Delayed-type Hypersensitivity Skin Reactions Research Articles

Regulation of cell-mediated immune responses in dairy bulls via long non-coding RNAs from submandibular lymph nodes, peripheral blood, and the spleen

Cell-mediated immune responses (CMIRs) are critical to building a robust immune system and reducing disease susceptibility in cattle. Long non-coding RNAs (lncRNAs) regulate various biological processes. However, to the best of our knowledge, the characterization and functions of lncRNAs and their regulations on the bovine CMIR have not been investigated comprehensively. In this study, experimental bulls were immunized with a heat-killed preparation of Candida albicans (HKCA) to induce delayed-type hypersensitivity (DTH). Three bulls were classified as high- CMIR responders and three were low-CMIR responders, based on their classical DTH skin reactions. LncRNAs were identified in the submandibular lymph nodes, peripheral blood, and spleen of high- and low-CMIR animals using strand-specific RNA sequencing. A total of 21,003 putative lncRNAs were identified across tissues, and 420, 468, and 599 lncRNAs were differentially expressed between the two groups in the submandibular lymph node, peripheral blood, and spleen tissues, respectively. Functional analysis of the differentially expressed lncRNA (DElncRNA) target genes showed that a number of immune-related Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were enriched, including immune response, cell adhesion, nucleosome, DNA packaging, antigen processing and presentation, and complement and coagulation cascades. Tissue specificity analysis indicated that lncRNA transcripts have stronger tissue specificity than mRNA. Furthermore, an interaction network was constructed based on DElncRNAs and DEGs, and 11, 14, and 11 promising lncRNAs were identified as potential candidate genes influencing immune response regulation in submandibular lymph nodes, peripheral blood, and spleen tissues, respectively. These results provide a foundation for further research into the biological functions of lncRNAs associated with bovine CMIR and identify candidate lncRNA markers for cell-mediated immune responses.

A phase I trial of diphencyprone for cutaneous neurofibromas in adult patients with neurofibromatosis type 1.

TPS2678 Background: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic tumor predisposition syndrome affecting about 1 in 2500 people. Affected patients develop a variety of skin findings including café-au-lait macules, axillary freckling, and cutaneous neurofibromas (cNFs). These patients also have an increased risk of malignant tumors including gliomas and soft tissue sarcomas. However, the cNFs, of which a patient can have thousands, are often cited as the most burdensome sign. Despite their benign nature, these tumors can be physically bothersome and cause significant emotional distress. To date, there are no effective pharmacotherapies for these tumors. This is a single-center, phase I, open label trial to evaluate the safety, tolerability, and efficacy of diphencyprone (DPCP), a topical hapten that induces a delayed-type hypersensitivity skin reaction, for the treatment of cNFs in adults with NF1. Methods: This trial is enrolling NF1 patients aged 18 and older with at least four cNFs greater than 4mm. Subjects taking systemic immunosuppressants, those with underlying immunodeficiency or uncontrolled intercurrent illnesses, and those who are pregnant or nursing are excluded from the study. DPCP 0.04% ointment is administered topically once weekly to up to 20 cNFs in a localized area for 10 weeks. The primary endpoint is to determine the safety and tolerability of DPCP ointment in the treatment of cNFs. Adverse events are graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. To assess subjective tolerability, subjects score their symptoms, including pain, stinging, burning, and pruritus from 0 (none) to 3 (severe). Efficacy and tumor regression are assessed using the Response Evaluation Criteria in Solid Tumors guidelines in conjunction with photographs and manual tri-axial tumor measurements. Additionally, qualitative assessments are made by the study team using 3D whole-body photography. One treated tumor is tracked throughout the study with optical coherence tomography (OCT) imaging. Skin biopsies of a cNF and surrounding tissue are collected at baseline, on Day 17 after treatment initiation, and four weeks post-treatment for exploratory endpoints. Quantitative RT-PCR and single-cell RNA sequencing studies will assess gene expression changes in immune and tumor cell-related genes pre- and post-treatment with DPCP. Immunohistochemistry and proteomic profiling will be performed to characterize changes in the tumor microenvironment. Genetic testing for the NF1 germline mutation will be correlated with treatment response. Enrollment is ongoing with a target of 20 participants. Since September 2022, the study has enrolled 12 patients and five have completed the study. Clinical trial information: NCT05438290 .

