Purpose: The goal of the present study was to investigate the role of platelet activating factor (PAF) and PAF receptor (PAF-R) in the recruitment of eosinophils into the conjunctiva in the course of PAF induced conjunctivitis. Eosinophils are important players in the immediate hypersensitivity reactions and in allergic conjunctivitis. PAF-R is expressed in many ocular tissues including conjunctival cells. Although it is known that PAF is one of the most potent chemotactic agents for the recruitment of eosinophils, factors responsible for it in conjunctivitis are not clear. Colocalization analysis has been employed to quantify the degree of colocalization of major basic protein (MBP) and PAF-R antigens in the course of PAF induced conjunctivitis.
Methods: A 1% solution of PAF was applied in eye drops to male Brown Norway rats. Eyes were harvested with intact conjunctivas at different time points and examined using histology, immunohistochemistry, confocal immunofluorescence microscopy, and reverse transcription-polymerase chain reaction. PAF-R and MBP (a marker of eosinophils) antibodies have been used for immunohistochemical studies. Quantitative analysis of the colocalization of PAF-R and major basic protein (MBP) antigens was performed.
Results: Instillation of PAF caused a time dependent recruitment of eosinophils. Eosinophils revealed PAF-R in the intact state. An influx of eosinophils into the conjunctiva was caused by the interaction of PAF with PAF-R and, possibly, with MBP antigen. PAF appeared to enhance the expression of PAF-R by eosinophils and to act toward the PAF-R directly, without chemokine mediation.
Conclusions: Quantitative colocalization analysis helped to determine that the recruitment of eosinophils in PAF induced conjunctivitis is accomplished via direct action of PAF toward the PAF-R. It also ensured an objective evaluation of the changes of the degree of colocalization of MBP and PAF-R antigens and the degree of PAF-R expression in dynamics, the findings not otherwise obtainable using qualitative approaches alone.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
The Innate Immune Sensor Zbp1 Mediates Central Nervous System Inflammation Induced by Angiostrongylus Cantonensis by Promoting Macrophage Inflammatory Phenotypes.
Adv Sci (Weinh)
January 2025
Key Laboratory of Tropical Disease Control (Sun Yat-Sen University), Ministry of Education, Guangzhou, Guangdong, 510080, China.
Angiostrongylus cantonensis (AC) is the leading cause of eosinophilic meningoencephalitis worldwide. The neuroimmune interactions between peripheral and central immune systems in angiostrongyliasis remain unclear. In this study, significant infiltration of eosinophils, myeloid cells, macrophages, neutrophils, and Ly6C monocytes is observed in the brains of AC-infected mice, with macrophages being the most abundant.
View Article and Find Full Text PDFAntagonism of CD28 blocks allergic responses in the ovalbumin-induced asthmatic model mice.
Int Immunopharmacol
January 2025
Allergen-reactive T helper (Th) 2 cells play a pivotal role in initiating asthma pathogenesis. The absence or interruption of CD28 signaling causes significant consequences for T-cell activation, leading to reduced cell proliferation and interleukin (IL)-2 production. A novel compound, Cyn-1324, exhibits a higher binding affinity to CD28 than CD80.
View Article and Find Full Text PDFcan persist asymptomatically within tissues for extended periods. This remarkable feat is achieved through intricate host-pathogen interactions in immune cell aggregates called granulomas, wherein find favorable cellular niches to exploit while the host limits its expansion and tissue dissemination. Here, using a mouse model of persistent infection, we identify a host-protective role of eosinophils in control of Typhimurium (Tm) infection within the mesenteric lymph nodes (MLN), the main lymphoid tissue of Tm persistence.
View Article and Find Full Text PDFSputum Microbiota Correlates With Metabolome and Clinical Outcomes in Asthma-Bronchiectasis Overlap.
Arch Bronconeumol
January 2025
Department of Allergy and Clinical Immunology, Department of Respiratory and Critical Care Medicine, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China; Guangzhou National Laboratory, Guangzhou, Guangdong, China. Electronic address:
Objectives: To investigate the microbiota and metabolome of patients with ABO compared with bronchiectasis and asthma, and determine the relevance with clinical characteristics, inflammatory endotype and exacerbation risks.
Methods: In this prospective cohort study, patients underwent comprehensive assessments, including sputum differential cell count, and sputum collection at baseline. Sputum microbiota was profiled via 16S rRNA gene sequencing and metabolome via liquid chromatography/mass spectrometry.
Identification of Bronchial Epithelial Genes Associated with Type-2 Eosinophilic Inflammation in Asthma.
J Allergy Clin Immunol
January 2025
Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin-Madison, Madison, Wis. Electronic address:
Background: Airway inflammation has a critical role in asthma pathogenesis and pathophysiology. Yet, the molecular pathways contributing to airway inflammation are not fully known, particularly Type-2 (T2) inflammation characterized by both eosinophilia and higher FeNO levels.
Objective: To identify genes whose level of expression in epithelial brushing samples were associated with both bronchoalveolar lavage (BAL) eosinophilia and generation of FeNO.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!