The Leuven Immunomodulatory Protocol Promotes T-Regulatory Cells and Substantially Prolongs Survival After First Intestinal Transplantation.

Intestinal transplantation (ITx) remains challenged by frequent/severe rejections and immunosuppression-related complications (infections/malignancies/drug toxicity). We developed the Leuven Immunomodulatory Protocol (LIP) in the lab and translated it to the clinics. LIP consists of experimentally proven maneuvers, destined to promote T-regulatory (Tregs)-dependent graft-protective mechanisms: donor-specific blood transfusion (DSBT); avoiding high-dose steroids/calcineurin-inhibitors; and minimizing reperfusion injury and endotoxin translocation. LIP was tested in 13 consecutive ITx from deceased donors (2000-2014) (observational cohort study). Recipient age was 37 years (2.8-57 years). Five-year graft/patient survival was 92%. One patient died at 9 months due to aspergillosis, another at 12 years due to nonsteroidal anti-inflammatory drug-induced enteropathy. Early acute rejection (AR) developed in two (15%); late AR in three (23%); all were reversible. No chronic rejection (CR) occurred. No malignancies developed and estimated glomerular filtration rate remained stable post-Tx. At last follow-up (3.5 years [0.5-12.5 years]), no donor-specific antibodies were detected and 11 survivors were total parenteral nutrition free with a Karnofsky score >90% in 8 recipients (follow-up >1 years). A high frequency of circulating CD4+ CD45RA- Foxp3hi memory Tregs was found (1.8% [1.39-2.21]), comparable to tolerant kidney transplant (KTx) recipients and superior to stable immunosuppression (IS)-KTx, KTx with CR, and healthy volunteers. In this ITx cohort we show that DSBT in a low-inflammatory/pro-regulatory environment activates Tregs at levels similar to tolerant-KTx, without causing sensitization. LIP limits rejection under reduced IS and thereby prolongs long-term survival to an extent not previously attained after ITx.

Maternal exposure to GOS/inulin mixture prevents food allergies and promotes tolerance in offspring in mice.

BACKGROUND: Food allergies affect 4-8% of children and are constantly on the rise, thus making allergies a timely issue. Most importantly, prevention strategies are nonexistent, and current therapeutic strategies have limited efficacy and need to be improved. One alternative to prevent or reduce allergies, particularly during infancy, could consist of modulating maternal immunity and microbiota using nondigestible food ingredients, such as prebiotics. For this purpose, we studied the preventive effects of prebiotics in Balb/c mothers during pregnancy and breastfeeding on food allergy development in offspring mice. METHODS: After weaning, the offspring from mothers that were exposed to GOS/inulin mixture or fed a control diet were intraperitoneally sensitized to wheat proteins to induce a systemic allergic response and orally exposed to the same allergen. Immunological, physiological, and microbial parameters were analyzed. RESULTS: GOS/inulin mixture diet modified the microbiota of mothers and their offspring. Offspring from mothers that received GOS/inulin prebiotics were protected against food allergies and displayed lower clinical scores, specifically of IgE and histamine levels, compared to offspring from mothers fed a control diet. Moreover, GOS/inulin supplementation for the mother resulted in stronger intestinal permeability in the offspring. Enhancement of the regulatory response to allergic inflammation and changes in the Th2/Th1 balance toward a dampened Th2 response were observed in mice from GOS/inulin mixture-exposed mothers. CONCLUSION: The treatment of pregnant and lactating mice with nondigestible GOS/inulin prebiotics promotes a long-term protective effect against food allergies in the offspring.

Regulatory T Cells in Kidney Transplantation: New Directions?

The contribution of regulatory T cells in the maintenance of kidney graft survival is of major interest. Although many experimental models suggest a role in the induction of graft tolerance, reproducing these findings in clinic is less clear. While modulation of the regulatory T cell response is a promising therapeutic concept in transplantation, a better understanding of function, phenotype and biology is needed to be able to optimally exploit these cells in order to induce graft tolerance. With this in mind, we review here the current understanding of the phenotypic-functional delineation of Tregs and how Tregs can contribute to graft survival. We highlight their potential role in long-term graft survival and kidney operational tolerance. We also discuss the mechanisms needed for the molecular development of regulatory T cells: A combination of FOXP3 molecular partners, epigenetic, metabolic, and posttranslational modifications are necessary to generate well-functioning regulatory T cells and maintain their core identify. We discuss how an improved understanding of these mechanisms will permit the identification of new potent therapeutic strategies to improve kidney graft survival.

