A novel recombinantly produced banana lectin isoform is a valuable tool for glycoproteomics and a potent modulator of the proliferation response in CD3(+), CD4(+), and CD8(+) populations of human PBMCs

Lectins as carbohydrate-binding proteins have been employed in various biological assays for the detection and characterization of glycan structures on glycoproteins, including clinical biomarkers in disease states. A mannose-specific banana lectin (BanLec) is unique in its specificity for internal alpha 1,3 linkages as well as beta 1,3 linkages at the reducing termini. The immunomodulatory potential of natural BanLec was recognized by a strong immunoglobulin G4 antibody response and T cell mitogen activity in humans. To explore its applicability in glycoproteomics and its modulatory potential, the gene of banana lectin was cloned, sequenced and a recombinant protein was produced in Escherichia coli. The obtained cDNA revealed a novel banana lectin isoform, with an open reading frame of 426 nucleotides, encoding a cytoplasmatic protein of 141 amino acids. The molecular mass of rBanLec determined by ESI FT-MS and N-terminal sequencing confirmed the cDNA at the protein level. The specificity of rBanLec for detection glycan structures was the same as for natural BanLec, as examined with five protein extracts rich in glycoprotein content, as well as with horseradish peroxidase glycoprotein. Besides, the immunomodulatory potential of rBanLec and nBanLec were comparable as assessed by an inhibition assay and a human T cell proliferation assay where they induced a strong proliferation response in CD3(+), CD4(+), and CD8(+) populations of human PBMCs. This recombinant BanLec is a useful reagent for glycoprotcomics and lectin microarrays, with a potential for modulation of the immune response. (C) 2007 Elsevier Ltd. All rights reserved

Conjunctival effects of a selective nasal pollen provocation

status: publishe

Dexamethasone-induced apoptosis of freshly isolated human nasal epithelial cells concomitant with abrogation of IL-8 production

SUMMARY Background: Human nasal epithelial cells (hNECs) are the first line of immune defense and are able to produce mediators that recruit, activate and prolong survival of immune cells, among which IL-8 takes an important place. Studies on IL-8 and effects of dexamethasone on hNECs have been hampered by methodological shortcomings. The purpose of the study is to investigate the contribution of freshly isolated hNECs to IL-8 production in chronic rhinosinusitis with nasal polyps (CRSwithNP). Secondly, the effects of dexamethasone treatment on hNEC apoptosis and IL-8 production are investigated. Methodology: hNECs were freshly isolated from nasal polyp tissue and healthy inferior turbinate of NP patients (n=12) and from inferior turbinates of healthy donors (n=19) by protease treatment and two negative selection procedures. hNECs were incubated with IL-1β (10ng/ml), TNFα (10ng/ml) or dexamethasone (10, 100 and 1000 Amicrog/ml). After 24h, IL-8 levels were determined in the supernatants by ELISA. Finally, hNECs were incubated with increasing doses of dexamethasone and stained with trypan-blue and annexin-FITC/PI to study apoptosis. Results: hNECs isolated from nasal turbinates of healthy and NP patients and polyp tissue from NP patients produced similar levels of IL-8. IL-1β induced higher levels of IL-8 production in all types of hNECs without differences between control and NP tissue. Dexamethasone induced apoptosis of hNECs concomitant with abrogation of IL-8 production by hNECs. Conclusions: IL-8 production by human nasal epithelial cells does not differ between NP and healthy tissue under baseline nor stimulatory conditions. Dexamethasone induces apoptosis of hNECs and abrogates IL-8 productio

Intranasal delivery of a cDC1 targeted influenza vaccine with poly(I:C) enhances T cell responses and protects against influenza infection