WT1 Trio Peptide-Based Cancer Vaccine for Rare Cancers Expressing Shared Target WT1.

No standard treatment has been established for most rare cancers. Here, we report a clinical trial of a biweekly WT1 tri-peptide-based vaccine for recurrent or advanced rare cancers. Due to the insufficient number of patients available for a traditional clinical trial, the trial was designed for rare cancers expressing shared target molecule WT1. The recruitment criteria included WT1-expressing tumors as well as HLA-A*24:02 or 02:01. The primary endpoints were immunoglobulin G (IgG) antibody (Ab) production against the WT1-235 cytotoxic T lymphocyte (CTL) epitope and delayed-type hypersensitivity (DTH) skin reactions to targeted WT1 CTL epitopes. The secondary endpoints were safety and clinical efficacy. Forty-five patients received WT1 Trio, and 25 (55.6%) completed the 3-month protocol treatment. WT1-235 IgG Ab was positive in 88.0% of patients treated with WT1 Trio at 3 months, significantly higher than 62.5% of the weekly WT1-235 CTL peptide vaccine. The DTH positivity rate in WT1 Trio was 62.9%, which was not significantly different from 60.7% in the WT1-235 CTL peptide vaccine. The WT1 Trio safety was confirmed without severe treatment-related adverse events, except grade 3 myasthenia gravis-like symptoms observed in a patient with thymic cancer. Fifteen (33.3%) patients achieved stable disease after 3 months of treatment. In conclusion, the biweekly WT1 Trio vaccine containing the WT1-332 helper T lymphocyte peptide induced more robust immune responses targeting WT1 than the weekly WT1-235 CTL peptide vaccine. Therefore, WT1-targeted immunotherapy may be a potential therapeutic strategy for rare cancers.

Evaluation of Antineoplastic Delayed-Type Hypersensitivity Skin Reactions In Vitro.

Delayed-type hypersensitivity (DTH) is caused by a broad number of drugs used in clinic, and antineoplastic drugs show an elevated proportion of DTH, which potentially affects the quality of life of patients. Despite the serious problem and the negative economic impact deriving from market withdrawal of such drugs and high hospitalization costs, nowadays, there are no standard validated methods in vitro or in vivo to evaluate the sensitizing potential of drugs in the preclinical phase. Enhanced predictions in preclinical safety evaluations are really important, and for that reason, the aim of our work is to adapt in vitro DPRA, ARE-Nrf2 luciferase KeratinoSensTM, and hCLAT assays for the study of the sensitizing potential of antineoplastic agents grouped by mechanism of action. Our results reveal that the above tests are in vitro techniques able to predict the sensitizing potential of the tested antineoplastics. Moreover, this is the first time that the inhibition of the VEGFR1 pathway has been identified as a potential trigger of DTH.

Milk microRNA-146a as a potential biomarker in bovine tuberculosis.

In this research communication we exploited the potential use of milk microRNAs (miRs) as biomarkers for bovine tuberculosis (bTB). bTB is a zoonotic disease caused by Mycobacterium bovis which affects animal health, influencing herd economic sustainability. Diagnosis is based on skin delayed-type hypersensitivity reaction and quantification of interferon gamma but both techniques are influenced by several confounding factors. Thus, new methods for early diagnosis are required. In this context, microRNAs have been used as promising biomarkers for both infectious and non-infectious diseases. To determine the possible involvement of microRNAs in bTB, we analysed the expression of four immune-related miRs in 200 cows grouped in cases and controls with respect to positivity to tuberculosis. The analysis showed a different magnitude of expression in the groups indicating that active tuberculosis could influence miRs expression. We used expression values of miR-146a, the highest differentially expressed miR, for Receiver operating characteristic (ROC) curve analysis. In order to determine a test cut-off value for miR-146a expression that would differentiate cases and controls, a value for the miR-146a expression higher than 8 was selected as this gave a test specificity and sensitivity of 80·0% and 86·0% respectively. These values confirm the possibility of using miR-146a as a milk prognostic biomarker for bovine tuberculosis.