A regulatory CD9(+) B-cell subset inhibits HDM-induced allergic airway inflammation.

BACKGROUND: Exposure to respiratory allergens triggers airway hyperresponsiveness and inflammation characterized by the expansion of TH 2 cells and the production of allergen specific IgE. Allergic asthma is characterized by an alteration in immune regulatory mechanisms leading to an imbalance between pro- and anti-inflammatory components of the immune system. AIMS: Recently B cells have been described as central regulators of exacerbated inflammation, notably in the case of autoimmunity. However, to what extent these cells can regulate airway inflammation and asthma remains to be elucidated. MATERIALS & METHODS: We took advantage of a allergic asthma model in mice induced by percutaneous sensitization and respiratory challenge with an extract of house dust mite. RESULTS: In this study, we showed that the induction of allergic asthma alters the homeostasis of IL-10(+) Bregs and favors the production of inflammatory cytokines by B cells. Deeper transcriptomic and phenotypic analysis of Bregs revealed that they were enriched in a CD9(+) B cell subset. In asthmatic mice the adoptive transfer of CD9(+) B cells normalized airway inflammation and lung function by inhibiting TH 2- and TH 17-driven inflammation in an IL-10-dependent manner, restoring a favorable immunological balance in lung tissues. Indeed we further showed that injection of CD9(+) Bregs controls the expansion of lung effector T cells allowing the establishment of a favorable regulatory T cells/effector T cells ratio in lungs. CONCLUSION: This finding strengthens the potential for Breg-targeted therapies in allergic asthma.

Unique B cell differentiation profile in tolerant kidney transplant patients.

Operationally tolerant patients (TOL) display a higher number of blood B cells and transcriptional B cell signature. As they rarely develop an allo-immune response, they could display an abnormal B cell differentiation. We used an in vitro culture system to explore T-dependent differentiation of B cells into plasma cells. B cell phenotype, apoptosis, proliferation, cytokine, immunoglobulin production and markers of differentiation were followed in blood of these patients. Tolerant recipients show a higher frequency of CD20(+) CD24(hi) CD38(hi) transitional and CD20(+) CD38(lo) CD24(lo) naïve B cells compared to patients with stable graft function, correlating with a decreased frequency of CD20(-) CD38(+) CD138(+) differentiated plasma cells, suggestive of abnormal B cell differentiation. B cells from TOL proliferate normally but produce more IL-10. In addition, B cells from tolerant recipients exhibit a defective expression of factors of the end step of differentiation into plasma cells and show a higher propensity for cell death apoptosis compared to patients with stable graft function. This in vitro profile is consistent with down-regulation of B cell differentiation genes and anti-apoptotic B cell genes in these patients in vivo. These data suggest that a balance between B cells producing IL-10 and a deficiency in plasma cells may encourage an environment favorable to the tolerance maintenance.

Regulatory functions of B cells in allergic diseases.

B cells are essentially described for their capacity to produce antibodies ensuring anti-infectious immunity or deleterious responses in the case of autoimmunity or allergy. However, abundant data described their ability to restrain inflammation by diverse mechanisms. In allergy, some regulatory B-cell subsets producing IL-10 have been recently described as potent suppressive cells able to restrain inflammatory responses both in vitro and in vivo by regulatory T-cell differentiation or directly inhibiting T-cell-mediated inflammation. A specific deficit in regulatory B cells participates to more severe allergic inflammation. Induction of allergen tolerance through specific immunotherapy induces a specific expansion of these cells supporting their role in establishment of allergen tolerance. However, the regulatory functions carried out by B cells are not exclusively IL-10 dependent. Indeed, other regulatory mechanisms mediated by B cells are (i) the production of TGF-ß, (ii) the promotion of T-cell apoptosis by Fas-Fas ligand or granzyme-B pathways, and (iii) their capacity to produce inhibitory IgG4 and sialylated IgG able to mediate anti-inflammatory mechanisms. This points to Bregs as interesting targets for the development of new therapies to induce allergen tolerance. In this review, we highlight advances in the study of regulatory mechanisms mediated by B cells and outline what is known about their phenotype as well as their suppressive role in allergy from studies in both mice and humans.

