Epitopes

reconstructionists often determine pre-collision conditions based on post-collision evidence. Energy-based speed calculations for skidding vehicles are commonly used and have been the basis for numerous theoretical and experimental works. The simplest analysis technique, "skid-to-stop" is fairly well understood, however the more complex circumstance of a spinning trajectory is less well understood. This paper will describe a series of experiments conducted to evaluate the frictional values applicable to a spinning vehicle as it rotates and translates without brake application.

Our aim was to investigate the existence of an association between B cell responsiveness to hepatitis C virus (HCV) core protein and progression of liver disease. In fact, the persistence of HCV infection is permitted by avoidance of viral clearance, despite chronic inflammation in the liver; this process ends with the development of hepatocellular carcinoma in many patients. On the basis of computerized prediction of antigenicity of the genomic sequence of HCV core protein, three 15-mer peptides (named Q15V, R15P, and G15V) were synthesized to be used as antigens in an enzyme immunoassay. Sera from 97 patients (65 males and 32 females) were tested: 43 patients had mild chronic liver disease (steatofibrosis, chronic persistent, or chronic active hepatitis) and 54 had cirrhosis, which was complicated by hepatocellular carcinoma (HCC) in 19. Seventy-six patients were positive to anti-HCV testing by second generation ELISA and 21 were negative. Rates of positivity for synthetic peptide...

Viral entry targets with therapeutic neutralizing potential are subject to multiple escape mechanisms, including antigenic drift, immune dominance of functionally irrelevant epitopes, and subtle variations in host cell mechanisms. A surprising finding of recent years is that potent neutralizing antibodies to viral epitopes independent of strain exist, but are poorly represented across the diverse human population. Identifying these antibodies and understanding the biology mediating the specific immune response is thus difficult. An effective strategy for meeting this challenge is to incorporate multiplexed antigen screening into a high throughput survey of the memory B cell repertoire from immune individuals. We used this approach to discover suites of cross-clade antibodies directed to conformational epitopes in the stalk region of the influenza A hemagglutinin (HA) protein and to select high-affinity anti-peptide antibodies to the glycoprotein B (gB) of human cytomegalovirus. In e...

We have examined by immunoblotting the antigen profiles of Leishmania parasites which have undergone upward shifts in ambient temperature during culture. Parasites in the promastigote insect vector stage were grown to stationary growth phase at 25 degrees C, and then further cultured at the 37 degrees C temperature experienced in the mammalian host. Changes in the immunoblot profiles of the parasites occurred within one day of culture at mammalian ambient temperature. Serum antibodies from patients with active Leishmania infections showed reactivity with antigenic determinants of greater than Mr 38,000 that were expressed by parasites at 37 degrees C, and which were not comparably observed on immunoblots of 25 degrees C cultured organisms. The promastigotes of Leishmania species which cause either cutaneous or visceral leishmaniasis express differing forms of the 37 degrees C induced high molecular weight determinants, however, these molecules express cross-reactive epitopes. Previous studies have suggested that temperature may play a role in the differentiation process between the insect and host life cycle stages of Leishmania. Our results suggest that the antigenic profile of Leishmania parasites may also be affected by the expression of products from temperature sensitive biosynthetic pathways.

A potential limitation of anti-thrombotic therapies directed at platelet GPIIb/IIIa is immune mediated thrombocytopenia. Reagents that mimic the behavior of patient antibodies would provide a valuable tool for studies directed at understanding the basis of the immune mechanism involved in GPIIb/IIIa antagonist induced thrombocytopenia. Such reagents would bind epitopes that are exposed when the conformation of the receptor is modified in response to inhibitor binding. We describe the production and characterization of monoclonal antibodies that were raised against platelet GPIIb/IIIa bound to a potent antagonist, XP280. These antibodies have high affinity and specificity for XP280 bound GPIIb/IIIa using either purified protein or human platelets. We have demonstrated that the antibodies recognize a conformationally altered form of the receptor, that both subunits are required for binding, and that the antagonist itself does not form part of the binding epitope. Competition experiments indicate that multiple drug-dependent epitopes are exposed on the receptor in response to antagonist binding. The antibodies bind with high specificity to some but not all GP IIb/IIIa/antagonist complexes indicating that different conformational epitopes are exposed when GP IIb/IIIa is bound to different antagonists.

A human monoclonal anti-HBsAg antibody (IgG1, lambda) was used as a reference for an ELISA determination of the serum levels of anti-HBsAg antibodies in human volunteers after vaccination with H-B vax. The IgG subclass distribution of specific antibodies showed a marked dominance of IgG1 antibodies. In addition, small amounts of specific IgG4 antibodies were occasionally found, suggesting a different pattern from that found after natural disease. The novel use of a human monoclonal antibody to measure specific antibodies may give a more accurate determination of specific IgG subclass levels than previously available methods.

The gluten proteins from wheat, barley and rye are responsible both for celiac disease (CD) and for non-celiac gluten sensitivity, two pathologies affecting up to 6-8% of the human population worldwide. The wheat α-gliadin proteins contain three major CD immunogenic peptides: the p31-43, which induces the innate immune response; the 33-mer, formed by six overlapping copies of three highly stimulatory epitopes; and an additional DQ2.5-glia-α3 epitope which partially overlaps with the 33-mer. NGS and Sanger sequencing of α-gliadin genes from diploid and polyploid wheat provided six types of α-gliadins (named 1 to 6) with strong differences in their frequencies in diploid and polyploid wheat, and in the presence and abundance of these CD immunogenic peptides. Immunogenic variants of the p31-43 peptide were found in most of the α-gliadins. Variants of the DQ2.5-glia-α3 epitope were associated with specific types of α-gliadins. Remarkably, only Type 1 α-gliadins contained 33-mer epitopes...

Anderson, SA, Carter, V., and Parsons, M. 1998.Trypanosoma brucei:Molecular cloning and stage-regulated expression of a malate dehydrogenase localized to the mitochondrion.Experimental Parasitology89,63–70. African trypanosomes exhibit dramatic developmental changes in ...

Vaccine development in human Plasmodium falciparum malaria has been hampered by the exceptionally high levels of CD8(+) T cells required for efficacy. Use of potently immunogenic human adenoviruses as vaccine vectors could overcome this problem, but these are limited by preexisting immunity to human adenoviruses.