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A recent increase in plasmid-mediated quinolone resistance ( PMQR) has been detected among Salmonella isolated from humans in the United States, and it is necessary to determine the sources of human infection. We had previously isolated Salmonella from dairy farm environmental samples collected in Texas, and isolates were tested for anti-microbial susceptibility. Two isolates, serotyped as Salmonella Muenster, showed the discordant pattern of nalidixic acid susceptibility and intermediate susceptibility to ciprofloxacin. For this project, whole-genome sequencing of both isolates was performed to detect genes associated with quinolone resistance. The plasmid-mediated qnrB19 gene and IncR plasmid type were identified in both isolates. To our knowledge, this is the first report of PMQR in Salmonella isolated from food animals or agricultural environments in the United States. [ABSTRACT FROM AUTHOR]

Early caries lesion is a demineralization process that takes place in the top 0.1 mm layer of tooth enamel. In this study, X-ray microbeam diffraction was used to evaluate the hydroxyapatite crystallites in the subsurface lesion of a bovine enamel section and the results are compared with those obtained by transversal microradiography, a method commonly used for evaluation of tooth mineral. Synchrotron radiation from SPring-8 was used to obtain a microbeam with a diameter of 6 μm. Wide-angle X-ray diffraction reports the amount of hydroxyapatite crystals, and small-angle X-ray scattering resorts that of voids in crystallites. All three methods showed a marked decrease in the enamel density in the subsurface region after demineralization. As these diffraction methods provide structural information in the nanometre range, they are useful for investigating the mechanism of the mineral loss in early caries lesion at a nanometre level. [ABSTRACT FROM AUTHOR]

Allergic rhinitis (AR) is an IgE-mediated inflammatory disease of the nasal mucous membranes, characterized by paroxysms of sneezing, itching of the nose, eyes, palate, pharynx, and conjunctivae, nasal stuffiness with partial or total obstruction of airflow and mucous secretion often accompanied by post-nasal drainage. A T helper (Th)1/Th2 cytokine imbalance with a predominance of Th2 cytokines has been suggested of pathogenic importance in AR. To evaluate the role of Th1/Th2 cytokines in AR, the subsets of Th1, Th2, T cytotoxic type 1 (Tc1) and Tc2 cells from patients with AR were examined by intracellular cytokine flow cytometry. The population of Tc1 cells (52.3±23.6%) in AR was significantly increased compared with that in control (35.4±14.6%, P<0.05). Th1, Th2 and Tc2 cells in AR were not significantly increased vs. control. However, the ratio of Th1/Th2 was significantly decreased and the ratio of Tc1/Tc2 was significantly higher in patients with AR compared with healthy individuals ( P<0.05 and P<0.01, respectively). These results indicate that the predominance of Th2 and Tc1 cells might contribute to the pathogenetic mechanism in AR. [ABSTRACT FROM AUTHOR]

We used a rapid, visually read, field applicable monoclonal antibody (MoAb)-dipstick assay for specific diagnosis of urinary schistosomiasis together with microscopy to determine the prevalence of infant schistosomiasis in a community in the Awutu-Efutu Senya District in the Central Region of Ghana. The study group consisted of 97 infants (51 males and 46 females) aged 2 months to 5 years. A total of 75 of 97 (77.3%) subjects submitted stool samples; none had Schistosoma mansoni. Three individuals (3.1%) had hookworms but there were no other intestinal helminths. The urinary schistosomiasis prevalence by MoAb-dipstick (30%) was higher ( P < 0.05) than that estimated by microscopy (11.2%). However, three of nine (33.3%) microscopically confirmed cases tested MoAb-dipstick positive after pre-treatment of the urine specimen with heat. The youngest infant to be found infected with S. haematobium microscopically was 4 months old. Fifteen of 71 S. haematobium egg negative individuals tested dipstick positive, giving a dipstick specificity of 78.9% as compared with microscopy as gold standard test. The relative sensitivity of the dipstick was 100%. [ABSTRACT FROM AUTHOR]

