Stimulatory and inhibitory epitopes in the T cell responses of mice to Der p 1

BACKGROUND: The responses of mice to the mite allergen Der p 1 have been used to study the mechanisms of allergic sensitization and the development of new types of immunotherapy. Many of the studies require a knowledge of the T cell epitopes, and because Der p 1 is polymorphic, the effect of natural amino acid substitution in the allergen. The intranasal administration of peptides containing T cell epitopes can induce a mucosal tolerance but it is not known if the major activity is limited to stimulatory peptides and if, as found for autoimmunity, some epitopes are not inhibitory. OBJECTIVE: To determine and compare the sequences of Der p 1 which contain stimulatory epitopes for the high responding H-2(b) and H-2(q) mice and the sequences which induce tolerance by intranasal administration of peptides. METHODS: T cell responses of mice immunized with Der p 1 were measured by in vitro T cell stimulation assays so an extensive study of epitope recognition and intranasal tolerance could be made. Synthetic peptides were used to examine the stimulatory and inhibitory ability of all Der p 1 sequences and to map the major H-2(b) epitope in detail. This included the effect of the common polymorphic amino acid 124 substitution found within this epitope. RESULTS: Three and two regions, respectively, were found to contain stimulatory T cell epitopes for H-2(b) and H-2(q) mice. The peptides in these regions were also the most active at inducing intranasal tolerance for the responding haplotype. The correspondence between inhibitory and stimulatory peptides was maintained for the fine mapping of the major H-2(b) epitope. This was found about a core region of 118-126 which was overlapping but separate to a consensus sequence for the binding of endogeneous peptides. Peptides with alanine at the naturally polymorphic residue 124 stimulated and inhibited responses to Der p 1 more effectively, while peptides with the valine 124 variant were immunogenic but poorly cross-reactive. CONCLUSIONS: The intranasal administration of peptides representing each of five epitopes recognized by two strains of mice were able to induce mucosal tolerance and the major tolerizing activity was limited to these epitopes. The position of the core major epitope for C57 mice, which differs from a previously predicted epitope, and its specificity for the natural alanine 124 variant is described.     

Influence of mattress characteristics on house dust mite allergen concentration

BACKGROUND: Exposure to a high level of house dust mite allergens (HDMAs) is considered as a risk factor for HDM sensitization and development of asthma in genetically disposed people. Mattresses are one of the most important sources of HDMA in people's living environment. OBJECTIVE: The aim of this study was to evaluate the association between mattress characteristics and HDMA concentrations on mattresses. METHODS: Dust samples of mattress surfaces were taken to evaluate the level of Der p 1 allergen. All participants filled in a questionnaire about the type of mattress, the type of covering (upper layer) of the mattress, dwelling characteristics and cleaning habits. Humidity and temperature of the bedroom were measured at the time of dust sampling. RESULTS: One hundred and sixty-eight questionnaires were filled in. Synthetic upper layer of the mattress was associated with a higher level of Der p 1 compared with cotton upper layer (2.6 vs. 0.8 microg/g Der p 1). Moreover, higher relative humidity (RH) was associated with significant higher concentrations and density of Der p 1. CONCLUSIONS: Two factors were associated with lower levels of Der p 1 found on mattresses, namely: a cotton upper layer of the mattress compared with a layer of synthetic material and lower RH at the time of sampling. As far as we know, the association between type of upper layer and concentration of Der p 1 has not been described before and could lead to the formulation of practical advices in order to reduce HDMA concentrations on mattresses.     

Immunoreactive p53 and metallothionein expression in duct carcinoma in situ of the breast

 Immunocytochemically detectable MT and p53 have been found more commonly in comedo DCIS of the breast with high-grade cytology. The aim of this study is to confirm these findings and to investigate the relationship between MT and p53 in a single large series of cases of DCIS of the breast. To this end, 127 cases of DCIS were classified histologically according to architecture, cytonuclear differentiation (grade), presence and extent of intraduct necrosis, and using the Van Nuys system. Sections were immunostained for p53 and MT (E9) using established techniques, and the extent and intensity of staining were assessed semi-quantitively. The results confirmed that there was generally more MT and p53 positivity in poorly differentiated (grade 3) DCIS with extensive necrosis and that MT expression was greater in grade 2 lesions than p53 expression. However, overall there was no statistically significant correlation between p53 and MT staining. The results indicate that MT and p53 overexpression may arise from independent mechanisms in early breast neoplasia. Received: 3 July 1996 / Accepted: 5 November 1996     

胎盘组织液氨基酸的含量测定及层析鉴别

本文采用层析法进行鉴定,用氨基酸分析仪测氨基酸的含量,为胎盘组织液的质量标准提供可靠依据。本法准确率为99%。     

The decay of house dust mite allergens, Der p I and Der p II, under natural conditions

Background: Fluctuations in the level of mite allergens in domestic house dust are the result of changes in the balance between synthesis, removal and decay. Purely physical forces as well as enzymatic degradation, mediated by house dust inhabiting microbes, may contribute to the decay of allergens in domestic dust. Knowledge about the speed of decay is essential for an understanding of the dynamics of allergen levels. Objective: The present study is a quantitative assessment of the speed of decay at nine combinations of temperature (15°C, 20°C and 25°C) and relative humidity (33%, 55% and 75%). Methods: Samples of mite infested material of an old rug were stored at these temperature/relative humidity-combinations for 6, 12 or 18 months, after the mites were killed by cither a freezing treatment or an acaricide (lindane). The microbes living in the rug presumably survive these treatments. Concentrations of Der p I and Der p II + Der f II. in extracts of the rug material, were measured by a radio immunoassay. Results: No significant changes in the levels of Der p I and Der p II +Der f II, could be detected even after 1¹/₂ year at a high temperature and humidity. Conclusion: These findings incidate that mite allergens can be extremely stable under normal domestic circumstances.     

