Increased incidence and mortality from Listeria monocytogenes infection in Spain.

BACKGROUND: Listeria monocytogenes (LM) is a health treat worldwide given its high mortality and the growing of high-risk susceptible populations. METHODS: All hospitalizations with a diagnosis of LM in the National Registry of Hospital Discharges were examined in Spain from 2000 to 2021. RESULTS: A total of 8,152 hospital admissions with LM were identified. The mean age was 59.5 years and 48% were immunosuppressed (IS). The rate of LM hospitalizations increased from 5 per 1 million population in 2000 to 8.9 in 2021 (p<0.001). A foodborne outbreak in Andalusia determined a sharp increase of admissions with LM during 2019. The COVID-19 pandemic and lockdowns were associated with a fall in LM admissions. The overall in-hospital mortality was 16.7%. The number of deaths in patients hospitalized with LM rose from 7.8 per 100,000 deceased in 2000 to 18 in 2021 (p<0.001). After adjustment, age >65 years-old (Odds ratio [OR]=2.16), sepsis (OR=2.60), meningoencephalitis (OR=1.72), endocarditis (OR=2.0), neonatal listeriosis (OR=2.10) and IS (OR=2.09) were associated with mortality. CONCLUSIONS: The number of patients hospitalized with LM in Spain has risen significantly from 2000 to 2021. The increase in the rate of admissions and deaths was largely driven by the growing proportion of elderly and of immunosuppressed patients.

Testing a vaccine candidate against Hepatitis C virus designed by combinatorial optimization.

This paper presents a new procedure for vaccine design against highly variable viruses such as Hepatitis C. The procedure uses an optimization algorithm to design vaccines that maximize the coverage of epitopes across different virus variants. Weighted epitopes based on the success ratio of immunological assays are used to prioritize the selection of epitopes for vaccine design. The procedure was successfully applied to design DC vaccines loaded with two HCV peptides, STG and DYP, which were shown to be safe, immunogenic, and able to induce significant levels of anti-viral cytokines, peptide-specific cellular immune responses and IgG antibodies. The procedure could potentially be applied to other highly variable viruses that currently lack effective vaccines.

Pirin is a prognostic marker of human melanoma that dampens the proliferation of malignant cells by downregulating JARID1B/KDM5B expression.

Originally considered to act as a transcriptional co-factor, Pirin has recently been reported to play a role in tumorigenesis and the malignant progression of many tumors. Here, we have analyzed the diagnostic and prognostic value of Pirin expression in the early stages of melanoma, and its role in the biology of melanocytic cells. Pirin expression was analyzed in a total of 314 melanoma biopsies, correlating this feature with the patient's clinical course. Moreover, PIR downregulated primary melanocytes were analyzed by RNA sequencing, and the data obtained were validated in human melanoma cell lines overexpressing PIR by functional assays. The immunohistochemistry multivariate analysis revealed that early melanomas with stronger Pirin expression were more than twice as likely to develop metastases during the follow-up. Transcriptome analysis of PIR downregulated melanocytes showed a dampening of genes involved in the G1/S transition, cell proliferation, and cell migration. In addition, an in silico approach predicted that JARID1B as a potential transcriptional regulator that lies between PIR and its downstream modulated genes, which was corroborated by co-transfection experiments and functional analysis. Together, the data obtained indicated that Pirin could be a useful marker for the metastatic progression of melanoma and that it participates in the proliferation of melanoma cells by regulating the slow-cycling JARID1B gene.

Gold Glyconanoparticles Combined with 91-99 Peptide of the Bacterial Toxin, Listeriolysin O, Are Efficient Immunotherapies in Experimental Bladder Tumors.

This study presents proof of concept assays to validate gold nanoparticles loaded with the bacterial peptide 91-99 of the listeriolysin O toxin (GNP-LLO91-99 nanovaccines) as immunotherapy for bladder tumors. GNP-LLO91-99 nanovaccines showed adjuvant abilities as they induce maturation and activation of monocyte-derived dendritic cells (MoDCs) to functional antigen-presenting cells in healthy donors and patients with melanoma or bladder cancer (BC), promoting a Th1 cytokine pattern. GNP-LLO91-99 nanovaccines were also efficient dendritic cell inducers of immunogenic tumor death using different bladder and melanoma tumor cell lines. The establishment of a pre-clinical mice model of subcutaneous BC confirmed that a single dose of GNP-LLO91-99 nanovaccines reduced tumor burden 4.7-fold and stimulated systemic Th1-type immune responses. Proof of concept assays validated GNP-LLO91-99 nanovaccines as immunotherapy by comparison to anti-CTLA-4 or anti-PD-1 antibodies. In fact, GNP-LLO91-99 nanovaccines increased percentages of CD4+ and CD8+ T cells, B cells, and functional antigen-presenting DCs in tumor-infiltrated lymphocytes, while they reduced the levels of myeloid-derived suppressor cells (MDSC) and suppressor T cells (Treg). We conclude that GNP-LLO91-99 nanovaccines can work as monotherapies or combinatory immunotherapies with anti-CTLA-4 or anti-PD-1 antibodies for solid tumors with high T cell infiltration, such as bladder cancer or melanoma.

