Analysis of All 34 Exons of the SPINK5 Gene in Japanese Atopic Dermatitis Patients.

Lympho-epithelial Kazal-type-related inhibitor (LEKTI) is a large multidomain serine protease inhibitor that is expressed in epidermal keratinocytes. Nonsense mutations of the SPINK5 gene, which codes for LEKTI, cause Netherton syndrome, which is characterized by hair abnormality, ichthyosis, and atopy. A single nucleotide polymorphism (SNP) of SPINK5, p.K420E, is reported to be associated with the pathogenesis of atopic dermatitis (AD). We studied all 34 exons of the SPINK5 gene in Japanese 57 AD patients and 50 normal healthy controls. We detected nine nonsynonymous variants, including p.K420E; these variants had already been registered in the SNP database. Among them, p.R654H (n=1) was found as a heterozygous mutation in the AD patients, but not in the control. No new mutation was detected. We next compared the data of the AD patients with data from the Human Genetic Variation Database provided by Kyoto University; a significant difference was found in the frequency of the p.S368N genotype distribution. PolyPhen-2 and SIFT, two algorithms for predicting the functional effects of amino acid substitutions, showed significant scores for p.R654H. Therefore, R654H might be a risk factor for epidermal barrier dysfunction in some Japanese AD patients.

Addition Rate Constants of Phosphorus- and Carbon-Centered Radicals to Double Bond of Monomers as Studied by a Pulsed Electron Paramagnetic Resonance Method.

Addition reaction of a radical to the double bond of a monomer, which is important at early stage of photopolymerization, has been studied by time-resolved (TR-) and pulsed electron paramagnetic resonance (EPR) spectroscopic methods. Reactions of one phosphorus-centered and three carbon-centered radicals attacking to several monomers have been employed. Intermediate radicals were identified by analyzing the recorded TR-EPR spectra, and the reaction rate constants were determined by the electron spin-echo detection method proposed by Weber and Turro [J. Phys. Chem. A, 2003, 107 (18), 3326 - 3334]. The quantum chemical calculation shows that the rate constants for the addition reactions are well-explained by introducing two factors of "enthalpy effect" and "polar effect" to control the activation barrier height. It was observed that the rate constants of the phosphorus-centered radical were larger than those of carbon-centered radicals for some monomers. The difference in the rate constants was argued on the basis of frequency factor and activation barrier both of which are influenced by an atom of radical center.

Photochemistry of the ozone-water complex in cryogenic neon, argon, and krypton matrixes.

The photochemistry of ozone-water complexes and the wavelength dependence of the reactions were studied by matrix isolation FTIR spectrometry in neon, argon, and krypton matrixes. Hydrogen peroxide was formed upon the irradiation of UV light below 355 nm. Quantitative analyses of the reactant and product were performed to evaluate the matrix cage effect of the photoreaction. In argon and krypton matrixes, a bimolecular O((1)D) + H2O → H2O2 reaction was found to occur to form hydrogen peroxide, where the O((1)D) atom generated by the photolysis of ozone diffused in the cryogenic solids to encounter water. In a neon matrix, hydrogen peroxide was generated through intracage photoreaction of the ozone-water complex, indicating that a neon matrix medium is most appropriate to study the photochemistry of the ozone-water complex.

Analysis of low-lying gerade Rydberg states of acetylene using two-photon resonance fluorescence excitation spectroscopy.

The np gerade Rydberg states of acetylene were analyzed using two-photon resonance fluorescence excitation spectroscopy in the 72,000-93,000 cm(-1) energy region. The npπ(1)Σ(g)(+) and npπ(1)Δ(g) Rydberg series (n = 3-5) were identified in the fluorescence excitation spectrum measured by monitoring the C(2) d(3)Π(g)-a(3)Π(u) Swan system. Some vibronic bands were assigned to the npπ(1)Δ(g)-X̃(1)Σ(g)(+) transition on the basis of rotational analysis. The 5pσ(1)Π(g) state was observed, which is the first such observation in an npσ(1)Π(g) series. Rotational analysis of the 5pσ(1)Π(g)-X̃(1)Σ(g)(+) transition showed e/f-symmetry dependent predissociation of acetylene in the 5pσ(1)Π(g) state. The 0(0)(0) band of the deuterated acetylene (C(2)D(2)) 4pπ(1)Σ(g)(+)-X̃(1)Σ(g)(+) transition exhibits an atypical structure, which was satisfactorily reproduced by a simple model of quantum interference between the discrete and quasi-continuum states. The predissociative lifetimes of the npπgerade Rydberg states were estimated from the spectral profiles. The predissociation mechanism of acetylene in the Rydberg states is discussed.

