Construction of a chimeric secretory IgA and its neutralization activity against avian influenza virus H5N1

Association of HLA-G Polymorphisms in the 3'UTR Region and Soluble HLA-G with Kidney Graft Outcome

Background: Human leukocyte antigen G (HLA-G) belongs to nonclassical HLA I molecule involving in the suppression of immune response. Besides its profound effect to induce fetal tolerance, HLA-G expression has been associated with allograft acceptance. For the regulation of HLA-G levels, polymorphic sites within the 3' untranslated region (3'UTR) are of crucial importance. The aim of the study was to analyze the association between several HLA-G 3'UTR variants (+3003T/C, +3010C/G, +3027C/A, +3035C/T, +3142G/C, +3187A/G, and +3196C/G), soluble HLA-G (sHLA-G) level, and kidney graft outcome in the Slovak Caucasian population. Methods: We investigated 69 kidney transplant recipients (45 males, 24 females) of age 27-65 years. Out of this group, 37 recipients developed acute rejection that was biopsy proven. Recipient's plasma was obtained at 1 day before transplantation and analyzed by ELISA. The HLA-G 3'UTR polymorphisms were typed by direct sequencing. Results: In the recipients with stable allograft function, significantly higher values of sHLA-G were found in the homozygous +3010GG, +3142CC, +3187GG, and +3196CC carriers in comparison to the acute rejection recipients (P = 0.01-0.05). Conclusion: The study demonstrated genetic association between HLA-G 3'UTR variants and sHLA-G level in kidney recipients leading to graft acceptance. We suggest to monitor the pretransplantation sHLA-G level as additional marker to predict kidney graft outcome. Abbreviations: AMR: Antibody-mediated rejection; APC: antigen-presenting cell; CD: cluster of designation; del: deletion; HLA: human leukocyte antigen; ILT: immunoglobulin-like transcript; ins: insertion; KIR: killer-cell immunoglobulin-like receptor; NK: natural killer; sHLA-G: soluble HLA-G; SNP: single nucleotide polymorphism; TCMR: T cell-mediated rejection; URR: upstream regulatory region; UTR: untranslated region.

Alternative skin sensitization prediction and risk assessment using proinflammatory biomarkers, interleukin-1 beta (IL-1β) and inducible nitric oxide synthase (iNOS)

As an alternative to animal tests for skin sensitization potency and risk assessment, cell viability and biomarkers related to skin sensitization were analyzed in THP-1 human monocytic leukemia cells. Cell viabilities of 90% (CV90) and 75% (CV75) were determined for 24 selected test chemicals. Further biomarkers related to skin sensitization were also determined under equivalent comparative conditions. In cell viability analyses, potent skin sensitizers exhibited high cytotoxicity, but non-sensitizers did not display this tendency. In biomarker analyses, interleukin-I beta (IL-1β), inducible nitric oxide synthase (iNOS), IL-1β+iNOS, and THP-1 IL-1β+Raw 264.7 IL-1β were found to be suitable for prediction of skin sensitization potency following classification as either skin sensitizers or non-sensitizers (accuracies of 91.7%, 87.5%, 83.3%, and 82.6%, respectively). A significant positive correlation was found between biomarkers and skin sensitization potency, with a correlation coefficient (R) of 0.7 or more (correlation coefficients of 0.77, 0.72, 0.7, and 0.84, respectively). Finally, the skin sensitization potency effective threefold concentration (EC) 3% was predicted using a biomarker equation, with resulting prediction rates (match rate with actual data) of 58.3%, 54.2%, 62.5%, and 60.9%, respectively. The prediction accuracy for the EC3 value obtained from animal data was calculated as 83.3%, 79.2%, 79.2%, and 73.9%, respectively. Thus, these biomarkers, IL-1β and iNOS, may be alternatively used to predict skin sensitization potency and risk assessment.

Association analysis of genetic polymorphisms and expression levels of selected genes involved in extracellular matrix turnover and angiogenesis with the risk of age-related macular degeneration

BACKGROUND

Age-related macular degeneration is a progressive eye disease affecting the macula and causing acute visual loss particularly in elder people. The aim of the study was an attempt to discern an influence of expression levels and functional genetic polymorphisms of selected genes related to the extracellular matrix turnover or neovascularization on age-related macular degeneration occurrence and progression.

METHODS

We conducted a case-control study of 200 polish patients with recognized age-related macular degeneration (dry and wet) and compared the results with those obtained from matched 100 healthy control subjects. TaqMan Genotyping Assays were employed to examine the following single nucleotide polymorphisms: matrix metalloproteinase (MMP)-2 -735C/T, MMP-7 -181A/G, MMP-9 -1702T/A, and -1562C/T; tissue inhibitors of metalloproteinase (TIMP)-2 -418G/C; vascular endothelial growth factor (VEGF) +405 G/C and +936 C/T, VEGFR-2 +1719 T/A and -271 G/A. Real-time polymerase chain reaction was assessed to determine the mRNA quantity. Serum levels of proteins were measured using enzyme-linked immunosorbent assay.