Psycho-immunological rehabilitation of advanced cancer patients with psychogenic medical history

The aim of this work is approbation of the pathogenetically substantiated psycho­immunological rehabilitation of advanced cancer patients with psychogenic medical history. 17 advanced cancer patients (with 6 various types of cancer) took part in this study. All psycho­emotional disorders were diagnosed clinically and psychometrically (SCL 90). The treatment of signs and symptoms of mentioned disorders included hypnotherapy and psychotropic drugs. The specific anti­tumor activity of the immune system was assessed by the delayed type hypersensitivity skin reaction on the tumor­associated antigens. An activation of specific anti­tumor immunity was provided only after stable clinical effect of psycho-correction by specially developed methods of epicutaneous and modified extra­corporeal activation. The effective treatment of psycho­emotional disorders had a direct correlation with spontaneous increase in specific anti­tumor activity of the immune system (p < 0.0008). The catamnesis showed that only 5 advanced cancer patients, who were provided with whole course of psycho­immunological rehabilitation survived for 1.5 years and up to 7 years after psycho­immunological rehabilitation. The rest 12 patients died. This study showed some clinical opportunities of positive influence of special psycho­immunological rehabilitation on to the course of a disease of advanced cancer patients with psychogenic medical history. Key words: Advanced cancer, anti-tumor immunity, cancer rehabilitation, psycho-emotional disorders, psychogenic medical history.

Psychogenic activation phenomenon of specific anti-tumor immunity in cancer patients

The present study aimed to identify the influence of the mind on specific anti-tumor immunity of cancer patients. The study involved 90 cancer patients (78 women and 12 men) with 18 various types of cancer. The presence of psychogenic medical history before diagnosis of cancer was the basic criterion of cancer patients selection for this study. The psychometric parameters, quality of life, delayed-type hypersensitivity skin reaction on the tumor-associated antigens of human melanoma cell line BRO, cytokines (30 Plex) in native plasma and 24 h blood supernatants were investigated before and after psycho-correction. The delayed-type hypersensitivity skin reaction on the tumor-associated antigens in all cancer patients significantly increased (p= 0.0001) after elimination of psycho-emotional disorders by psychotropic drugs. In this case, there were no detected reliable changes in the concentrations of cytokines. The described new pathophysiological phenomenon consists in a spontaneous (nonimmunogenic) increase of specific anti-tumor activity of the immune system of cancer patients who coped effectively with psycho-emotional disorders.

Silencing of indoleamine 2,3-dioxygenase enhances dendritic cell immunogenicity and antitumour immunity in cancer patients

Dendritic cells (DCs) are being explored as a therapeutic vaccine for cancers. However, their immunogenic potential is limited by the presence of immunosuppressive factors. Among these factors is the tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO). In this study, we have investigated the safety, immunogenicity and clinical response of IDO-silenced DC vaccine in four patients with gynecological cancers. DCs were transfected with IDO small interfering RNA and mRNA encoding human telomerase reverse transcriptase (hTERT) or survivin, two universal tumour antigens. Silencing of IDO in DCs did not affect the expression of the co-stimulatory molecules CD80 and CD86, but enhanced the expression of the CCR7 and CD40 molecules. IDO-silenced DCs showed superior potency to activate allogeneic T cells compared to their IDO-positive counterparts. The immunisation with this novel DC cancer vaccine was well tolerated and all patients developed delayed-type hypersensitivity skin reaction and specific T-cell response against hTERT and survivin tumour antigens. Perhaps most importantly, the immune response seen in the patients was related to objective clinical response. Thus, IDO silencing can enhance the immunogenic function of DCs in vitro and in vivo. Overall, the data provide proof-of-principle that immunisation with IDO-silenced DC vaccine is safe and effective in inducing antitumour immunity.

