Both CD45RA+ and CD45RO+ human CD4+ T cells drive direct xenogeneic T-cell responses against porcine aortic endothelial cells.
BACKGROUND
Xenogeneic cellular immune responses are mediated by either direct or indirect pathways depending on the participation of donor or host antigen presenting cells, respectively. The contribution of direct response of human T cells, especially memory T cells, to porcine antigen presenting cells is currently unknown. Here, we sought to determine whether human peripheral blood memory/activated phenotype T cells are directly responsive to porcine endothelial cells.


METHODS
Porcine aortic endothelial cells (PAECs) were prepared from Yorkshire or miniature pigs. Highly purified human T cells, including naïve and memory/activated phenotype cells, were incubated with PAECs with or without the addition of exogenous cytokines. T-cell proliferation and T-cell receptor (TCR) Vbeta usage in response to PAECs were analyzed.


RESULTS
Both CD8(+) and CD4(+) T cells responded directly to PAECs and exhibited exclusive responsiveness to SLA class I and class II molecules, respectively. Naïve and memory/activated phenotype CD4(+) T cells responded against PAECs, whereas only naïve phenotype CD8(+) T cells contributed to such a response. In addition, both populations of xenogeneic human CD4(+) T cells exhibited similar and diverse V beta usage.


CONCLUSIONS
Due to the considerable contribution of human CD45RO(+)CD4(+) T cells to the xenoreactivity against PAECs, effective control of xenogeneic memory/activated T-cell responses would significantly affect long-term survival of transplanted grafts.
Kim
Chi Hwa
CH
Laboratory of Immunology, Department of Anatomy, College of Medicine, Seoul National University, Seoul, Korea.
Oh
Keunhee
K
Kim
Dong-Eun
DE
Lee
Seul Bee
SB
Yang
Ji Hye
JH
Lee
Gene
G
Cho
Jaejin
J
Lee
Dong-Sup
DS
D000818:Animals; D015478:Antigens, Heterophile / Q000276:immunology*; D001011:Aorta / Q000166:cytology*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D042783:Endothelial Cells / Q000166:cytology / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D017493:Leukocyte Common Antigens / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D013552:Swine; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*
D015478:Antigens, Heterophile; D000949:Histocompatibility Antigens Class II; D016693:Receptors, Antigen, T-Cell, alpha-beta; D017493:Leukocyte Common Antigens