In view of recent studies on the mechanisms of the survival of peripheral memory T cells, we tested the biologic role of pectate lyase, a pectin-degrading enzyme, as the cross-reactive antigen required for the recurring survival signals for human T cells specific for Cha o 1, a pollen allergen molecule of the Japanese cypress. We determined a 16-mer epitope peptide for the T-cell clone, and prepared synthetic oligopeptides of homologous regions in putative pectate lyase of other plants. Of these homologous peptides, ZePel (Zinnia elegans), ban 17 (banana), and Amb a 1.1 (short ragweed) induced strong proliferative responses of the Cha o 1-specific T-cell clone in vitro. In addition, suboptimal doses of peptide homologs derived from banana and short ragweed enhanced the survival potency of this T-cell clone without detectable proliferative responses to the peptides. When there was no antigen stimulation, the T-cell clone decreased in viable cell number and lost antigen-specific proliferation activity on day 6 during in vitro incubation. On the other hand, T-cell clones incubated with these survival-inducing peptides maintained proliferative activity to Cha o 1 even on day 9. Serum derived from the donor patient did not contain detectable levels of IgE specific to banana or short ragweed by CAP-RAST. These results show that human T cells specific for pollen allergen seem to use cross-reactive pectate lyase peptides to deliver survival signals even in the absence of pollen allergen, and memory T cells maintained in such a manner might be functioning at the onset of allergic pollinosis, although pollen allergens are seasonal. [ABSTRACT FROM AUTHOR]

This study investigated the cellular response of human lymphocytes to Dematophagoides pteronyssinus crude antigen and 14 molecular weight (MW) fractions. The cells were derived from atopic patients and healthy individuals who were skin test-positive or skin test-negative to mite antigen. When stimulated with crude antigen, the group of patients showed elevated proliferation and production of lymphokine in comparison with the healthy skin test-negative individuals (P <0.01). By stimulation with fractions, there was a remarkable variety in the responding patterns to each fraction. However, when expressed as a mean value, the patient group exhibited a sharp and high peak at 95,000 MW, which is different from IgE responses. In the other two groups, no apparent peak response was observed. Lymphokine production by fraction stimulation was studied in six distinct individuals. The most important fractions for inducing lymphokine production differed in each individual tested. Moreover, fractions which induced active lymphokine production were not necessarily the main targets of proliferative response in a topic patients. [ABSTRACT FROM AUTHOR]

There is no doubt that HLA-DR molecules are acting as the products of HLA-linked immune response genes (Ir-genes), because (i) HLA-DR molecules are the restriction elements in the interaction between CD4+ helper T cells and antigen-presenting cells (APC) to respond to many antigens such as streptococcal cell wall antigen (SCW) (Nishimura & Sasazuki, 1983; Sone et al., 1985; Hizayama et al., 1986), schistosomal antigen (Sj) (Hirayama et al., 1987), Mycobacterium leprae antigen (ML) (Kikuchi et al., 1986) and so on; and (ii) anti-HLA-DR monoclonal antibodies completely abolish the immune response to those antigens (Nishimura & Sasazuki, 1983; Sone et al., 1985). However, genetic analysis of the immune response to those antigens in families or populations revealed that responsiveness is recessive and non-responsiveness to those antigens is a dominant genetic trait that is tightly linked to HLA (Sasazuki et al., 1980a, 1983; Watanabe et al., 1988). This is completely opposite to the situation under the Ir-gene control where responsiveness is dominant and non-responsiveness is recessive. In this paper, we report evidence of how we came across the concept of HLA-linked immune suppression genes (Is-genes) besides Ir-genes, and show evidence for the epistatic interaction between HLA-DR and DQ to determine the immune response to several antigens in humans. [ABSTRACT FROM AUTHOR]