Cytokine Responses to Novel Antigens in a Peri-Urban Population in Brazil Exposed to Leishmania infantum chagasi

Visceral leishmaniasis (VL) is fatal if untreated, and there are no vaccines for this disease. High levels of CD4-derived interferon-γ (IFN-γ) in the presence of low levels of interleukin-10 (IL-10) predicts vaccine success. Tumor necrosis factor-α (TNF-α) is also important in this process. We characterized human immune responses in three groups exposed to Leishmania infantum chagasi in Brazil: 1) drug-cured VL patients (recovered VL); 2) asymptomatic persons with positive Leishmania-specific delayed-type hypersensitivity skin reactions (DTH+); and 3) DTH-negative household contacts. Magnitude of DTH correlated with crude Leishmania antigen-driven IFN-γ, TNF-α, and IL-5, but not IL-10. DTH+ persons showed equivalent levels of IFN-γ, but higher levels of IL-10, to tryparedoxin peroxidase and Leishmania homolog of receptor for activated C kinase compared with recovered VL patients. The IFN-γ:IL-10 and TNF-α:IL-10 ratios were higher in recovered VL patients than in DTH+ persons. Seven of 11 novel candidates (R71, L37, N52, L302.06, M18, J41, and M22) elicited cytokine responses (36-71% of responders) in recovered VL patients and DTH+ persons. This result confirmed their putative status as cross-species vaccine/immunotherapeutic candidates.

Open label phase I/II study of Wilms' tumor gene 1 (WT1) mRNA-transfected autologous dendritic cell vaccination in patients with solid tumors.

e13051 Background: Active specific immunotherapy, aimed at stimulating tumor-specific immunity, is widely under investigation to determine its place in cancer treatment. Methods: We are conducting an open label phase I/II clinical trial to evaluate the feasibility, toxicity and immunogenicity of intradermal vaccination with keyhole limpet hemocyanin (KLH)-exposed WT1 mRNA-transfected autologous monocyte-derived dendritic cells (DC). Recruitment has finished, but vaccination and follow-up continue. Vaccination consists of biweekly intradermal injection of 10 million DC in the medial region of the arm close to the axilla. Clinical evaluation with PET, CAT or MRI is done before start of the vaccination and repeated every 8 weeks. After 4 vaccinations patients undergo a delayed-type hypersensitivity (DTH) skin test to evaluate immunological responses. Results: 18 patients (8 breast cancer and 3 astrocytoma patients, 1 melanoma, 1 mesothelioma, 1 ovarian, 1 colon, 1 esophageal, 1 renal cell and 1 peritoneal cancer patient) were included in this trial from May, 2010 until January, 2012 to whom we administered a total of 175 vaccines. The median number of vaccines produced per patient was 15 (range 5-34). Median follow-up from start of the vaccination is 26 weeks (range 2-83). All evaluable patients exhibited local symptoms such as itching and/or redness at the sites of injection after the second vaccination and onward (n=17) and displayed positive DTH skin reactions (induration ≥2 mm) to the vaccine and its components (n=15). Systemic side effects were limited to 2 patients who each experienced a single episode of flu-like symptoms within 24 hours after vaccination. Thus far, 3 patients died of disease progression, while 7 others had progressive disease and 6 had stable disease at the most recent evaluation compared to before vaccination according to RECIST 1.1. Of the latter group 4 patients received another form of therapy at some point during vaccination. Conclusions: Based on these results our WT1 mRNA-transfected DC vaccination appears to be feasible and safe for patients with solid tumors. Furthermore, our vaccine is capable of inducing immune responses in these patients.

