A reduction in the number of peripheral CD28+CD8+T cells in the acute phase of influenza.
Influenza patients show a high incidence of T lymphocytopenia in the acute phase of the illness. Since CD8+ T cells play an important role in influenza virus infection, we investigated which subset of CD8+ T cells was involved in this lymphocytopenia. CD8+ T cells from eight patients with influenza A were studied for lymphocyte count, surface marker, and intracellular IFN-gamma production in the acute (days 1-3) and recovery phases (days 9-12). Total and T lymphocyte counts in the acute phase were approximately three times less than in the recovery phase; however, the CD4/8 ratio was the same in both phases. The cell count reduction in the acute phase was attributed predominantly to the CD28+ CD8+ subset, compared with the CD28- CD8+ subset. The memory/activation marker CD45RO on the CD8+ T cells was assessed. The CD28+ CD45RO- subset, a naive phenotype, was reduced significantly in number in the acute phase compared with the recovery phase. The CD28+ CD45RO+ subset, a memory phenotype, was also reduced in the acute phase, but the reduction was not statistically significant. Intracellular IFN-gamma in the CD8+ subset after mitogenic stimulation was measured by flow cytometry; the percentage of CD28+ IFN-gamma-/CD8+ subset in the acute phase was significantly less than in the recovery phase. These results indicated that the predominant reduction of peripheral CD8+ T cells in the acute phase of influenza was from naive-type lymphocytes, suggesting that these quantitative and qualitative changes of CD8+ T cells in influenza are important for understanding the immunological pathogenesis.
Nabeshima
S
S
Department of General Medicine, Kyushu University Hospital, Higashiku, Fukuoka, Japan. snabe@genmedpr.med.kyushu-u.ac.jp
Murata
M
M
Kikuchi
K
K
Ikematsu
H
H
Kashiwagi
S
S
Hayashi
J
J
D000208:Acute Disease; D000328:Adult; D018106:CD28 Antigens / Q000276:immunology; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007111:Immunity, Cellular; D007251:Influenza, Human / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000276:immunology; D008297:Male
D018106:CD28 Antigens; D017493:Leukocyte Common Antigens