Asymptomatic SARS-CoV-2 infection in recipients of hematopoietic stem cells in the Omicron period.

Aim: We aimed to determine the prevalence of SARS-CoV-2 infection, including both symptomatic and asymptomatic courses, and to identify predictors of asymptomatic or symptomatic SARS-CoV-2 infection in patients within seven months after allo-HSCT (allogenic hematopoietic stem cell transplantation) in the Omicron period.

Methods: Prevalence of the past SARS-CoV-2 infection was determined in patients within seven months after allo-HSCT in the Omicron period using the cellular and humoral immune response against the SARS-CoV-2 nucleoprotein (NCP).

Results: Positive markers of past infection were identified in 45.

Specific immune response to mRNA vaccines against COVID-19 in patients receiving allogeneic stem cell transplantation for myeloid malignancy was altered by immunosuppressive therapy.

Background: Allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are at high risk of complications associated with COVID-19 infection due to dysfunction of their immune system. Vaccination can protect from the adverse consequences of COVID-19. However, studies on the efficacy of COVID-19 vaccines in HSCT recipients with insufficient post-HSCT immune reconstitution are still scarce.

Non-Mutated Nucleophosmin 1 Is Recognized by the CD8+ T Lymphocytes of an AML Patient after the Transplantation of Hematopoietic Stem Cells from an HLA-Haploidentical Donor.

Nucleophosmin (NPM1, B23) is a multifunctional phosphoprotein expressed in all tissues. The protein is mainly localized in nucleoli. In hematological malignancies, belongs to commonly altered genes.

Pretransplant BK Virus-Specific T-Cell-Mediated Immunity and Serotype Specific Antibodies May Have Utility in Identifying Patients at Risk of BK Virus-Associated Haemorrhagic Cystitis after Allogeneic HSCT.

BK polyomavirus (BKPyV) persists lifelong in renal and urothelial cells with asymptomatic urinary shedding in healthy individuals. In some immunocompromised persons after transplantation of hematopoietic stem cells (HSCT), the BKPyV high-rate replication is associated with haemorrhagic cystitis (HC). We tested whether the status of BKPyV immunity prior to HSCT could provide evidence for the BKPyV tendency to reactivate.

Investigation into powder tribo-charging of pharmaceuticals. Part II: Sensitivity to relative humidity.

Environmental conditions can have a profound impact on the bulk behaviour of pharmaceutical powders, including their tribo-charging tendency. Typically, high relative humidity (RH) has been associated to a reduction in the electrostatic charge of the material. However, the occurrence of charge mitigation seems to be related to the quantity of water molecules at the powder surface, which depends on intrinsic material attributes (i.

Investigation into powder tribo-charging of pharmaceuticals. Part I: Process-induced charge via twin-screw feeding.

Powder feeding is a crucial unit operation in continuous manufacturing (CM) of pharmaceutical products. Twin-screw feeders are typically employed to ensure the accurate mass flow of pharmaceutical materials throughout the production process. Here, contact and separation of particles can give rise to electrostatic charges, affecting feeder performance and final product quality.

Antigenic competition in the generation of multi-virus-specific cell lines for immunotherapy of human cytomegalovirus, polyomavirus BK, Epstein-Barr virus and adenovirus infection in haematopoietic stem cell transplant recipients.

Adoptive transfer of multivirus-specific T cell lines (MVST) is an advanced tool for immunotherapy of virus infections after hematopoietic stem cell transplantation (HSCT). Their preparation includes activation of donor virus-specific T cells by the mixture of oligopeptides derived from immunodominant antigens of several most harmful viruses, i.e.

Reconstitution of cytomegalovirus-specific T-cell response in allogeneic hematopoietic stem cell recipients: the contribution of six frequently recognized, virus-encoded ORFs.

Background: The reactivation of human cytomegalovirus (HCMV) in immunosuppressed patients is associated with significant morbidity. Testing HCMV-specific T-cell responses can help determine which patients are at high risk of HCMV disease. We optimized selection of HCMV antigens for detection of T-cell response of patients after allogeneic hematopoietic stem cell transplantation (HSCT) with the aim of identifying patients with insufficient control of HCMV reactivation.

Antitumor activity and immunogenicity of recombinant vaccinia virus expressing HPV 16 E7 protein SigE7LAMP is enhanced by high-level coexpression of IGFBP-3.

We constructed recombinant vaccinia viruses (VACVs) coexpressing the insulin-like growth factor-binding protein-3 (IGFBP-3) gene and the fusion gene encoding the SigE7Lamp antigen. The expression of the IGFBP-3 transgene was regulated either by the early H5 promoter or by the synthetic early/late (E/L) promoter. We have shown that IGFBP-3 expression regulated by the H5 promoter yielded higher amount of IGFBP-3 protein when compared with the E/L promoter.

Chemokine binding protein vCCI attenuates vaccinia virus without affecting the cellular response elicited by immunization with a recombinant vaccinia vector carrying the HPV16 E7 gene.

