Explore the vast range of titles available.

messenger RNA (mRNA)-based vaccines combine the positive attributes of both live-attenuated and subunit vaccines. In order for these to be applied for clinical use, they require to be formulated with delivery systems. However, there are limited in vivo studies which compare different delivery platforms. Therefore, we have compared four different cationic platforms: (1) liposomes, (2) solid lipid nanoparticles (SLNs), (3) polymeric nanoparticles (NPs) and (4) emulsions, to deliver a self-amplifying mRNA (SAM) vaccine. All formulations contained either the non-ionizable cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) or dimethyldioctadecylammonium bromide (DDA) and they were characterized in terms of physico-chemical attributes, in vitro transfection efficiency and in vivo vaccine potency. Our results showed that SAM encapsulating DOTAP polymeric nanoparticles, DOTAP liposomes and DDA liposomes induced the highest antigen expression in vitro and, from these, DOTAP polymeric nanoparticles were the most potent in triggering humoral and cellular immunity among candidates in vivo.

Ideal cancer treatments specifically target and eradicate tumor cells without affecting healthy cells. Therefore, antibody‐based therapies that specifically target cancer antigens can be considered ideal cancer therapies. Antibodies linked with small‐molecule drugs (i.e., antibody–drug conjugates [ADCs]) are widely used in clinics as antibody‐based therapeutics. However, because tumors express antigens heterogeneously, greater target specificity and stable binding of noncleavable linkers in ADCs limit their antitumor effects. To overcome this problem, strategies, including decreasing the binding strength, conjugating more drugs, and targeting tumor stroma, have been applied, albeit with limited success. Thus, further technological advancements are required to remotely control the ADCs. Here, we described a drug that is photo‐releasable from an ADC created via simple double conjugation and its antitumor effects both on target and nontarget tumor cells. Specifically, noncleavable T‐DM1 was conjugated with IR700DX to produce T‐DM1‐IR700. Although T‐DM1‐IR700 itself is noncleavable, with NIR‐light irradiation, it can release DM1‐derivatives which elicited antitumor effect in vitro mixed culture and in vivo mixed tumor model which are mimicking heterogeneous tumor‐antigen expression same as real clinical tumors. This cytotoxic photo‐bystander effect occurred in various types mixed cultures in vitro, and changing antibodies also exerted photo‐bystander effects, suggesting that this technology can be used for targeting various specific cancer antigens. These findings can potentially aid the development of strategies to address challenges associated with tumor expression of heterogeneous antigen.

Background and aims: We tested if host gastric Lewis antigens and the babA2 genotype of Helicobacter pylori correlated with clinicohistological outcome. Methods: We enrolled 188 dyspeptic patients (45 with duodenal ulcer, 45 with gastric ulcer, and 98 with chronic gastritis) with H pylori infection, proved by culture and gastric histology, reviewed by the updated Sydney system. Gastric expression of Lewis (Le) antigens Lea, Leb, Lex, and Ley was determined immunochemically to determine intensity (range 0–3). The corresponding 188 H pylori isolates were screened for babA2 genotype by polymerase chain reaction. Results: All H pylori isolates had a positive babA2 genotype. We identified Lea in 33.5%, Leb in 72.9%, Lex in 86.2%, and Ley in 97.4% of biopsies from these 188 patients. Patients who expressed Leb had a higher H pylori density than those who did not express Leb (p<0.001). Among 139 patients who expressed Leb, H pylori density increased with a higher Leb intensity (p<0.05). Gastric atrophy decreased with Leb intensity and thus resulted in lower H pylori density in the antrum (p<0.05). For the 49 patients without gastric Leb expression, H pylori density was positively related with Lex and Lea expression (p<0.05). Conclusions: Taiwanese H pylori isolates are 100% babA2 genopositive. Gastric Leb as well as Lex intensity may be major determinants of H pylori density. While lacking gastric Leb expression, Lex and Lea were closely related to H pylori colonisation.

