Comparison of the pathogenesis of two genetically different H3N2 influenza A viruses in pigs

In 1997 and 1998, H3N2 influenza A viruses emerged among pigs in North America. Genetic analyses of the H3N2 isolates demonstrated that they had distinctly different genotypes. The most commonly isolated viruses in the United States have a triple-reassortant genotype, with the hemagglutinin, neuraminidase, and PB1 polymerase genes being of human influenza virus origin, the nucleoprotein, matrix, and nonstructural genes being of classical swine influenza virus origin, and the PA and PB2 polymerase genes being of avian influenza virus origin. In contrast, a wholly human H3N2 virus was isolated from a single baby pig in Ontario, Canada, in 1997, but it did not spread within the swine population. Genetic differences between this wholly human virus and the triple-reassortant viruses may affect their replication efficiencies in pigs. In the present study we compared the pathogenicities and replication kinetics of the wholly human virus and a triple-reassortant virus in 7-week-old pigs that were infected intranasally with 2 x 10(3) to 2 x 10(6) 50% tissue culture infective doses of virus. Our results demonstrate that the wholly human virus replicated to significantly lower titers and that the onset of virus shedding was delayed compared to the replication titers and the time of onset of virus shedding in triple-reassortant viruses. In addition, infection with the triple-reassortant virus was associated with moderate to severe gross pathological and histological pulmonary lesions, while infection with the wholly human virus induced only mild pulmonary changes.     

Restriction maps of the DNA of cervid herpesvirus 1 and cervid herpesvirus 2, two viruses related to bovine herpesvirus 1

Summary Restriction maps of cervid herpesviruses 1 and 2 which are antigenically related to bovine herpesvirus 1, were deduced from Southern blot hybridization withHin dIII restriction fragments of BHV-1 DNA as probes.     

Genomic analysis of two Chinese strains of porcine reproductive and respiratory syndrome viruses with different virulence

Two strains of porcine reproductive and respiratory syndrome virus (PRRSV) were isolated, designated GDQJ and GDBY1. Experimental inoculation showed that GDBY1, caused 100% morbidity and 67% mortality, while GDQJ, caused 100% morbidity but no death. Full-length genomes were sequenced. Homologic and phylogenetic analyses indicated that these two strains were closely related to Chinese highly pathogenic PRRSV strains. Surprisingly, identical 30 amino acids (aa) deletion in the NSP2-coding region, a presumed high virulence marker, was present in low virulent strain GDQJ. Further comprehensive analysis of GDQJ genome in comparison with Chinese highly pathogenic PRRSV strains revealed multiple genomic variations, distributing in 5′ UTR, NSP1b, NSP2, NSP3, NSP5, NSP7, NSP9, NSP10, GP5, and N regions. Data present in this article confirm that the 30 aa deletion in the NSP2-coding region alone is not a reliable genomic indicator for the high virulence of PRRSV strains emerged in China. The genomic variations of GDQJ strain provided the basis for further studies of virulence determinants for PRRSVs.     

Genetic analysis of two porcine reproductive and respiratory syndrome viruses with different virulence isolated in China

The S1 and SY0608 strains of porcine reproductive and respiratory syndrome virus (PRRSV) were individually isolated and had different pathogenicity in pigs in 1997 and 2006. In order to understand their genomic characteristics, the full-length genome of S1 and SY0608 isolates were sequenced and analyzed. The results indicated that their genome composition differed significantly and shared only 88.5% nucleotide identity with each other. The genetic variation and amino acid substitutions were not randomly distributed in the genome, and mainly focused on ORF1a, ORF3 and ORF5. The SY0608 strain, with high pathogenicity, had a 30-amino-acid deletion at amino acid positions 480 and 532-560 in comparison with the S1 strain. The alignment of amino acid sequence of Nsp1-Nsp8, GP2-GP5, M and N of S1 and SY0608 with other PRRSV isolates demonstrated that variation was mainly found in the Nsp2, GP3 and GP5 proteins. In comparison with the S1 strain, the SY0608 strain showed some potential glycosylation site mutations in GP5 at amino acid positions between 26 and 39, which might be associated with viral antigenicity. Phylogenetic analysis showed that the two strains belonged to two different branches that do not indicate differences in pathogenicity. Interestingly, the deletion strains isolated recently in China formed a new minor branch, revealing the same evolutionary trend.     