A phase I study of vaccination with NY-ESO-1f peptide mixed with Picibanil OK-432 and Montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

We conducted a phase I clinical trial of a cancer vaccine using a 20-mer NY-ESO-1f peptide (NY-ESO-1 91-110) that includes multiple epitopes recognized by antibodies, and CD4 and CD8 T cells. Ten patients were immunized with 600 µg of NY-ESO-1f peptide mixed with 0.2 KE Picibanil OK-432 and 1.25 ml Montanide ISA-51. Primary end points of the study were safety and immune response. Subcutaneous injection of the NY-ESO-1f peptide vaccine was well tolerated. Vaccine-related adverse events observed were fever (Grade 1), injection-site reaction (Grade 1 or 2) and induration (Grade 2). Vaccination with the NY-ESO-1f peptide resulted in an increase or induction of NY-ESO-1 antibody responses in nine of ten patients. The sera reacted with recombinant NY-ESO-1 whole protein as well as the NY-ESO-1f peptide. An increase in CD4 and CD8 T cell responses was observed in nine of ten patients. Vaccine-induced CD4 and CD8 T cells responded to NY-ESO-1 91-108 in all patients with various HLA types with a less frequent response to neighboring peptides. The findings indicate that the 20-mer NY-ESO-1f peptide includes multiple epitopes recognized by CD4 and CD8 T cells with distinct specificity. Of ten patients, two with lung cancer and one with esophageal cancer showed stable disease. Our study shows that the NY-ESO-1f peptide vaccine was well tolerated and elicited humoral, CD4 and CD8 T cell responses in immunized patients.

Markedly elevated serum levels of calcium-binding S100A8/A9 proteins in psoriatic arthritis are due to activated monocytes/macrophages.

BACKGROUND: Serum levels of S100A8/A9 may correlate with disease activity in psoriasis. OBJECTIVE: We sought to elucidate the association of serum levels of S100A8/A9 heterodimers with the clinical subtypes of psoriasis and the major cell source. METHODS: Serum samples were collected from patients with psoriasis vulgaris (n = 30), psoriatic arthritis (PA) (n = 16), pustular psoriasis (n = 24), and atopic dermatitis (n = 14) and from healthy control subjects (n = 21). Serum concentrations of S100A8/A9 were measured, and the expression levels were examined in psoriatic lesions. The messenger RNA levels were quantified in circulating monocytes and neutrophils. RESULTS: Serum levels of S100A8/A9 were significantly increased in all subtypes of psoriasis as compared with healthy controls and atopic dermatitis. Among the psoriatic subtypes, PA and pustular psoriasis showed remarkably high concentrations of S100A8/A9 heterodimers. The higher serum levels were associated with the presence of articular symptoms, but not significantly correlated with body surface areas of psoriatic lesions. S100A8 was expressed by both keratinocytes and infiltrating mononuclear cells, whereas S100A9 was predominantly expressed by neutrophils. The expression levels of S100A8 and S100A9 messenger RNA in monocytes were increased by approximately 2.25- and 1.91-fold in PA, respectively, whereas no significant increase was observed in psoriasis vulgaris and pustular psoriasis. LIMITATIONS: Difficulty in acquisition of clinical and laboratory samples in untreated patients, and of a sufficient number of subjects, were limitations. CONCLUSIONS: Although serum levels of S100A8/A9 were increased in all types of psoriasis examined, patients with PA had higher levels of S100A8/A9, probably because of an activated monocyte/macrophage system.