Expression of p27 and p53: comparative analysis of uterine carcinosarcoma and endometrial carcinoma

The aim of the study was to assess both p27 and p53 expression in the stromal and epithelial component of carcinosarcoma and to assess if their expression in the latter is different than in endometrial carcinoma. Immunohistochemical staining for p27 and p53 was performed on paraffin-embedded tissue blocks of 18 uterine specimens with carcinosarcoma and their expression assessed. Their expression in the epithelial element was also compared to that in 35 paraffin-embedded tissue blocks of endometrial endometrioid carcinoma. Reduced p27 expression was observed in a similarly high proportion of the stromal (77.8%) as well as of the epithelial component (66.7%) of carcinosarcoma. Although statistically not significant, the proportion of reduced p27 expression in endometrial carcinoma (85.7%) was higher than in the epithelial element of carcinosarcoma. The percentage of p53 overexpression in both elements of carcinosarcomas and in endometrial carcinomas was low and also similar (27.8 and 20.0%, respectively). Our results indicate that reduced p27 expression is common and p53 overexpression is infrequent in carcinosarcoma. Their similar rates of expression in the stromal and epithelial elements of the tumor support the contention of a monoclonal origin of carcinosarcoma. Unexpectedly, reduced p27 expression is more common in endometrial carcinoma than in the epithelial element of carcinosarcoma, in spite of the less favorable prognosticators and outcome in the latter. Further studies of p27 expression in carcinosarcoma are indicated to establish its clinical value in this aggressive malignancy.     

HLA and Down syndrome (DS): parents at the origin of the nondisjunction share no more HLA-A and -B antigens with their DS child than controls

Fifty couples and their children with Down syndrome (D.S.) were typed for HLA-A and HLA-B antigens and compared to 50 control families and 464 blood donors. The parental origin of the extra chromosome 21 was determined by cytogenetic methods. All individuals were caucasians and there was no history of consanguinity. No excessive HLA sharing was present in D.S. parents. The mothers of D.S. shared no more HLA antigens with their D.S. children than the control mothers with their normal children (14% vs. 18%). Thirteen of the fifty pairs (26%) (parent in whom the nondisjunction occurred and D.S. child) shared three HLA antigens at the A and/or B locus. This was not significantly higher than the proportion in the control group (12/50 or 24%). These data suggest that it is not the sharing of HLA-A and HLA-B antigens between the parents or between the parent who was the origin of the nondisjunction and the D.S. child that is related either to the occurrence of trisomy 21 zygotes or to prenatal survival of affected embryos and fetuses.     

Correlation of Nuclear Morphometry and Immunostaining for p53 and Proliferating Cell Nuclear Antigen in Transitional Cell Carcinoma of the Bladder

Background :
In an attempt to determine the biological significance of nuclear morphometric findings, measurements of mean nuclear volume (MNV) and nuclear roundness factor (NRF) were compared to the immunoreactivityof p53 expression and proliferating cell nuclear antigen (PCNA) in human bladder cancer.
Methods :
MNV and NRF were measured using stereological methods. Expression of p53 and PCNA were determined by immunohistochemical staining. Specimens from 111 patients with previously untreated bladder cancer were analyzed.
Results :
The mean MNV was 235.8 ± 1 33.6 μm³ for the 81 patients with p53-labeling index (LI) less than 10% and 337.2 ± 141.0 μn³ for the 30 patients with p53 LI greater than 10% (P = 0.008). There was Resign if icant correlation between NRF and expression of p53. The mean MNV was 220.1 ± 1 20.5 μm³ for the 67 patients with PCNA LI less than 28% (the mean value of PCNA LI) and 328.9 ± 149.2 μm³ in 44 patients with PCNA LI greater than 28% (P= 0.0001). The mean NRF was 80.7 ± 4.2 for the 67 patients with PCNA LI less than 28%, and 82.3 ± 3.4 for the 44 patients with PCNA LI more than 28% (P= 0.04). Conclusion: Nuclear morphometric findings may reflect the proliferative potential of cancer eel Is of the bladder, as indicated by findings of immunostaining for p53 and PCNA.     

Nuclear p53 Overexpression in Bladder, Prostate, and Renal Carcinomas

Background :
The aim of this study was to examine nuclear p53 overexpression in transitional cell carcinoma of the bladder, adenocarcinoma of the prostate, and renal cell carcinoma.
Methods :
Forty-four pathologic specimens from 39 bladder cancer patients, 41 prostatic adenocarcinoma, and 39 renal cell carcinoma specimens were analyzed immunohistochemically with D07 monoclonal antibody to detect the expression of the mutant p53 gene. Overexpression was said to occur when the number of positively-stained tumor nuclei were≥ 10% in each specimen. p53 overexpression was correlated with the clinical and histopathological features of these cancers.
Results :
Nuclear p53 overexpression occurred in 18.2% of transitional cell bladder cancer specimens, 12.2% of prostate cancer specimens, and 17.9% of renal cell cancer specimens. Statistical analyses showed that grade, vascular invasion, and necrosis in bladder cancer, a high Gleason score in prostate cancer, and the 1-year mortality rate in renal cancer were significantly related with p53 nuclear overexpression (P<0.05).
Conclusion :
Using the D07 monoclonal antibody, nuclear p53 overexpression is relatively uncommon in urologic malignancies, and moderately correlates with several histopathological and clinical features of urologic malignancies.