RESULTS

The single nucleotide polymorphism genotyping showed that TT genotype for MMP-9 -1702T/A and CC genotype for VEGF +936C/T increase markedly the risk of age-related macular degeneration but do not influence on its progression. Additionally, the possible protective effect of CC genetic variant in MMP-9 -1562C/T polymorphism against progression of age-related macular degeneration was observed. We also found significant differences in systemic expression levels of MMP-2, -7, -9, TIMP-2, vascular endothelial growth factor, VEGFR-2, and pigment epithelium-derived factor between studied group. The research demonstrated evident differences in serum levels of MMP-2, -7, -9, TIMP-2, vascular endothelial growth factor, and pigment epithelium-derived factor between wet and dry age-related macular degeneration patients.

CONCLUSIONS

We can conclude that disturbances in angiogenic homeostasis and processes of extracellular matrix turnover occurring in age-related macular degeneration-affected ocular tissues may be reflected in changes in systemic expression levels of the investigated genes.

Modulation of the immune system by the gut microbiota in the development of type 1 diabetes

T1D is an autoimmune disease characterized by T cell-mediated destruction of insulin-producing β-cells in the pancreatic islets of Langerhans, resulting in hyperglycemia, with patients requiring lifelong insulin treatment. Many studies have shown that genetics alone are not sufficient for the increase in T1D incidence and thus other factors have been suggested to modify the disease risk. T1D incidence has sharply increased in the developed world, especially amongst youth. In Europe, T1D incidence is increasing at an annual rate of 3-4%. Increasing evidence shows that gut microbiota, as one of the environmental factors influencing diabetes development, play an important role in development of T1D. Here, we summarize the current knowledge about the relationship between the microbiota and T1D. We also discuss the possibility of T1D prevention by changing the composition of gut microbiota.

IL-1α and IL-1β as alternative biomarkers for risk assessment and the prediction of skin sensitization potency

Potential biomarkers of skin sensitization in RAW264.7 mouse macrophages were investigated as alternatives to animal experiments and risk assessment. The concentrations that resulted in a cell viability of 90% (CV90) and 75% (CV75) were calculated by using a water-soluble tetrazolium salt (WST)-1 assay and used to analyze the skin sensitization potency of 23 experimental materials under equivalent treatment conditions. In addition, the expression of interleukin (IL)-1α, IL-1β, IL-31, tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), prostaglandin E2 (PGE2), and cyclooxygenase-2 (COX-2) was analyzed utilizing Western blotting. In the cell viability analysis, skin sensitizers were generally more cytotoxic and exhibited increased skin sensitization potency. However, nonsensitizers did not show any marked cytotoxic tendency. Biomarker analysis demonstrated that IL-1α, IL-1β, and the combination of IL-1α and IL-1β (IL-1α + IL-1β) predicted reliably skin sensitization potential (1) sensitivities of 94.4%, 83.3%, and 83.3%, specificities of 100%, 100%, and 100%, and (2) accuracies of 95.7%, 87%, and 87%, respectively. These observations correlated most reliably as indicators for skin sensitization potency. Data suggest that IL-1α and IL-1β may serve as potential biomarkers for skin sensitization and provide an alternative method to animal experiments for prediction of skin sensitization potency and risk assessment.

Transient Expression of Secretory IgA In Planta is Optimal Using a Multi-Gene Vector and may be Further Enhanced by Improving Joining Chain Incorporation

Secretory IgA (sIgA) is a crucial antibody in host defense at mucosal surfaces. It is a promising antibody isotype in a variety of therapeutic settings such as passive vaccination and treatment of inflammatory disorders. However, heterologous production of this heteromultimeric protein complex is still suboptimal. The challenge is the coordinate expression of the four required polypeptides; the alpha heavy chain, the light chain, the joining chain, and part of the polymeric-Ig-receptor called the secretory component, in a 4:4:1:1 ratio. We evaluated the transient expression of three sIgAκ variants, harboring the heavy chain isotype α1, α2m1, or α2m2, of the clinical antibody Ustekinumab in planta. Ustekinumab is directed against the p40 subunit that is shared by the pro-inflammatory cytokines interleukin (IL)-12 and IL-23. A sIgA variant of this antibody may enable localized treatment of inflammatory bowel disease. Of the three different sIgA variants we obtained the highest yield with sIgA1κ reaching up to 373 μg sIgA/mg total soluble protein. The use of a multi-cassette vector containing all four expression cassettes was most efficient. However, not the expression strategy, but the incorporation of the joining chain turned out to be the limiting step for sIgA production. Our data demonstrate that transient expression in planta is suitable for the economic production of heteromultimeric protein complexes such as sIgA.