Acoustic stress induces long term severe intestinal inflammation in the mouse.

The influence of noise on the presentation and progression of inflammatory bowel diseases has been poorly analyzed. We designed this study to investigate immediate and late effects of acoustic stress (AS) on small intestine. To this aim, CBA/J, BALB/c and DBA/2 mice were divided into AS and control groups. AS mice were exposed to noise (300Hz-70dB) during 24hs and randomized into: A) Acute effects group: mice were killed after AS; L) Late effects group: mice were killed 3 weeks after AS and O) Over-exposed effects group: mice were submitted to AS once a week during a month and killed. Small intestine sections were histologically examined. The expression of cytokines (IL-17, IL-22, TNF-α, INF-É£ and TGF-ß), CCL-25 and Ki67 was studied by immunohistochemistry and immunofluorescence techniques. "A" group displayed short and fragmented villi, diminished number of lamina propria cells, leucocyte infiltration, higher number of goblet cells and predominance of IL-17 expression. "L" group showed epithelial proliferative foci (CCL25+Ki67+) and increased TNFα/TGF-ß expression. Tissue damage was aggravated in "O" group. In conclusion, AS is able to trigger a severe intestinal inflammatory process in healthy mice, which spontaneously amplifies and perpetuates. Noise might be harmful to humans by aggravating inflammatory bowel diseases.

Flow cytometric analysis of T-lymphocytes from nasopharynx-associated lymphoid tissue (NALT) in a model of secondary immunodeficiency in Wistar rats.

Nasopharynx-associated lymphoid tissue (NALT) is responsible for immune responses in the upper respiratory tract of rodents. In our model of protein malnutrition (R21 group), bronchus-associated lymphoid tissue (BALT), situated in the lower respiratory tract, showed a decrease of CD4(+), CD8alpha(+), and TCRalphabeta(+) lymphocytes but TCRgammadelta(+) cells were increased. Besides, there is no information regarding the frequencies of T-cell populations in 60-day-old Wistar rats (C60 group). So, the aim of the present study was to analyze by flow cytometry NALT T-cells from both groups. NALT lymphocytes were isolated from R21 and C60 groups and stained with different antibodies. Samples were run on a FACScalibur flow cytometer. Background staining was evaluated using isotype controls. Data analysis was performed using BD Cell Quest and WinMDI 2.9. In C60, the predominant population was CD4(+)TCRalphabeta(+), which was significantly diminished in the R21 group. However, CD8alpha(+), the majority expressing CD8alphabeta, and TCRgammadelta(+) cells were not affected. In our model of secondary immunodeficiency, there is a compartmentalization between NALT and BALT because they differ in the populations affected even though they are inductive sites of the respiratory tract in the common mucosal immune system.

Nutrition disorder and immunologic parameters: study of the intestinal villi in growing rats.

OBJECTIVE: The aim of the present work was to study how a diet in which cereals were the only protein source would affect B and T lymphocytes and a cell population positive for thymus-expressed chemokine (TECK) in the intestinal villi of growing rats. METHODS: Wistar rats were fed a 6.5% precooked maize protein diet for 18-20 d (M group). An age-matched control group received stock diet (C group). Body weight (grams) was determined, ponderal growth rate (grams per day per 100 g) was calculated, and intestines were removed and processed by Saint-Marie's technique. Tissue sections were studied by indirect immunofluorescence. CD5(+) T cells and the T-cell subsets TCRalphabeta(+), TCRgammadelta(+), CD4(+), CD8alpha(+), and CD8beta(+) in the lamina propria (LP) and intraepithelium, in addition to immunoglobulin A-positive B cells in the LP were determined (n cells/30 fields were read). In addition, the presence of the TECK(+) cell population was qualitatively assessed. RESULTS: The M versus C group showed statistically significant differences in body weight and ponderal growth rate. The number of immunoglobulin A-positive B cells in the LP and the CD5(+) T cells and CD4(+), CD8alpha(+), CD8beta(+), TCRalphabeta(+), and TCRgammadelta(+) T-cell subpopulations of the M group in the LP and intraepithelium of the gut villi were significantly decreased compared with the C group (P < 0.001). The M group also showed differences in the size and cellularity of the gut villi and in the distribution of TECK. CONCLUSION: The results show that intake of a low concentration of a low-quality dietary protein as the only source of protein produces an important disorder in the mucosal immunity of experimental rats.

Comparative immunohistochemical study of M-CSF and G-CSF in feto-maternal interface in a multiparity mouse model.