Aggression and prosocial behaviors in social conflicts mediating the influence of cold social intelligence and affective empathy on children's social preference.

This study proposes a model in which aggressive and prosocial behaviors exhibited in social conflicts mediate the influence of empathy and social intelligence to children's social preference by same-sex peers. Data were obtained from kindergarten to the end of the first grade. The sample yielded 117 Spanish children (64 girls and 53 boys) with a mean age of 62.8 months (SD = 3.3) at the beginning of the study. For boys, affective empathy contributed to boys' social preference through a decrease in physical aggression as responses to social conflict. For girls, affective empathy had an indirect effect on girls' preference by increasing assistance to others in their conflicts. No mediating effect in the contribution of social intelligence on girls' social preference was detected. Our results suggest that, only for girls, cold social intelligence can promote both indirect aggression (coercive strategic that do not leave social preference, at least at these ages) and behaviors that lead social preference (such as prosocial behaviors).

Three opportunistic infections associated with ectopic corticotropin syndrome.

Cytomegalovirus pneumonia, Pneumocystis carinii pneumonia, and pulmonary and disseminated aspergillosis occurred simultaneously in a 66-year-old white man with oat cell carcinoma and ectopic corticotropin production. Hypokalemia, a recent normal chest roentgenogram, and a large left adrenal mass on a computed tomographic scan confused the initial clinical evaluation. The aspergillosis proved fulminant and lethal.

Cushing's syndrome due to ectopic production of corticotropin-releasing factor.

A patient with Cushing's syndrome is described who had a metastatic medullary carcinoma of the thyroid which contained corticotropin-releasing factor. ACTH was found by an immunohistochemical method in the patient's pituitary, but not in the thyroid tumor. This is the second report demonstrating corticotropin-releasing factor in tumor tissue in this syndrome. Wider use of immunohistological methods can help distinguish this variety from other tumors associated with the ectopic ACTH syndrome when bioassays are not available.

Ductal carcinoma of male breast with prominent lipid-rich component.

We report a case of mammary duct carcinoma with a prominent lipid-rich, sebaceous-like component, occurring in a 55 yr old white male. The patient presented with a painless, subareolar left breast mass and the diagnosis of malignancy was made by fine needle aspiration. Subsequent modified radical mastectomy revealed an infiltrating and in situ ductal carcinoma with dermal invasion and numerous vacuolated sebaceous-like tumor cells, positive for neutral lipid by Oil Red O stain. We propose that this case represents an unusual variant of lipid-secreting breast carcinoma. To the best of our knowledge, this subtype of mammary carcinoma is unprecedented in male breast.

Cytogenetic profile of a thymoma. A case report and review of the literature.

Cytogenetic analysis of mixed lymphocyte and epithelial thymoma in a nonmyasthenic female patient revealed deletion of part of the short arm of chromosome 6. To our knowledge, this cytogenetic abnormality in a benign thymoma has not been previously described in the literature, which is reviewed.

An analysis of mother-young behaviour of fallow deer during lactation period.

In the Doñana National Park (SW Spain) female fallow deer (Dama dama ) give birth during the first fortnight of June, the next breeding season starting at the beginning of October. Between these two events the most important part of lactation takes place. Daily observations were made during the summer of 1984 and 1985. The population studied was made up of fourteen mother-young pairs that we were able to recognize individually. During each sampling period a pair of mother-young was scanned. Activities were categorized as follows: feeding, walking, selfgrooming, vigilance, mother-young interactions, and social interactions. No differences were observed in the ontogeny of behaviour neither between male and female fawns nor between their mothers. However, analysing individual differences there appeared a variation between mothers in relation to the rate of interactions towards their fawns, which was in positive correlation with the fawn's weight in the case of males. Our results also suggest the possibility of higher investment in heavier female fawns. Furthermore, there is an annual variation in the maternal behaviour in relation to the availability of resources.