Use of recombinant CFP-10 protein for a skin test specific for Mycobacterium tuberculosis infection

Although the delayed-type hypersensitivity (DTH) skin reaction to tuberculin is used worldwide for tuberculosis (TB) detection, it has poor diagnostic specificity due to the presence of common antigens in tuberculin shared by many mycobacterial species. The problem is noticed, especially in countries where the Bacillus Calmette-Gue´rin (BCG) vaccination is widely practiced. Thus, a new skin test antigen specific for the diagnosis of Mycobacterium tuberculosis (MTB) infection is urgently needed. CFP-10, a mycobacterial secretary protein that is absent in Mycobacterium bovis BCG and most other mycobacterial species including Mycobacterium avium, Mycobacterium intracellulare, has been shown to elicit cellular immune responses in MTB infected individuals and can be a good candidate for MTB specific diagnosis. We prepared recombinant MTB CFP-10, rCFP-10, and its utility as specific antigen for TB diagnosis was evaluated by skin testing in guinea pigs sensitized with M . tuberculosis, M. bovis, and M. bovis BCG. Our results show that the purified MTB rCFP-10 antigen elicits a positive skin response only in the guinea pigs sensitized with M. tuberculosis and M. bovis , and not in the animals sensitized with M. bovis BCG vaccine. The data presented in this study supports further testing of the use rCFP-10 as the specific antigen in the skin test for the diagnosis of MTB infection in humans. Key words : Recombinant CFP-10 protein, skin test, delayed-type hypersensitivity, tuberculosis infection, Mycobacterium tuberculosis, Mycobacterium bovis, Bacillus Calmette-Gue´rin.

Optimizing dendritic cell‐based immunotherapy in multiple myeloma: intranodal injections of idiotype‐pulsed CD40 ligand‐matured vaccines led to induction of type‐1 and cytotoxic T‐cell immune responses in patients

Vaccination with idiotype (Id) protein-pulsed dendritic cells (DCs) has been explored in multiple myeloma and the results have been disappointing. To improve the efficacy of DC vaccination in myeloma, we investigated the use of Id- and keyhole limpet haemocyanin (KLH)-pulsed, CD40 ligand-matured DCs administered intranodally. Nine patients with smouldering or stable myeloma without treatment were enrolled and DC vaccines were administered at weekly intervals for a total of four doses. Following vaccination, all patients mounted Id-specific gamma-interferon T-cell response. Interleukin-4 response was elicited in two, and skin delayed-type hypersensitivity reaction occurred in seven patients. More importantly, Id-specific cytotoxic T-cell responses were also detected in five patients. Most if not all patients mounted a positive T-cell response to KLH following vaccination. At 1-year follow-up, six of the nine patients had stable disease, while three patients had slowly progressive disease even during the vaccination period. At 5-year follow-up, four of the six patients continued with stable disease. No major side effects were noted. In summary, intranodal administration of Id-pulsed CD40 ligand-matured DCs was able to induce Id-specific T and B-cell responses in patients. Current efforts are geared towards breaking tumour-mediated immune suppression and improving clinical efficacy of this immunotherapy.

Phase 1 Trial of Allogeneic Gene-Modified Tumor Cell Vaccine RCC-26/CD80/IL-2 in Patients with Metastatic Renal Cell Carcinoma

Preclinical studies showed that the allogeneic tumor cell line RCC-26 displayed natural immunogenic potential that was enhanced through expression of CD80 costimulatory molecules and secretion of interleukin-2. Here we report the study of RCC-26/CD80/IL-2 cells in a phase 1 vaccine trial of renal cell carcinoma patients with metastatic disease (mRCC). Fifteen patients of the HLA-A*0201 allotype, with at least one metastatic lesion, were included. Irradiated vaccine cells were applied in increasing doses of 2.5, 10, and 40 x 10(6) cells over 22 weeks. Primary study parameters included safety and toxicity. Sequential blood samples were analyzed by interferon-gamma enzyme-linked immunospot assays to detect tumor antigen-associated (TAA) effector cells. The vaccine was well tolerated and the designated vaccination course was completed in 9 of 15 patients. Neither vaccine-induced autoimmunity nor systemic side effects were observed. Delayed-type hypersensitivity skin reactions were detected in 11 of 12 evaluated patients and were particularly strong in patients with prolonged survival. In parallel, vaccine-induced immune responses against vaccine or overexpressed TAA were detected in 9 of 12 evaluated patients. No tumor regressions occurred according to RECIST (Response Evaluation Criteria in Solid Tumors) criteria; however, median time to progression was 5.3 months and median survival was 15.6 months, indicating substantial disease stabilization. We conclude that vaccine use was safe and feasible in mRCC. Clinical benefits were limited in these patients with advanced disease; however, immune monitoring revealed vaccine-induced responses against multiple TAAs in the majority of study participants. These results suggest that this vaccine could be useful in combination therapies and/or minimal residual disease.

