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S Vitiello

Publications and source records attributed to S Vitiello.

31 records · Page 2Linked to original sources
PubMed1989

Brain neocortex modulation of mitogen-induced interleukin 2, but not interleukin 1, production.

Interleukin 2 (IL-2) production by splenic T cells stimulated by Concanavalin A was studied in mice after unilateral or bilateral brain neocortex ablation. The brain cortex was shown to modulate IL-2 production in an asymmetrical way. IL-2 levels were higher in animals with a right cortical lesion (group R) and lower in mice with a symmetrical lesion (group L) as compared to controls, differences between groups R and L being significant. Such variations of IL-2 production that were observed after unilateral lesions were abolished with bilateral cortical ablations. These results extend the immunoregulatory roles of the brain neocortex to IL-2 production by splenic T cells and may provide molecular support for neuro-immunological networks.

Animals↗
PubMed1989

Brain neocortex influence on the mononuclear phagocyte system.

The cerebral neocortex is known to modulate asymmetrically certain components of the immune system. It was previously shown that large ablation of the left cortex reduces B and T cell-mediated responses, whereas symmetrical right lesions enhance these responses. We have studied the immunomodulatory role of the brain cortex on the mononuclear phagocytic system. Resident and BCG-activated macrophages were investigated in female C3H/He mice at 8-10 weeks after right or left cortical ablation. After an intraperitoneal injection of BCG, the number of peritoneal macrophages was found to be lower in both right- and left-lesioned mice, the difference being stronger and more significant in left-lesioned animals than in sham-operated controls. Furthermore, the oxidative metabolism as assessed by chemiluminescence was depressed only in left-lesioned mice. On the other hand, cortical lesions were shown to have no effect on either the number or the endocytic activity of resident peritoneal macrophages. The possible implication of the brain neocortex on infectious diseases was assayed by using the Trypasonoma musculi model, in which macrophages are known to be effective in parasite eradication. Although the number of peritoneal macrophages was significantly depressed after left cortical lesions 11 days after T. musculi inoculation, the course of the infection was not modified significantly. Our results argue in favor of brain neocortex modulation of the mononuclear system.

Animals↗
PubMed1988

Brain neocortex immunomodulation in rats.

The influence of the cerebral neocortex on the immune system was studied in groups of male Wistar rats after lesioning the right or the left fronto-parietal cortex. In left-lesioned rats, mitogenesis of T-lymphocytes induced either by phytohemagglutinin or Urtica Dioca Agglutinin was depressed by about 25-40% as compared to controls. In contrast, T-cell mitogenesis in animals with right lesions, was enhanced by about 20-45% as compared to controls and by about 90% as compared to that observed in left-lesioned animals. Cortical lesions of either side were shown not to modify antibody synthesis and plasma levels of ACTH, or prolactin. These results, quite similar to those that we have previously observed in female mice, suggest that lateralization in brain cortex immunomodulatory functions may exist in both sexes and in several species of mammals.

Animals↗
PubMed1988

Brain modulation of the immune system: association between lymphocyte responsiveness and paw preference in mice.

An association between handedness and immune disorders has been described in man, left-handers being more susceptible to autoimmune or allergic diseases. However, this correlation was established between handedness and clinical signs of immune disorders without studying immune functions. Using an animal model, we demonstrated for the first time an association between handedness and lymphocyte reactivity. Left-handed mice were shown to exhibit higher mitogen-induced T lymphocyte proliferation than right-handed animals.

Animals↗
PubMed1988

Early effects of right or left cerebral cortex ablation on mitogen-induced spleen lymphocyte DNA synthesis.

The cerebral neocortex has been shown to modulate the immune system in an asymmetrical way. In mice, ablation of the left cortex decreases whereas a symmetrical right lesion enhances B and T cell-mediated responses measured at 6-8 weeks after lesioning. In order to study the possibility of neuronal reorganisation during the post-operative period, immunological parameters were determined as early as 2 weeks after right or left cortical ablation. Right lesions depressed lymphocyte DNA synthesis induced by concanavalin A (ConA) and phytohemagglutinin whereas left lesions only depressed ConA-induced blastogenesis. Right or left lesions had no effect on lipopolysaccharide-induced proliferation of B lymphocytes as well as on serum antibody levels. Comparisons between early and late effects of right or left cortical ablation on the immune system showed that each hemicortex differentially modulates lymphocyte subpopulations but also that the neuronal reorganisation following surgery can be different according to the side of cortex lesion.

Animals↗
PubMed1988

Brain norepinephrine levels after BCG stimulation of the immune system.