Factors affecting the social ability in pre-school children: An exploratory study.

In a previous paper (Braza et al., 1993) we quantified the social ability of pre-school children by means of two Indices: Amplitude of Behaviour (I.A.B.) and Amplitude of Partnership (I.A.P.). The aim of this study is to explore their possible relations with some agents of socialisation and to validate these indices of amplitude as a measure of social ability. The variables considered (biometrical measurements, family characteristics, and social behaviours in peer groups) were ordered by means of a prior analysis of the principal components, and the factor scores of each individual in these analyses were chosen as new variables. Twenty-six pre-school children attending a nursery in Cádiz (SW Spain) were filmed at school during their free-play period. Our results confirm the fitness of the Index of Amplitude of Behaviour (I.A.B.) not only as a useful tool for the study of socialisation, but also as a possible predictor of later success and social adjustment.

Human papovavirus in a routine urine specimen of a four-year-old boy.

Cellular changes produced by viruses can be readily identified using light microscopy and Papanicolaou stain of a fixed specimen. These findings can then be confirmed by viral culture and/or electron microscopy studies. Human polyomavirus, common in transplant recipients or otherwise immunocompromised patients, is one virus that can be identified using these methods. The following is a case study of a 4-yr-old boy with no known immune impairment who exhibited human papovavirus (polyomavirus) on a routine urine examination. The diagnosis was confirmed by electron microscopy.

Ectopic ACTH and adrenal myelolipoma.

We describe a case of adrenal myelolipoma that occurred in a 66-year-old male with an ACTH producing oat cell lung carcinoma. To our knowledge, this is the first case in which myelolipoma has occurred in association with ectopic ACTH-induced Cushing's syndrome. The literature is reviewed and the pathogenesis of myelolipoma is discussed.

Reproductive status of mothers affects sex-biased parental investment in humans.

An analysis of the sexual differences in birth weights of 381 children showed that boys are heavier than girls for multiparous mothers but not for primiparous ones. The results support the current hypotheses that predict sex biases in parental investment, with higher costs of producing male offspring in some mammals.

Repeated measurement of intestinal permeability as an assessment of colitis severity in HLA-B27 transgenic rats.

We report on the development of a method for repeated monitoring of mucosal permeability that allows assessment of the severity of colitis and evaluation of treatment efficacy in HLA-B27 transgenic rats. We determined the extent to which intestinal permeability related to stool condition, colon weight, and histological pathology in precolitic and diseased rats up to 29 weeks old. Intestinal permeability was measured by the urinary excretion of iodixanol at 24 h after oral administration. Mean permeability values increased significantly with age in HLA-B27 rats but remained decreased in the background strain Fischer-344 (F-344) control animals. Macroscopic evaluation of HLA-B27 rat colons between 20 and 24 weeks old showed colonic thickening with colonic wet weights increased from 3.4+/-0.13 mg/kg b.wt. in F-344 rats to 6.79+/-0.73 mg/kg b.wt. (p<.05) in HLA-B27 rats. Histological examination of HLA-B27 rat colons confirmed the colonic inflammation as a chronic active mononuclear cell infiltrate. The increase in colon weight was associated with an increase in permeability: 1.16+/-0.17 mg iodixanol versus 5.37+/-1.3 mg of iodixanol in F-344 and HLA-B27 rats, respectively. Three weeks treatment of HLA-B27 rats with cyclosporin A, but not sulfasalazine, showed a dose-dependent decrease in mucosal permeability and colon weight. Neither treatment improved stool condition. We conclude that the measurement of intestinal permeability by iodixanol excretion is a useful biochemical marker that is associated with increases in colonic weight and histological evaluation of inflammation. These data indicate that this technique may be valuable for diagnostic and evaluation purposes in preclinical models of inflammatory bowel disease.