An increasing number of studies support a potential role for coccoid forms in Helicobacter pylori infection. Evidence for this was obtained through scanning microscopy, genetic analysis for virulence traits, examination of the presence and activity of key enzymes, and other methods. We studied the serum immunoglobulin G responses to coccoid H. pylori forms by enzyme-linked immunosorbent assay (...

The Clostridium difficile exotoxin, TcdB, which is a major virulence factor, varies between strains of this pathogen. Herein, we show that TcdB from the epidemic BI/NAP1/027 strain of C. difficile is more lethal, causes more extensive brain hemorrhage, and is antigenically variable from TcdB produced by previously studied strains of this pathogen (TcdB003). In mouse intoxication assays, TcdB fr...

Rapid identification of influenza antigenic variants will be critical in selecting optimal vaccine candidates and thus a key to developing an effective vaccination program. Recent studies suggest that multiple simultaneous mutations at antigenic sites accumulatively enhance antigenic drift of influenza A viruses. However, pre-existing methods on antigenic variant identification are based on ana...

salmonella enterica serovar typhimurium and s.enterica serovar enteritidis are the most frequently isolated serovars from food-borne diseases throughout the world. according to their antigenic profiles, salmonella shows different disease syndromes and host specificities. it is necessary and important to discriminate salmonella serovars from each other in order to ensure that each pathogen and i...

Antigenic variance may be defined as phenotypic expressions that are due to slight differences in gene sequences coding for viral proteins with antigenic reactivity (CALISHER 1988). Evidence for antigenic variance due to mutations and reassortment in the Bunyaviridae family is great and has been obtained by several different approaches. The main intent of this review, however, is not to discuss...

Antigenic modulation (the loss of TL antigens from TL+ cells exposed to TL antibody in the absence of lytic complement) has been demonstrated in vitro. An ascites leukemia, phenotype TL.1,2,3, which modulates rapidly and completely when incubated with TL antiserum in vitro, was selected for further study of the phenomenon. Over a wide range of TL antibody concentrations modulation at 37 degrees...

Committed T helper type 1 (Th1) and Th2 effector cells, resulting from chronic antigenic stimulation in interleukin (IL)-12 and IL-4, are implicated in the pathology of autoimmune and allergic diseases. Committed Th1 cells cannot be induced to change their cytokine profiles in response to antigenic stimulation and Th2 cytokine-inducing conditions. Here, we report that ectopic expression of GATA...

The Kaposi sarcoma associated herpesvirus (KSHV) genome encodes more than 85 open reading frames (ORFs). Serological evaluation of KSHV infection now generally relies on reactivity to just one latent and/or one lytic protein (commonly ORF73 and K8.1). Most of the other polypeptides encoded by the virus have unknown antigenic profiles. We have systematically expressed and purified products from ...

Transfer factors (TF) are proteins that transfer the ability to express cell-mediated immunity from immune donors to non-immune recipients. The mechanisms of these effects have not been defined. The experiments described in this report were undertaken to test the hypothesis that a mechanism through which the beneficial effects of TF are expressed in clinical situation is through "education" of ...

Zika virus (ZIKV) infection during pregnancy can cause adverse fetal outcomes and severe irreversible congenital birth defects including microcephaly. Immunohistochemistry (IHC) is a valuable diagnostic tool for detecting ZIKV antigens in tissues from cases of fetal loss in women infected with ZIKV, and for providing insights into disease pathogenesis. As a result, there is increasing demand fo...