Sowmya Angusamy1, Tamer Mansour2,3, Mohammed Abdulmageed1,4, Rachel Han1, Brian C Schutte2, John LaPres5, Jack R Harkema6, Said A Omar1,7. 1. Department of Pediatrics and Human Development College of Human Medicine, Division of Neonatology, Michigan State University, East Lansing, MI, USA. 2. Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA. 3. Department of Clinical Pathology, Mansoura University, Mansoura, Egypt. 4. Department of Pediatrics, Faculty of Medicine, South Valley University, Qena, Egypt. 5. Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA. 6. Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, USA. 7. Regional Neonatal Intensive Care, Sparrow Health System, Lansing Michigan, 48912 MI, USA, Phone: +517-364-2670, Fax: +517-364-3994.
Abstract
BACKGROUND: The adaptive immune system of neonates is relatively underdeveloped. The thymus is an essential organ for adaptive T cell development and might be affected during the natural course of oxygen induced lung injury. The effect of prolonged hyperoxia on the thymus, thymocyte and T cell development, and its proliferation has not been studied extensively. METHODS: Neonatal mice were exposed to 85% oxygen (hyperoxia) or room air (normoxia) up to 28 days. Flow cytometry using surface markers were used to assay for thymocyte development and proliferation. RESULTS: Mice exposed to prolonged hyperoxia had evidence of lung injury associated alveolar simplification, a significantly lower mean weight, smaller thymic size, lower mean thymocyte count and higher percentage of apoptotic thymocytes. T cells subpopulation in the thymus showed a significant reduction in the count and proliferation of double positive and double negative T cells. There was a significant reduction in the count and proliferation of single positive CD4+ and CD8+ T cells. CONCLUSIONS: Prolonged hyperoxia in neonatal mice adversely affected thymic size, thymocyte count and altered the distribution of T cells sub-populations. These results are consistent with the hypothesis that prolonged hyperoxia causes defective development of T cells in the thymus.
BACKGROUND: The adaptive immune system of neonates is relatively underdeveloped. The thymus is an essential organ for adaptive T cell development and might be affected during the natural course of oxygen induced lung injury. The effect of prolonged hyperoxia on the thymus, thymocyte and T cell development, and its proliferation has not been studied extensively. METHODS: Neonatal mice were exposed to 85% oxygen (hyperoxia) or room air (normoxia) up to 28 days. Flow cytometry using surface markers were used to assay for thymocyte development and proliferation. RESULTS:Mice exposed to prolonged hyperoxia had evidence of lung injury associated alveolar simplification, a significantly lower mean weight, smaller thymic size, lower mean thymocyte count and higher percentage of apoptotic thymocytes. T cells subpopulation in the thymus showed a significant reduction in the count and proliferation of double positive and double negative T cells. There was a significant reduction in the count and proliferation of single positive CD4+ and CD8+ T cells. CONCLUSIONS: Prolonged hyperoxia in neonatal mice adversely affected thymic size, thymocyte count and altered the distribution of T cells sub-populations. These results are consistent with the hypothesis that prolonged hyperoxia causes defective development of T cells in the thymus.
Entities:
Keywords:
Hyperoxia; T cells; neonatal; thymocyte development; thymus
Authors: Said A Omar; Amal Abdul-Hafez; Sherif Ibrahim; Natasha Pillai; Mohammed Abdulmageed; Ranga Prasanth Thiruvenkataramani; Tarek Mohamed; Burra V Madhukar; Bruce D Uhal Journal: Cells Date: 2022-04-09 Impact factor: 7.666
Authors: Monica Reis; Gareth R Willis; Angeles Fernandez-Gonzalez; Vincent Yeung; Elizabeth Taglauer; Margaret Magaletta; Teagan Parsons; Alan Derr; Xianlan Liu; Rene Maehr; Stella Kourembanas; S Alex Mitsialis Journal: Front Immunol Date: 2021-04-15 Impact factor: 7.561