Central nervous system-associated macrophages modulate the immune response following stroke in aged mice.

Age is a major nonmodifiable risk factor for ischemic stroke. Central nervous system-associated macrophages (CAMs) are resident immune cells located along the brain vasculature at the interface between the blood circulation and the parenchyma. By using a clinically relevant thromboembolic stroke model in young and aged male mice and corresponding human tissue samples, we show that during aging, CAMs acquire a central role in orchestrating immune cell trafficking after stroke through the specific modulation of adhesion molecules by endothelial cells.

Intestinal MAdCAM-1 imaging as biomarker for prognostic in murine models of multiple sclerosis.

Introduction: Multiple sclerosis (MS) is an autoimmune disease of the central nervous system. Recent evidence suggests that lymphocyte trafficking in the intestines could play a key role in its etiology. Nevertheless, it is not clear how intestinal tissue is involved in the disease onset nor its evolution.

Immuno-MRI for Stroke Diagnosis and Prognosis.

Following a stroke, an inflammatory response occurs, characterized by an increased blood-brain barrier permeability, expression of endothelial trafficking molecules, and infiltration of immune cells. Adhesion molecules expressed on activated brain endothelial cells are potential biomarkers of intraparenchymal inflammation. However, in current clinical practice, it is not possible to measure endothelial activation using clinically available imaging.

DICAM promotes T17 lymphocyte trafficking across the blood-brain barrier during autoimmune neuroinflammation.

The migration of circulating leukocytes into the central nervous system (CNS) is a key driver of multiple sclerosis (MS) pathogenesis. The monoclonal antibody natalizumab proved that pharmaceutically obstructing this process is an effective therapeutic approach for treating relapsing-remitting MS (RRMS). Unfortunately, the clinical efficacy of natalizumab is somewhat offset by its incapacity to control the progressive forms of MS (PMS) and by life-threatening side effects in RRMS rising from the expression of its molecular target, very late antigen 4 (VLA4), on most immune cells and consequent impairment of CNS immunosurveillance.

Identification of SARS-CoV-2-specific immune alterations in acutely ill patients.

Dysregulated immune profiles have been described in symptomatic patients infected with SARS-CoV-2. Whether the reported immune alterations are specific to SARS-CoV-2 infection or also triggered by other acute illnesses remains unclear. We performed flow cytometry analysis on fresh peripheral blood from a consecutive cohort of (a) patients hospitalized with acute SARS-CoV-2 infection, (b) patients of comparable age and sex hospitalized for another acute disease (SARS-CoV-2 negative), and (c) healthy controls.

Environmental enrichment alleviates the deleterious effects of stress in experimental autoimmune encephalomyelitis.

Background: Clinical observations support the hypothesis that stressful events increase relapse occurrence in multiple sclerosis patients, while stress-reduction strategies can modulate this effect. However, a direct cause-effect relationship between stress level and relapse cannot be firmly established from these data.

Objectives: The purpose of this work was to address whether modulation of stress could interfere with symptom relapse in an animal model of multiple sclerosis with relapsing-remitting course.

Ultrasensitive molecular imaging of intestinal mucosal inflammation using leukocyte-mimicking particles targeted to MAdCAM-1 in mice.

Mucosal tissues play critical roles in health and disease as the primary barrier between the external world and the inner body, lining the digestive, respiratory, urinary, mammary, and reproductive tracts. Clinical evaluation of mucosal tissues is currently performed using endoscopy, such as ileocolonoscopy for the intestinal mucosa, which causes substantial patient discomfort and can lead to organ damage. Here, we developed a contrast agent for molecular magnetic resonance imaging (MRI) that is targeted to mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1), an adhesion molecule overexpressed by inflamed mucosal tissues.

Molecular Magnetic Resonance Imaging of Endothelial Activation in the Central Nervous System.

Endothelial cells of the central nervous system over-express surface proteins during neurological disorders, either as a cause, or a consequence, of the disease. Since the cerebral vasculature is easily accessible by large contrast-carrying particles, it constitutes a target of choice for molecular magnetic resonance imaging (MRI). In this review, we highlight the most recent advances in molecular MRI of brain endothelial activation and focus on the development of micro-sized particles of iron oxide (MPIO) targeting adhesion molecules including intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), P-Selectin and E-Selectin.

Reduced spinal cord parenchymal cerebrospinal fluid circulation in experimental autoimmune encephalomyelitis.

An alteration of parenchymal cerebrospinal fluid circulation (CSF) has been proposed to take part in the pathophysiology of multiple sclerosis. By using an intragate T1-weighted high-resolution MRI of the spinal cord of freely breathing mice injected with a gadolinium chelate in the , we show that a parenchymal CSF circulation exists in the spinal cord, in addition to that originally described in the brain. In experimental autoimmune encephalomyelitis, a model of multiple sclerosis, we show a reduction of parenchymal CSF circulation specifically in the spinal cord but not in the brain.

Molecular Magnetic Resonance Imaging (mMRI).

Molecular magnetic resonance imaging (mMRI) enables the detection of a protein of interest in vivo, in a noninvasive manner. The general concept of mMRI is to target a contrast agent to a protein of interest, and to perform a contrast-sensitive MRI sequence. Typically, contrast agents are made of a "contrastophore" (the part of the construct responsible for the contrast on the images) and a targeting moiety ("pharmacophore").

Prediction of disease activity in models of multiple sclerosis by molecular magnetic resonance imaging of P-selectin.

New strategies for detecting disease activity in multiple sclerosis are being investigated to ameliorate diagnosis and follow-up of patients. Today, although magnetic resonance imaging (MRI) is widely used to diagnose and monitor multiple sclerosis, no imaging tools exist to predict the evolution of disease and the efficacy of therapeutic strategies. Here, we show that molecular MRI targeting the endothelial adhesion molecule P-selectin unmasks the pathological events that take place in the spinal cord of mice subjected to chronic or relapsing experimental autoimmune encephalomyelitis.