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Objective: To test the safety and efficacy of combination treatment for pleural mesothelioma (PM) with intracavitary cisplatin-fibrin (cis-fib) plus hemithoracic irradiation (IR) applied after lung-sparing surgery in an orthotopic immunocompetent rat model. Methods: We randomized male F344 rats into 5 groups: cis-fib (n = 9), 10 Gy IR (n = 6), 20 Gy IR (n = 9), cis-fib+10 Gy IR (n = 6), and cis-fib+20 Gy IR (n = 9). Subpleural tumor implantation was performed on day 0 with 1 million syngeneic rat mesothelioma cells (IL45-luciferase). Tumors were resected on day 9, followed by treatment with intracavitary cis-fib or vehicle control (NaCl-fib). On day 12, computed tomography–guided local irradiation in a single high dose of the former tumor region was applied. Results: We observed only short-term side effects related to 20 Gy radiotherapy. Compared to 20 Gy, 10 Gy IR did not show an impact on tumor growth. At 3 days after treatment with 20 Gy IR (day 15 of the experiment), we detected significantly smaller tumors in the cis-fib+IR group compared to IR alone (mean tumor growth, 252% vs 539%; P = .04). On day 21, there was a significant difference in tumor growth between cis-fib–treated and cis-fib+IR– treated tumors (mean tumor growth, 2295% vs 660%; P = .01). Conclusions: Localized treatment after tumor resection in PM aims to improve local tumor control. Irradiation applied in combination with intracavitary cis-fib in rats is safe up to a dosage of 20 Gy and shows an additive effect on tumor growth delay compared to the single treatments.

Summary: Immunoglobulin A (IgA) plays an important role in protecting our mucosal surfaces from viral infection, in maintaining a balance with the commensal bacterial flora, and in extending maternal immunity via breast feeding. Here, we report an additional innate immune effector function of human IgA molecules in that we demonstrate that the C-terminal tail unique to IgA molecules interferes with cell-surface attachment of influenza A and other enveloped viruses that use sialic acid as a receptor. This antiviral activity is mediated by sialic acid found in the complex N-linked glycans at position 459. Antiviral activity was observed even in the absence of classical antibody binding via the antigen binding sites. Our data, therefore, show that the C-terminal tail of IgA subtypes provides an innate line of defense against viruses that use sialic acid as a receptor and the role of neuraminidases present on these virions. : Vertebrate IgA molecules possess a conserved N-linked glycosylated C-terminal tail. Maurer et al. show that sialic acid found in the complex glycosylation of the C-terminal tail of human IgA1 inhibits sialic-acid-binding viruses and, therefore, may constitute an additional line of innate immunity. Keywords: immunoglobulin, antibodies, IgA, glycosylation, virus neutralization, innate immunity, influenza virus, heterosubtypic antibodies, mucosal immunity, neuraminidase

Detection of HIV-1 p24 antigen permits early identification of primary HIV infection and timely intervention to limit further spread of the infection. Principally, HIV screening should equally detect all viral variants, but reagents for a standardised test evaluation are limited. Therefore, we aimed to create an inexhaustible panel of diverse HIV-1 p24 antigens.We generated a panel of 43 recombinantly expressed virus-like particles (VLPs), containing the structural Gag proteins of HIV-1 subtypes A-H and circulating recombinant forms (CRF) CRF01_AE, CRF02_AG, CRF12_BF, CRF20_BG and group O. Eleven 4th generation antigen/antibody tests and five antigen-only tests were evaluated for their ability to detect VLPs diluted in human plasma to p24 concentrations equivalent to 50, 10 and 2 IU/ml of the WHO p24 standard. Three tests were also evaluated for their ability to detect p24 after heat-denaturation for immune-complex disruption, a pre-requisite for ultrasensitive p24 detection.Our VLP panel exhibited an average intra-clade p24 diversity of 6.7%. Among the 4th generation tests, the Abbott Architect and Siemens Enzygnost Integral 4 had the highest sensitivity of 97.7% and 93%, respectively. Alere Determine Combo and BioRad Access were least sensitive with 10.1% and 40.3%, respectively. Antigen-only tests were slightly more sensitive than combination tests. Almost all tests detected the WHO HIV-1 p24 standard at a concentration of 2 IU/ml, but their ability to detect this input for different subtypes varied greatly. Heat-treatment lowered overall detectability of HIV-1 p24 in two of the three tests, but only few VLPs had a more than 3-fold loss in p24 detection.The HIV-1 Gag subtype panel has a broad diversity and proved useful for a standardised evaluation of the detection limit and breadth of subtype detection of p24 antigen-detecting tests. Several tests exhibited problems, particularly with non-B subtypes.