Detection and genetic typing of type 2 porcine circoviruses in archived pig tissues from the UK

Summary. Porcine circovirus 2 (PCV-2) is implicated as the causative agent of post-weaning multisystemic wasting syndrome (PMWS) and is also associated with porcine dermatitis and nephropathy syndrome (PDNS). The recent emergence of epidemic PMWS in the United Kingdom was predated by sporadic cases of PDNS dating back to the early 1980s. The aim of this study was to investigate whether PCV-2 DNA was present in archival tissues, and if so, to investigate the relatedness of these viruses with contemporary strains of PCV-2. DNA extracted from paraffin wax-embedded tissue blocks (n=68), was subjected to a TaqMan® polymerase chain reaction (PCR) targeting a fragment of ORF1 of PCV-2. Positive results were obtained from 41% (9/22), 31% (4/13) and 32% (8/25) of submissions from the 1990s, 1980s and 1970s respectively. The presence of PCV-2 antigen in some of these tissues was confirmed by immunohistochemistry (IHC). A PCR targeting ORF2 was used to obtain sequence data for phylogenetic analysis. Sequences from 5 archival tissues were unique but showed high genetic identity to PCV-2 sequence obtained from a 2000 PDNS case. These data demonstrate that similar isolates of PCV-2 have been present in the UK pig population for more than 30 years.     

Crystal-storing histiocytosis associated with only one of two consecutive,but genetically unrelated B-cell lymphomas

A localized crystal-storing histiocytosis (CSH) making the underlying marginal zone lymphoma (MZL) hardly discernible microscopically is described. Image analysis of the hyper electron dense crystals localized light microscopically in swollen histiocytic cells exhibited a major equatorial periodicity of 6.6 nm. Rarely, crystals of this type were detected within plasma cells, but were always surrounded by smooth membrane in contrast to Russell bodies. IgM/lambda restriction and VH3-21*02, DH4-17*01, JH4*02 gene usage were detected behind the lesion. Within 26 months, a genetically unrelated lymphoma of CD5–CD20–CD23-positive phenotype with a different VH1-24*01, DH2-21*02, JH2*01 heavy chain rearrangement, but with the same light chain gene usage, was identified without CSH. This might indicate that the unique condition responsible for the crystal formation is likely to rely on the sequence of the first clonally rearranged heavy chain exhibiting much higher CDRIII pI value (6.0) than the average.     

Echoviruses 1 and 8 are closely related genetically, and bind to similar determinants within the VLA-2 I domain

Echoviruses (EV) 1 and 8 were originally considered to be distinct serotypes, but more recently have been considered strains of the same virus. In experiments with chimeric recombinant fusion proteins, both viruses bound to the I domain of the integrin VLA-2, and both required the same receptor residues for attachment. A full-length, infectious cDNA clone encoding EV1 was obtained; its nucleotide sequence was determined, as were the sequences encoding the EV8 capsid. EV1 and 8 show 94% amino acid identity within the capsid region and are more similar to each other than to any other human picornavirus.     

Amitriptyline and citalopram,two different types of antidepressant drugs,relax histamine-contracted porcine coronary artery

Inflammation Research -     

The long-standing history of Corynebacterium parvum,immunity, and viruses

We report a review of all the experimental and clinical studies performed in the last 60 years on the antiviral activity of inactivated Corynebacterium parvum (Cutibacterium acnes). This bacterium has been originally investigated and used for its oncolytic properties linked to immunomodulating activity, but the interest to successfully prevent and treat bacterial, fungal, and viral infections and lethality, uprising the innate immunity barriers produced many experimental models and very few clinical studies. The dramatic defenseless situation due to impending CoViD-19 pandemic claims to exhume and highlight this aspecific strategy in preventive and therapeutic settings; as a matter of fact, no new or mutated virus can potentially escape to this strong innate immune surveillance strengthened by adequate C. parvum protocols.     

Isolation of two H1N2 influenza viruses from swine in France

Summary Samples collected in 1987 and 1988 in Brittany from influenzainfected swine made it possible to isolate and antigenically characterize two H1N2 recombinant viruses (Sw/France/5027/87 and Sw/France/5550/88). The former virus was cloned and reinoculated to swine to allow reproduction of the disease and reisolation of a strain similar to the original one. The serodiagnostic tests carried out on both the original sera and those from the experimentally infected animals confirmed that the virus was actually type Sw/H1N2.     