Brain norepinephrine, dopamine and serotonin levels were determined in right and left hemisphere from female C3H/He mice 13 days after their immune system was stimulated by an intraperitoneal injection of bacillus Calmette-Guérin (BCG) (10(7) bacilli/mouse). Increased norepinephrine levels were observed in both hemispheres but significantly only in the right one. No concomitant variations in dopamine or serotonin levels were detected. Furthermore, norepinephrine levels in the right hemisphere appeared to be correlated with the ability of lymphocytes to proliferate after concanavalin A stimulation. The modulation of the immune system by the brain neocortex has been previously shown to be lateralized. Here we show that the information from the immune system towards the central nervous system also appears to be expressed in a lateralized manner.

Animals↗
PubMed1987

Functional heterogeneity of the right and left cerebral neocortex in the modulation of the immune system.

The cerebral neocortex is now known to modulate the immune system but this modulation is hemispherically asymmetrical. It was previously reported that large ablation, including the anterior prefrontal part of the left cortex decreased whereas symmetrical right lesions enhanced B and T cell-mediated responses. However, the neocortex is an heterogeneous structure from anatomical and physiological points of view and it could be speculated that different aspects of the immune system could be regulated by various cortical areas. In these experiments, restricted neocortical lesions involving the parieto-occipital lobes were performed in C3H/He mice. Animals with right lesions showed depressed mitogen-induced lymphoproliferation and enhanced antibody production to sheep erythrocytes as compared to that of animals with bilateral lesions. Left lesions appeared not to modify these reactions. Furthermore, the percentage of suppressor/cytotoxic T lymphocytes was depressed more in animals with bilateral lesions as compared to any of the other groups. None of the lesions performed appeared to modify the natural killer cell activity. These results confirm that connections between left and right cortex are involved in the modulation of the immune system and suggest that the immunomodulatory functions of the cortex depend upon the specific regions within the right cortex.

Animals↗
PubMedDate not supplied

Lymphocyte homing after left or right brain neocortex ablation.

The cerebral neocortex is known to modulate the immune system in an asymmetrical way. Ablations of the left cortex decrease, whereas symmetrical right lesions have no effect, or enhance, T cell functions measured 6-8 weeks after lesioning. However, modifications of immune responses induced by lesions of the brain neocortex could result from a lymphocyte redistribution mediated by glucocorticoids, like that observed during stress. We tested this possibility in the present experiments. Cortical lesions modulated concanavalin A-induced proliferation of both lymph node and spleen lymphocytes in a similar way. Cortical lesions of either side modified neither the lymphocyte distribution of 51Cr-labelled injected lymph node cells, nor the percentage of blood cell subsets. These results show that cortical lesions do not affect lymphocyte homing, and suggest that the brain neocortex immunomodulatory effects are not mediated by glucocorticoids.

Animals↗
PubMedDate not supplied

New insights into the role of neuroactive steroids in cognitive aging.

The aim of this article is to describe neuroactive steroid research that has been focused on their physiological role in cognitive aging, an attractive new field in experimental gerontology. Neuroactive steroids have been recently proposed as biomarkers of cognitive aging, however, their specific functions have not yet been fully established. For instance, data emerging from human and animal studies suggest a complex relationship between neuroactive steroids and/or metabolites and cognitive processes during aging. Thus, a better knowledge of neuroactive steroid brain distribution and function could broaden our understanding of their physiological roles and lead to novel and more effective treatments for the management of age-related brain disorders. To this end, newly developed sensitive, specific, and accurate mass spectrometry assays may allow the quantification of neuroactive steroids in discrete brain regions and greatly contribute to unravel their role in age-related cognitive deficits.

Aged↗
PubMedDate not supplied

Inflammatory reaction induced by agarose implants reduced by adding adrenal cells to the polymer.

Microencapsulation of adrenal cells is proposed for reducing the non-specific inflammatory reaction observed around polymer implants. This hypothesis was tested by comparing both host cellular reaction and the surrounding graft cell populations that appeared when either agarose embedded cells or empty agarose beads were implanted. The authors' results showed that the fibrotic material that surrounded the implanted empty agarose microbeads was not as severe when adrenal cells were present. Similarly, the T lymphocyte population surrounding the graft was considerably reduced, along with the percentage of CD4 and CD8 positive cell subpopulations. The activation macrophage marker IaD disappeared. The authors' results support the hypothesis that embedded adrenal cells may be a suitable solution for reducing early inflammatory events due to microcapsule implantation.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Hemispheric asymmetry in the effects of substantia nigra lesioning on lymphocyte reactivity in mice.

Asymmetry in brain modulation of the immune system has previously been demonstrated at the neocortex level. In these experiments, the possibility of subcortical immunomodulation was investigated. In mice the substantia nigra was lesioned using the neurotoxin 6-hydroxydopamine. Four and six weeks after left or right lesions of the substantia nigra, spleen lymphocyte mitogenesis was slightly depressed or enhanced respectively as compared to sham operated controls. Differences appeared when comparing left and right lesioned groups. However, natural killer cell activity was unaffected by unilateral lesions of the substantia nigra. These results show that asymmetrical brain modulation may occur at the sub-cortical level and suggest that central dopamine is involved in neuroimmunomodulation.

Animals↗