PROBLEM: Multiparity status has been found to bring beneficial effects both to the maintenance of pregnancy and to the offspring; however, these effects have not been fully explained. We have previously reported that placentae obtained from multiparous females belonging to a syngeneic mouse crossbreeding showed an important increase in the number of placental macrophages, suggesting that they might constitute a protective subpopulation. Taking into account that macrophage-colony stimulating factor (M-CSF) and granulocyte-colony stimulating factor (G-CSF) have proved to modulate macrophage activity and that both factors and/or their receptors have been found at feto-maternal interface, in this paper we analyzed the presence of M-CSF and G-CSF in placental tissue employing the same multiparity mouse model in order to investigate the influence of parity status on local immunoregulation factors of macrophage activity. METHOD OF STUDY: Three groups of mice (CBA/J x CBA/J) were analyzed: Primiparous Young, 3.0 +/- 0.5 months old (PY); Primiparous Old, 8.5 +/- 0.5 months old (PO) and Multiparous Old, 8.5 +/- 0.5 months old, with three to four previous pregnancies (MO). The presence of M-CSF and G-CSF in placental tissue was analyzed by immunohistochemistry. Cytokeratin (CK) and vimentin (VIM) expression and PAS staining were also studied. RESULTS: The three groups showed a similar immunostaining pattern for M-CSF in the whole placental trophoblast, while the expression of G-CSF was significantly higher only in the spongy zone in the MO group. Furthermore, all the MO placentae showed 5-11 layers of cells adjacent to the decidua, where G-CSF and M-CSF were highly detected. Conversely, they constituted a thin layer in PY and PO placentae. These cells were proved to be CK(+) and VIM(-) thus demonstrating their trophoblast origin. In addition, the layers closer to the decidua were also PAS+ suggesting that they could be interstitial cells, a type of invading trophoblast. CONCLUSIONS: In our mouse model, we observed an increase in the expression of G-CSF in placental spongiotrophoblast cells in multiparous females, which have been previously proposed as progenitors of the interstitial cells. Furthermore, this is the first report that indicates that parity status increases trophoblast invasion inducing a proliferative effect of the invading cells on the maternal tissue. We suggest that M-CSF and G-CSF secreted by these invading cells could favor the recruitment of macrophages to the trophoblast and might modulate their activity inducing a switch to a protective, non-inflammatory population.

Asymmetric antibodies (AAb) in the female reproductive tract.

Vaginal mucosa has been shown to play an important role in fertility, since several changes during the estrous cycle determine fertility and pregnancy outcome. The contribution of vaginal fluid IgG antibodies (Abs) to these changes is not fully characterized. Asymmetric Abs (AAb) are a subpopulation of IgG Abs bearing a carbohydrate residue in only one Fab region of the molecule, being therefore functionally univalent and unable to trigger immunological mechanisms tending to destroy the antigens. Here, we investigated the presence of AAb in vaginal secretions of virgin mice. Vaginal fluids were extracted from CBA/J female, where asymmetric IgG molecules were characterized by differential ELISA tests. Additionally, the phenotype of vaginal lymphocytes (VL) was analyzed by flow cytometry. Our data indicate a variation in the percentage of AAb during estrous cycle, since we observed a significant increase in asymmetric IgG molecules levels after ovulation. Regarding the AAbs isotypes, we identified IgG1 as the principal component of the synthesized AAbs. Eighty percent of the AAbs were directed against normal flora, and about 20% of them reacted with vaginal epithelium antigens. Flow cytometry studies revealed TCRalphabeta and gammadelta populations, but a lack of CD8+ T-cells in vaginal mucosa. Since we found a high concentration of AAbs in murine vaginal secretions during metestrus and AAbs were previously found to be protective, it is tempting to speculate that AAbs would provide protection of normal flora in the vaginal lumen. Additionally, we observed that the levels of AAbs decrease when susceptibility to infection in mice occurs at proestrus/estrus, further suggesting a protective role for AAbs.

The role of transforming growth factor-{beta} in a model of oral tolerance to the diet antigen dextrin.

In a model of immunodeficiency provoked by protein deficiency, cytosol fractions from gut IELS isolated from immunodeficient rats presenting oral tolerance to dextrin showed increased expression of TGF-beta to reduce the effect of higher levels of inflammatory cytokines.

Murine abortion is associated with enhanced interleukin-6 levels at the feto-maternal interface.

CBA/JXDBA/2J murine abortion is known to be associated with increased local and peripheral Th1-cytokines levels. The role of the pro-inflammatory interleukin-6 (IL-6) in murine abortion remains unclear. In humans, IL-6 was reported to be elevated at the onset of spontaneous abortion. The aim of our study was to evaluate the levels of IL-6 during murine pregnancy in (1) the normal murine pregnancy combination CBA/JXBALB/c and in (2) the CBA/JXDBA/2J abortion prone mating combination. We measured IL-6 serum levels by ELISA and local (placental and decidual) IL-6 levels by flow cytometry and immunohistochemistry. The expression of the IL-6 receptor gp80 was further analyzed. We additionally evaluated the number of mast cells and macrophages at the feto-maternal interface as a putative IL-6 source in reproductive tissues. IL-6 and gp80 were expressed in decidual cells as well as in different trophoblast types. Flow cytometry analysis showed increased numbers of IL-6+ cells in abortion placentas and deciduas compared to control pregnant mice. We observed an elevated number of mast cells and macrophages at the feto-maternal interface from abortion mice in comparison to control mice. Interestingly, we found very high numbers of mast cells, macrophages and IL-6+ cells in resorption tissue compared to control tissues. Flow cytometry studies confirmed that macrophages are being an important source of IL-6 at the feto-maternal interface. The mRNA IL-6 levels were also enhanced in placenta and decidua from mice with high abortion rate compared to normal pregnant mice, as analyzed by RT-PCR. Our results suggest that IL-6 produced not only by immunocompetent cells such as macrophages and mast cells, but also by trophoblasts and decidua cells, is directly involved in the pathology of abortion.

