The influence of the thymus on multinucleate giant cell formation.

Glass coverslips were implanted in nude athymic mice and normal controls and the development of multinucleated giant cells on the implant investigated. Although the percentage of the surface area of the coverslip covered by cellular exudate was reduced in older implants (12 days or more) in athymic mice, the proportion of nuclei within syncytia was the same as in normal controls. It is concluded that the multinucleated giant cells in this type of inflammatory lesion are not thymus derived nor is the efficiency of fusion between their precursor mononuclear phagocytes thymus dependent. The number of exuded mononuclear phagocytes on the other hand may be influenced directly or indirectly by the thymus.