PurposeThe prostate-specific membrane antigen (PSMA) has emerged as an interesting target for radionuclide therapy of metastasized castration-resistant prostate cancer (mCRPC). The aim of this study was to investigate 161Tb (T1/2 = 6.89 days; Eβ͞av = 154 keV) in combination with PSMA-617 as a potentially more effective therapeutic alternative to 177Lu-PSMA-617, due to the abundant co-emission of conversion and Auger electrons, resulting in an improved absorbed dose profile.Methods161Tb was used for the radiolabeling of PSMA-617 at high specific activities up to 100 MBq/nmol. 161Tb-PSMA-617 was tested in vitro and in tumor-bearing mice to confirm equal properties, as previously determined for 177Lu-PSMA-617. The effects of 161Tb-PSMA-617 and 177Lu-PSMA-617 on cell viability (MTT assay) and survival (clonogenic assay) were compared in vitro using PSMA-positive PC-3 PIP tumor cells. 161Tb-PSMA-617 was further investigated in therapy studies using PC-3 PIP tumor-bearing mice.Results161Tb-PSMA-617 and 177Lu-PSMA-617 displayed equal in-vitro properties and tissue distribution profiles in tumor-bearing mice. The viability and survival of PC-3 PIP tumor cells were more reduced when exposed to 161Tb-PSMA-617 as compared to the effect obtained with the same activities of 177Lu-PSMA-617 over the whole investigated concentration range. Treatment of mice with 161Tb-PSMA-617 (5.0 MBq/mouse and 10 MBq/mouse, respectively) resulted in an activity-dependent increase of the median survival (36 vs 65 days) compared to untreated control animals (19 days). Therapy studies to compare the effects of 161Tb-PSMA-617 and 177Lu-PSMA-617 indicated the anticipated superiority of 161Tb over 177Lu.Conclusion161Tb-PSMA-617 showed superior in-vitro and in-vivo results as compared to 177Lu-PSMA-617, confirming theoretical dose calculations that indicate an additive therapeutic effect of conversion and Auger electrons in the case of 161Tb. These data warrant more preclinical research for in-depth investigations of the proposed concept, and present a basis for future clinical translation of 161Tb-PSMA-617 for the treatment of mCRPC.

Fibromyalgia (FM) is defined as a widely distributed pain. While many rheumatologists and pain physicians have considered it to be a pain disorder, psychiatry, psychology, and general medicine have deemed it to be a syndrome (FMS) or psychosomatic disorder. The lack of concrete structural and/or pathological evidence has made patients suffer prejudice that FMS is a medically unexplained symptom, implying inauthenticity. Furthermore, FMS often exhibits comorbidity with rheumatoid arthritis (RA) or spondyloarthritis (SpA), both of which show similar indications. In this study, disease specific biomarkers were sought in blood samples from patients to facilitate objective diagnoses of FMS, and distinguish it from RA and SpA. Peripheral blood mononuclear cells (PBMCs) from patients and healthy donors (HD) were subjected to multicolor flow cytometric analysis. The percentage of mucosal-associated invariant T (MAIT) cells in PBMCs and the mean fluorescent intensity (MFI) of cell surface antigen expression in MAIT cells were analyzed. There was a decrease in the MAIT cell population in FMS, RA, and SpA compared with HD. Among the cell surface antigens in MAIT cells, three chemokine receptors, CCR4, CCR7, and CXCR1, a natural killer (NK) receptor, NKp80, a signaling lymphocyte associated molecule (SLAM) family, CD150, a degrunulation marker, CD107a, and a coreceptor, CD8β emerged as potential biomarkers for FMS to distinguish from HD. Additionally, a memory marker, CD44 and an inflammatory chemokine receptor, CXCR1 appeared possible markers for RA, while a homeostatic chemokine receptor, CXCR4 deserved for SpA to differentiate from FMS. Furthermore, the drug treatment interruption resulted in alternation of the expression of CCR4, CCR5, CXCR4, CD27, CD28, inducible costimulatory molecule (ICOS), CD127 (IL-7 receptor α), CD94, NKp80, an activation marker, CD69, an integrin family member, CD49d, and a dipeptidase, CD26, in FMS. Combined with the currently available diagnostic procedures and criteria, analysis of MAIT cells offers a more objective standard for the diagnosis of FMS, RA, and SpA, which exhibit multifaceted and confusingly similar clinical manifestations.

Genotoxic stress and RAS induce the expression of CD155, a ligand for the immune receptors DNAM-1, CD96 and TIGIT. Here we show that antigen-presenting cells upregulate CD155 expression in response to Toll-like receptor activation. Induction of CD155 by Toll-like receptors depended on MYD88, TRIF and NF-κB. In addition, IRF3, but not IRF7, modulated CD155 upregulation in response to TLR3 signals. Immunization of CD155-deficient mice with OVA and the TLR9 agonist CpG resulted in increased OVA-specific IgG2a/c titers when compared to wild type mice. Splenocytes of immunized CD155-deficient mice secreted lower levels of IL-4 and fewer IL-4 and GATA-3 expressing CD4(+) T cells were present in the spleen of Cd155(-/-) mice. Our data suggest that CD155 regulates T(h)2 differentiation. Targeting of CD155 in immunization protocols using peptides may represent a promising new approach to boost protective humoral immunity in viral vaccines.