First computational design using lambda-superstrings and in vivo validation of SARS-CoV-2 vaccine.

Coronavirus disease 2019 (COVID-19) is the greatest threat to global health at the present time, and considerable public and private effort is being devoted to fighting this recently emerged disease. Despite the undoubted advances in the development of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, uncertainty remains about their future efficacy and the duration of the immunity induced. It is therefore prudent to continue designing and testing vaccines against this pathogen. In this article we computationally designed two candidate vaccines, one monopeptide and one multipeptide, using a technique involving optimizing lambda-superstrings, which was introduced and developed by our research group. We tested the monopeptide vaccine, thus establishing a proof of concept for the validity of the technique. We synthesized a peptide of 22 amino acids in length, corresponding to one of the candidate vaccines, and prepared a dendritic cell (DC) vaccine vector loaded with the 22 amino acids SARS-CoV-2 peptide (positions 50-71) contained in the NTD domain (DC-CoVPSA) of the Spike protein. Next, we tested the immunogenicity, the type of immune response elicited, and the cytokine profile induced by the vaccine, using a non-related bacterial peptide as negative control. Our results indicated that the CoVPSA peptide of the Spike protein elicits noticeable immunogenicity in vivo using a DC vaccine vector and remarkable cellular and humoral immune responses. This DC vaccine vector loaded with the NTD peptide of the Spike protein elicited a predominant Th1-Th17 cytokine profile, indicative of an effective anti-viral response. Finally, we performed a proof of concept experiment in humans that included the following groups: asymptomatic non-active COVID-19 patients, vaccinated volunteers, and control donors that tested negative for SARS-CoV-2. The positive control was the current receptor binding domain epitope of COVID-19 RNA-vaccines. We successfully developed a vaccine candidate technique involving optimizing lambda-superstrings and provided proof of concept in human subjects. We conclude that it is a valid method to decipher the best epitopes of the Spike protein of SARS-CoV-2 to prepare peptide-based vaccines for different vector platforms, including DC vaccines.

A Comparison Between Recombinant Listeria GAPDH Proteins and GAPDH Encoding mRNA Conjugated to Lipids as Cross-Reactive Vaccines for Listeria, Mycobacterium, and Streptococcus.

Cross-reactive vaccines recognize common molecular patterns in pathogens and are able to confer broad spectrum protection against different infections. Antigens common to pathogenic bacteria that induce broad immune responses, such as the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of the genera Listeria, Mycobacterium, or Streptococcus, whose sequences present more than 95% homology at the N-terminal GAPDH1-22 peptide, are putative candidates for universal vaccines. Here, we explore vaccine formulations based on dendritic cells (DC) loaded with two molecular forms of Listeria monocytogenes GAPDH (LM-GAPDH), such as mRNA carriers or recombinant proteins, and compare them with the same molecular forms of three other antigens used in experimental vaccines, listeriolysin O of Listeria monocytogeness, Ag85A of Mycobacterium marinum, and pneumolysin of Streptococcus pneumoniae. DC loaded with LM-GAPDH recombinant proteins proved to be the safest and most immunogenic vaccine vectors, followed by mRNA encoding LM-GAPDH conjugated to lipid carriers. In addition, macrophages lacked sufficient safety as vaccines for all LM-GAPDH molecular forms. The ability of DC loaded with LM-GAPDH recombinant proteins to induce non-specific DC activation explains their adjuvant potency and their capacity to trigger strong CD4+ and CD8+ T cell responses explains their high immunogenicity. Moreover, their capacity to confer protection in vaccinated mice against challenges with L. monocytogenes, M. marinum, or S. pneumoniae validated their efficiency as cross-reactive vaccines. Cross-protection appears to involve the induction of high percentages of GAPDH1-22 specific CD4+ and CD8+ T cells stained for intracellular IFN-γ, and significant levels of peptide-specific antibodies in vaccinated mice. We concluded that DC vaccines loaded with L. monocytogenes GAPDH recombinant proteins are cross-reactive vaccines that seem to be valuable tools in adult vaccination against Listeria, Mycobacterium, and Streptococcus taxonomic groups.