Induction of delayed-type hypersensitivity and interferon-gamma to Candida albicans and anti-hen-egg white lysozyme antibody as phenotypic markers of enhanced bovine immune response

Delayed-type hypersensitivity (DTH) is a protective localized cell-mediated immune response (CMIR), primarily against intracellular pathogens. DTH is widely used in research to assess immune responsiveness and has been a valuable diagnostic test in commercial settings. In pigs and other species both antibody (AMIR) and CMIR have been considered as reliable phenotypic markers of selection programs for disease resistance. Therefore in cattle, it was also considered important to find antigen/adjuvant combinations capable of inducing AMIR and CMIR without interfering with diagnostic tests. The objectives of the present study were to evaluate the combined use of hen-egg white lysozyme (HEWL) and Candida albicans adjuvanted with Quil A in lactacting Holstein cows for the induction of anti-HEWL antibody, as well as DTH and IFN-γ to C. albicans as phenotypic markers of enhanced immune responsiveness. Thirty one lactating Holstein cows were immunized with HEWL to induce antibody responses and C. albicans to sensitize for DTH. Two test antigens, candin and C. albicans whole cell (CaWC), were used to induce the effector phase of DTH. PBS was used as the negative control. In addition, two different skin sites (neck versus tail) were tested to evaluate differences in skin site responsiveness. C. albicans-induced IFN-γ production, as an indicator of a type 1 response, was evaluated by ELISA. Microscopic evaluation of skin samples at DTH sites was performed in five randomly selected cows and these skin biopsies were scored based on inflammation and cell infiltration. Results demonstrated the presence of classical DTH response to C. albicans, in that DTH responses peaked at 24 h post-intradermal injections and cell infiltration was composed largely of mononuclear leukocytes, typical of DTH skin reactions in cattle. The only difference in test antigens was that DTH to candin showed a higher early response (6 h) than CaWC and a rapid decrease in inflammation from 24 to 48 h. The neck was significantly more sensitive than the tail skin-fold as a DTH test site. IFN-γ was detected on days 14 and 21 post-immunization in plasma from blood incubated with candin. Significant primary and secondary anti-HEWL antibodies were also detected, indicating that this combination of test antigens could be used as phenotypic markers of immune responsiveness in cattle.

Secreted dipeptidyl peptidases as potential virulence factors forMicrosporum canis

Dermatophytoses caused by Microsporum canis are frequently encountered in cats and dogs; they are highly contagious and readily transmissible to humans. In this study, two single genes, respectively coding for dipeptidyl peptidases IV and V (DppIV and DppV), were isolated and characterized. Both proteins share homology with serine proteases of the S9 family, some of which display properties compatible with implication in pathogenic processes. Both genes are expressed in vivo in experimentally infected guinea-pigs and in naturally infected cats, and when the fungus is grown on extracellular matrix proteins as the sole nitrogen and carbon source. DppIV and V were produced as active recombinant proteases in the yeast Pichia pastoris; the apparent molecular weight of rDppV is 83 kDa, whereas rDppIV appears as a doublet of 95 and 98 kDa. Like other members of its enzymatic subfamily, rDppIV has an unusual ability to cleave Pro-X bonds. This activity does not enhance the solubilization of keratin by fungal secreted endoproteases, and the protease probably acts solely on small soluble peptides. RDppV showed no ability to induce delayed-type hypersensitivity (DTH) skin reactions in guinea-pigs, despite the known immunogenic properties of homologous proteins.

