Mitogenic effects of glycolipoprotein extract from Pseudomonas aeruginosa

Glycolipoprotein extracted from the extracellular of slime of Pseudomonas aeruginosa has been tested for its ability to cause murine spleen cells to proliferate and differentiate. The extracted glycolipoprotein was found to be mitogenic for a subpopulation of murine B cells. It also caused an increase in the number of specific antibody forming cells in vitro. The activity of this extract was sensitive to low doses of cyclosporin A. These findings may be important in understanding the mechanism(s) of host resistance to this organism.

Clinical psychologists' use of transformative models of psychosis

Some theories (e.g. Jackson's Paradigm Shifting Hypothesis) and many personal accounts suggest that some psychotic crises, whilst distressing, can also be transformative, leading to growth and valued outcomes. However, little is known about the extent to which this idea informs mainstream mental health care. Clinical psychologists are influential advocates of psychosocial approaches more broadly: This study explored their use of transformative models. Twelve U.K. clinical psychologists were interviewed: Transcripts informed a grounded theory. No participants saw psychosis as a purely biological problem where the content of experiences is irrelevant. Two held a "biopsychosocial" model, viewing psychosis as an illness with psychosocial elements. Most either held a continuum view (i.e., schizotypy), in which psychosis proneness was also associated with positive attributes such as creativity or sensitivity, or a "fully psychological" view, seeing experiences as meaningful and/or as adaptive responses to events. Many believed that psychosis can be transformative in a broad sense, that is, lead to "post-traumatic growth." Some went further, believing that it can be a purposeful (e.g., an attempt, albeit painful and sometimes unsuccessful, to solve problems) or even a spiritual phenomenon. Participants' perspectives influenced their therapeutic approach: Those who saw experiences as purposeful were more likely to facilitate direct engagement with them and to support clients to explore potentially transformative aspects. However, this represented an extension of conventional approaches rather than being qualitatively different. More research is needed to clarify how widespread this approach is, to explore its utility, and to establish for whom and when it may be appropriate.

A cross-reactive idiotype on anti-DNA and lymphocytotoxic antibodies

The possibility that shared idiotypes may be present on antibodies of different specificities was explored using sera from 13 patients with systemic lupus erythematosus. Eleven sera had anti-DNA and seven carried the 16/6 idiotype (ID). Two of the sera with 16/6 ID also had lymphocytotoxic antibodies, the activity of which was blocked by antibody to the 16/6 ID. Our studies reveal that 16/6 ID is present on two antibodies with different binding specificities.

Lack of autoantigen-specific splenic suppressor cells in mice with an X-linked B-lymphocyte defect

Male and female progeny of a cross between CBA/N female and BALB/c male mice were tested for their ability to generate autoantigen-specific suppressor cells as a result of stimulation with crossreacting rat RBC. Male mice, hemizygous for the X-linked defect, were unable to generate these antigen-specific suppressor cells, whereas their female littermates behaved like the normal (CBA/Ca x BALB/c)F1 mice.

Studies on the thymus of non-obese diabetic (NOD) mice: effect of transgene expression

The non-obese diabetic (NOD) mouse is a good model of insulin-dependent diabetes mellitus. Autoreactive T cells may play a fundamental role in disease initiation in this model, while disregulation of such cells may result from an abnormal thymic microenvironment. Diabetes is prevented in NOD mice by direct introduction of an E alpha d transgene (NOD-E) or a modified I-A beta chain of NOD origin (NOD-PRO or NOD-ASP). To investigate if disease pathology in NOD mice, protection from disease in transgenic NOD-E and NOD-PRO and partial protection from disease in NOD-ASP can be attributed to alterations in the thymic microenvironment, immunohistochemical and flow cytometric analysis of the thymi of these mouse strains was studied. Thymi from NOD and NOD-E mice showed a progressive increase in thymic B-cell percentage from 12 weeks of age. This was accompanied by a concomitant loss in thymic epithelial cells with the appearance of large epithelial-free areas mainly at the corticomedullary junction, which increased in size and number with age and contained the B-cell clusters. Such thymic B cells did not express CD5 and were absent in CBA, NOD-ASP and NOD-PRO mice as were the epithelial cell-free spaces, even at 5 months of age. Therefore the mechanisms of disease protection in the transgenic NOD-E and NOD-ASP/NOD-PRO mice may differ if these thymic abnormalities are related to disease.