Glyceraldehyde-3-phosphate Dehydrogenase Common Peptides of Listeria monocytogenes, Mycobacterium marinum and Streptococcus pneumoniae as Universal Vaccines.

Universal vaccines can be prepared with antigens common to different pathogens. In this regard, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a common virulence factor among pathogenic bacteria of the genera Listeria, Mycobacterium and Streptococcus. Their N-terminal 22 amino acid peptides, GAPDH-L1 (Listeria), GAPDH-M1 (Mycobacterium) and GAPDH-S1 (Streptococcus), share 95-98.55% sequence homology, biochemical and MHC binding abilities and, therefore, are good candidates for universal vaccine designs. Here, we used dendritic cells (DC) as vaccine platforms to test GAPDH epitopes that conferred protection against Listeria monocytogenes, Mycobacterium marinum or Streptococcus pneumoniae in our search of epitopes for universal vaccines. DC loaded with GAPDH-L1, GAPDH-M1 or GAPDH-S1 peptides show high immunogenicity measured by the cellular DTH responses in mice, lacked toxicity and were capable of cross-protection immunity against mice infections with each one of the pathogens. Vaccine efficiency correlated with high titers of anti-GAPDH-L1 antibodies in sera of vaccinated mice, a Th1 cytokine pattern and high frequencies of GAPDH-L1-specific CD4+ and CD8+ T cells and IFN-γ producers in the spleens. We concluded that GAPDH-L1 peptide was the best epitope for universal vaccines in the Listeria, Mycobacterium or Streptococcus taxonomic groups, whose pathogenic strains caused relevant morbidities in adults and especially in the elderly.

Rational Vaccine Design in Times of Emerging Diseases: The Critical Choices of Immunological Correlates of Protection, Vaccine Antigen and Immunomodulation.

Vaccines are the most effective medical intervention due to their continual success in preventing infections and improving mortality worldwide. Early vaccines were developed empirically however, rational design of vaccines can allow us to optimise their efficacy, by tailoring the immune response. Establishing the immune correlates of protection greatly informs the rational design of vaccines. This facilitates the selection of the best vaccine antigens and the most appropriate vaccine adjuvant to generate optimal memory immune T cell and B cell responses. This review outlines the range of vaccine types that are currently authorised and those under development. We outline the optimal immunological correlates of protection that can be targeted. Finally we review approaches to rational antigen selection and rational vaccine adjuvant design. Harnessing current knowledge on protective immune responses in combination with critical vaccine components is imperative to the prevention of future life-threatening diseases.

Epitopes for Multivalent Vaccines Against Listeria, Mycobacterium and Streptococcus spp: A Novel Role for Glyceraldehyde-3-Phosphate Dehydrogenase.

The glycolytic enzyme and bacterial virulence factor of Listeria monocytogenes, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH, Lmo2459), ADP-ribosylated the small GTPase, Rab5a, and blocked phagosome maturation. This inhibitory activity localized within the NAD binding domain of GAPDH at the N-terminal 1-22 peptides, also conferred listeriosis protection when used in dendritic cell-based vaccines. In this study, we explore GAPDH of Listeria, Mycobacterium, and Streptococcus spp. taxonomic groups to search for epitopes that confer broad protection against pathogenic strains of these bacteria. GAPDH multivalent epitopes are selected if they induce inhibitory actions and wide-ranging immune responses. Proteomic isolation of GAPDH from dendritic cells infected with Listeria, Mycobacterium, or Streptococcus confirmed similar enzymatic, Rab5a inhibitory and immune stimulation abilities. We identified by bioinformatics and functional analyses GAPDH N-terminal 1-22 peptides from Listeria, Mycobacterium, and Streptococcus that shared 95% sequence homology, enzymatic activity, and B and T cell immune domains. Sera obtained from patients or mice infected with hypervirulent pathogenic Listeria, Mycobacterium, or Streptococcus presented high levels of anti-GAPDH 1-22 antibodies and Th2 cytokines. Monocyte derived dendritic cells from healthy donors loaded with GAPDH 1-22 peptides from Listeria, Mycobacterium, or Streptococcus showed activation patterns that correspond to cross-immunity abilities. In summary, GAPDH 1-22 peptides appeared as putative candidates to include in multivalent dendritic based vaccine platforms for Listeria, Mycobacterium, or Streptococcus.

