Regulation of the immune response by prostaglandins.

Of all the arachidonic acid metabolites, only prostaglandin E (PGE) has been shown to have a clear role in the regulation of cellular and humoral immune responses. In cellular immune responses such as T cell proliferation, lymphokine production, and cytotoxicity, PGE usually acts as a feedback inhibor of the response. This is also true of macrophage and natural killer cytotoxicity. In some instances PGE is responsible for cellular activation rather than inhibition. This is clearest in the control of humoral immunity, where PGE production is a necessary component in the generation of some type of T suppressor cells. Disturbances in immune function found in several human conditions and diseases have been linked to changes in PGE mediated immunoregulation. Either increased production of PGE or increased sensitivity to PGE results in depressed cellular immunity. Conversely drugs which inhibit PGE production act as stimulants of cellular immune functionin vitro andin vivo.

Regulation of the immune response by prostaglandins

Lymphocyte response is enhanced by supplementation of elderly subjects with selenium-enriched yeast.

PROBLEM: In normal pregnancy the maternal immune system should be directed towards tolerance or suppression in order not to reject the partly foreign feto-placental unit. The aim of this investigation was to find hallmarks of systemic immunosuppression during normal pregnancy.



METHODS: Five healthy primigravidae were examined during pregnancy and postpartum with flow cytometric analysis to define T and B lymphocyte subsets in peripheral blood. In addition, we studied the proliferative response of lymphocytes to mitogens or interleu-kin-2 (IL-2) alone or in combination with immunomodulating drugs or interleukin-4 (IL-4). The results were compared to healthy, non-pregnant women.



RESULTS: During pregnancy and early puerperium we noted an immune balance in favour of suppression, as measured by increased numbers of T “helper/suppressor” (CD4+ CD45RA+) and “suppressor”/effector T cells (CD8+S6F1-), and decreased numbers of T “helper/inducer” (CD4+CD29+), T “helper/memory” (CD4+CD45RO+), killer/effector T cells (CD8+S6F1+), and Natural Killer cells (CD56+), as well as decreased numbers of activated lymphocytes expressing IL-2 receptor (CD25+) and T cells expressing HLA-DR (HLA-DR+CD3+). During pregnancy, lymphocyte proliferation was impaired in autologous serum with concanavalin A (ConA), phytohemagglutinin (PHA), or IL-2. A difference in proliferative response to PHA or IL-2 between cultures with AB serum and autologous serum is suggestive of an immunosuppressor factor in serum during pregnancy. Indomethacin significantly increased lymphocyte proliferation in autologous serum with ConA, indicating PGE2 mediated suppressor activity during pregnancy. Chlorambucil and cimetidine modulated the proliferative response to ConA, indicating an alkylating agent sensitive and a histamine dependent suppressor activity during pregnancy.



CONCLUSIONS: During normal pregnancy, a state of systemic suppression of the maternal immune system seems to be present.

Lymphocyte subsets and mitogen stimulation of blood lymphocytes in normal pregnancy.

Hormonal and pregnancy relationships to rheumatoid arthritis: Convergent effects with immunologic and microvascular systems*

Primiparous and multiparous healthy pregnant women were tested at the end of the gestation period, or immediately after delivery, for their lymphocyte reactivity to paternal or neonatal cells in mixed lymphocyte culture and in cell-mediate cytotoxicity assays. Freshly isolated maternal lymphocytes had no spontaneous cytotoxic activity against PHA-activated neonatal or paternal lymphocytes. In conventional 6-day mixed lymphocyte cultures and in cytotoxicity assays, maternal lymphocytes displayed a response similar to that of paternal or third party lymphocytes when stimulated with neonatal, paternal, or third party lymphocytes. By contrast, in 3-day mixed lymphocyte cultures maternal cells had a selectively lower response to paternal antigens (expressed either on cord blood cells or on paternal lymphocytes), than to unrelated alloantigens. Removal of T-lymphocytes with IgG receptors (T), or of T-lymphocytes reacting with OKT8 monoclonal antibody, corrected the depressed response of maternal cells in these 3-day cultures. It is suggested that circulating maternal lymphocytes contain antigenspecific suppressor cells characterized by their membrane receptors for IgG and the T8 antigen.