Cellular infiltration in induced rat thyroiditis: phenotypic analysis and relationship to genetic restriction

We have investigated the responsiveness to thyroglobulin (Tg) plus complete Freund's adjuvant (CFA) and B. pertussis in a variety of inbred and MHC congenic strains of rats in terms of both Tg-autoantibody titres and histological thyroiditis index. Severity of thyroiditis was strongly Tg-dependent and closely related to the RT.1-MHC haplotype. Phenotypic examination of the inflammatory thyroid infiltrate using single and double indirect immunofluorescence techniques revealed a high proportion of macrophages and T lymphocytes, mainly of the cytotoxic/suppressor subset, in the high responder strains. Thyroid epithelial class II MHC expression although not prominent was strain-restricted and related to the amount of Ia+ leukocyte infiltrate.

Heterogeneity in rheumatoid factor isotypes and specificities in MRL mice

MRL/lpr mice spontaneously develop an arthritis which, in several respects, is similar to human rheumatoid arthritis, including joint inflammation and circulating rheumatoid factors. In human disease, circulating IgM rheumatoid factor (RF) predominates but, surprisingly, in these mice we have detected much more IgA rheumatoid factor. This IgA rheumatoid factor has a major specificity for IgG2a, but heterogeneity in binding specificity was seen between different mice. IgG rheumatoid factors were determined in a heterologous mouse IgG assay, in which each subclass of rheumatoid factor was tested for its ability to bind to the remaining IgG subclasses. Rheumatoid factor activity was detected in all the IgG subclasses, but particularly elevated levels were seen in IgG3 and IgG1. Both the levels and specificities of IgG rheumatoid factors were markedly different between each mouse.

The implications of the failure to generate autoantibody-producing hybridomas from rat erythrocyte-immunized mice

Injection of mice with rat erythrocytes (RRBC) has long been thought to provide an experimental model in which suppressor T cells (Ts) control autoimmunity. The basis of this is that whilst mice immunized with RRBC produce an antibody response, of which a proportion cross-reacts with autologous red cells, the RRBC-immunized recipients of RRBC-primed spleen cells make no, or little, autoantibody, and secondly because the transfer of this autoantibody-specific suppression can be abrogated by T-cell depletion of transferred spleen cells. Here an alternative explanation of these phenomena is described.

Rabbit anti-EL4 serum. A reagent with specificity for a population of murine suppressor cells

Antisera against the C57B1 (H-2b) mouse lymphoma, EL4 were prepared in rabbits. After absorption with mouse liver, red cells and thymocytes the antisera appeared to be cytotoxic for a subpopulation of peripheral T cells. The absorbed antisera blocked the immunosuppressor function of Con A-stimulated splenic lymphocytes, but was unreactive against Con A-stimulated and allogeneically primed cytotoxic cells, or helper T cells. Consequently, heteroantiserum against EL4 may provide a useful reagent for the differentiation of cytotoxic from suppressor T-cell subsets.

3H-collagen turnover in non-cross-linked and aldehyde-cross-linked dermal collagen grafts

Using trypsin-purified rat dermal collagen labelled with tritiated hydroxyproline and proline, a study has been made of hydroxyproline turnover in non-cross-linked and glutaraldehyde- and formaldehyde-cross-linked collagen when implanted s.c. in unlabelled isogenic rats. Grafts cross-linked with 0.01% glutaraldehyde maintained their collagen mass over a 22-week period, loss of original collagen being balanced by the gain in new collagen (22% at 22 weeks). Cross-linking with 5% formaldehyde temporarily inhibited collagen loss as compared with non-cross-linked grafts. However, at 22 weeks both had lost some 30% of their collagen mass, the gain of new collagen (some 8%) only partially compensating for the loss of original implant collagen.

Multinucleated giant cells in PHA-stimulated leucocyte cultures of children with measles

Multinucleated giant cells were seen in 3-day leucocyte cultures from some children with measles. The production of the giant cells was PHA dependent, and therefore constitute another form of abnormal PHA response by leucocytes in vitro.

