Bovine Herpesvirus Type 1 (BHV-1) UL49.5 Luminal Domain Residues 30 to 32 Are Critical for MHC-I Down-Regulation in Virus-Infected Cells

Bovine herpesvirus type 1 (BHV-1) UL49.5 inhibits transporter associated with antigen processing (TAP) and down-regulates cell-surface expression of major histocompatibility complex (MHC) class I molecules to promote immune evasion. We have constructed a BHV-1 UL49.5 cytoplasmic tail (CT) null and several UL49.5 luminal domain mutants in the backbone of wild-type BHV-1 or BHV-1 UL49.5 CT- null viruses and determined their relative TAP mediated peptide transport inhibition and MHC-1 down-regulation properties compared with BHV-1 wt. Based on our results, the UL49.5 luminal domain residues 30–32 and UL49.5 CT residues, together, promote efficient TAP inhibition and MHC-I down-regulation functions. In vitro, BHV-1 UL49.5 Δ30–32 CT-null virus growth property was similar to that of BHV-1 wt and like the wt UL49.5, the mutant UL49.5 was incorporated in the virion envelope and it formed a complex with gM in the infected cells

Community-acquired pneumonia related to intracellular pathogens

Community-acquired pneumonia (CAP) is associated with high rates of morbidity and mortality worldwide; the annual incidence of CAP among adults in Europe has ranged from 1.5 to 1.7 per 1000 population. Intracellular bacteria are common causes of CAP. However, there is considerable variation in the reported incidence between countries and change over time. The intracellular pathogens that are well established as causes of pneumonia are Legionella pneumophila, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Chlamydophila psittaci, and Coxiella burnetii. Since it is known that antibiotic treatment for severe CAP is empiric and includes coverage of typical and atypical pathogens, microbiological diagnosis bears an important relationship to prognosis of pneumonia. Factors such as adequacy of initial antibiotic or early de-escalation of therapy are important variables associated with outcomes, especially in severe cases. Intracellular pathogens sometimes appear to cause more severe disease with respiratory failure and multisystem dysfunction associated with fatal outcomes. The clinical relevance of intracellular pathogens in severe CAP has not been specifically investigated. We review the prevalence, general characteristics, and outcomes of severe CAP cases caused by intracellular pathogens

Chaperones and foldases in endoplasmic reticulum stress signaling in plants

Molecular chaperones and foldases are a diverse group of proteins that in vivo bind to misfolded or unfolded proteins (non-native or unstable proteins) and play important role in their proper folding. Stress conditions compel altered and heightened chaperone and foldase expression activity in the endoplasmic reticulum (ER), which highlights the role of these proteins, due to which several of the proteins under these classes were identified as heat shock proteins. Different chaperones and foldases are active in different cellular compartment performing specific tasks. The review will discuss the role of ER chaperones and foldases under stress conditions, to maintain proper protein folding dynamics in the plant cells and recent advances in the field. The ER chaperones and foldases, which are described in article, are binding protein (BiP), glucose regulated protein (GRP94), protein-disulfide isomerase (PDI), peptidyl-prolyl isomerases (PPI) or immunophilins, calnexin and calreticulin

Multilocus Sequence Typing (MLST) of Chlamydiales

Developed two decades ago as a molecular method to provide definite characterization of a bacterial isolate, Multilocus Sequence Typing (MLST) is today globally adopted as a universal fine-detailed molecular typing tool and has been applied to numerous pathogenic and nonpathogenic bacterial as well eukaryotic organisms. MLST utilizes DNA sequence of several conserved housekeeping (HK) genes which are assigned an allelic number, which then collectively constitute an allelic profile or sequence type (ST), a “molecular barcode” of the interrogated bacterial strain or a eukaryotic organism. Here, we describe the principles and molecular approaches for generating MLST data for an analysis of a bacteria in the order Chlamydiales, using a Chlamydia pecorum-specific MLST scheme as an example

Avian Chlamydiosis

Recent findings in research on avian chlamydiosis include an increase in the reported prevalence of Chlamydia (C.) psittaci in poultry flocks, detailed descriptions of molecular processes governing the course of infection in vivo, as well as the discovery of new chlamydial species. Here we review the major advances of the last 6 years. In particular, we suggest that the observed re-emergence of C. psittaci infections in domestic poultry are due to a reduction in the use of antibiotics and better diagnostic assays. Cellular and animal models have significantly contributed to improving our understanding of the pathogenesis, including the events leading to systemic disease. The elucidation of host-pathogen interactions revealed the efficiency of C. psittaci in proliferating and disseminating despite the action of pro-inflammatory mediators and other factors during host immune response. Finally, the recent introduction of C. avium and C. gallinacea sheds new light on the epidemiology and aetiopathology of avian chlamydiosis