Infrared spectroscopy and quantum chemical calculations of OH-(H2O)n complexes.

Infrared spectra of OH-(H2O)n (n = 1, 2) isolated in solid Ne were measured by FT-IR spectroscopy. Complexes of OH-(H2O)n were prepared by vacuum ultraviolet (VUV) photolysis of water clusters, and the OH radical stretch and HOH bending vibrations of OH-H2O and OH-(H2O)2 complexes were identified with the aid of quantum chemical calculations. Observation of the recombination reaction OH-H2O + H --> (H2O)2 under dark conditions provides undisputed evidence for our spectroscopic assignment. Quantum chemical calculations predict the cyclic structure to be the most stable for OH-(H2O)2 and OH-(H2O)3. The strength of the hydrogen bond within OH-(H2O)n depends on cluster size.

Tracing of the molecular remnants of herpes virus infections in necrotic skin tissue.

We have established an assay system to detect herpesvirus-derived transcripts in lesional crusts. Fifteen patients with herpes simplex (HS), 21 with herpes zoster (HZ), 2 with varicella, and 20 with irrelevant diseases were enrolled in the present study. Total RNA was extracted from crusts or scales, and converted to cDNA. Virus-encoded transcripts were amplified using reverse transcriptase (RT)-PCR. Housekeeping gene transcripts such as beta2-microglobulin (beta2-MG) and beta-actin (beta-actin) mRNA were also examined, and an efficient preservative condition of the crusts was determined. With extracted RNAs, beta2-MG and beta-actin mRNA were successfully amplified in all crust samples. Herpes simplex virus (HSV)-specific, lytic cycle-related transcript, UL30 mRNA was detected in all 15 HS samples, including 13 samples of HSV-1- and 2 of HSV-2-encoded UL30 mRNA, respectively. Of 23 samples, including 21 HZ and 2 varicella cases, varicella zoster virus (VZV)-specific, lytic cycle-related transcript, ORF40 mRNA was detected in 22 samples. In a control group, no UL30 and ORF40 mRNA were detected. Crust samples that had been stored without any pretreatment or preservative for 6 months at room temperature (RT) were available for the present assay. When compared with the freshly obtained materials, the amount of beta2-MG mRNA was reduced to 51% in the stored samples covered with adhesive tape, to 48% in a sample left at R.T. without any treatment, and to 1.2% in the samples stocked in saline for 5 days. Herpes virus- and host-derived transcripts contained in crusts can be detected by RT-PCR amplification. Crusts or dry epidermal necrosis with inflammatory cells may provide beneficial diagnostic information.

T cell immunomonitoring and tumor responses in patients immunized with a complex of cholesterol-bearing hydrophobized pullulan (CHP) and NY-ESO-1 protein.

We recently showed that vaccination with a complex of cholesterol-bearing hydrophobized pullulan and NY-ESO-1 protein (CHP-NY-ESO-1) elicited antibody responses in 9 of 9 patients vaccinated in a clinical trial. In this study, we performed T cell immunomonitoring and analyzed tumor responses in these patients. To evaluate CD4 and CD8 T cell responses, an IFN-gamma secretion assay was used. The assay showed low background and was sensitive for detecting antigen-specific T cells. An increase in the CD4 T cell response was observed in 2 of 2 initially sero-positive and 5 of 7 initially sero-negative patients after vaccination. An increase in the CD8 T cell response was also observed in 2 of 2 sero-positive and 5 of 7 sero-negative patients after vaccination. Analysis of peptides recognized by CD4 and CD8 T cells revealed two dominant NY-ESO-1 regions, 73-114 and 121-144. Tumor responses were observed in 3 esophageal cancer patients and a malignant melanoma patient. In 3 of 4 prostate cancer patients, prostate-specific antigen (PSA) values stabilized during the course of vaccination. The use of whole protein, containing multiple CD4 and CD8 epitopes, may be beneficial for cancer vaccines to prevent tumors from evading the immune response.

