Correlation between Cytomegalovirus and Toxoplasma gondii Serology and Lymphocyte Phenotypes in Peripheral Blood and Cord Blood

Abstract

Increased numbers of peripheral blood HNK1+ lymphocytes have been reported in transplant recipients, hemophilia patients treated with clotting factor concentrates, and HIV carriers. Our previous work has revealed a significant effect of cytomegalovirus (CMV) carrier status on HNK1+ lymphocytes. Since other antigenic stimuli may be also involved, we compared the effects of Toxoplasma gondii and CMV carrier status on lymphocyte subsets as defined by the CD3 and HNK1 markers in 288 healthy individuals. In contrast to CMV, T gondii carrier status had no significant effects on the CD3+, HNK1+ and CD3-, HNK1+ lymphocyte subsets. That result may be explained by the different relationships between these 2 microorganisms and their hosts. We also studied the effect of maternal CMV carrier status on the HNK1 expression by their offsprings' cord blood lymphocytes. None of the 100 newborns studied had serological evidence of congenital CMV infection. There were only few HNK1+ lymphocytes in the cord bloods, of which the majority was CD3-, and their proportions were not significantly influenced by maternal CMV carrier status. Since there has been probably no direct contact between maternal CMV and the newborns' immune systems, we suggest that the effect of CMV on the HNK1+ lymphocytes of its carriers, results from a direct interaction between virus or virus-infected cells and the immune system.