Suppressor T-lymphocytes in pregnancy.

Anti-IgM stimulation of B cells is decreased in the presence of maternal serum as compared to control media. This inhibiting influence of maternal serum is observed during the priming of the B cells. The progression of B cells into cellular proliferation was not influenced by maternal serum. At the level of the immunoglobulin secretion, the influence of maternal serum was also shown. A significant down regulation of the IgM, no change of the IgG production, and an enhanced secretion of IgA and IgE was demonstrated in the presence of maternal serum as compared to control media. It has been suggested that the maternal IgG fraction contains a molecule partly responsible for these changes. Furthermore, the CD23 antigen is increased when B cells are stimulated in the presence of a pool of maternal IgG. All the findings concerning maternal IgG were more pronounced when retroplacental IgG was used instead of peripheral maternal IgG. This observation suggests that the factor responsible for the B cell changes is ...

Modulation of B cell stimulation by maternal serum

The lymphocyte response to optimal and suboptimal doses of phytohemagglutinin (PHA) has been investigated in 33 healthy pregnant women compared with 27 controls. Standard preparations of lymphocytes, isolated from the two groups of participants by Ficoll-Metrizoate density gradient centrifugation, contained the same amount of peroxidase positive cells (± 10%) and exhibited the same response to PHA. Removal of cells adhering to plastic dishes (AC) led to an increased lymphocyte response in pregnant subjects but to a reduced response in the controls. Maternal lymphocytes depleted in AC had a significantly higher PHA response than did AC-depleted lymphocytes from the control subjects. The apparent suppressor activity of AC on maternal lymphocytes is not mediated by prostaglandins as shown by the observations that indomethacin (10−6 M) had the same enhancing effect and prostaglandin E1 (10−6 to 10−8 M) the same inhibiting effect in the two groups of subjects. Collectively the data indicate that during pregnancy the cellular interactions involved in the lymphocyte response to PHA are altered; the data also explain some of the contradictory results in the literature.

Regulation of the Lymphocyte Response to Phytohemagglutinin During Pregnancy: Role of Adherent Cells and Prostaglandins

Numerous experiments have been performed to try to explain the successful gestation of the semiallogeneic mammalian fetus in the immuno-competent mother (1, 3, 4, 5). A popular hypothesis is that localized intra uterine suppression mediates the immune response and contributes directly to the survival of the fetus (6). Suppressive factors synthesized at the fetomaternal interface may be transported by the bloodstream and be found in the retroplacental and peripheral blood circulation (7). In this report we aim to study these modulating factors by exposing a proteinaceous antigen (Candidine or human mono nuclear cells) to unrelated human lymphocytes in the presence of a pool of maternal serum, retroplacental (MAT SR) or peripheral (MAT SP), or to a pool of male or calf serum (MALS or CS).A significant downregulation of the candidine mediated lymphocytic stimulation was observed in the case of the maternal serum. In order to further characterize this inhibition, a quantitative evaluation of the expre...

Functional modifications of the CD4+ and the CD8+ subset due to maternal serum

The recent immunological literature has described the existence of a retroplacental serum factor being responsible for the downregulation of the MHC Class II antigen expression In this report, the same property has been found in peripheral maternal serum the HLA Class II modulating activity is however diminished in the presence of peripheral maternal serum as compared to retroplacental serum suggesting that the IA like inhibiting factor is released at the fetomaternal interfaceAfter a three-day incubation period of unrelated lymphocytes in a maternal serum pool, it was shown that the HLA Dr, the HLA Dp, and more significantly, the HLA Dq molecules were modulated When third party lymphocytes were stimulated by Candidine or unrelated mononuclear cells in the presence of retroplacental serum, only the cellular subpopulation belonging to the CD4+ subset showed an HLA Dq downregulation the molecular constituents of the MHC Class II antigen expression characterizing cells belonging to other sub

Modulation of the HLA class II antigen at a molecular level by maternal serum.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Y.E. Vanderbeeken

Author Tools

Chat about Author