Natural history of clinical features in two brothers with acromesomelic dysplasia related to PRKG2

Acromesomelic dysplasias (AMD) are a group of skeletal dysplasia characterized by shortening of the middle and distal segments of the limbs. Recently, biallelic PRKG2 variants have been reported to cause a new type of AMD. We detected biallelic novel variant (c.1635-1G > C) in PRKG2 in two brothers with mild to severe short stature, short limbs, cubitus varus, and brachydactyly. Radiological examination showed platyspondyly with anterior beaking of the vertebral bodies, stubby long bones with metaphyseal flaring and moderate brachydactyly with cone-shaped epiphyses of the middle and proximal phalanges. Upper limb proportions of the older brother were clinically classified as rhizomelic, however radiologic findings supported acromesomelia, along with the elbow limitation. Annual follow-ups of the older brother from the age of 5 to 20 years revealed progression of short stature with age but platyspondyly and anterior beaking became less conspicuous. The younger brother showed milder short stature and less conspicuous disproportion of the limbs than those of the older brother; however, platyspondyly and anterior beaking were more prominent on the radiographs obtained at the same age. In conclusion, this report provides new insights into the natural history of AMD type PRKG2 confirming the intrafamilial heterogeneity.     

PB1-F2 gene in influenza a viruses of different hemagglutinin subtype

The second ORF frame (+1) of PB1 polymerase gene of Influenza A virus (IAV) encodes the PB1-F2 protein. The length of PB1-F2 encoded by the A/Puerto Rico/8/34 (H1N1) (PR8) virus is 87 aa. The analysis of nucleotide sequences of PB1 gene of 626 IAV isolates available in GenBank and Influenza Sequence Database revealed that this gene has mostly the capacity to encode a putative protein of 90 aa. The predicted extra three amino acids in the 90-aa PB1-F2 are to a great extent conservative. Some IAV isolates, particularly human, avian and swine with hemagglutinin (HA) of H1 subtype can potentially encode a C-terminally truncated PB1-F2 of various lengths. The C-terminally truncated PB1-F2 in H1 isolates is lacking the region responsible for mitochondrial targeting and apoptosis. About 50% of avian isolates of H9 subtype possess an ORF for truncated PB1-F2. Eighteen aa, 10 at the N-terminus and 8 at the C terminus are strictly conservative in all 148 human isolates.     

JNK1, but not JNK2, is required in two mechanistically distinct models of inflammatory arthritis

The roles of the c-Jun N-terminal kinases (JNKs) in inflammatory arthritis have been investigated; however, the roles of each isotype (ie, JNK1 and JNK2) in rheumatoid arthritis and conclusions about whether inhibition of one or both is necessary for amelioration of disease are unclear. By using JNK1- or JNK2-deficient mice in the collagen-induced arthritis and the KRN T-cell receptor transgenic mouse on C57BL/6 nonobese diabetic (K/BxN) serum transfer arthritis models, we demonstrate that JNK1 deficiency results in protection from arthritis, as judged by clinical score and histological evaluation in both models of inflammatory arthritis. In contrast, abrogation of JNK2 exacerbates disease. In collagen-induced arthritis, the distinct roles of the JNK isotypes can, at least in part, be explained by altered regulation of CD86 expression in JNK1- or JNK2-deficient macrophages in response to microbial products, thereby affecting T-cell-mediated immunity. The protection from K/BxN serum-induced arthritis in Jnk1(-/-) mice can also be explained by inept macrophage function because adoptive transfer of wild-type macrophages to Jnk1(-/-) mice restored disease susceptibility. Thus, our results provide a possible explanation for the modest therapeutic effects of broad JNK inhibitors and suggest that future therapies should selectively target the JNK1 isoform.     

Characterization of mycobacterial isolates phylogenetically related to, but different from Mycobacterium simiae.

The use of high-performance liquid chromatography (HPLC) revealed four previously unreported profiles within a group of mycobacteria consisting of 14 clinical isolates. These mycobacteria, whose identification by conventional tests appeared problematic, mostly resembled Mycobacterium avium complex or Mycobacterium simiae. Genetic analysis revealed, within this group, six different nucleic acid sequences in a hypervariable 16S rRNA segment, but all the isolates appeared to be phylogenetically related to M. simiae. Six isolates representing the largest of groups defined by means of genetic sequencing turned out to belong to the newly described species Mycobacterium lentiflavum. Furthermore, three such clusters precisely coincided with three of those defined by HPLC, while the three remaining clusters shared almost identical HPLC profiles. All but one strain (which, although clearly not belonging to the M. avium complex, hybridized with specific commercial DNA probes) showed high-grade resistance to the majority of antimycobacterial drugs. Three of the isolates were clinically significant according to stringent criteria. Sophisticated techniques, like genetic sequencing or HPLC, by now seem indispensable for differentiating unusual and new mycobacteria from well-established ones.     

