Search results for "Activation"

Cytomegalovirus pneumonia in patients with inflammatory bowel disease: a systematic review

2012

Summary Background Inflammatory bowel disease (IBD) patients are at increased risk of cytomegalovirus (CMV) reactivation, and although CMV pneumonia may be a fatal disease in IBD patients, little information is available on this issue. The objectives of this study were to identify risk factors for the development of CMV pneumonia in IBD patients and to find useful information to better manage this potentially fatal complication. Methods A computerized search without language restrictions was conducted using PubMed and SCOPUS. An article was considered eligible for inclusion in the systematic review if it reported detailed data on patients with IBD presenting with pneumonia due to CMV. Resul…

T lymphocyte-stimulating microbial toxins as ?superantigens?

1991

Infectious pathogens generally have to cope with the host's adaptive immune system, i.e., T and B lymphocytes. Common evasion mechanisms in this complex interaction are antigenic variations, the escape to immunologically priviledged sites or the use of immunosuppressive mechanisms. Many bacteria and other microorganisms eleborate soluble factors or toxins that act suppressively on cells of the immune system, such as pore-forming molecules or proteins that interfere with the function of G proteins. Gram-positive cocci and a mycoplasma have developed an extremely potent mechanism of T cell stimulation by closely mimicking recognition of specific antigen. From the functional similarity to anti…

Proliferation and MHC-unrestricted bystander lysis by virus-specific cytotoxic T cells following antigen self-presentation.

1998

Cytotoxic T cells (CTL) not only act as effector cells, but can also serve as antigen-presenting cells (APC) for other CTL due to their expression of major histocompatibility complex (MHC) class I molecules. In the present study we show that independently derived CTL lines (CTLL) with specificity for an L(d)-presented nonapeptide corresponding to amino acids 168-176 of the immediate-early 1 (IE1) protein of murine cytomegalovirus not only lyse syngeneic but also allogeneic target cells, if the peptide is present during the cytolytic assay. Whereas a short peptide pulse is sufficient to render syngeneic cells susceptible to lysis, continued presence of soluble peptide is mandatory for the ly…

Effect of cytomegalovirus (CMV) serostatus on the incidence and virological features of active CMV infection in allogeneic stem cell transplant recip…

2011

ESAT-6 Peptide Recognition by Bovine CD8 + Lymphocytes of Naturally Infected Cows in Herds from Southern Italy

2006

ABSTRACT The aim of this study was to define epitopes of Mycobacterium bovis from ESAT-6 (early secretory antigen of 6 kDa) recognized by CD8 + T lymphocytes from cows naturally infected with Mycobacterium bovis . We found that bovine CD8 + T cells recognized 10 out of 11 ESAT-6 peptides tested.

Inactivation of Pepper Mild Mottle Virus in Water by Cold Atmospheric Plasma

2021

Water scarcity is one of the greatest threats for human survival and quality of life, and this is increasingly contributing to the risk of human, animal and plant infections due to waterborne viruses. Viruses are transmitted through polluted water, where they can survive and cause infections even at low concentrations. Plant viruses from the genus Tobamovirus are highly mechanically transmissible, and cause considerable damage to important crops, such as tomato. The release of infective tobamoviruses into environmental waters has been reported, with the consequent risk for arid regions, where these waters are used for irrigation. Virus inactivation in water is thus very important and cold a…

Understanding the Effects of High Pressure on Bacterial Spores Using Synchrotron Infrared Spectroscopy

2020

International audience; Bacterial spores are extremely resistant life-forms that play an important role in food spoilage and foodborne disease. The return of spores to a vegetative cell state is a three-step process, these being activation, germination, and emergence. High-pressure (HP) processing is known to induce germination in part of the spore population and even to inactivate a high number of Bacillus spores when combined with other mild treatments such as the addition of nisin. The aim of the present work was to investigate the mechanisms involved in the sensitization of spores to nisin following HP treatment at ambient temperature or with moderate heating leading to a heterogeneous …

Major histocompatibility complex class II binding site for streptococcal pyrogenic (erythrogenic) toxin A.

1994

Streptococcal pyrogenic exotoxin A (SPEA) is an important pathogenicity factor of group A streptococci. It is a member of the family of „superantigens” produced by Staphylococcus aureus and Streptococcus pyogenes and its T lymphocyte stimulating activity is involved into the pathogenesis of certain diseases caused by pyogenic streptococci. In this study we have produced and characterized recombinant SPEA molecules in Escherichia coli. These molecules are indistinguishable from natural SPEA in both T cell stimulatory and HLA class II binding activities. Human class II molecules are more efficient than mouse class II molecules in presenting SPEA to T cells. In binding tests to major histocomp…

Recombinant epidermolytic (exfoliative) toxin A of Staphylococcus aureus is not a superantigen

1992

The epidermolytic (exfoliative) toxins produced by Staphylococcus aureus cause epidermolysis and skin blistering. In addition, they have been implicated to belong to the group of T lymphocyte stimulating molecules known as "superantigens". Here we show that recombinant epidermolytic toxin A produced in S. aureus is not mitogenic for human and murine T lymphocytes. We discuss the possibility that minute contaminations of highly mitogenic exoproteins may cause the mitogenicity in several proteins that are reported to be superantigens.

Transcriptional expression of selected genes associated with excretion of carboxylic acids from aci mutants of Saccharomyces cerevisiae

2013

Introduction: Saccharomyces cerevisiae is an excellent model organism for studies of transcriptional regulation of metabolic processes in other eukaryotic cells including human cells. Cellular acid-base balance can be disturbed in pathologic situations such as renal acidosis or cancer. The extracellular pH of malignant solid tumors is acidic in the range of 6.5-6.9. EG07 and EG37 aci mutants of Saccharomyces cerevisiae excessively excrete carboxylic acids to glucose-containing media or distilled water. The excreted acids are Krebs and/or glyoxylate cycle intermediates. The genes restoring the wild-type phenotype have function that does not easily explain theAci phenotype.Material/Methods: I…