PubMed Health⌕ Search

Biomedical subjects

E Brose

Publications and source records attributed to E Brose.

11 recordsLinked to original sources
PubMed1991

Activation of human CD4+ and CD8+ cells by Sarcocystis gigantea lectin.

As recently reported, Sarcocystis gigantea lectin (SGL) is a powerful mitogen and a polyclonal activator (Syn. S. ovifelis) of human peripheral B-cells. In the present study we investigated the reactivity of human T-helper (CD4) and T-suppressor (CD8) cells to SGL. Mononuclear cells (MNCs) from five newborns and six adults were examined cytofluorometrically for the expression of cell-surface differentiation and activation antigens using a set of seven monoclonal antibodies. In all, 96% of cord-blood and 81% of adult CD4 cells expressed receptors for interleukin-2 (Tac+) after 64 and 164 h microgram/ml). The percentages of neonatal and adult Tac+ CD8 cells amounted to 67% and 59%, respectively. Major histocompatibility complex (MHC) class II antigens identified using the monoclonal anti-human leukocyte antigen (HLA)-DR antibody L243 were expressed on 30% (CD4) and 44% (CD8) of adult T-cells. Neonatal HLA-DR+ T-lymphocytes were not detectable. In parallel, functional tests were performed to examine cell proliferation and MNC antibody production.

Adult↗
PubMed1990

Sarcocystis gigantea lectin--mitogen and polyclonal B-cell activator.

The present study further examined the in vitro response of human mononuclear cells (MNC) to the Sarcocystis gigantea lectin (SGL). The results confirm our previous report that SGL is mitogenic for human MNC. We now report that SGL is not only a potent mitogen but also a polyclonal activator for human peripheral B cells. As was true for pokeweed mitogen (PWM, 2 micrograms/ml), the addition of SGL (25 micrograms protein/ml) to cultures of MNC caused lymphocyte proliferation and B-cell maturation, indicated by a marked increase in IgG and IgM production. As measured by the [3H]-thymidine incorporation assay, SGL induced significantly higher proliferative responses than PWM (P less than 0.01, n = 24). The values obtained by SGL and PWM for IgG and IgM synthesis were essentially identical. As opposed to SGL, the sarcotoxin-containing fraction (SGTF) did not induce antibody formation or proliferative responses in human MNC.

Animals↗
PubMed1989

Interactions between Sarcocystis gigantea lectin and toxin-containing fractions in human lymphocyte cultures.

Sarcocystis gigantea extract (SGE) was separated by affinity chromatography into one lectin-containing fraction (SGL) that was mitogenic to mononuclear cells (MNC) and another that lacked this lectin activity. The SGL-depleted Sarcocystis extract (SGTF) contained the so-called Sarcotoxin, inducing only a slight increase in MNC proliferation. Furthermore, preincubation of MNC with SGTF for 60 min suppressed the mitogenic capacity of SGL by 60%-90%. The results presented indicate that SGTF interacts with human MNC differently than SGL, particularly by interfering with the mitogenic lectin. These findings suggest that SGL and SGTF may be involved in different immunomechanisms induced by the parasite.

Animals↗
PubMed1989

[The protein pattern of Gasterophilus intestinalis larva (Diptera: Gasterophilidae), Psoroptes cuniculi and Chorioptes bovis (Acarida: Psoroptidae)].

SDS-PAGE and chromatography of the mange mites Chorioptes bovis and Psoroptes cuniculi and Gasterophilus intestinalis instars revealed a species and stage specific distribution of proteins. This specific protein pattern is responsible for an immune response depending on the course of the parasitic infection. Therefore, identification and isolation of the adequate antigens are necessary for diagnostic purposes.

Animals↗
PubMed1986

Extracts from Sarcocystis gigantea macrocysts are mitogenic for human blood lymphocytes.

Extracts were prepared from macrocysts of Sarcocystis gigantea, an animal parasite, by sonication and high speed centrifugation. Mononuclear cells were obtained from the blood of 14 adults and 5 newborns and used for transformation assays. Addition of Sarcocystis extracts (equivalent to 400 micrograms protein/ml) to these cells increased the lymphocyte proliferation approximately 71 fold over the background. The control with Pokeweed mitogen (5 micrograms/ml) gave a stimulation index of 58. There was no difference in the response to the Sarcocystis extract between the lymphocytes of adults and those of newborns. This findings show that the effect of the extract is mitogenic and not due an anamnestic reaction.

Adult↗
PubMedDate not supplied

Phenotypic and genotypic variation in the interaction between Arabidopsis thaliana and Albugo candida.

Two biotrophic parasites of the wild crucifer Arabidopsis thaliana (L.) Heynh, are being used to explore the molecular basis and evolution of genotype-spcific recognition and host defense. Genes for recognition of Peronospora parasitica (downy mildew) are numerous in A. thaliana and located on four of the five chromosomes as described previously. Genes for recognition of the closely related parasite Albugo candida (white blister) are described here. In contrast to teh former parasite, less than 15% of the host accessions tested were capable of recognizing either of two isolates of A. candida. The geographic regions represented by these accessions included countries in eastern and western Europe, Asia, North America and Africa. Extensive collections from England and Germany were required to identify examples of incompatible interactions. Phenotypic variation among incompatible interactions included reduced blister formations of complete lack of asexual reproduction by the parasite. Variation in the extent of the host response was also observed. Three host genes for recognition of A. candida (RAC), each associated with different interactions phenotypes, were identified through inheritance studies with three accessions. One of these genes at locus RAC1 appeared to be completely dominant, whereas the other two genes were only partially dominant or recessive under certain conditions, possibly including the effect of genetic background. One of the later two genes defined a second locus RAC2. RAC1 was mapped to the top arm of chromosome 1 in the 1 cM interval between RFLP markers M254 and M253.

Arabidopsis↗