To determine whether B7 signals are associated with atopic responses in man, we assayed CD80 and CD86 expression on B cells and monocytes from atopic patients and controls. Peripheral blood mononuclear cells from 10 patients with perennial allergic rhinitis and from 10 normal subjects were cultured in the presence or absence of house-dust-mite antigen, and B cells and monocytes were assayed for expression of CD80 and CD86 by flow cytometry. CD86 on B cells was significantly and selectively upregulated in all atopic subjects, but not in normal subjects, whereas CD80 expression was not altered in B cells from the atopic subjects or controls. In contrast, both CD80 and CD86 were upregulated in monocytes from the atopic subjects as well as the controls. However, CD86 upregulation was significantly higher in the atopic subjects than in controls. Our results seem to suggest that selective upregulation of CD86 on B cells by a challenging antigen may play a critical role in the development of Th2 cells in patients with atopic disease. [ABSTRACT FROM AUTHOR]

T-cell epitopes of Der p II, a major allergen of Dermatophagoides pteronyssinus, were analyzed by using human T-cell clones. We tested 38 cloned T cells from two Japanese patients with allergic rhinitis, and identified at least two peptides (K33-T47 and I58-C73) as helper T-cell epitopes. The former epitope was shown to be restricted by HLA-DRB1*1502, and the latter by HLA-DRB1*0405, both of which are typical Japanese HLA-DR alleles, suggesting that those T-cell epitopes might be important for the onset of house-dust mite allergy in the Japanese population. We prepared 15 analog peptides of the HLA- DRB1*1502-restricted 15-mer peptide. Of those 15 residues, five (F35, L37, A39, F41, and E42) were critical for the epitope activity, and three residues (F35, A39, and E42) seemed to be included in anchor motifs for HLA-DRB1*1502. The epitope peptide was also recognized by HLA-DRB1*1502-positive healthy donors; however, only allergic T cells showed Th2 functions. Antigen-presenting cells of nonallergic donors were able to activate allergic T cells to express Th2 function. This seemed to suggest that antigen recognition of T cells, as well as additional unknown factors which promote Th2, rather than Th1, responses, might be important for the onset of house-dust mite allergy. [ABSTRACT FROM AUTHOR]

To determine the importance of silkworm moth allergens, we tested 267 patients with allergic rhinitis with CAP-RAST® a new assay system for detecting specific IgE in sera. We used the following allergen sources: house-dust mite, Candida, Alternaria, cat dander, orchard grass, ragweed, mugwort,. Japanese hops, Japanese cedar, Japanese cypress, cotton, silk, larval chironomid nudge, adult chironomid midge, and silkworm moth. As axpected, the highest positive rate of reaction, as determined by CAP-RAST, was 73.8°c for Japanese cedar, followed by 53.2% for mite and 50.6% for Japanese cypress. Although the positive rate for silkworm. moth was not as high as for cedar pollen, one-third of patients had specific IgE against silkworm moth. The positive rate of reaction to silkworm moth was much higher than that to chironomid. It was interesting to note that the patients reported had not been documented as having frequent contact with silkworm moth allergen. Correlations between silkworm moth and silk, and silkworm moth and chironomid nudge were found to be significant (P < 0.001). Silkworm moth allergen showed the third highest reaction rate in patients with severe symptoms. These results suggest that silkworm moth allergen should be considered to be important in patients with allergic rhinitis in Japan. [ABSTRACT FROM AUTHOR]

Responses of peripheral blood mononuclear cells to synthetic oligopeptides of Der p IL one of the major allergen molecules of Dermatophagoides pteronyssinus were compared between allergic and nonallergic subjects. Healthy subjects showed positive responses to crude extracts of D. pteronyssinus but only allergic subjects showed elevated cellular responses to Der p II. We synthesized three oligopeptides of Der pII in which motifs of a possible T-cell epitope were included. Of 14 subjects with positive response to Der p II three responded to all three peptides, while five did not respond to any peptide tested. In 11 allergic patients who showed positive response to Der p II responsiveness to the peptide K33-T47 was significantly higher than that to other peptides (P < 0.05)1 All the responding patients were also positive for scratch test to Der p IL suggesting that those epitopes induced IgE-promoting helper T-cell response in allergic persons On the other hand the in vitro cellular responses were not necessarily correlated to IgE production against Der pII in healthy subjects. [ABSTRACT FROM AUTHOR]