Analysis of the cells involved in the lymphoproliferative response toCoxiella burnetiiantigens

Vaccination with an inactivated, whole cell, Q fever vaccine (Q-vax) induces lasting antibody conversion and a positive delayed-type hypersensitivity (DTH) skin reaction in about 60% of recipients but a long-lasting positive lymphoproliferative or mitogenic response to C. burnetii antigens with peripheral blood mononuclear cells (PBMC) in 85-95% of subjects. Analysis of the lymphoproliferative response to C. burnetii antigens has now been made by fractionation-reconstitution experiments with PBMC from vaccines, from past infections, and from healthy controls. The major contributor to the response in immune subjects proved to be the T lymphocyte. T cells were stimulated by both the phase I and phase II antigens of two prototype strains of C. burnetii and responses were greatly amplified by addition of IL-2. Similar T lymphocyte stimulation profiles were obtained with the 'Priscilla' strain of C. burnetii which represents a different biotype of Coxiella isolated from Q fever endocarditis; Q-vax is therefore likely to protect against endocarditis strains. Fractionation-reconstitution experiments with T and B cells from vaccines and subjects infected in the past, using various antigenic or haptenic fractions from C. burnetii indicate that protein, non-lipopolysaccharide components of the organism are responsible for the mitogenic response of immune T cells. However, the role of the lipopolysaccharide in the protective immunogen has still to be defined.

IFN-α Skews Monocytes into CD56+-Expressing Dendritic Cells with Potent Functional Activities In Vitro and In Vivo

The antitumor effect of IFN-alpha is mediated by the activation of CTLs, NK cells, and the generation of highly potent Ag-presenting dendritic cells (IFN-DCs). In this study, we show that IFN-DCs generated in vitro from monocytes express CD56 on their surface, a marker which has been thought to be specific for NK cells. FACS analyses of CD56(+) and CD56(-) IFN-DCs showed a nearly identical pattern for most of the classical DC markers. Importantly, however, only CD56(+) IFN-DCs exhibited cytolytic activity up to 24% that could almost completely be blocked (-81%) after coincubation with anti-TRAIL. Intracytoplasmatic cytokine staining revealed that the majority of IFN-DCs independently of their CD56 expression were IFN-gamma positive as well. In contrast, CD56(+) IFN-DCs showed stronger capacity in stimulating allogenic T cells compared with CD56(-) IFN-DC. Based on these results, five patients with metastasized medullary thyroid carcinoma were treated for the first time with monocyte-derived tumor Ag-pulsed IFN-DCs. After a long term follow-up (in mean 37 mo) all patients are alive. Immunohistochemical analyses of delayed-type hypersensitivity skin reaction showed a strong infiltration with CD8(+) cells. In two patients no substantial change in tumor morphology was detected. Importantly, by analyzing PBMCs, these patients also showed an increase of Ag-specific IFN-gamma-secreting T cells. In summary, we here describe for the first time that cytotoxic activity of IFN-DCs is mainly mediated by an IFN-DC subset showing partial phenotypic and functional characteristics of NK cells. These cells represent another mechanism of the antitumor effect induced by IFN-alpha.

