18 research outputs found

    Review of Antlions (Insecta: Neuroptera: Myrmeleontidae) in North Macedonia

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    We present the state of knowledge on the family Myrmeleontidae occurring in North Macedonia based on published records, museum specimens and new samples, and provide a comprehensive species list. North Macedonia represents only 3.9% of the area of the Balkan Peninsula but harbours 19 species belonging to 14 antlion genera, i.e., 61% of the peninsular fauna. We report collection localities, literature records and biological data for each species. Three species, Nemoleon poecilopterus, Neuroleon assimilis and Myrmeleon inconspicuus, are reported for the first time in North Macedonia. The genus Nemoleon Navás is also reported for the first time in the country

    Human Cytomegalovirus Fcγ Binding Proteins gp34 and gp68 Antagonize Fcγ Receptors I, II and III

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    Human cytomegalovirus (HCMV) establishes lifelong infection with recurrent episodes of virus production and shedding despite the presence of adaptive immunological memory responses including HCMV immune immunoglobulin G (IgG). Very little is known how HCMV evades from humoral and cellular IgG-dependent immune responses, the latter being executed by cells expressing surface receptors for the Fc domain of IgG (FcγRs). Remarkably, HCMV expresses the RL11-encoded gp34 and UL119-118-encoded gp68 type I transmembrane glycoproteins which bind Fcγ with nanomolar affinity. Using a newly developed FcγR activation assay, we tested if the HCMV-encoded Fcγ binding proteins (HCMV FcγRs) interfere with individual host FcγRs. In absence of gp34 or/and gp68, HCMV elicited a much stronger activation of FcγRIIIA/CD16, FcγRIIA/CD32A and FcγRI/CD64 by polyclonal HCMV-immune IgG as compared to wildtype HCMV. gp34 and gp68 co-expression culminates in the late phase of HCMV replication coinciding with the emergence of surface HCMV antigens triggering FcγRIII/CD16 responses by polyclonal HCMV-immune IgG. The gp34- and gp68-dependent inhibition of HCMV immune IgG was fully reproduced when testing the activation of primary human NK cells. Their broad antagonistic function towards FcγRIIIA, FcγRIIA and FcγRI activation was also recapitulated in a gain-of-function approach based on humanized monoclonal antibodies (trastuzumab, rituximab) and isotypes of different IgG subclasses. Surface immune-precipitation showed that both HCMV-encoded Fcγ binding proteins have the capacity to bind trastuzumab antibody-HER2 antigen complexes demonstrating simultaneous linkage of immune IgG with antigen and the HCMV inhibitors on the plasma membrane. Our studies reveal a novel strategy by which viral FcγRs can compete for immune complexes against various Fc receptors on immune cells, dampening their activation and antiviral immunity.DFG grant He 2526/6-2.European Commission grants QLRT-2001-01112 and MRTN-CT-2005-019248.Helmholtz Association through VISTRIE VH-VI-242.UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

    GMP-production of purified human B lymphocytes for the adoptive transfer in patients after allogeneic hematopoietic stem cell transplantation

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    Abstract Background We have recently shown that memory B cells from murine CMV immune donor animals adoptively transferred into immunodeficient mice were highly effective in protecting from a viral infection indicating a therapeutic potential of virus specific memory B cells. These preclinical data provided evidence that a cell-based strategy supporting the humoral immune response might be effective in a clinical setting of immunodeficiency after allogeneic hematopoietic stem cell transplantation. As adoptive transfer of B cells has not been used before in a clinical setting it was necessary to establish a technology for the generation of good manufacturing practice (GMP)-grade B cell products. Methods Starting from the leukapheresis product of healthy blood donors, B cells were purified by two different separation strategies using GMP-grade microbeads and the CliniMACS system. A one-step protocol was used for positive enrichment of B lymphocytes with anti-CD19 microbeads. In a two-step enrichment protocol, first T lymphocytes were depleted by anti-CD3 microbeads and the remaining fraction was positively selected by anti-CD19 microbeads. Results The purity and recovery after enrichment of B lymphocytes from the leukapheresis material in both separations strategies was not statistically different. However, contamination of the B-cell product with T cells was significantly lower after the two-step protocol (0.16%, range 0.01–0.43% after two-step separation and 0.55%, range 0.28–0.85% after one-step separation, p < 0.05). Therefore, a combined CD3 depletion and CD19 enrichment was used for the production of GMP-conform B-cell products from the leukapheresis material of 17 healthy stem cell donors. The absolute B-cell numbers obtained in the final product was 4.70 ± 3.64 × 108 with a purity of 95.98 ± 3.31% B lymphocytes and a recovery of 18.9 ± 10.6%. Importantly, the contamination with CD3+ T cells was extremely low in the final B- cell products (0.10 ± 0.20%). Purified B cells exhibited normal antibody production after in vitro stimulation and showed excellent viability after cryopreservation. Conclusions A GMP-grade B-cell product can be obtained with high purity and very low T-cell contamination using the two-step enrichment protocol based on CliniMACS® technology

    Absence of Cross-Presenting Cells in the Salivary Gland and Viral Immune Evasion Confine Cytomegalovirus Immune Control to Effector CD4 T Cells

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    Horizontal transmission of cytomegaloviruses (CMV) occurs via prolonged excretion from mucosal surfaces. We used murine CMV (MCMV) infection to investigate the mechanisms of immune control in secretory organs. CD4 T cells were crucial to cease MCMV replication in the salivary gland (SG) via direct secretion of IFNγ that initiated antiviral signaling on non-hematopoietic cells. In contrast, CD4 T cell helper functions for CD8 T cells or B cells were dispensable. Despite SG-resident MCMV-specific CD8 T cells being able to produce IFNγ, the absence of MHC class I molecules on infected acinar glandular epithelial cells due to viral immune evasion, and the paucity of cross-presenting antigen presenting cells (APCs) prevented their local activation. Thus, local activation of MCMV-specific T cells is confined to the CD4 subset due to exclusive presentation of MCMV-derived antigens by MHC class II molecules on bystander APCs, resulting in IFNγ secretion interfering with viral replication in cells of non-hematopoietic origin
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