaction (RT-PCR). Various clinicopathological factors were also analyzed. No MAGE gene expression was seen in any of the 42 normal esophageal tissue specimens. In contrast, tumor tissue expressed MAGE-1, -2, and -3 in 26, 18 and 24 specimens, respectively. Thirty-three of 42 tumors expressed at least one MAGE gene. Significant clinicopathologic differences between the tumors were not observed, regardless of the presence or absence of MAGE gene expression. In cell lines, MAGE-1, -2, and -3 gene expression was recognized in 5, 4 and 4 cell lines, respectively. This study demonstrates that MAGE genes are frequently expressed in clinical samples as well as in cell lines of esophageal carcinoma. The identification of MAGE genes, therefore, may open up a new modality of treatment, namely specific immunotherapy, for patients with esophageal carcinoma.

Differences in MHC class I self peptide repertoires among HLA-A2 subtypes

To investigate how single amino acid substitutions in MHC class I molecules affect differences in peptide repertoires, we eluted and sequenced the naturally processed peptides from three HLA-A2 subtypes (HLA-A*0204, -A*0206, and -A*0207) that differ by a single amino acid residue substitution each with HLA-A*0201 at the floor of the binding groove. Allele-specific peptide motifs for each HLA-A2 subtype substantially differed from that of HLA-A*0201 in the dominant anchor residues. The relative signal intensities for 18 self peptides, determined by mass spectrometry, precisely reflected these peptide motifs. Some overlapping peptides were isolated from both HLA-A*0201 and a single HLA-A2 variant, but no peptide was ubiquitously found across all variants. To rationalize the differences in peptide motifs, possible conformations of each allele were computer modeled by energy minimization calculations based on the reported crystal structure of HLA-A*0201. According to our models, the differences in peptide motifs could be explained by substituted-residue-driven conformational changes for each MHC-peptide complex. These results demonstrate the fine differences between HLA-A2 subtype self peptide repertoires and contribute to the prediction of antigenic peptides.