title: [Identification and functional study of Tim-1(+)CD19(+) regulatory B cell in kidney transplantation recipients].
abstract: OBJECTIVE
  To observe the ratio of Tim-1(+)CD19(+) B cell in the peripheral blood of kidney transplantation recipients and elucidate its functions.
  
  
  METHODS
  From December 2009 to June 2010, a total of 35 pairs of kidney transplant recipients were selected and divided into 3 groups: healthy donors as control (n = 35), pre-transplantation (n = 35) and post-transplantation (n = 35). The profiles of Tim-1(+)CD19(+) B cell in kidney transplantation donors and recipients were analyzed and sorted by flow cytometry (FCM). Mixed lymphocyte culture (MLC) was carried out between kidney transplantation donors and recipients. After the additions of Tim-1(+)CD19(+) and Tim-1(-)CD19(+) B cells, there were 3 groups: Tim-1(+), Tim-1(-) and blank. Lymphocyte proliferation and inhibition status were evaluated by propidium iodide uptake and Annexin V binding. And the cytokine levels were detected by FCM.
  
  
  RESULTS
  The absolute values of peripheral CD19(+)B cells were (170 ± 90), (202 ± 99), (155 ± 71) cells/µl in the pre-transplantation, post-transplantation and control groups respectively, post-transplantation group were higher than control group (P = 0.0300). The Tim-1(+)CD19(+) cell ratios were (2.20 ± 0.98)%, (35.46 ± 10.66)% and (1.95 ± 0.95)% in three groups. And the differences were statistically significant (both P < 0.01). Tim-1(+)CD19(+) B and Tim-1(-)CD19(+) B cells were added into MLC respectively. The early apoptotic cells of the Tim-1(+) group were higher than those in the Tim-1(-) group [(45.31 ± 12.37)% vs (10.92 ± 2.14)%, P < 0.05] and significantly higher than the blank group [(1.93 ± 0.26)%, P < 0.01]. Late apoptotic and dead cells of the Tim-1(+) group were higher than those in the Tim-1(-) group [(21.32 ± 5.67)% vs (2.32 ± 0.31)%, P < 0.01] and the blank group [(1.27 ± 0.19)%, P < 0.05]. The interleukin 10 levels in MLC supernatant of the Tim-1(+) group were significantly higher than those in the Tim-1(-) group [(5.32 ± 0.37) pg/ml vs (2.46 ± 0.25) pg/ml, P = 0.0001]. However, the interferon-γ levels were lower than those in the Tim-1(-) group [(1.51 ± 0.22) pg/ml vs (4.69 ± 0.32) pg/ml, P = 0.0015].
  
  
  CONCLUSIONS
  Present in the peripheral blood of kidney transplantation recipients, Tim-1(+)CD19(+) B cell has the capacity of promoting lymphocytic apoptosis. As a new regulatory subset of B cells, it plays important roles in the immune responses of transplantation.
authors.affiliation: No. 309 Hospital of PLA, Beijing, China. shibingyi@medmail.com.cn
authors.forename: Bing-yi
authors.initials: BY
authors.lastname: Shi
authors.forename: Li
authors.initials: L
authors.lastname: Xiao
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.forename: Xiu-yun
authors.initials: XY
authors.lastname: He
authors.forename: Xiao-guang
authors.initials: XG
authors.lastname: Xu
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Huang
authors.forename: Wen-qiang
authors.initials: WQ
authors.lastname: Zhou
authors.forename: Yong
authors.initials: Y
authors.lastname: Han
mesh_terms: D018941:Antigens, CD19 / Q000378:metabolism*; D060151:B-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D016022:Case-Control Studies; D000072596:Hepatitis A Virus Cellular Receptor 1; D006801:Humans; D016030:Kidney Transplantation / Q000276:immunology*; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011991:Receptors, Virus / Q000378:metabolism*
chemical_list: D018941:Antigens, CD19; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D008562:Membrane Glycoproteins; D011991:Receptors, Virus