Differential chemotactic potential of mouse platelet basic protein for thymocyte subsets.
Mouse platelet basic protein (CXCL7/mPBP) was cloned from thymic stromal cells and further identification indicated that it was expressed in thymic monocytes/macrophages (Mo/Mphis). Recombinant mPBP was chemoattractive for target cells of polymorphonuclear leucocytes, peritoneal Mo/Mphis and splenic lymphocytes with distinct potencies. CXCR2 was identified to be a cognate receptor for mPBP. Mouse thymocyte subsets of CD4-CD8- double-negative (DN), CD4+CD8+ double-positive (DP), CD4+CD8- single-positive (CD4SP) and CD4-CD8+ single-positive (CD8SP) expressed cell surface CXCR2 with different positive percentages and expression levels. mPBP was chemoattractive for thymocyte subsets with the potency order DN>DP> CD8SP>CD4SP, consistent with the levels of CXCR2 expressed on the respective cells. Thus, mPBP in thymus is functionally redundant with chemokine CXCL12/ SDF-1. Moreover, our finding that thymic Mo/Mphis can produce mPBP implies that they may have other functions apart from acting as scavengers in thymus.
Department of Immunology, Peking University Health Science Center, 100083, Beijing, China.
W X
WX
Fu
S Y
SY
Gong
X P
XP
Qian
Y
Y
Li
M L
ML
Zhu
X Y
XY
Dong
Y
Y
Li
W F
WF
Chen
D000818:Animals; D019743:Chemokines, CXC / Q000235:genetics / Q000378:metabolism*; D002633:Chemotaxis / Q000235:genetics / Q000502:physiology*; D018076:DNA, Complementary; D007107:Immune System / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D009000:Monocytes / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D023063:Receptors, Interleukin-8B / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology / Q000378:metabolism*
D019743:Chemokines, CXC; C446301:Cxcl7 protein, mouse; D018076:DNA, Complementary; D012333:RNA, Messenger; D023063:Receptors, Interleukin-8B