Abnormalities in the SJL mouse provide evidence for different mechanisms for the induction and transfer of tolerance to mouse thyroglobulin

Experimental autoimmune thyroiditis (EAT) induced by immunization of susceptible (H-2k) mice can be significantly suppressed by pretreatment with soluble mouse thyroglobulin administered intravenously. Lightly irradiated recipients of spleen cells from donors pretreated in this way show a reduced response when subsequently challenged with mouse thyroglobulin and adjuvant (Kong et al., 1982; Parish et al., 1988). Previous studies on the SJL mouse revealed, among other abnormalities, a lack of suppressor cells (Cooke & Hutchings, 1984; Hutchings, Varey & Cooke, 1986; Amagai & Cinader, 1981) and therefore tolerance induction to mouse thyroglobulin and subsequent transfer was examined in these animals. The SJL mouse could be tolerized by i.v. administration of mouse thyroglobulin, but transfer of spleen cells from these animals failed to mediate suppression in syngeneic recipients. Several congenic strains of B10 mice showed similar 'in situ' tolerance without subsequent successful transfer and we conclude that the tolerance system described may be mediated by two distinct pathways and that the SJL appears to be defective only in the second pathway. Studies on other mouse strains suggest that the ability to be tolerized or to transfer tolerance is not dependent on a particular H-2 or I-E.

Lifting the lid on impact and peer review

Brain and Neuroscience Advances has grown in tandem with the British Neuroscience Association’s campaign to build Credibility in Neuroscience, which encourages actions and initiatives aimed at improving reproducibility, reliability and openness. This commitment to credibility impacts not only what the Journal publishes, but also how it operates. With that in mind, the Editorial Board sought the views of the neuroscience community on the peer review process, and on how they should respond to the Journal Impact Factor that will be assigned to Brain and Neuroscience Advances. In this editorial, we present the results of a survey of neuroscience researchers conducted in the autumn of 2020 and discuss the broader implications of our findings for the Journal and the neuroscience community.

Cyclosporine affects the function of antigen-presenting cells

The immunosuppressant drug cyclosporine (CsA) is known to affect T-cell function. We have studied the effect of CsA on the specific proliferative response of T-cell lines to antigen. In addition to blocking IL-2 release by specifically activated T-cell lines, CsA also affected the ability of irradiated spleen cells to present preprocessed antigen to T-cell lines. Irradiated spleen cells pulsed with antigen for 2 hr were able to stimulate a proliferative response in T-cell lines. Following a 2-hr pulse with CsA, antigen presentation by these irradiated spleen cells was reduced significantly, suggesting that CsA not only affects T cells, but also affects the function of antigen-presenting cells.

Insulin autoantibodies, islet cell surface antibodies and the development of spontaneous diabetes in the BB/Edinburgh rat

The presence of insulin autoantibodies (IAA) and islet cell surface antibodies (ICSA) was sought in two longitudinal studies, involving BB/Edinburgh rats of high (BB/E/H, n = 157) and low (BB/E/L, n = 61) susceptibility to diabetes development. Both studies were designed to correlate pancreatic morphology with cellular and humoral immunity. In Study I, groups of eight male and eight female non-diabetic rats of the BB/E/H line were killed at 15 day intervals from 30-105 days and plasma samples were obtained by cardiac puncture. In study II, 61 BB/E/H and 41 BB/E/L rats underwent pancreatic biopsy 1-3 times from 30 days of age until onset of diabetes or 150 days, plasma samples being taken from the tail vein at biopsy. Both studies revealed a higher prevalence for ICSA than IAA in BB/E rats. Whereas a highly significant association of ICSA with diabetes development was observed in study II (chi 2 = 8.30, P less than 0.005), IAA were associated with diabetes development only weakly (P less than 0.03, Mann-Witney U-rank test). No correlation between the presence of ICSA and IAA in individual rats was observed and IAA were not significantly associated with BB/E/H in preference to BB/E/L rats, although positive IAA values were significantly elevated in the former compared with the latter (P less than 0.01). These observations support the concept that IAA form part of a background of heightened autoimmunity against which frank diabetes develops in some animals.

Helper and suppressor activities of an autoreactive mouse thyroglobulin-specific T-cell clone

An autoreactive T-cell clone, MTg9B3, specific for mouse thyroglobulin, has been characterized. This clone has properties consistent with it an being autoreactive T helper cell. It is I-A restricted, with a surface phenotype of Thy 1+, L3T4+, Ly2-, and produces a number of non-specific lymphokine activities following specific triggering with antigen. Furthermore, antigen-stimulated clone cells were capable of providing bystander help in SRBC-specific antibody responses. Surprisingly, MTg9B3 cells had a profound suppressive effect on thyroglobulin autoantibody responses in vitro.