Streptococcus suis (S. suis) is a major pathogen that poses a long-term threat to swine populations. Due to its foodborne transmission, this pathogen has recently emerged as a leading cause of meningitis in humans, presenting a significant public health challenge. Currently, no vaccine is available to combat this disease, particularly a universal vaccine capable of addressing multiple subtypes of S. suis. In this study, we developed a universal live vaccine candidate against multiple serotypes S. suis based on the polyvalent antigen protein SE6. A live Salmonella Choleraesuis (S. Choleraesuis) vector was employed for the production and in vivo delivery of the polyvalent antigen. The SE6 protein was efficiently expressed within the S. Choleraesuis vector and delivered to the host's lymphatic system. The antiserum of mice immunized with SE6-delivering S. Choleraesuis vector produced a broader and potent opsonophagocytic response against multiple serotypes of S. suis. Finally, the SE6-delivering S. Choleraesuis vector demonstrated high efficacy in providing protection against S. suis serotypes 2, 7, and 9 in vivo. •A live Salmonella Choleraesuis vector rSC0016 that carries a SE6 polyvalent antigen.•The SE6 protein was efficiently expressed within the S. choleraesuis vector rSC0016.•rSC0016(pS-SE6) induces good mucosal, humoral, and cellular immune responses.•rSC0016(pS-SE6) protects against Streptococcus suis serotypes 2, 7, and 9 in mice.

Recent advances in cancer immunotherapy, particularly the success of immune checkpoint inhibitors, have reignited interest in targeted monoclonal antibodies for immunotherapy. Antibody therapies aim to minimize on-target, off-tumor toxicity by targeting antigens overexpressed on tumor cells but not on healthy cells. Despite considerable efforts, some therapeutic antibodies have been linked to dose-limiting side effects. Our hypothesis suggests that the efficacy of IgG leads to a lower target expression threshold for tumor cell killing, contributing to these side effects. Earlier, therapeutic IgG antibodies were reformatted into the IgA isotype. Unlike IgG, which primarily engages Fc gamma receptors (FcγR) to induce antibody-dependent cellular cytotoxicity (ADCC) by NK cells and antibody-dependent cellular phagocytosis (ADCP) by monocytes/macrophages, IgA antibodies activate neutrophils through the Fc alpha receptor I (CD89, FcαRI). In previous studies, it appeared that IgA may require a higher target expression threshold for effective killing, and we aimed to investigate this in our current study. Moreover, we investigated how blocking the myeloid checkpoint CD47/SIRPα axis affect the target expression threshold. Using a tetracycline-inducible expression system, we regulated target expression in different cell lines. Our findings from ADCC assays indicate that IgA-mediated PMN ADCC requires a higher antigen expression level than IgG-mediated PBMC ADCC. Furthermore, blocking CD47 enhanced IgA-mediated ADCC, lowering the antigen threshold. Validated in two in vivo models, our results show that IgA significantly reduces tumor growth in high-antigen-expressing tumors without affecting low-antigen-expressing healthy tissues. This suggests IgA-based immunotherapy could potentially minimize on-target, off-tumor side effects, improving treatment efficacy and patient safety.

Bordetella pertussis isolates which do not express some of acellular pertussis vaccine (aPv) antigens, e.g. pertactin (PRN), have been increasingly reported in countries using aPvs. In Finland, primary pertussis vaccination with whole-cell vaccine was replaced by aPv containing pertussis toxin (PT) and filamentous hemagglutinin (FHA) in 2005 and then by aPv containing PT, FHA, and PRN in 2009. We aimed to study alterations in the expression of FHA, PRN, and PT, three antigens included in aPvs and adenylate cyclase toxin (ACT) not included in current aPvs, among Finnish isolates collected during 1991–2020. Of 904 isolates collected by the Finnish Reference Laboratory for Pertussis during 1991–2020, 302 were randomly included. An adapted, monoclonal antibody based, antigen expression ELISA, including the culture of B. pertussis in Stainer-Scholte medium, was performed to quantify the expression of ACT, FHA, PRN, and PT of each isolate. ACT activity was also measured for 16 isolates. Arbitrary units were used for comparing levels of each antigen expression of isolates grouped in every five years. Following the implementation of aPv in 2005, B. pertussis isolates exhibited a 1.75-fold increase for FHA (p < 0.001) and a 1.5-fold increase for ACT (p < 0.0041) expression until 2020. No FHA or ACT deficient isolates were detected. As the number of PRN deficient isolates has significantly increased with the time, the amount of PRN produced by the positive isolates has also started to decrease, especially after the use of aPv containing PRN. During this period, fluctuations in PT expression were observed. The study demonstrated that in response to aPv-induced selection pressure, different types of selection of B. pertussis has occurred. For FHA and ACT, a steady increase in their production is observed, whereas the frequency of PRN deficient isolates is increased with time.

Quantitation of mHLA-DR and nCD64 is useful in understanding the dysregulated host response. The down regulation of HLA-DR expression on the circulating monocytes (mHLA-DR) is associated with anti-inflammatory response, and an increased expression of CD64 on neutrophil surface (nCD64) is associated with pro-inflammatory response. Quantitation of these antigen expression using beads (QuantiBRITE™ PE) is a precision technique. These beads are reported to be stable for 24 h after reconstitution. We report the results of our investigation examining the stability of QuantiBRITE PE beads over a period of 4-week post-reconstitution. The data suggest that reconstituted QuantiBRITE PE beads, if stored in dark at 2–8 °C, can be effectively used for up to 2 weeks for determining nCD64 and mHLA-DR antibody bound per cell (ABC) values.