Pre-clinical development of Listeria-based nanovaccines as immunotherapies for solid tumours: insights from melanoma.

Gold glyconanoparticles loaded with the listeriolysin O peptide 91-99 (GNP-LLO91-99), a bacterial peptide with anti-metastatic properties, are vaccine delivery platforms facilitating immune cell targeting and increasing antigen loading. Here, we present proof of concept analyses for the consideration of GNP-LLO91-99 nanovaccines as a novel immunotherapy for cutaneous melanoma. Studies using mouse models of subcutaneous melanoma indicated that GNP-LLO91-99 nanovaccines recruite and modulate dendritic cell (DC) function within the tumour, alter tumour immunotolerance inducing melanoma-specific cytotoxic T cells, cause complete remission and improve survival. GNP-LLO91-99 nanovaccines showed superior tumour regression and survival benefits, when combined with anti-PD-1 or anti-CTLA-4 checkpoint inhibitors, resulting in an improvement in the efficacy of these immunotherapies. Studies on monocyte-derived DCs from patients with stage IA, IB or IIIB melanoma confirmed the ability of GNP-LLO91-99 nanovaccines to complement the action of checkpoint inhibitors, by not only reducing the expression of cell-death markers on DCs, but also potentiating DC antigen-presentation. We propose that GNP-LLO91-99 nanovaccines function as immune stimulators and immune effectors and serve as safe cancer therapies, alone or in combination with other immunotherapies.

Dendritic cell therapy in melanoma.

Dendritic cell (DC) vaccines are cancer vaccines used currently as melanoma therapies. They act as adjuvants initiating the immune responses, but not only as they can also have effector activities redirecting cytotoxic CD8+ T cells against melanoma. Ex vivo preparation of monocyte derived DCs has been implemented to produce large numbers of DCs for clinical therapy, highlighting the necessity of activate DC s to produce Th1 cytokines, especially TNF-a and IL-12 with potent anti-tumour actions. Several clinical trials both in the European Union and USA are open currently using DC vaccines, alone or in combination with other immunotherapies. The type of antigen is also an active area of investigation involving tumour antigens and bacterial epitopes, both providing good responses. Bacterial epitopes presented the advantage versus tumour antigens that they can prepare the vaccination site as they induce innate and specific immune responses as they are potent recall antigens that expand cytotoxic responses.

GNP-GAPDH1-22 nanovaccines prevent neonatal listeriosis by blocking microglial apoptosis and bacterial dissemination.

Clinical cases of neonatal listeriosis are associated with brain disease and fetal loss due to complications in early or late pregnancy, which suggests that microglial function is altered. This is believed to be the first study to link microglial apoptosis with neonatal listeriosis and listeriosis-associated brain disease, and to propose a new nanovaccine formulation that reverses all effects of listeriosis and confers Listeria monocytogenes (LM)-specific immunity. We examined clinical cases of neonatal listeriosis in 2013-2015 and defined two useful prognostic immune biomarkers to design listeriosis vaccines: high anti-GAPDH1-22 titres and tumor necrosis factor (TNF)/interleukin (IL)-6 ratios. Therefore, we developed a nanovaccine with gold glyco-nanoparticles conjugated to LM peptide 1-22 of GAPDH (Lmo2459), GNP-GAPDH1-22 nanovaccinesformulated with a pro-inflammatory Toll-like receptor 2/4-targeted adjuvant. Neonates born to non-vaccinated pregnant mice with listeriosis, showed brain and vascular diseases and significant microglial dysfunction by induction of TNF-α-mediated apoptosis. This programmed TNF-mediated suicide explains LM dissemination in brains and livers and blocks production of early pro-inflammatory cytokines such as IL-1ß and interferon-α/ß. In contrast, neonates born to GNP-GAPDH1-22-vaccinated mothers before LM infection, did not develop listeriosis or brain diseases and had functional microglia. In nanovaccinated mothers, immune responses shifted towards Th1/IL-12 pro-inflammatory cytokine profiles and high production of anti-GAPDH1-22 antibodies, suggesting good induction of LM-specific memory.

Biomarker Tools to Design Clinical Vaccines Determined from a Study of Annual Listeriosis Incidence in Northern Spain.