Epidermolysis bullosa (EB) is a heterogeneous group of inherited disorders characterized by the blistering of the skin and mucous membranes. Although the molecular basis of EB has been significantly elucidated, the precise phenotypes of the lethal types of EB have not been completely characterized. Herein, we report a severe case of EB with pyloric atresia (PA). The patient was a Japanese boy who not only had skin lesions but also various complications such as PA, dysphagia, hypotonia, infectious keratitis with corneal ulcer, obstructive uropathy and protein-losing enteropathy. Genetic analysis led to the identification of two novel compound heterozygous mutations in the last exon of the plectin (PLEC) gene. Based on this finding, EB simplex with PA was diagnosed. Immunostaining with anti-plectin antibodies revealed truncated plectin proteins lacking the C-terminus in the patient's skin. We also conducted a prenatal diagnosis in subsequent pregnancy. Our report further highlights the crucial role of plectin in many organs and provides valuable information regarding the phenotypes resulting from mutations in the PLEC gene., (© 2022 Japanese Dermatological Association.)

Background: The human monoclonal antibody dupilumab blocks interleukin (IL)-4 andIL-13, key and central drivers of type 2 inflammation. Dupilumab, on background mometasone furoate nasal spray (MFNS), improved outcomes in the phase III SINUS-52 study (NCT02898454) in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). This posthoc analysis of SINUS-52 examined whether eosinophilic status of CRSwNP was a predictor of dupilumab efficacy., Methods: Patients were randomized 1:1:1 to dupilumab 300 mg every 2 weeks (q2w) until week 52; dupilumab 300 mg q2w until Week 24, then 300 mg every 4 weeks until week 52; or placebo (MFNS) until week 52. Coprimary endpoints were change from baseline in nasal polyps score (NPS), nasal congestion (NC), and Lund-Mackay score assessed by CT (LMK-CT) at week 24. Patients (n = 438) were stratified by eosinophilic chronic rhinosinusitis (ECRS) status according to the Japanese Epidemiological Survey of Refractory Eosinophilic Rhinosinusitis algorithm., Results: Dupilumab significantly improved NPS, NC, and LMK-CT scores versus placebo at week 24 in all ECRS subgroups (p < 0.001), with improvements maintained or increased at week 52 (p < 0.001). There was no significant interaction between ECRS subgroup (non-/mild or moderate/severe) and dupilumab treatment effect for all endpoints at weeks 24 and 52 (p > 0.05), except LMK-CT at week 24 (p = 0.0275). Similar results were seen for the secondary endpoints. Dupilumab was well tolerated across all ECRS subgroups., Conclusion: Dupilumab produced consistent improvement in symptoms of severe CRSwNP irrespective of ECRS status. Therefore, blood eosinophil level may not be a suitable biomarker for dupilumab efficacy in CRSwNP., (© 2021 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Objective: Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized disease entity characterized by high-serum IgG4 concentration and IgG4-producing plasma cell production with fibrotic or sclerotic changes in affected organs. We aimed to clarify the roles of Epstein-Barr virus (EBV) in patients with IgG4-RDs., Study Design and Setting: A retrospective clinical study at the Yamagata University School of Medicine, Yamagata, Japan., Methods: The patient group consisted of four males and four females with an average age of 62 years (range: 48-73). Expression of IgG4, latent member protein 1, EBV nuclear antigens-2, and EBV-encoded RNA in affected salivary glands from patients with IgG4-RD was examined by using immunohistochemistry and in situ hybridization. The copy number of EBV DNA in the salivary glands was also investigated by real-time polymerase chain reaction., Results: All patients had hard masses in the salivary or lacrimal glands, or both, bilaterally. Serum concentrations of IgG4 were elevated in all cases (mean 589.1, range 129-1750), and IgG4-positive plasmacytes were observed in the involved salivary glands. Four patients developed potentially life-threatening systemic involvement after initial salivary gland swelling. EBV-associated