Viral CC chemokine inhibitor (vCCI) of the clone P13 vaccinia virus (VACV) strain PRAHA lacks eight amino acids in the signal peptide sequence. To study the influence of vCCI on virus biology, a virus with the vCCI gene coding for a prolonged signal sequence was prepared. We found that secreted vCCI attenuated the virus in vivo, and that it correlated with decreased levels of RANTES, eotaxin, TARC, and MDC in the blood in comparison with the parental virus.

Immunization with WT1-derived peptides by tattooing inhibits the growth of TRAMP-C2 prostate tumor in mice.

The expression of the transcription factor encoded by the Wilms tumor gene 1 (WT1) is associated with a variety of human cancers. WT1 protein has been reported to serve as a target antigen for tumor-specific immune responses. We observed that the immunization of mice with peptide vaccines derived from WT1 in a mixture with the CpG adjuvant (ODN 1826) by tattoo administration was superior to subcutaneous delivery of the peptides in combination with CpG formulated with the mineral oil adjuvant or a DNA vaccine or a recombinant vaccinia virus vaccine expressing the truncated WT1 protein.

Expression of soluble TGF-β receptor II by recombinant Vaccinia virus enhances E7 specific immunotherapy of HPV16 tumors.

Therapeutic immunization with double recombinants of vaccinia virus (VACV) co-expressing sTβRII increased rejection of established TC-1 tumors in C57BL/6 mice in comparison with single recombinant expressing SigE7LAMP. Recombinant VACV derived from vaccination strain Praha expressed either the sTβRII (ectodomain) or chimeric protein fused to immunoglobulin Fc fragment (sTβRII-Fc-Jun) under control of two different promotors together with the immunogenic tumor associated antigen HPV16 E7 oncoprotein in a form of SigE7LAMP fusion molecule. The ability of soluble receptors to bind TGF-β in vitro was proved.

Attenuation of vaccinia virus by the expression of human Flt3 ligand.

Background: Vaccinia virus, one of the best known members of poxvirus family, has a wide host range both in vivo and in vitro. The expression of Flt3 ligand (FL) by recombinant vaccinia virus (rVACV) highly influenced properties of the virus in dependence on the level of expression.

Results: High production of FL driven by the strong synthetic promoter decreased the growth of rVACV in macrophage cell line J774.

The expression of the soluble isoform of hFlt3 ligand by recombinant vaccinia virus enhances immunogenicity of the vector.

Recombinant vaccinia viruses (rVACV) expressing various tumor-associated antigens have been shown to elicit anti-tumor effect in numerous experimental models and clinical trials. We tested the hypotheses that rVACV expressing biologically active fms-like tyrosine kinase 3 ligand (Flt3L) would show higher immunogenicity than control viruses expressing only model antigen and that coexpression of Flt3L would influence anti-tumor activity of rVACV in the preventive and therapeutic arrangements of the in vivo experiment. To answer these questions, we took advantage of the well-described model of transplanted tumor cells expressing HPV16 E6 and E7 oncoproteins.

Combination of intratumoral injections of vaccinia virus MVA expressing GM-CSF and immunization with DNA vaccine prolongs the survival of mice bearing HPV16 induced tumors with downregulated expression of MHC class I molecules.

Downregulation of MHC class I molecules is believed to be often the cause of tumor immune escape and at the same time it is the major obstacle to T-cell based immunotherapy of tumors. In our experimental model, the C57BL/6 mice bearing tumors induced by TC-1/A9 cells characterized by expression of HPV16 oncogenes and downregulation of H-2b molecules were immunized with highly immunogenic E7GGG.GUS DNA vaccine expressing the fused gene of modified HPV16 E7 (E7GGG) with E.

Prime/boost immunotherapy of HPV16-induced tumors with E7 protein delivered by Bordetella adenylate cyclase and modified vaccinia virus Ankara.

The Bordetella adenylate cyclase toxoid (CyaA) targets cells expressing the alphaMbeta2 integrin receptor CD11b/CD18 (CR3 or Mac-1) and can penetrate into cytosol of professional antigen-presenting cells, such as dendritic cells. This allows us to use CyaA for delivery of passenger antigens into the cytosolic pathway of processing and MHC class I-restricted presentation, which can promote induction of antigen-specific CD8+ cytotoxic T-lymphocyte immune responses. We show here that vaccination with a genetically detoxified CyaA336/E7 protein, carrying the full-length oncoprotein E7 of the human papilloma virus 16 inserted at position 336 of the cell-invasive AC domain of CyaA, induces an E7-specific CD8+ T-cell immune response and confers on mice protective, as well as therapeutic immunity against challenge with TC-1 tumor cells expressing the E7 oncoprotein.

Adjuvant effect of dendritic cells transduced with recombinant vaccinia virus expressing HPV16-E7 is inhibited by co-expression of IL12.

Dendritic cells (DC) enhanced the immunogenicity of recombinant vaccinia viruses (rVV) expressing the E7 protein of HPV16, a tumor-associated antigen (TAA). Immunization with DC transduced by rVV generated from strain Praha or MVA induced better protection against the growth of transplanted TC-1 tumors in C57Bl/6 mice than did immunization with either of these rVVs administered alone by the same route. Interestingly, DC transduced with a double recombinant vaccinia virus expressing E7 protein together with the Th1-polarizing cytokine IL12, which has been shown to enhance the cellular response in several other systems, induced lower anti-tumor immunity than DC transduced with rVV expressing E7 protein alone.

