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Biomedical subjects

W L Irving

Publications and source records attributed to W L Irving.

64 records · Page 4Linked to original sources
PubMed1985

Modulation of Epstein-Barr virus-induced B-cell activation by concanavalin A.

Direct addition of the T-cell mitogen, concanavalin A (Con A), to cultures of Epstein-Barr virus (EBV)-stimulated peripheral blood mononuclear cells (PBMC) resulted in a dose-dependent inhibition of immunoglobulin M (IgM) secreted in the supernatant, as measured by an enzyme-linked immunosorbent assay. Furthermore, Con A inhibited IgM secretion of isolated T-depleted cells stimulated with EBV, and both the proliferation and IgM secretion of EBV-driven lymphoblastoid cell lines. T-Enriched cells, precultured for 48 hr with Con A, were also able to suppress the IgM response of fresh autologous PBMC stimulated with EBV. This suppression was radiation sensitive (2000 rad), a procedure which resulted in enhancement of the IgM secretion of the responder cells in two out of three experiments. Studies on the long-term effects of Con A showed that the early suppression of IgM secretion was transient and that the mitogen prevented the development of the cytotoxic T-cell response normally seen with lymphocytes from EBV-seropositive donors after 5 weeks of culture. Thus, Con A appears to modulate human lymphocyte responses to EBV by multiple mechanisms.

B-Lymphocytes↗
PubMed1985

Abnormal responses of rheumatoid arthritis lymphocytes to Epstein-Barr virus infection in vitro: evidence for multiple defects.

Blood lymphocytes from 53 patients with rheumatoid arthritis (RA) and 44 controls were cultured with the polyclonal B cell activator Epstein-Barr virus (EBV). Culture supernatants were removed at weekly intervals and the amount of IgM secreted by the lymphocytes measured by an enzyme-linked immunosorbent assay (ELISA). Three major differences in the pattern of EBV-induced IgM synthesis by RA versus control lymphocytes were observed. Lymphocytes from RA patients, in general, produced less IgM after one week in culture than controls. In contrast, they increased their IgM secretion significantly by the end of the second week, whereas control lymphocyte cultures showed little change in IgM secretion at this time. Control lymphocytes from EBV seropositive individuals produced undetectable amounts of IgM after five weeks in culture. However, lymphocytes from 40% of the RA patients, even though they were EBV seropositive, secreted greater than 2000 ng/ml (microgram/l) IgM after five weeks. The data are discussed in terms of defective B and T cell responses to EBV in lymphocytes from patients with RA.

Adult↗
PubMed1985

A cell surface monoclonal antibody (H366) helps to discriminate human cytotoxic from suppressor T cells.

A study has been undertaken to differentiate T cytotoxic (Tc) and T suppressor (Ts) cell subsets using a monoclonal antibody termed H366 (mouse IgG2b) previously reported to phenotype natural killer and killer (NK/K) cells. Mononuclear cell suspensions from 14 normal subjects were depleted of H366+ cells by means of complement dependent cytotoxicity and the remaining cells were phenotyped with CD8 and CD4 monoclonal antibodies. The effects of depletion with H366 plus complement (C1) on the induction and activity of suppressor and cytotoxic T cells was also examined. The results indicate that H366 antibody recognizes in addition to NK/K cells, a population of Tc but not Ts or helper cells. Therefore, H366 antibody can be useful for obtaining Ts enriched lymphocyte subpopulations and this property may also be used for the enumeration of suppressor cells in the peripheral blood in disease states.

Antibodies, Monoclonal↗
PubMed1984

Variation in expression of mouse erythrocyte receptors on Epstein-Barr virus-induced B-cell lines.

To explain the variation in the percentage of mouse erythrocyte rosette-forming cells (MERFC) during culture of Epstein-Barr virus (EBV)-induced B-cell lines, we provide evidence that (i) there is an altered expression of mouse red blood cell (MRBC) receptors on cell line cells during the mitotic cycle, and (ii) putative receptor-negative cells are capable of de novo synthesis of the receptor, and passively adsorbing receptor shed from receptor-positive cells.

Adsorption↗
PubMed1984

Evidence for B cell activation in patients with active rheumatoid arthritis.

Peripheral blood lymphocytes and in some cases synovial eluate cells from 51 patients with rheumatoid arthritis (RA), were analysed for the percentages of cells bearing surface light chains (total B cells), IgM and IgD. In addition, their capacity to form rosettes with mouse erythrocytes (mRFC)--a property of a B cell subpopulation--was determined. Activity of the disease was assessed by clinical and laboratory criteria and classified as very active, moderately active and inactive. Normal, age and sex matched individuals and a group of patients with a variety of other rheumatological disorders, were used as control populations. Although there was no significant difference in percentages of total B cells in any of the groups compared with normal controls, there was a small but significant increase in the ratio of cells bearing IgM to those bearing IgD in patients with very active disease. This was paralleled by a significant decrease in the mRFC in this disease activity group. Patients with inactive disease showed no change in their proportions of IgM:IgD, but did show a significant increase in mRFC. These results are discussed in terms of the presence of activated B cells in patients with very active RA.

Adult↗