molecules (EBNA and EBER) were overexpressed in the affected salivary glands. The copy number of EBV DNA was significantly higher in patients with potentially life-threatening systemic involvement than in patients without systemic involvement (P < 0.05)., Conclusion: These results suggest that the copy number of EBV DNA could be useful as diagnostic findings in IgG4-RD to predict potentially life-threatening systemic involvement., Level of Evidence: 4., (© 2015 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives/hypothesis: Immunoglobulin G4 (IgG4)-related sclerosing sialadenitis is a recently recognized disease entity characterized by high serum IgG4 concentration and IgG4-producing plasma cell expansion in affected organs, which show fibrotic or sclerotic changes. However, little is known about the roles of CD4+ and CD8+ T cells or interleukin (IL)-17 in this disease. The purpose of this study was to evaluate the characteristics of CD4+ and CD8+ T cells and IL-17 in patients with IgG4-related sclerosing sialadenitis., Study Design: A retrospective clinical study at the Yamagata University School of Medicine., Methods: The patient group consisted of six males and four females with an average age of 57.9 years (range, 38 to 73 years). Subsets of T helper (Th)1, Th2, T cytotoxic type (Tc)1, and Tc2 cells from patients with IgG4-related sclerosing sialadenitis were examined by using intracellular cytokine flow cytometry. Expression of IL-17 in the patients' lesions was also investigated immunohistochemically., Results: Six patients with IgG4-related sclerosing sialadenitis with high ratios of IgG4/IgG and prominent infiltration of IgG4-positive plasmacytes in the involved salivary glands had systemic complications, including pancreatitis, retroperitoneal fibrosis, and/or inflammatory pseudotumor of the lung after the initial swelling of the salivary glands. Populations of Th1 and Tc1 cells were significantly greater in IgG4-related sclerosing sialadenitis than in the controls (P < .05), but Th2 and Tc2 cell populations were not significantly increased. Expression of IL-17 was observed in the lesions of affected patients., Conclusions: Increases in Th1 and Tc1 cell populations and IL-17 expression might be involved in the mechanism of pathogenesis of IgG4-related sclerosing sialadenitis., (Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.)

Objectives/hypothesis: A new concept of IgG4-related sclerosing sialadenitis characterized by high serum IgG4 levels and tissue infiltration of IgG4-expressing plasmacytes has recently been proposed. To determine appropriate serum levels of IgG4 for monitoring disease activity, a total of 36 serum samples and eight tissue samples from patients with IgG4-related sclerosing sialadenitis were studied., Study Design: A retrospective clinical study at Yamagata University School of Medicine., Methods: The patient group consisted of six males and four females with an average age of 60 years (range, 47-74 years). Serum levels of IgG4 and the density of IgG4-positive plasmacytes in affected tissues were studied., Results: All patients had elevated serum IgG4 levels (>135 mg/dL), and IgG4-positive plasmacytes (IgG4+ plasma cells/IgG+ plasma cells >50%) were observed in the involved salivary glands. Six patients with IgG4-related sclerosing sialadenitis with high IgG4/IgG ratios and prominent infiltration of IgG4-positive plasmacytes in the involved salivary glands had systemic complications, including pancreatitis, retroperitoneal fibrosis, and/or inflammatory pseudotumor of the lung after swelling of the salivary glands. All six of these patients were successfully treated with systemic corticosteroids., Conclusions: In the six patients with systemic complications, treatment with systemic corticosteroids reduced the salivary gland enlargement and lowered serum IgG4 concentrations. These results suggest that IgG4 plays an important role in the pathogenesis of IgG4-related sclerosing sialadenitis, and that IgG4 levels and IgG4/IgG ratios may be used as additional indicators of disease activity and as biomarkers for potential life-threatening complications., (Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.)

