Background And Purpose: The present study was performed to determine the role of alpha4 (CD49d), a member of the integrin family of adhesion molecules, in ischemic brain pathology.
Methods: Male spontaneously hypertensive rats (SHR) or Sprague-Dawley rats underwent 60-minute middle cerebral artery occlusion (MCAO) followed by 23-hour reperfusion. Animals were injected intravenously with 2.5 mg/kg anti-rat alpha4 antibody (TA-2) or isotype control antibody (anti-human LFA-3 IgG(1), 1E6) 24 hours before MCAO. Infarct volume was quantified by staining of fresh tissue with tetrazolium chloride and myeloperoxidase activity measured in SHR tissue homogenates 24 hours after MCAO. In SHR, mean arterial blood pressure was recorded before and after MCAO in animals treated with TA-2 and 1E6. Fluorescence-activated cell sorting analysis was performed on peripheral blood leukocytes before and after MCAO.
Results: TA-2 treatment significantly reduced total infarct volume by 57.7% in normotensive rats (1E6, 84.2+/-11.5 mm(3), n=17; TA-2, 35.7+/-5.9 mm(3), n=16) and 35.5% in hypertensive rats (1E6, 146.6+/-15.5 mm(3), n=15; TA-2, 94.4+/-25.8 mm(3), n=11). In both strains, TA-2 treatment significantly reduced body weight loss and attenuated the hyperthermic response to MCAO. In SHR, treatment with TA-2 significantly reduced brain myeloperoxidase activity. Resting mean arterial blood pressure was unaffected by treatment. Leukocyte counts were elevated in TA-2-treated rats. Fluorescence-activated cell sorting analysis demonstrated the ability of TA-2 to bind to CD3+, CD4+, CD8+, and CD11b+ cells in both naive animals and after MCAO.
Conclusions: These data demonstrate that inhibition of alpha4 integrin can protect the brain against ischemic brain injury and implicate endogenous alpha4 integrin in the pathogenesis of acute brain injury. The mechanism by which alpha4 integrin inhibition offers cerebroprotection is independent of blood pressure modulation and is likely due to inhibition of leukocyte function.
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http://dx.doi.org/10.1161/01.str.32.1.199 | DOI Listing |
Clin Immunol
February 2025
Department of Immunology, Erasmus MC, University Medical Center, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands; Department of Immunology, Central Clinical School, Monash University and Alfred Hospital, Commercial Road 89, 3004 Melbourne, Victoria, Australia. Electronic address:
Objective: Studies in mouse models and human adults have shown that the intestinal microbiota composition can affect peripheral immune cells. We here examined whether the gut microbiota compositions affect B and T-cell subsets in children.
Methods: The intestinal microbiota was characterized from stool samples of 344 10-year-old children from the Generation R Study by performing 16S rRNA sequencing.
Cancer Immunol Immunother
January 2025
Department of Medical Oncology, Institut de Cancérologie de L'Ouest, 44805, Saint Herblain, France.
Front Immunol
December 2024
Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
The functional specialization of CD4 T lymphocytes into various subtypes, including T1 and T cells, is crucial for effective immune responses. T cells facilitate B cell differentiation within germinal centers, while T1 cells are vital for cell-mediated immunity against intracellular pathogens. Integrin α4, a cell surface adhesion molecule, plays significant roles in cell migration and co-stimulatory signaling.
View Article and Find Full Text PDFHematol Oncol
January 2025
Hematology, Oncology R&D, AstraZeneca, Cambridge, UK.
Contemporary studies of Bruton tyrosine kinase inhibitor (BTKi) resistance focus on mutations in the B-cell receptor (BCR) pathway, but alternative mechanisms of resistance remain undefined. Here, we sought to identify novel predictive markers of acquired resistance to acalabrutinib, a second-generation BTKi, in patients with chronic lymphocytic leukemia (CLL). Clinical samples from 41 patients with relapsed/refractory or treatment-naive CLL receiving acalabrutinib as part of a clinical trial (NCT02029443) were divided into two groups: those who continued to respond to treatment (NP, n = 23) and those who developed progressive disease on acalabrutinib therapy (PD, n = 18).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!