Two regions of northern Spain, Gipuzkoa, and Cantabria present high annual incidence of listeriosis (1.86 and 1.71 cases per 100,000 inhabitants, respectively). We report that the high annual incidences are a consequence of infection with highly virulent Listeria monocytogenes isolates linked to fatal outcomes in elderly patients with cancer. In addition, listeriosis patients with cancer present low IL-17A/IL-6 ratios and significantly reduced levels of anti-GAPDH1-22 antibodies, identified as two novel biomarkers of poor prognosis. Analysis of these biomarkers may aid in reducing the incidence of listeriosis. Moreover, GAPDH1-22-activated monocyte-derived dendritic cells of listeriosis patients with cancer seem useful tools to prepare clinical vaccines as they produce mainly Th1 cytokines.

Exceptional antineoplastic activity of a dendritic-cell-targeted vaccine loaded with a Listeria peptide proposed against metastatic melanoma.

Vaccination with dendritic cells (DCs) is proposed to induce lasting responses against melanoma but its survival benefit in patients needs to be demonstrated. We propose a DC-targeted vaccine loaded with a Listeria peptide with exceptional anti-tumour activity to prevent metastasis of melanoma. Mice vaccinated with vaccines based on DCs loaded with listeriolysin O peptide (91-99) (LLO91-99) showed clear reduction of metastatic B16OVA melanoma size and adhesion, prevention of lung metastasis, enhanced survival, and reversion of immune tolerance. Robust innate and specific immune responses explained the efficiency of DC-LLO91-99 vaccines against B16OVA melanoma. The noTable features of this vaccine related to melanoma reduction were: expansion of immune-dominant LLO91-99-specific CD8 T cells that helped to expand melanoma-specific CD8+ T cells; high numbers of tumour-infiltrating lymphocytes with a cytotoxic phenotype; and a decrease in CD4+CD25high regulatory T cells. This vaccine might be a useful alternative treatment for advanced melanoma, alone or in combination with other therapies.

Pregnancy Vaccination with Gold Glyco-Nanoparticles Carrying Listeria monocytogenes Peptides Protects against Listeriosis and Brain- and Cutaneous-Associated Morbidities.

Listeriosis is a fatal infection for fetuses and newborns with two clinical main morbidities in the neonatal period, meningitis and diffused cutaneous lesions. In this study, we vaccinated pregnant females with two gold glyconanoparticles (GNP) loaded with two peptides, listeriolysin peptide 91-99 (LLO91-99) or glyceraldehyde-3-phosphate dehydrogenase 1-22 peptide (GAPDH1-22). Neonates born to vaccinated mothers were free of bacteria and healthy, while non-vaccinated mice presented clear brain affections and cutaneous diminishment of melanocytes. Therefore, these nanoparticle vaccines are effective measures to offer pregnant mothers at high risk of listeriosis interesting therapies that cross the placenta.

Novel nanoparticle vaccines for Listeriosis.

In recent years, nanomedicine has transformed many areas of traditional medicine, and enabled fresh insights into the prevention of previously difficult to treat diseases. An example of the transformative power of nanomedicine is a recent nano-vaccine against listeriosis, a serious bacterial infection affecting not only pregnant women and their neonates, but also immune-compromised patients with neoplastic or chronic autoimmune diseases. There is a major unmet need for an effective and safe vaccine against listeriosis, with the challenge that an effective vaccine needs to generate protective T cell immunity, a hitherto difficult to achieve objective. Now utilizing a gold nanoparticle antigen delivery approach together with a novel polysaccharide nanoparticulate adjuvant, an effective T-cell vaccine has been developed that provides robust protection in animal models of listeriosis, raising the hope that one day this nanovaccine technology may protect immune-compromised humans against this serious opportunistic infection.

Identification and characterisation of T-cell epitopes for incorporation into dendritic cell-delivered Listeria vaccines.

Dendritic cells loaded with antigenic peptides, because of their safety and robust immune stimulation, would be ideal for induction of immunity to protect against listeriosis. However, there is no currently accepted method to predict which peptides derived from the Listeria proteome might confer protection. While elution of peptides from MHC molecules after Listeria infection yields high-affinity immune-dominant epitopes, these individual epitopes did not reliably confer Listeria protection. Instead we applied bioinformatic predictions of MHC class I and II epitopes to generate antigenic peptides that were then formulated with Advax™, a novel polysaccharide particulate adjuvant able to enhance cross-presentation prior to being screened for their ability to induce protective T-cell responses. A combination of at least four intermediate strength MHC-I binding epitopes and one weak MHC-II binding epitope when expressed in a single peptide sequence and formulated with Advax adjuvant induced a potent T-cell response and high TNF-α and IL-12 production by dendritic cells resulting in robust listeriosis protection in susceptible mice. This T-cell vaccine approach might be useful for the design of vaccines to protect against listeriosis or other intracellular infections.

