Persistence ofToxoplasma gondiiin the central nervous system: a fine-tuned balance between the parasite, the brain and the immune system

2015 ◽  
Vol 37 (3) ◽  
pp. 150-158 ◽  
Author(s):  
N. Blanchard ◽  
I. R. Dunay ◽  
D. Schlüter
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Oscar Kurt Bitzer-Quintero ◽  
Ignacio González-Burgos

The central nervous system is closely linked to the immune system at several levels. The brain parenchyma is separated from the periphery by the blood brain barrier, which under normal conditions prevents the entry of mediators such as activated leukocytes, antibodies, complement factors, and cytokines. The myeloid cell lineage plays a crucial role in the development of immune responses at the central level, and it comprises two main subtypes: (1) resident microglia, distributed throughout the brain parenchyma; (2) perivascular macrophages located in the brain capillaries of the basal lamina and the choroid plexus. In addition, astrocytes, oligodendrocytes, endothelial cells, and, to a lesser extent, neurons are implicated in the immune response in the central nervous system. By modulating synaptogenesis, microglia are most specifically involved in restoring neuronal connectivity following injury. These cells release immune mediators, such as cytokines, that modulate synaptic transmission and that alter the morphology of dendritic spines during the inflammatory process following injury. Thus, the expression and release of immune mediators in the brain parenchyma are closely linked to plastic morphophysiological changes in neuronal dendritic spines. Based on these observations, it has been proposed that these immune mediators are also implicated in learning and memory processes.


2017 ◽  
Vol 19 (3) ◽  
pp. 45
Author(s):  
Karol Ramírez Chan DDS, MSc, PhD ◽  
Jaime Jaime Fornaguera-Trías PhD

Objective: Standardize a protocol of immunohistochemistry that has been widely used in C57BL/6J mice to identify microglia of the central nervous system in Wistar rats.  Materials and Methods: This research activity was carried out in two parts. In the first part, a protocol of immunohistochemistry was implemented to identify microglia in the central nervous system of 6 Wistar rats. A primary antibody with reactivity to rat and a specific secondary antibody to the primary were used. Once the protocol was established in rats' brains, an immunological challenge was produced with the intraperitoneal application of lipopolysaccharide in 2 Wistar rats, in order to evidence the changes in microglia morphology.  Results and Discussion: We demonstrate that without making major modifications to the original protocol, it can also be used to identify microglia in adult Wistar rats. In the near future, this immunostaining protocol will be applied to elucidate the bidirectional interaction between the brain and the immune system, under homeostatic conditions and different physiological and pathological stimuli.


1988 ◽  
Vol 14 ◽  
pp. 159-186
Author(s):  
Edwin Levy

In 1973 Niels Kaj Jerne announced an important new hypothesis about the immune system (‘IS’). That suggestion is based on several similarities between IS and the central nervous system. Jerne postulated that IS, like the nervous system, is a network.I am convinced that the description of the immune system as a functional network of lymphocytes and antibody molecules is essential to its understanding, and that the network as a whole functions in a way that is peculiar to and characteristic of the internal interactions of the elements of the immune system itself: it displays what I call eigen-behavior. (Jerne [1973), 59)This proposal has a number of implications, including some philosophical ones. Here I focus on the question whether the network hypothesis and subsequent developments shed any light on the use of teleological concepts in biology. In part one I present some of the background story of network ideas in immunology, including a reverse hypothesis to the effect that IS-Net could serve as a basis for modeling the brain. In part two I locate the teleological implications of IS-Net with respect to current mainstream discussions of teleology.