Xenovaccinotherapy for colorectal cancer

The objectives of this phase I–II trial were to assess the toxicity, immunological and clinical responses induced in 37 patients with stage IV colorectal cancer by the subcutaneous administration of a xenogenic polyantigenic vaccine (XPV) prepared from disrupted murine melanoma (B16) and carcinoma (LLC) cells. An inducing course of vaccinotherapy consisted of 10 immunizations (5 at weekly and 5 at fortnight intervals). Twenty-four hours later each of first 5 vaccinations the patient was subcutaneously given a low dose of the recombinant interleukin-2 (IL-2). A consolidating course of vaccinotherapy consisted of monthly vaccinations. No grade III or IV toxicities, but also laboratory and clinical signs of developing systemic autoimmune disorders were noted in any XPV-treated patient. A significant increase in cell-mediated immunoreactivity to both LLC and B16 antigens (Ags) occurred in the patients after inducing vaccinations, as determined by delayed-type hypersensitivity (DTH) skin reactions, as well as by blood lymphocyte proliferation responses. Vaccinations also led to increased cell-mediated reactivity to murine non-tumor, spleen cell (SC)-associated Ags. This reactivity, however, was not as significant as that to tumor-associated antigens (TAAs). XPV was also found to capable of generating IgG antibody-mediated responses. With immunotherapy concentrations of both interferon-gamma (IFN-γ) and interleukin-4 (IL-4) detectably elevated in patients' sera, suggesting intensification of T helper 1-/T helper 2-mediated responses in the XPV-treated patients. The average survival of the XPV-treated patients was noticeably superior than was that of the clinically comparable control patients (17 vs 7 months). Collectively the results suggest that xenogenic TAAs are safe to use, able to induce measurable cellular and humoral immune responses, and may be clinically effective in certain colorectal cancer patients.

Topical Calcineurin Inhibitors in Pediatric Atopic Dermatitis

Atopic dermatitis (AD) is a common disease in children. Despite good skin care and trigger avoidance, many children with AD require pharmacologic treatment to manage their disease. In recent years, topical calcineurin inhibitors (TCIs) have been used as an alternative to topical corticosteroids to treat some children with AD. However, revisions to the US labeling for TCIs (i.e. a boxed warning and a medication guide) have generated concern among pediatricians regarding TCI safety and raised questions about the appropriate use of TCIs in the pediatric population. Data from several well designed studies support the efficacy of TCIs in the treatment of AD. Safety concerns arise from a small number of reported malignancies, animal toxicology studies, and the potential adverse effects (including immunosuppression and risk of lymphoma) observed in patients who received systemically administered calcineurin inhibitors for suppression of solid-organ transplant rejection. Several factors indicate that these effects do not occur with topical administration: (i) systemic levels following topical administration are at least 10-fold lower than with oral administration; (ii) the small number of lymphomas reported to date in persons exposed to TCI use are not consistent with the types seen in transplant patients or other immunosuppressed patients; and (iii) no adverse effects on the immune system (as assessed by measures including vaccination response and skin delayed-type hypersensitivity reaction) have been observed in clinical trials of TCIs in children with AD. Overall, TCIs have an established safety and efficacy profile as long-term maintenance therapy in children with AD.

Telomerase peptide vaccination of patients with non-resectable pancreatic cancer: a dose escalating phase I/II study

Patients with inoperable pancreatic cancer have a dismal prognosis with a mean life expectancy of 3–6 months. New treatment modalities are thus urgently needed. Telomerase is expressed in 85–90% of pancreas cancer, and immunogenic telomerase peptides have been characterised. A phase I/II study was conducted to investigate the safety, tolerability, and immunogenecity of telomerase peptide vaccination. Survival of the patients was also recorded. Forty-eight patients with non-resectable pancreatic cancer received intradermal injections of the telomerase peptide GV1001 at three dose levels, in combination with granulocyte–macrophage colony-stimulating factor. The treatment period was 10 weeks. Monthly booster vaccinations were offered as follow-up treatment. Immune responses were measured as delayed-type hypersensitivity skin reaction and in vitro T-cell proliferation. GV1001 was well tolerated. Immune responses were observed in 24 of 38 evaluable patients, with the highest ratio (75%) in the intermediate dose group. Twenty-seven evaluable patients completed the study. Median survival for the intermediate dose-group was 8.6 months, significantly longer for the low- (P=0.006) and high-dose groups (P=0.05). One-year survival for the evaluable patients in the intermediate dose group was 25%. The results demonstrate that GV1001 is immunogenic and safe to use. The survival data indicate that induction of an immune response is correlated with prolonged survival, and the vaccine may offer a new treatment option for pancreatic cancer patients, encouraging further clinical studies.