A novel, noninvasive diagnostic probe for hydroa vacciniforme and related disorders: detection of latency-associated Epstein-Barr virus transcripts in the crusts.

OBJECTIVE: To establish a new diagnostic method for Epstein-Barr virus (EBV)-associated cutaneous disorders. DESIGN: Skin biopsy is usually required to confirm the latent EBV infections in cutaneous lesions of EBV-associated NK/T-cell lymphoproliferative disorders, including hydroa vacciniforme (HV) and hypersensitivity to mosquito bites (HMB). We have devised a novel, noninvasive method to detect EBV-encoded small RNA (EBER), BamHI A rightward transcripts (BARTs) in the skin crusts and scales of such patients. PATIENTS: Six patients with EBV-associated cutaneous lesions were enrolled in the present study, including three patients with HV, one with HV-like eruptions and chronic active EBV infection, and two with EBV-associated cutaneous lymphoma. MAIN OUTCOME MEASURES: RNA was extracted from the crusts obtained from the cutaneous lesions by forceps, converted to cDNA, and processed for polymerase chain reaction (PCR) amplification with a specific set of primers. The PCR products were assayed by a DNA sequencer. RESULTS: Intact RNAs were successfully extracted from the crusts as well as control materials. EBER1 and BARTs RNAs were detected in all 7 crusts, and in 6 of 7 crusts of EBV-associated cutaneous diseases, respectively. One of 23 crusts from non EBV-associated diseases was positive for EBER1 RNA. The sensitivity and specificity of our assay for latent EBV infection were 100% and 95.8% for EBER1 RNA, and 85.7% and 100% for BARTs mRNA, respectively. The correct DNA sequence for EBER1 and BARTs was confirmed in the PCR products by a direct sequencing method. CONCLUSIONS: Our procedure may be of use as a biomarker for EBV-associated cutaneous lesions, including HV, HMB, and NK/T-cell lymphomas.

Prospective study of clinical symptoms and skin test reactions in medical students exposed to formaldehyde gas.

Previous investigators have reported the occurrence of both allergic and non-allergic systemic complications due to exposure to formaldehyde gas. However, little is known about the pathogenic link between formaldehyde-induced clinical symptoms and patch test results, or about the long-term effects of formaldehyde exposure. In the present study, a questionnaire was administered to 143 medical students, and 60 of them were tested by patch test for formaldehyde at the beginning and end of a human anatomy laboratory course. Another group of 76 students who had finished the course 2-4 years previously were administered another questionnaire, and the patch test was carried out on 58 of them. The frequencies of skin irritation, eye soreness, lacrimation, eye fatigue, rhinorrhea, throat irritation, general fatigue and mood swings increased after repeated exposure. Two (3.3%) of 60 students became positive to 1% formaldehyde at the end of the anatomy course (one male with allergic hand dermatitis due to direct contact with formaldehyde, and one female with an atopic background with unbearable physical symptoms) while the remaining 58 showed a negative reaction throughout the study period. The vast majority of students complained of various non-allergic, physical symptoms, and recovered from such symptoms without subsequent complications. No progression to multiple chemical sensitivity was found. Students with an episode of atopic dermatitis and allergic rhinitis were susceptible to formaldehyde exposure, and developed mucocutaneous symptoms, probably due to the impaired barrier function and remodeling of the skin and mucosa.

Pathogenic link between hydroa vacciniforme and Epstein-Barr virus-associated hematologic disorders.

