Decreased expression of 20-kD homologous restriction factor (HRF20, CD59) on T lymphocytes in Epstein-Barr virus (EBV)-induced infectious mononucleosis.
HRF20 (CD59) is one of the membrane-associated complement regulatory proteins. The characteristic function of CD59 is to prevent membrane attack complex (MAC) formation on the cell surface and to protect the cell from complement-mediated cell lysis. We examined the expression of CD59 antigen on T cell subpopulations in patients with acute infectious mononucleosis (IM) and analysed the relationship between the amount of CD59 expression and activation-induced cell death of mature T cells with apoptosis. Decreased expression of CD59 on CD8+ T cells, especially on CD45RO+ and HLA-DR+ activated T cells, was marked in acute IM patients. In contrast, activated CD4+ T cells from IM patients expressed as much CD59 antigen as CD4+ T cells from healthy volunteers. After incubation-induced cell death, viable CD8+ T cells showed normal amounts of CD59 antigen on their surface. CD59dim CD8+ T cells were more susceptible to apoptosis than CD59bright CD8+ T cells. These findings suggest that decreased expression of CD59 on CD8+ T cells may discriminate the susceptibility of activated CD8+ T cells to activation-induced cell death in IM.
Kawano
M
M
Second Department of Internal Medicine, School of Medicine, Kanazawa University, Japan.
Tsunoda
S
S
Koni
I
I
Mabuchi
H
H
Muramoto
H
H
Yachie
A
A
Seki
H
H
D000208:Acute Disease; D000328:Adult; D017209:Apoptosis / Q000276:immunology; D018957:CD59 Antigens / Q000096:biosynthesis*; D016827:CD8 Antigens / Q000032:analysis; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007244:Infectious Mononucleosis / Q000276:immunology* / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000032:analysis; D016176:T-Lymphocyte Subsets / Q000145:classification / Q000276:immunology / Q000378:metabolism*
D018957:CD59 Antigens; D016827:CD8 Antigens; D017493:Leukocyte Common Antigens