A series of new 6,6-dimethyl-9-oxo-4,5,6,7,8,9-hexahydropyrazolo[5,1-b]quinazoline substituted benzenesulfonohydrazide and 1,3,4-oxadiazole derivatives has been synthesised and characterised using spectral techniques. The antiviral activity of these compounds against an avian paramyxovirus (APMV-1) has been screened and the results show that some of the compounds possess good antiviral activity

No abstract

Viruses adopt strategies to e ciently utilize their compact genome. Members of the family Paramyxoviridae, exhibit a cotranscriptional RNA editing mechanism wherein polymerase stuttering generates accessory proteins from Phosphoprotein (P) gene. Newcastle disease virus (NDV), an avian paramyxovirus, expresses two accessory proteins, V and W, by RNA editing. While P and V proteins are well studied, very little is known about W protein. Recent studies con rmed W protein expression in NDV and the unique subcellular localization of W proteins of virulent and avirulent NDV. We characterized the W protein of NDV strain Komarov, a moderately virulent vaccine strain. W mRNA expression ranged between 7 and 9% of total P gene transcripts similar to virulent NDV. However, W protein expression, detectable by 6 hours, peaked at 24 hours and dropped by 48 hours post infection in DF1 cells indicating a kinetically regulated expression by the virus. The W protein localized in the nucleus and by mutations, a strong nuclear localization signal was identi ed in the C-terminal region of W protein. The viral growth kinetics study suggested neither supplementation of W protein nor subcellular localization pattern of the supplemented W protein in uenced viral replication in vitro similar to that noticed in avirulent NDV. A cytoplasmic mutant of W protein localized in cytoplasm unlike speci c mitochondrial colocalization as recorded in velogenic NDV strain SG10 indicating a possible role of W protein in determining the viral pathogenicity. This study describes for the rst time, the distinct features of W protein of moderately virulent NDV.

Lymphoid cell-based adaptive immunity first arose in jawed fish ~500 mya and fish lymphoid cells share many conserved features with their mammalian counterparts. Both fish and mammalian B cells respond to T-dependent antigen by proliferating, differentiating into plasma cells, and generating high-affinity, antigen-specific antibody. In mammals, this response occurs in the germinal center (GC) and is highly dependent on GC architecture and cellular dynamics, which direct B cell SHM and clonal selection. Though most cellular components are conserved, little is known with regard to the immune architecture of the fish humoral adaptive response. Therefore, we sought to investigate the organization of B cell activation within the lymphoid tissues of the fish, threespine stickleback (Gasterosteus aculeatus). Stickleback splenic B cells are organized around melanomacrophages (MM), highly pigmented melanomacrophages which are proposed homologues to mammalian follicular dendritic cells (FDCs). We find that MM aggregates, known as melanomacrophage centers (MMCs), increase in size in response to immunization, but not control injection with adjuvant alone, suggesting that the MMC response is antigen driven. Analysis of lymphoid tissue architecture indicates B and T lymphocytes inhabit distinct regions of the stickleback spleen. For instance, IgM mRNA-expressing cells aggregate in discrete regions surrounding MMC clusters, comparable to the organization of mammalian B cells around FDCs. These findings support the hypothesis that MMCs are evolutionary precursors to GCs. Furthermore, it suggests that the microarchitecture necessary to sustain somatic hypermutation and clonal selection evolved early in vertebrates.

The study of immunity in non-model organisms has the potential to reveal the evolved diversity of the immune system. However, such studies are hampered by the paucity of species-specific reagents. Advances in single-molecule RNA-ISH overcomes these setbacks and allows for the detection of potentially dozens of gene targets in a single tissue section. We examined the spatial expression of immune genes in the splenic tissue of a teleost, threespine stickleback, using the advanced multiplexed RNAScope Hiplex assay. Threespine stickleback, a small teleost found throughout the Northern Hemisphere, is an emerging immunologic model. It has been proposed that teleost humoral adaptive immunity initiates in the melanomacrophage center (MMC), a putative evolutionary precursor to germinal centers (GC), however this has not been directly tested. Teleosts lack GCs, yet still generate affinity matured antibodies in response to antigen challenge. We find that stickleback MMCs increase in size in response to antigen immunization but not to control injection, suggesting that MMC response is antigen driven, similar to the mammalian GC. Analysis of splenic tissue indicates that IgM mRNA expressing cells aggregate in discrete regions around stickleback MMCs. Similarly, CD4 and TCR-β expressing cells aggregate near IgM+ cells, comparable to the organization of B and T cells in mammalian GCs. These findings suggest that stickleback splenic tissues have an organized structure, focused around the MMCs, and support the hypothesis that MMCs could be the site of teleost adaptive immunity and the evolutionary precursors to GCs. This study also highlights the application of RNAScope in a non-model organism. Supported by NIH RO1AI146168