Experimental therapy of HPV16 induced tumors with IL12 expressed by recombinant vaccinia virus in mice.

Recombinant vaccinia viruses derived from strain Praha, clone P13, and strain MVA were used for intratumoral delivery and expression of IL12 genes in tumors induced by HPV16 E6+E7 oncogenes in mice. Intratumoral injection of 10(3) PFU of P13-IL12 virus resulted in an increase of intra-tumoral IL12 on days 6-13, while only low levels of IL12 were found in sera. After the inoculation of 10(6) PFU of MVA-IL12, the same levels of IL12 were found as in animals injected with control virus.

[Vaccinia virus as a vector for transduction of dendritic cells].

Dendritic cells (DC) are very heterogenous population of professional antigen-presenting cells. Precursor cells migrate from bone marrow to peripheral tissues, where immature DC ingest pathogenic microorganisms and then migrate to secondary lymphoid organs. DC differentiate into mature cells that are capable to prime naive T lymphocytes.

Immune response to E7 protein of human papillomavirus type 16 anchored on the cell surface.

To target the E7 protein of human papilloma virus 16 to the cell surface, a fusion gene was constructed. It encodes the signal peptide, part of the immunoglobulin (IgG)-like domain, the transmembrane anchor of vaccinia virus (VV) hemagglutinin (HA), and the complete E7-coding sequence. The fusion gene was expressed under the HA late promoter by a recombinant VV, designated VV-E7-HA.

Early gene expression of vaccinia virus strains replicating (Praha) and non-replicating (modified vaccinia virus strain Ankara, MVA) in mammalian cells.

Modified vaccinia virus Ankara strain (MVA) is a safe highly attenuated non-pathogenic virus suitable as a vector for developing various vaccines. Study of expression of a reporter beta-galactosidase gene under the control of an early vaccinia virus (VV) promoter in MVA and non-modified vaccinia virus Praha strain showed that early transcription in MVA is elevated in comparison with non modified VV. This property was demonstrated in various cell cultures including CV1 cells, human lung diploid cells, chicken primary fibroblasts but not in bone marrow-derived mouse dendritic cells.

Effect of IFN-gamma receptor gene deletion on vaccinia virus virulence.

Two vaccina virus (VV) strains, WR and Praha, were selected for a study undertaken to determine whether the virus-encoded interferon-gamma receptor (IFN-gamma R) plays any role in virus virulence. Both of the viruses expressed the B8R gene coding for IFN-gamma R in infected cell cultures. The nucleotide sequence of the Praha virus B8R gene was determined, and, when compared with the published sequence of the WR virus, it only displayed one silent nucleotide substitution.

Immune response to vaccinia virus recombinants expressing glycoproteins gE, gB, gH, and gL of Varicella-zoster virus.

Immunogenicity of Varicella-zoster virus glycoproteins gE, gB, gH, and gL expressed by recombinant vaccinia viruses (VV) separately or simultaneously was determined in mice and guinea pigs by ELISA, Western blotting, radioimmunoprecipitation, plaque reduction assay, and skin test. Single VV-gE and VV-gB recombinants and double VV-gH/gL recombinant elicited specific antibodies with VZV neutralizing activity in mice. Co-expression of gE and gB by one recombinant VV resulted in an increased antibody response in comparison with immunization with single recombinants or their mixtures.

Effect of virulence on immunogenicity of single and double vaccinia virus recombinants expressing differently immunogenic antigens: antibody-response inhibition induced by immunization with a mixture of recombinants differing in virulence.

It has been shown recently that the residual virulence of vaccinia virus (VV) is an important factor that influences the outcome of immunization with VV recombinants. This study focused on the correlation of the residual virulence of several VV recombinants with antibody responses against the strongly immunogenic extrinsic glycoprotein E of varicella-zoster virus and the weakly immunogenic extrinsic protein preS2-S of hepatitis B virus and against VV proteins, with mice used as a model organism. Furthermore, the effects of mixing different recombinants on the antibody response were studied.

Secondary vaccination with vaccinia virus recombinants: role of residual virulence of recombinants and immunogenicity of extrinsic antigens.

ICR mice were immunized intraperitoneally with two doses (10(6) PFU per dose) of vaccinia virus (VV) recombinants of variable virulence expressing either the strongly immunogenic glycoprotein E (gE) of varicella zoster virus (VZV) or weakly immunogenic hepatitis B virus (HBV) preS2-S (S) antigen. Recombinants expressing gE were able to elicit primary and secondary anti-gE antibody irrespective of their residual virulence; after the second dose they did so even in the presence of VV antibody resulting from primary vaccination dose or under other conditions limiting VV replication. As for the S-recombinants, pronounced anti-S antibody development was only observed in mice which had received the more virulent recombinant virus as the first dose.