2006 ◽  
Vol 64 (4) ◽  
pp. 976-982 ◽  
Author(s):  
Henrique Costa ◽  
Marcello Franco ◽  
Myriam Dumas Hahn

CONTEXT: Primary central nervous system lymphomas (PCNSL) are a rare subgroup of lymphomas generally associated with HIV and EBV. OBJECTIVE: To study ten autopsy cases of PCNSL, to describe the neuropathological findings, to characterize the phenotype of the neoplastic cells, to detect EBV in the lesion and to compare the findings with the clinical and laboratory data of the patients. METHOD: The clinical, histological and immunohistochemical data of ten cases of PCNSL, eight cases from patients with AIDS, identified among 265 autopsies of these patients were analyzed. RESULTS: Seven patients were males and the mean age was 40.9 years. The most frequent symptomatology was focal neurologic deficit (70%). Six patients presented with only one lesion. Histologically, densely cellular and polymorphous neoplasms with angiocentrism were observed, in 90% of cases. An association with other diseases was observed in four cases. Most patients had diffuse large B cell non-Hodgkin’s lymphoma. EBV was detected by immunohistochemistry in only one case. The lack of detection of the virus might have been due to the long time of fixation of the brain which might have inactivate epitopes therefore compromising the testing. CONCLUSION: In the present series, PCNSL presented with focal symptoms, with unifocal or multifocal lesions, with a predominant B-cell CD20 positive phenotype, rarely associated with EBV.


2018 ◽  
Vol 15 (13) ◽  
pp. 1179-1190 ◽  
Author(s):  
Vilma M. Junges ◽  
Vera E. Closs ◽  
Guilherme M. Nogueira ◽  
Maria G.V. Gottlieb

The role of diet and gut microbiota in the pathophysiology of neurodegenerative diseases, such as Alzheimer's, has recently come under intense investigation. Studies suggest that human gut microbiota may contribute to the modulation of several neurochemical and neurometabolic pathways, through complex systems that interact and interconnect with the central nervous system. The brain and intestine form a bidirectional communication axis, or vice versa, they form an axis through bi-directional communication between endocrine and complex immune systems, involving neurotransmitters and hormones. Above all, studies suggest that dysbiotic and poorly diversified microbiota may interfere with the synthesis and secretion of neurotrophic factors, such as brain-derived neurotrophic factor, gammaaminobutyric acid and N-methyl D-Aspartate receptors, widely associated with cognitive decline and dementia. In this context, the present article provides a review of the literature on the role of the gutbrain axis in Alzheimer's disease.


2003 ◽  
Vol 5 (2) ◽  
pp. 139-153

Recent research has overcome the old paradigms of the brain as an immunologically privileged organ, and of the exclusive role of neurotransmitters and neuropeptides as signal transducers in the central nervous system. Growing evidence suggests that the signal proteins of the immune system - the cytokines - are also involved in modulation of behavior and induction of psychiatric symptoms. This article gives an overview on the nature of cytokines and the proposed mechanisms of immune-to-brain interaction. The role of cytokines in psychiatric symptoms, syndromes, and disorders like sickness behavior, major depression, and schizophrenia are discussed together with recent immunogenetic findings.


Author(s):  
S.S. Spicer ◽  
B.A. Schulte

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.


2018 ◽  
Vol 23 (1) ◽  
pp. 10-13
Author(s):  
James B. Talmage ◽  
Jay Blaisdell

Abstract Injuries that affect the central nervous system (CNS) can be catastrophic because they involve the brain or spinal cord, and determining the underlying clinical cause of impairment is essential in using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), in part because the AMA Guides addresses neurological impairment in several chapters. Unlike the musculoskeletal chapters, Chapter 13, The Central and Peripheral Nervous System, does not use grades, grade modifiers, and a net adjustment formula; rather the chapter uses an approach that is similar to that in prior editions of the AMA Guides. The following steps can be used to perform a CNS rating: 1) evaluate all four major categories of cerebral impairment, and choose the one that is most severe; 2) rate the single most severe cerebral impairment of the four major categories; 3) rate all other impairments that are due to neurogenic problems; and 4) combine the rating of the single most severe category of cerebral impairment with the ratings of all other impairments. Because some neurological dysfunctions are rated elsewhere in the AMA Guides, Sixth Edition, the evaluator may consult Table 13-1 to verify the appropriate chapter to use.


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