Indoleamine 2,3-dioxygenase [IDO] is expressed at feto-placental unit throughout mouse gestation: An immunohistochemical study

The cells expressing Indoleamine 2, 3-dioxygenase [IDO] in feto-maternal interface mediate tryptophan catabolism, hence protect allogeneic fetus from lethal rejection by maternal immune responses. In this study, we report immuno-localization of IDO cells in murine reproductive tract and placenta throughout mouse pregnancy by immunohistochemistry. Syngeneic pregnant mice were examined for vaginal plug to discover about their state of pregnancy. A total of three pregnant mice were examined at each stage. The examination was further confirmed by the detection of sperm in vaginal smear. On the gestational days of 2[nd], 12[th] and 18[th], the uterus and oviduct were removed and expression of IDO was investigated in the endometrium, placenta and oviduct by immunohistochemistry. Our results showed that IDO is expressed consistently in feto-maternal interface throughout pregnancy. In endometrium, expression of IDO was predomin-antly confined to luminal and glandular epithelial cells. Cells at junctional and labyrinth zones of placenta showed strong IDO immunoreactivity as well. Expression of IDO at the protein level in reproductive tract of pregnant mice during entire periods of gestation points to its potential protective role in maintenance of pregnancy. In our knowledge this is the first report of expression of IDO in feto-maternal phase during murine pregnancy

Heterologous immunization, a way out of the problem of monoclonal antibody production against carcinoma antigen 125

Monoclonal antibodies [mAbs] are essential tools for many molecular immunology investigations, epitope mapping and molecular modelling, clinical laboratory diagnostic tests and immunotherapy. Humoral immune response of immunized animals largely depends on the nature of antigen and the immunization technique. Polysaccharides and heavily-glycosylated proteins are very elusive targets incapable of mounting long-lasting, high affinity antibody responses. Carcinoma antigen 125 [CA 125], a well known tumor marker of ovarian cancer, is a mucin type antigen consisting of repetitive units of heavily glycosylated moieties which render production of mAbs very difficult. To evaluate the efficacy of heterologous antigen preparations as a way of mouse immunization in the production of anti-CA 125 mAb. Two different protocols of immunization were used for priming of NMRI mice. In the first method, mice conventionally immunized by three intraperitoneal injections of purified CA 125 and boosted by the antigen three days before fusion. In the second approach, mice were primed by three intraperitoneal injections of living CA 125 positive cells of OVCAR-3 cell line, and boosted by intravenous injection of the purified extracellular domain of CA 125. Production of mAb was performed by standard hybridoma technology and mAbs were characterized by different immunoassays. The first method failed to produce stable clones despite six time fusion. A total of ten stable clones, however, were produced in the second approach. Some of the clones were characterized and found to have excellent immunoreactivity when tested by ELISA assay, western blotting, intracellular and surface immunofluorescent staining of OVCAR-3 cell line and immunohistochemical staining of ovarian cancer tissues. Altogether the results of the present study clearly showed that heterologous antigen preparation is the method of choice for immunization when production of monoclonal antibody against highly glycosylated poorly immunogenic antigens is concerned

Alteration of peripheral blood T-Reg cells and cytokines production in angiography personnel exposed to scattered X-rays

Angiocardiography is an X-ray examination of the blood vessels or chambers of the heart. Cardiologists and staff members applying this procedure are exposed to high levels of scattered radiation. In our previous study the incidence of unstable chromosomal aberrations and cytokinesis-blocked micronuclei were found to be significantly higher in exposed individuals than the age and sex matched controls. In the present study we assessed cytokine production by peripheral blood mononuclear cells of the above cases and the percentage of Treg cells. According to film dosimeter analysis, personnels received 0.25-15 mSv during the previous year [average of 3 mSv/y]. Isolated PBMCs from the test and control groups were stimulated with Phorbol Myristate Acetate/Ionomycin [PMA/I]. Cytokine production was measured in the supernatants of cultured lymphocytes. The percentage of Treg cells was studied by flow cytometry. The production of IL-10 and IL-5 was significantly down-regulated in the test group compared to the control group. In contrast, IL-12 was up-regulated. Yet, no statistically significant difference was found for IFN-gamma between two groups. In addition, we found higher percentage of CD4+CD25+bright Treg cells in the study group compared to the controls. Taken together, it was shown that low doses of scattered X-rays could skew cytokine profile of peripheral blood mononuclear cells in favour of inflammatory response causing the increase of Treg cells