An investigation of the antigenicity of bovine prothrombin and several of its fragments: fragment 1 (NHz-terminal 156 amino acid residues of bovine prothrombin released by thrombin digestion) and NHz-terminal residues 1-39, employed a rabbit antibovine prothrombin fragment 1 antibody which had previously been fractionated by affinity chromatography and which shows an absolute specificity fo...

Pregnant women are infected by specific variants of Plasmodium falciparum that adhere and accumulate in the placenta. Using serological and molecular approaches, we assessed the global antigenic diversity of surface antigens expressed by placenta-binding isolates to better understand immunity to malaria in pregnancy and evolution of polymorphisms and to inform vaccine development. We found that...

Antigenic variation allows pathogenic microorganisms to evade the immune system of the infected host. The variable structure must play an important role in pathogenesis, but its function is in most cases unknown. Here, we identify a function for the surface-exposed hypervariable region of streptococcal M5 protein, a virulence factor that inhibits phagocytosis. The hypervariable region of M5 was...

Objective(s): Streptococcus pyogenes produces extracellular hyaluronidase enzyme. This enzyme is directly associated with the spread of the organism during infection. The objective of the present study was to clone and express the nucleotide sequence of the enzyme which is involved in hyaluronidase enzymatic activity. Materials and Methods: The enzymatic region of hyaluronidase gene was detecte...

The importance of rainbow trout (Onchorhynchus mykiss) in Iran aquaculture industry on one hand, and increasing the mortality of this fish due to outbreaks of infectious diseases, on the other hand, indicate the requirement for more profound understanding the rainbow trout immune system and access to laboratory tools for definitive diagnosis of its diseases. One of the most important defense me...

The complete sequence of the neuraminidase gene of influenza virus A/NT/60/68 (N2 subtype) was determined following cloning of full length complementary DNA into pBR322. Comparison of the predicted amino acid sequence with a closely related neuraminidase from A/Udorn/72 suggests that point mutations over an extensive region of the primary sequence can contribute to antigenic drift, although the...

Many of the remaining challenges in infectious disease control involve pathogens that fail to elicit long-lasting immunity in their hosts. Antigenic variation is a common reason for this failure and a contributor to the complexity of vaccine design. Diversifying selection by the host immune system is commonly, and often correctly, invoked to explain antigenic variability in pathogens. However, ...

Three forms of the amino terminal half (variable region) of human pathological lambda light chains of immunolglobulins were identified antigenically. By study of all completely sequenced Bence Jones proteins hitherto analyzed and a greater number of proteins subjected to automated sequence determination as well as normal light chains three distinct isotypic basic sequences were identified. The ...

Campylobacter coli and Campylobacter jejuni share a limited number of highly conserved DNA sequences with members of the family Enterobacteriaceae. One of these sequences was cloned from C. coli VC167, and the region of homology to the enteric sequences was determined to be confined to a 700-base-pair region. The DNA represented in this clone undergoes a programmed, reversible rearrangement in ...