A novel therapy for melanoma developed in mice: transformation of melanoma into dendritic cells with Listeria monocytogenes.

Listeria monocytogenes is a gram-positive bacteria and human pathogen widely used in cancer immunotherapy because of its capacity to induce a specific cytotoxic T cell response in tumours. This bacterial pathogen strongly induces innate and specific immunity with the potential to overcome tumour induced tolerance and weak immunogenicity. Here, we propose a Listeria based vaccination for melanoma based in its tropism for these tumour cells and its ability to transform in vitro and in vivo melanoma cells into matured and activated dendritic cells with competent microbicidal and antigen processing abilities. This Listeria based vaccination using low doses of the pathogen caused melanoma regression by apoptosis as well as bacterial clearance. Vaccination efficacy is LLO dependent and implies the reduction of LLO-specific CD4+ T cell responses, strong stimulation of innate pro-inflammatory immune cells and a prevalence of LLO-specific CD8+ T cells involved in tumour regression and Listeria elimination. These results support the use of low doses of pathogenic Listeria as safe melanoma therapeutic vaccines that do not require antibiotics for bacterial removal.

A gold glyco-nanoparticle carrying a Listeriolysin O peptide and formulated with Advax™ delta inulin adjuvant induces robust T-cell protection against listeria infection.

In the search for an effective vaccine against the human pathogen, Listeria monocytogenes (Listeria), gold glyconanoparticles (GNP) loaded with a listeriolysin O peptide LLO91-99 (GNP-LLO) were used to immunise mice, initially using a dendritic cell (DC) vaccine approach, but subsequently using a standard parenteral immunisation approach. To enhance vaccine immunogenicity a novel polysaccharide adjuvant based on delta inulin (Advax™) was also co-formulated with the GNP vaccine. Confirming previous results, DC loaded in vitro with GNP-LLO provided better protection against listeriosis than DC loaded in vitro using free LLO peptide. The immunogenicity of GNP-LLO loaded DC vaccines was further increased by addition of Advax™ adjuvant. However, as DC vaccines are expensive and impracticable for prophylactic use, we next asked whether the same GNP-LLO antigen could be used to directly target DC in vivo. Immunisation of mice with GNP-LLO plus Advax™ adjuvant induced LLO-specific T-cell immunity and protection against Listeria challenge. Protection correlated with an increased frequency of splenic CD4(+) and CD8(+) T cells, NK cells and CD8α(+) DC, and Th1 cytokine production (IL-12, IFN-γ, TNF-α, and MCP-1), post-challenge. Enhanced T-cell epitope recruitment post-challenge was seen in the groups that received Advax™ adjuvant. Immunisation with GNP-LLO91-99 plus Advax™ adjuvant provided equally robust Listeria protection as the best DC vaccine strategy but without the complexity and cost, making this a highly promising strategy for development of a prophylactic vaccine against listeriosis.

Influence of interleukin 10 promoter polymorphisms in polymyalgia rheumatica: disease susceptibility and functional consequences.

OBJECTIVES: To investigate the functional consequences of IL10 (-592C/A and -1082A/G) gene polymorphisms and their association with susceptibility to, and disease phenotype, in patients with polymyalgia rheumatica (PMR). METHODS: A total number of 168 with PMR and 124 age-matched controls were genotyped using allele-specific primers and restriction fragment length polymorphism analysis. The levels of circulating IL10 and the production of IL10 by PBMCs after in vitro stimulation were studied by Cytometric Bead Array. RESULTS: No significant differences were observed in genotype or allele frequency distribution between patients and controls. The clinical characteristics and prognosis of these patients were also unrelated to the presence of these polymorphisms. No significant differences between PMR patients with low ESR (<40 mm/hr) and classic PMR (>40 mm/hr) were found. Furthermore, we did not observe any influence of circulating IL10 with the intensity of the acute phase response. In both, PMR patients and age-matched controls, no differences in circulating IL10 levels or IL10 production were observed depending on the genotypes of the IL10 gene. CONCLUSIONS: These results do not support the impact of IL10 variants in susceptibility or clinical phenotype of PMR patients. In this aged population no functional association was found between IL10 gene variants and IL10 production.