Affiliation: | (1) Central Laboratory of the Netherlands Red Cross Blood Transfusion Service and Laboratory of Experimental and Clinical Immunology, University of Amsterdam, 1006 AD Amsterdam, The Netherlands;(2) Institute for Experimental Gerontology, TNO, Rijswijk, The Netherlands;(3) Present address: Immunology Branch, National Cancer Institutes, NIH, 20205 Bethesda, Maryland |