TY - JOUR
T1 - rC5a directs the in vitro migration of human memory and naive tonsillar B lymphocytes
T2 - Implications for B cell trafficking in secondary lymphoid tissues
AU - Ottonello, Luciano
AU - Corcione, Anna
AU - Tortolina, Giuseppe
AU - Airoldi, Irma
AU - Albesiano, Emilia
AU - Favre, Anna
AU - D'Agostino, Roberto
AU - Malavasi, Fabio
AU - Pistoia, Vito
AU - Dallegri, Franco
PY - 1999/6/1
Y1 - 1999/6/1
N2 - Human C5a is a potent chemoattractant for granulocytes, monocytes, and dendritic cells. In mice C5a has been shown to be chemotactic for germinal center (GC) B cells. To date, no information is available on the effects of C5a on human B cell locomotion. Here we demonstrate that rC5a increases polarization and migration of human tonsillar B cells. The locomotory response was due to both chemokinetic and chemotactic activities of rC5a. Moreover, memory and, at a lesser extent, naive B cell fractions from purified tonsillar populations displayed rC5a-enhanced migratory properties, whereas GC cells did not. Flow cytometry revealed C5aR (CD88) on approximately 40% memory and 10% naive cells, respectively, whereas GC cells were negative. Immunohistochemistry showed that a few CD88+ cells were of the B cell lineage and localized in tonsillar subepithelial areas, where the majority of memory B cells settle. Pretreatment of memory B cells with the CD88 mAb abolished their migratory responsiveness to rC5a. Finally, the C5 gene was found to be expressed in naive, GC, and memory B lymphocytes at both the mRNA and the protein level. This study delineates a novel role for C5a as a regulator of the trafficking of human memory and naive B lymphocytes and supports the hypothesis that the B cells themselves may serve as source of C5 in secondary lymphoid tissues.
AB - Human C5a is a potent chemoattractant for granulocytes, monocytes, and dendritic cells. In mice C5a has been shown to be chemotactic for germinal center (GC) B cells. To date, no information is available on the effects of C5a on human B cell locomotion. Here we demonstrate that rC5a increases polarization and migration of human tonsillar B cells. The locomotory response was due to both chemokinetic and chemotactic activities of rC5a. Moreover, memory and, at a lesser extent, naive B cell fractions from purified tonsillar populations displayed rC5a-enhanced migratory properties, whereas GC cells did not. Flow cytometry revealed C5aR (CD88) on approximately 40% memory and 10% naive cells, respectively, whereas GC cells were negative. Immunohistochemistry showed that a few CD88+ cells were of the B cell lineage and localized in tonsillar subepithelial areas, where the majority of memory B cells settle. Pretreatment of memory B cells with the CD88 mAb abolished their migratory responsiveness to rC5a. Finally, the C5 gene was found to be expressed in naive, GC, and memory B lymphocytes at both the mRNA and the protein level. This study delineates a novel role for C5a as a regulator of the trafficking of human memory and naive B lymphocytes and supports the hypothesis that the B cells themselves may serve as source of C5 in secondary lymphoid tissues.
UR - http://www.scopus.com/inward/record.url?scp=0033152775&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033152775&partnerID=8YFLogxK
M3 - Article
C2 - 10352266
AN - SCOPUS:0033152775
VL - 162
SP - 6510
EP - 6517
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 11
ER -