OBJECTIVES: To determine the pathogenic association of latent Epstein-Barr virus (EBV) infections with both typical hydroa vacciniforme (HV) and severe HV-like eruptions, and to survey the complications and outcomes of patients. DESIGN: Case series. PATIENTS: Twenty-nine patients with HV or severe HV-like eruptions. INTERVENTIONS: In situ hybridization and immunostaining of biopsy specimens; extraction of DNA samples from cutaneous lesions and/or peripheral blood mononuclear cells for EBV DNA assay. MAIN OUTCOME MEASURES: Clinicopathologic manifestations, hematologic findings, complications, and outcomes; presence of latent EBV infection. RESULTS: T cells positive for EBV-encoded small nuclear RNA (EBER) were detected, to various degrees, in cutaneous infiltrates in 28 (97%) of 29 patients, including all 6 patients with definite HV with a positive phototest reaction, 11 of 12 patients with probable HV without evidence of photosensitivity, and all 11 patients with severe HV associated with systemic symptoms. In addition to EBER-positive T cells, many cytotoxic T lymphocytes expressing T-cell intracellular antigen 1 and granzyme B were present in the cutaneous lesions. Natural killer (NK) cells were absent or at a background level. The UV-induced cutaneous lesions showed histopathologic findings consistent with those of HV, containing many EBER-positive cells. Although no hematologic abnormalities were found in the definite and probable HV groups, the amounts of EBV DNA were increased in the peripheral blood mononuclear cells. By contrast, the severe HV group had markedly increased levels of EBV DNA associated with NK-cell lymphocytosis, and complications including chronic active EBV infection, hypersensitivity to mosquito bites, and hemophagocytic syndrome. Five patients with severe disease died of EBV-associated NK/T-cell lymphomas or hemophagocytic syndrome 2 to 14 years after onset. CONCLUSION: Both typical and severe HV are included within the spectrum of cutaneous disorders mediated by EBV-infected T cells, and the severe HV group may have overt EBV-associated NK/T-cell lymphoproliferative disorders with a frequently fatal outcome.

Primary cutaneous marginal zone B-cell lymphoma.

We report a Japanese case of primary cutaneous marginal zone B-cell lymphoma (PCMZL). This 46-year-old woman presented with a subcutaneous nodule on her right forearm. With the combined morphology,the immunophenotype, and molecular analysis, we diagnosed this lesion as PCMZL. Furthermore, we reviewed the 16 cases of PCMZL in the Japanese literature. The ages of the patients ranged from 26 to 75 years (mean 55.7 years) with a slight female predilection. Clinically, most of the skin lesions were erythematous nodular lesions. The involved regions were the face and neck in eight cases, the trunk in six and the arms in five. None had Borrelia burgdorferi infection or a history of thyroiditis. Two patients had suffered from Sjögren's syndrome. Histopathologically, lymphoepithelial lesions were found in nine cases. The chromosomal aberrations in MALT lymphoma such as t(11;18)(q21;q21), t(14;18)(q32;q21) and t(3;14)(p14.1;q32) were not reported in any of the Japanese cases. Although two patients developed metastasis on the skin after radiation therapy, none died of lymphoma.

Fatal natural killer cell lymphoma arising in a patient with a crop of Epstein-Barr virus-associated disorders.

Natural killer (NK) lymphoma in Asia is frequently associated with latent Epstein-Barr (EBV) infection. Unlike the adult cases, EBV-associated NK/T cell lymphomas in children are often preceded by various EBV-related disorders, including chronic active EBV infection (CAEBV), hypersensitivity to mosquito bites (HMB), virus-associated haemophagocytic syndrome (VAHS), and hydroa vacciniforme (HV)-like eruptions. Here, we report a 14-year-old Japanese girl who sequentially developed all the symptoms related to EBV-associated NK/T cell lymphoproliferative disorders in a 12-year clinical course. Our observations confirm the spectrum of EBV-associated cutaneous disorders and indicate the importance of long-term follow-up.

Evidence that the mouse 3' kappa light chain enhancer confers position-independent transgene expression in T- and B-lineage cells.