To evaluate a modified rapid ELISA method for detecting CAg during Toxoplasma gondii infection, we analyzed the specificity and sensitivity of the ELISA method by using experimental Toxoplasma infection in rabbits and also tested this method in human samples including 5428 serum, 548 cerebrospinal fluid and two breast milk samples. We prepared PcAb, and used it for rapid one-step sandwich ELISA testing in which an incubation time in the regular ELISA procedure was omitted. This method detected CAg at the concentration of 31.2 ng/mL, and no cross-reaction was found with antigens of protozoa (Cryptosporidium parvum, Plasmodium falciparum), trematode (Schistosoma japonicum, Paragonimus sp.) and nematode (Brugia malayi, Ancylostoma duodenale, Ascaris lumbricoides and Trichinella spiralis). CAg was detected in rabbit serum 3 days after infection, and optical density values reached a peak 9-13 days after infection, then declined gradually. Among human serum samples, the positive rate of CAg was 2.11% in cerebral paralysis patients, whereas it was 0.22% or 0.71% in patients without neurological symptoms or in uncomplicated pregnant women. The difference among these three groups was statistically significant (P < 0.05). The positive rate of cerebrospinal fluid samples from cerebral paralysis patients was 10.58%. There is a statistically significant difference between the positive rates of meat-packing workers and blood donors (P < 0.01). In the retrospective analysis, CAg was detected in accordance with the onset of clinical symptoms, suggesting that CAg could reflect the clinical course in humans. Together with these results, CAg detected in the modified rapid sandwich ELISA could be a sensitive marker for acute and active infection of T. gondii.

Infection with the intracellular protozoan parasite Toxoplasma gondii causes serious public health problems to both humans and livestock and of great economic impact worldwide. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote Th1 responses, an adjuvant activity that is desirable for vaccination against intracellular pathogens. We investigated the feasibility of using CpG as an adjuvant combined with Toxoplasma lysate antigen (TLA) as a vaccine against toxoplasmosis. Genetically susceptible C57BL/6 mice were vaccinated with TLA with or without CpG ODN as an adjuvant and then challenged with 85 cysts of the moderately virulent RRA (Beverley) strain of T. gondii. Prior to challenge infection, immunization with TLA plus CpG ODN directed cellular and humoral immunity toward a Th1 pattern, characterized by enhanced INF gamma production by splenic cells in response to TLA, and enhanced production of toxoplasma-specific IgG and IgG (2a) antibodies. Consequently, CpG/TLA-treated mice showed prolonged survival and 64% reduction in brain parasite burden compared to non-CpG/TLA treated group. Our results suggest that CpG ODN would provide a stable and effective adjuvant for use in vaccination against toxoplasmosis.

DivK is an essential response regulator involved in the complex signal transduction network required for cell division and cell differentiation in Caulobacter crescentus. Small-angle X-ray scattering analysis was valuable for obtaining single crystals of the DivK recombinant protein. These crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 37.2, b = 40.5, c = 67.1 A and diffract beyond 1.6 A on a synchrotron beamline.