IgA B and T cells in the intestinal villi of immunodeficient rats orailly treated with thymomodulin

Previous studies on the effect of the oral administration of bacterial immunomodulators (IM-104 and RN-301) during the protein free diet period, have shown an increase on B and T cell gut repopulation, accompanied by IgA antibody production. The usefulness of oral administration of the immunomodulator thymomodulin (TmB) during the protein refeeding period was investigated. TmB allowed the recovery of a normal repopulation of gut lamina propria with IgA B and CD5 T cells and decreases to control values the number of activated intraepithelial lymphocytes (CD25+T cell subset). Therefore, the oral administration of TmB may be useful as a therapeutic agent as it seems to improve the repopulation of intestinal villi with immunocompetent cells. Also, it seems to regulate the immunosurveillance at the epithelium level as it increases the CD5+T cells but decreases the activated ones.

IgA B and T cells in the intestinal villi of immunodeficient rats orailly treated with thymomodulin

Previous studies on the effect of the oral administration of bacterial immunomodulators (IM-104 and RN-301) during the protein free diet period, have shown an increase on B and T cell gut repopulation, accompanied by IgA antibody production. The usefulness of oral administration of the immunomodulator thymomodulin (TmB) during the protein refeeding period was investigated. TmB allowed the recovery of a normal repopulation of gut lamina propria with IgA B and CD5 T cells and decreases to control values the number of activated intraepithelial lymphocytes (CD25+T cell subset). Therefore, the oral administration of TmB may be useful as a therapeutic agent as it seems to improve the repopulation of intestinal villi with immunocompetent cells. Also, it seems to regulate the immunosurveillance at the epithelium level as it increases the CD5+T cells but decreases the activated ones. (AU)

Effect of RN-301 immunomodulator on bronchus-associated lymphoid tissue (Balt) in protein depleted rats at weaning

It has been previously demonstrated in Wistar rats that severe protein deprivation at weaning, even after refeeding with a 20 percent casein diet for 21 days, provokes alterations in IgA+ B cell and T cell populations from gut and GALT (gut associated lymphoid tissue) that are reverted by immunomodulator IM-104. In the present report, we investigated the influence of RN-301 (quite similar to IM-104) given by the oral or subcutaneous route during the protein deprivation period, in the seeding of BALT with IgA+ B and CD5+T cells. The immunomodulator RN-301 contains LPS from E. coli and membrane and ribosomal fractions of P. acne. Tissue sections of the lower respiratory tract were studied by immunohistochemistry. The immunomodulator RN-301 administered by the oral route favours the significant increase in the seeding of the BALT lamina propria with IGA+B and CD5+T cells (p < 0.001). However, the RN-301 given by the subcutaneous route does not favour the repopulation of the BALT lamina propria. The ribosomal fractions from P. acne associated with LPS from E. coli contained in the immunomodulator RN-301 administered by the oral route may rescue the small resting lymphocytes in the gut-associated lymphoid tissue (GALT). This event favours their proliferation and migration to the BALT.

Effect of RN-301 immunomodulator on bronchus-associated lymphoid tissue (Balt) in protein depleted rats at weaning

It has been previously demonstrated in Wistar rats that severe protein deprivation at weaning, even after refeeding with a 20 percent casein diet for 21 days, provokes alterations in IgA+ B cell and T cell populations from gut and GALT (gut associated lymphoid tissue) that are reverted by immunomodulator IM-104. In the present report, we investigated the influence of RN-301 (quite similar to IM-104) given by the oral or subcutaneous route during the protein deprivation period, in the seeding of BALT with IgA+ B and CD5+T cells. The immunomodulator RN-301 contains LPS from E. coli and membrane and ribosomal fractions of P. acne. Tissue sections of the lower respiratory tract were studied by immunohistochemistry. The immunomodulator RN-301 administered by the oral route favours the significant increase in the seeding of the BALT lamina propria with IGA+B and CD5+T cells (p < 0.001). However, the RN-301 given by the subcutaneous route does not favour the repopulation of the BALT lamina propria. The ribosomal fractions from P. acne associated with LPS from E. coli contained in the immunomodulator RN-301 administered by the oral route may rescue the small resting lymphocytes in the gut-associated lymphoid tissue (GALT). This event favours their proliferation and migration to the BALT. (AU)