One of the major obstacles for successful application of murine leukemia virus (MLV) vectors to genetic therapy of lymphocyte disorders is low levels of transgene expression or the eventual loss of expression. To overcome this problem, an improved retroviral vector was constructed utilizing the myeloproliferative sarcoma virus (MPSV) long terminal repeat (LTR), which provided a significantly higher level of transgene expression in human lymphoid cells than did MLV vectors. Nevertheless, transgene expression remained low in a large percentage of transduced cells. To address whether lymphocyte enhancer elements might improve transgene expression mediated by retroviral vectors in lymphocytes, we cloned the mouse immunoglobulin 3' kappa light chain enhancer gene (mE3') into the MPSV vector. We found that the mE3' conferred a higher, more uniform and sustained level of expression in transduced T- and B-cell lines, and in primary T cells, than did the control vector lacking this element. Integration sites were diverse and a single copy of the proviral genome was present in all examined transduced cells. The mE3' failed to enhance transgene expression in most nonlymphoid cells, indicating it is relatively lineage-specific. Taken together, these results provide strong evidence that the mE3' functions as a locus control region (LCR) in conferring enhanced integration-site-independent expression of a retroviral transgene.

A convenient method for positive selection of retroviral producing cells generating vectors devoid of selectable markers.

Early retroviral vectors containing both a therapeutic gene and a dominant selectable marker gene, offered some distinct advantages with respect to gene therapy, in that they simplified the generation, isolation, and titration of retroviral producer cell clones, as well as the evaluation and selection of successfully targeted cells. However, a number of problems were engendered by this strategy: the promoter driving the selectable marker gene could interfere with transcription of the therapeutic gene, and immune responses could be induced to cells expressing foreign proteins of selection marker origin. Simplified retroviral vectors, which lack a selection marker gene, were constructed to address these problems, but the inability to use a selection marker has made identification and cloning of virus producing transfected cells a heavy burden. To maintain the benefits of simplified retroviral vectors, while providing a facile means to select packaging cells transfected with retroviral DNA, we cloned the bacterial selection marker gene encoding neomycin phosphotransferase (neo) into the plasmid backbone of the vector, but outside of the provirus, resulting in efficient selection of transfected packaging cells and generation of packaged virus which lacks the neo gene. This novel approach generates greater numbers of high infectious titer producing clones, after selection in G418 media, than does a co-transfection approach, due to integration of higher construct copy numbers per cell. No transmission of the selection marker gene to target cells was observed following retroviral transduction. Thus, our strategy eliminates the adverse consequences of a selection-based method, while diminishing the burden of identification of packaging cells transfected with vectors devoid of selectable markers.

A spectrum of clinical manifestations caused by host immune responses against Epstein-Barr virus infections.

Epstein-Barr virus (EBV), or human herpesvirus 4 (HHV-4), infects the vast majority of adults worldwide, and establishes both nonproductive (latent) and productive (lytic) infections. Host immune responses directed against both the lytic and latent cycle-associated EBV antigens induce a diversity of clinical symptoms in patients with chronic active EBV infections who usually contain an oligoclonal pool of EBV-infected lymphocyte subsets in their blood. Episomal EBV genes in the latent infection utilize an array of evasion strategies from host immune responses: the minimized expression of EBV antigens targeted by host cytotoxic T lymphocytes (CTLs), the down-regulation of cell adhesion molecule expression, and the release of virokines to inhibit the host CTLs. The oncogenic role of latent EBV infection is not yet fully understood, but latent membrane proteins (LMPs) expressed during the latency cycle have essential biological properties leading to cellular gene expression and immortalization, and EBV-encoded gene products such as viral interleukin-10 (vIL-10) and bcl-2 homologue function to survive the EBV-infected cells. The subsequent oncogenic DNA damage may lead to the development of neoplasms. EBV-associated NK/T cell lymphoproliferative disorders are prevalent in Asia, but quite rare in Western countries. The genetic immunological background, therefore, is closely linked to the development of EBV-associated neoplasms.