Binding capacities of synthetic peptides to HLA-DR molecules were tested on filter papers to identify putative helper T-cell epitopes on a malarial protein. The antigen tested was the merozoite surface glycoprotein 1 (MSP1) of Plasmodium falciparum, a vaccine candidate targeting the asexual erythrocytic stage. Bindings between synthetic oligopeptides and HLA-DR molecules were tested. Such bindings were not non-specific, and a known helper T-cell epitope peptide showed positive binding to the restricting HLA-DR molecule. By using this screening system, we observed the unequal distribution of HLA-DR-binding peptides in 10 out of 17 MSP1 blocks tested. Block #6 of MSP1 seemed to show the highest frequency in the positive binding; on the other hand, blocks #1 and #17, both of which were thought to be vaccine candidate regions, contained fewer HLA-DR binding peptides. This was not inconsistent with the results that block #17 was less stimulatory to peripheral T cells than block #6. The peptides with positive binding to HLA-DR showed actual epitope activities when we tested peptide-driven proliferation of human bulk T-cell lines, and association between the two parameters was statistically significant (P<0.001). For more detailed information for vaccine development, peptides with both IgG- and HLA-DR binding activities were mapped in block #17 of MSP1. Together with these results, we demonstrate that our simple screening system seems to provide essential information for vaccine development through uncovering locations of putative epitopes for human helper T cells.

T-cell epitopes of Der p II, a major allergen of Dermatophagoides pteronyssinus, were analyzed by using human T-cell clones. We tested 38 cloned T cells from two Japanese patients with allergic rhinitis, and identified at least two peptides (K33-T47 and I58-C73) as helper T-cell epitopes. The former epitope was shown to be restricted by HLA-DRB1*1502, and the latter by HLA-DRB1*0405, both of which are typical Japanese HLA-DR alleles, suggesting that those T-cell epitopes might be important for the onset of house-dust mite allergy in the Japanese population. We prepared 15 analog peptides of the HLA- DRB1*1502-restricted 15-mer peptide. Of those 15 residues, five (F35, L37, A39, F41, and E42) were critical for the epitope activity, and three residues (F35, A39, and E42) seemed to be included in anchor motifs for HLA-DRB1*1502. The epitope peptide was also recognized by HLA-DRB1*1502-positive healthy donors; however, only allergic T cells showed Th2 functions. Antigen-presenting cells of nonallergic donors were able to activate allergic T cells to express Th2 function. This seemed to suggest that antigen recognition of T cells, as well as additional unknown factors which promote Th2, rather than Th1, responses, might be important for the onset of house-dust mite allergy.

Responses of peripheral blood mononuclear cells to synthetic oligopeptides of Der p II, one of the major allergen molecules of Dermatophagoides pteronyssinus, were compared between allergic and nonallergic subjects. Healthy subjects showed positive responses to crude extracts of D. pteronyssinus, but only allergic subjects showed elevated cellular responses to Der p II. We synthesized three oligopeptides of Der p II in which motifs of a possible T-cell epitope were included. Of 14 subjects with positive response to Der p II, three responded to all three peptides, while five did not respond to any peptide tested. In 11 allergic patients who showed positive response to Der p II, responsiveness to the peptide K33-T47 was significantly higher than that to other peptides (P < 0.05). All the responding patients were also positive for scratch test to Der p II, suggesting that those epitopes induced IgE-promoting helper T-cell response in allergic persons. On the other hand, the in vitro cellular responses were not necessarily correlated to IgE production against Der p II in healthy subjects.

To analyse the cross-reactivity of T-cell-mediated immunity between Dermatophagoides pteronyssinus (Dp) and Chironomus yoshimatsui (Cy), the most common allergens in Japan, we established antigen-specific human T-cell lines and clones. Some but not all of the Cy-induced T-cell lines showed a significant proliferative response not only to Cy, but also to Dp. No T-cell line responded to other unrelated antigens. When we stimulated the Dp-induced T-cell clones with Cy, 3 of the 40 clones (7.5%) showed a significant proliferation, and 2 of the 3 clones produced interleukin-4 and interferon-gamma, indicating their helper function. Cross-reactivity was diminished significantly after the absorption of Dp antigen in an anti-Cy affinity column. The cross-reactive epitopes were thought to be expressed on the Dp molecule of 45-53 kD. The presence of helper T cells reactive to both allergens suggests a possibility that this cross-reactivity might be involved in part in the high incidence of allergy to the 2 major allergens.