The expression and function of human CD300 receptors on blood circulating mononuclear cells are distinct in neonates and adults.
Neonates are more susceptible to infections than adults. This susceptibility is thought to reflect neonates' qualitative and quantitative defects in the adaptive and innate immune responses. Differential expression of cell surface receptors may result in altered thresholds of neonatal immune cell activation. We determined whether the expression and function of the lipid-binding CD300 family of receptors are different on neonatal immune cells compared to adult immune cells. A multiparametric flow cytometry analysis was performed to determine the expression of CD300 receptors on adult peripheral blood mononuclear cells and neonatal cord blood mononuclear cells. The expression of the CD300a inhibitory receptor was significantly reduced on cells from the newborn adaptive immune system, and neonatal antigen presenting cells exhibited a different CD300 receptors expression pattern. We also found differential LPS-mediated regulation of CD300 receptors expression on adult monocytes compared to cord blood monocytes, and that CD300c and CD300e-mediated activation was quantitatively different in neonatal monocytes. This is the first complete study examining the expression of CD300 receptors on human neonatal immune cells compared with adult immune cells. Significant differences in the expression and function of CD300 receptors may help to explain the peculiarities and distinctness of the neonatal immune responses.
Immunopathology Group, BioCruces Health Research Institute, Barakaldo, Spain.
Olatz
O
Zenarruzabeitia
Immunopathology Group, BioCruces Health Research Institute, Barakaldo, Spain.
Joana
J
Vitallé
Pediatric Oncology Group, BioCruces Health Research Institute, Barakaldo, Spain.
Susana
S
García-Obregón
Pediatric Oncology Group, BioCruces Health Research Institute, Barakaldo, Spain.|Pediatrics Service, Cruces University Hospital, Barakaldo, Spain.|Department of Pediatrics, Faculty of Medicine and Dentistry. University of the Basque Country, Leioa, Spain.
Itziar
I
Astigarraga
Cell Therapy and Stem Cell Group, Basque Center for Transfusion and Human Tissues, Galdakao, Spain.
Cristina
C
Eguizabal
Cell Therapy and Stem Cell Group, Basque Center for Transfusion and Human Tissues, Galdakao, Spain.
Silvia
S
Santos
Division of Biotechnology Review and Research-I, Office of Biotechnology Products Review and Research, CDER, Food and Drug Administration, USA.
Venkateswara R
VR
Simhadri
Immunopathology Group, BioCruces Health Research Institute, Barakaldo, Spain.|Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
Francisco
F
Borrego
D000328:Adult; D006801:Humans; D016130:Immunophenotyping; D007231:Infant, Newborn; D009000:Monocytes / Q000276:immunology / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism*
D011971:Receptors, Immunologic