Vaccination with NY-ESO-1 overlapping peptides mixed with Picibanil OK-432 and montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

We conducted a clinical trial of an NY-ESO-1 cancer vaccine using 4 synthetic overlapping long peptides (OLP; peptides #1, 79-108; #2, 100-129; #3, 121-150; and #4, 142-173) that include a highly immunogenic region of the NY-ESO-1 molecule. Nine patients were immunized with 0.25 mg each of three 30-mer and a 32-mer long NY-ESO-1 OLP mixed with 0.2 KE Picibanil OK-432 and 1.25 mL Montanide ISA-51. The primary endpoints of this study were safety and NY-ESO-1 immune responses. Five to 18 injections of the NY-ESO-1 OLP vaccine were well tolerated. Vaccine-related adverse events observed were fever and injection site reaction (grade 1 and 2). Two patients showed stable disease after vaccination. An NY-ESO-1-specific humoral immune response was observed in all patients and an antibody against peptide #3 (121-150) was detected firstly and strongly after vaccination. NY-ESO-1 CD4 and CD8 T-cell responses were elicited in these patients and their epitopes were identified. Using a multifunctional cytokine assay, the number of single or double cytokine-producing cells was increased in NY-ESO-1-specific CD4 and CD8 T cells after vaccination. Multiple cytokine-producing cells were observed in PD-1 (-) and PD-1 (+) CD4 T cells. In conclusion, our study indicated that the NY-ESO-1 OLP vaccine mixed with Picibanil OK-432 and Montanide ISA-51 was well tolerated and elicited NY-ESO-1-specific humoral and CD4 and CD8 T-cell responses in immunized patients.

Hydroa vacciniforme is associated with increased numbers of Epstein-Barr virus-infected γδT cells.

Hydroa vacciniforme (HV) is a rare photosensitivity disorder of childhood associated with Epstein-Barr virus (EBV)(+) T-cell infiltration. We have summarized clinical manifestations of HV, and analyzed EBV(+) T-cell subsets as well as EBV DNA load in lymphocyte fractions, in comparison with hypersensitivity to mosquito bites (HMB), an EBV-associated T/natural killer (NK) lymphoproliferative disorder. We found that 31 of 33 (93.9%) HV lesions were composed of EBV(+) T cells and reactive EBV(-) cytotoxic T cells, without significant CD56(+) cell infiltration, whereas many CD56(+) cells were present in 8 of 9 (88.9%) HMB lesions. Of 13 (20.6%) HMB patients with or without HV, 12 (92.3%) showed increased percentages (>32%) of NK cells in the peripheral blood, whereas in the 16 patients with HV alone, 14 (87.5%) showed no increase. Of the 11 HV patients, 10 (90.9%) had increased percentages (>5%) of circulating γδT cells, with a mean value of 15.7 ± 2.9%, and the γδT-cell fractions contained larger amounts of EBV DNA than non-γδT-cell fractions. A triple-labeling method revealed that all three HV patients examined had increased percentages of EBER(+), T-cell receptor (TCR)γδ(+), and TCRαß(-) cells. Our observations indicate that HV is associated with increased numbers of EBV(+) γδT cells, whereas HMB is associated with EBV(+) NK cells.

Regulatory T cells in γ irradiation-induced immune suppression.

Sublethal total body γ irradiation (TBI) of mammals causes generalized immunosuppression, in part by induction of lymphocyte apoptosis. Here, we provide evidence that a part of this immune suppression may be attributable to dysfunction of immune regulation. We investigated the effects of sublethal TBI on T cell memory responses to gain insight into the potential for loss of vaccine immunity following such exposure. We show that in mice primed to an MHC class I alloantigen, the accelerated graft rejection T memory response is specifically lost several weeks following TBI, whereas identically treated naïve mice at the same time point had completely recovered normal rejection kinetics. Depletion in vivo with anti-CD4 or anti-CD25 showed that the mechanism involved cells consistent with a regulatory T cell (T reg) phenotype. The loss of the T memory response following TBI was associated with a relative increase of CD4+CD25+ Foxp3+ expressing T regs, as compared to the CD8+ T effector cells requisite for skin graft rejection. The radiation-induced T memory suppression was shown to be antigen-specific in that a third party ipsilateral graft rejected with normal kinetics. Remarkably, following the eventual rejection of the first MHC class I disparate skin graft, the suppressive environment was maintained, with markedly prolonged survival of a second identical allograft. These findings have potential importance as regards the immunologic status of T memory responses in victims of ionizing radiation exposure and apoptosis-inducing therapies.