Targeting antigens to dendritic cells represent a promising method for enhancing immune responses against specific antigens. However, many studies have focused on systemic delivery (intravenous or intraperitoneally) of targeted antigen, approaches that are not easily transferable to humans. Here we evaluate the efficacy of an influenza vaccine targeting Xcr1+ cDC1 administered by intranasal immunization. Intranasal delivery of antigen fused to the chemokine Xcl1, the ligand of Xcr1, resulted in specific uptake by lung CD103+ cDC1. Interestingly, intranasal immunization with influenza A/PR/8/34 haemagglutinin (HA) fused to Xcl1, formulated with poly(I:C), resulted in enhanced induction of antigen-specific IFNγ+CD4+ and IFNγ+CD8+ T cell responses in lung compared non-targeted anti-NIP-HA (αNIP-HA). Induction of antibody responses was, however, similar in Xcl1-HA and αNIP-HA immunized mice, but significantly higher than in mice immunized with monomeric HA. Both Xcl1-HA and αNIP-HA vaccines induced full protection when mice were challenged with a lethal dose of influenza PR8 virus, reflecting the strong induction of HA-specific antibodies. Our results demonstrate that i.n. delivery of Xcl1-HA is a promising vaccine strategy for enhancing T cell responses in addition to inducing strong antibody responses

Effect of nasal anti-inflammatory treatment in chronic obstructive pulmonary disease

Sinonasal inflammation and symptoms are often underdiagnosed in chronic obstructive pulmonary disease (COPD) patients. So far, it is not known to what extent anti-inflammatory nasal treatment may reduce sinonasal symptoms in COPD patients. This study was designed to examine the effects of nasal anti-inflammatory treatment on sinonasal symptoms and cough in COPD patients. Thirty-three COPD patients on stable bronchial therapy (salmeterol/fluticasone propionate 50/500 mg b.i.d. for >6 weeks) were randomized to receive fluticasone furoate (FF) or placebo nasal spray at 110 μg once daily for 12 weeks. Sinonasal symptoms and cough were monitored at baseline, at 6 and12 weeks of treatment, and at 4 weeks after cessation of the treatment using a visual analog scale. Levels of cytokines were measured in nasal secretions. In contrast to the placebo group (n = 13), FF patients (n = 14) reported less nasal blockage (10.62 ± 4.21 mm versus 36.57 ± 8.01 mm; p = 0.0026), postnasal drip (1.46 ± 0.29 score versus 2.83 ± 0.38 score; p = 0.03), and nasal discharge (0.23 ± 0.12 score versus 1.77 ± 0.43 score; p = 0.01) after 6 weeks of treatment compared with baseline, which was still present at 12 weeks. FF patients reported less cough compared with baseline (25.54 ± 4.46 mm versus 36.79 ± 5.75 mm; p = 0.04), which was not the case in the placebo group (49.58 ± 10.44 mm versus 42.00 ± 8.05 mm; p = 0.38). Nine of 14 patients in the FF group (64%) reported slight to total relief of nasal symptoms, and this subgroup had a significant decrease in IL-8 levels in nasal secretions after 6 weeks of treatment (850.7 ± 207.2 pg/mL versus 1608 ± 696.5 pg/mL; p = 0.03) compared with baseline. Nasal FF treatment in COPD patients significantly reduced sinonasal symptoms, in parallel with reduced IL-8 in nasal secretion levels and coug

A DNA Vaccine That Encodes an Antigen-Presenting Cell-Specific Heterodimeric Protein Protects against Cancer and Influenza

Immunogenicity of DNA vaccines can be increased by constructing the DNA in such a way that it encodes secreted homodimeric fusion proteins that target antigen-presenting cells (APCs). In this study, we have developed novel APC-targeting vaccine molecules with an increased flexibility due to introduction of a heterodimerization motif. The heterodimeric proteins permit four different fusions within a single molecule, thus allowing expression of two different APC-targeting moieties and two different antigens. Two types of heterodimeric fusion proteins were developed that employed either the ACID/BASE or the Barnase/Barstar motifs, respectively. The ACID/BASE heterodimeric vaccines conferred protection against challenges with either influenza virus or tumor cells in separate preclinical models. The ACID/BASE motif was flexible since a large number of different targeting moieties and antigens could be introduced with maintenance of specificity, antigenicity, and secretion. APC-targeting ACID/BASE vaccines expressing two different antigens induced antibody and T cell responses against either of the two antigens. Heterodimeric ACID/BASE DNA vaccines were of approximately the same potency as previously reported homodimeric DNA vaccines. The flexibility and potency of the ACID/BASE format suggest that it could be a useful platform for DNA vaccines that encode APC-targeting fusion proteins