Regulation of ZAP-70 activation and TCR signaling by two related proteins, Sts-1 and Sts-2

T cells play a central role in the recognition and elimination of foreign pathogens. Signals through the T cell receptor (TCR) control the extent and duration of the T cell response. To ensure that T cells are not inappropriately activated, signaling pathways downstream of the TCR are subject to multiple levels of positive and negative regulation. Herein, we describe two related proteins, Sts-1 and Sts-2, that negatively regulate TCR signaling. T cells from mice lacking Sts-1 and Sts-2 are hyperresponsive to TCR stimulation. The phenotype is accompanied by increased Zap-70 phosphorylation and activation, including its ubiquitinylated forms. Additionally, hyperactivation of signaling proteins downstream of the TCR, a marked increase in cytokine production by Sts1/2(-/-) T cells, and increased susceptibility to autoimmunity in a mouse model of multiple sclerosis is observed. Therefore, Sts-1 and Sts-2 are critical regulators of the signaling pathways that regulate T cell activation.     

Histamine release from isolated and intact mast cells of two types of genetically different rat

A comparison has been made of the release of histamine from tissues of conventional rats, induced by injections of antigen, concanavalin A and clinical dextran, with that from rat isolated peritoneal mast cells. Concanavalin A was less active than dextran when injected into the skin or paws, but the reverse was found when the substances were tested on isolated cells. Similar results were obtained when a pure line of rats relatively resistant to dextran was used, concanavalin A being much more active on isolated cells than on intact mast cells. Antigen was equally active in the two types of rat. It is important, therefore, to state the experimental conditions when comparisons of the activities of histamine releasers are being made.     

Chimeric porcine reproductive and respiratory syndrome viruses reveal full function of genotype 1 envelope proteins in the backbone of genotype 2

Earlier studies indicated that transgenic (tg) mice engineered to express prion protein (PrP) lacking the glycophosphatidylinositol (GPI^−/−) membrane anchor formed abnormal proteinase-resistant prion (PrPsc) amyloid deposits in their brains and hearts when infected with the RML strain of murine scrapie. In contrast, RML scrapie infection of normal mice with a GPI-anchored PrP did not deposit amyloid with PrPsc in the brain or the heart. Here we report that scrapie-infected GPI^−/− PrP tg mice also deposit PrP and transmissible infectious material in the gut, kidneys, and islets of Langerhans. Similar to previously reported amyloid deposits in the brain and heart, amyloid deposits were found in the gut; however, no amyloid deposited in the islets. By high-resolution electron microscopy, we show PrP is located primarily in α cells and also β cells. Islets contain abundant insulin and there is no abnormality in glucose metabolism in infected GPI^−/− PrP tg mice.     

Virus-receptor interactions of human parainfluenza viruses types 1, 2 and 3.

Human parainfluenza viruses types 1, 2 and 3 (HPF 1, 2 and 3) are important pathogens in children. While these viruses share common structures and replication strategies, they target different parts of the respiratory tract; the most common outcomes of infection with HPF3 are bronchiolitis and pneumonia, while HPF 1 and 2 are associated with croup. While the HPF3 fusion protein (F) is critical for membrane fusion, our previous work revealed that the receptor binding hemagglutinin-neuraminidase (HN) is also essential to the fusion process; interaction between HN and its sialic acid-containing receptor on cell surfaces is required for HPF3 mediated cell fusion. Using our understanding of HPF3 HN's functions in the cell-binding and viral entry process, we are investigating the ways in which these processes differ in HPF 1 and 2, in part by manipulating receptor availability. Three experimental treatments were used to compare the HN-receptor interaction of HPF 1, 2 and 3: infection at high multiplicity of infection (m.o.i.); bacterial neuraminidase treatment of cells infected at low m.o.i.; and viral neuraminidase treatment of cells infected at low m.o.i. (using Newcastle disease virus [NDV] neuraminidase or UV irradiated HPF3 as sources of neuraminidase). In cells infected with HPF3, we have shown that infection with high m.o.i. blocks fusion, by removing sialic acid receptors for the viral HN. However, in cells infected with HPF 1 and 2, infection with high m.o.i. did not block fusion; the fusion increases with increasing m.o.i. In cells infected with HPF 1 and 2, neither bacterial nor NDV neuraminidase blocked cell fusion, using amounts of neuraminidase that completely block fusion of HPF3 infected cells. However, when inactivated HPF3 was used as a source of viral neuraminidase, the treatment inhibited fusion of cells infected with HPF 1 and 2 as well as 3. The differences found between these viruses in terms of their interaction with the cell, ability to modulate cell-cell fusion and response to exogenous neuraminidases of various specificities, may reflect salient differences in biological properties of the three viruses.