Binding and Internalization of Herpes Simplex Virus-Antibody Complexes by Polymorphonuclear Leukocytes

We studied the interactions between rabbit polymorphonuclear leukocytes (PMN) and the RE strain of herpes simplex virus type 1 (HSV-1) to determine better the role of inflammatory cells in herpetic stromal keratitis. PMN were found to be nonpermissive for HSV replication and were unable to bind virus in the absence of antibody. However, PMN did bind and internalize HSV-antibody complexes in vitro as was demonstrated visually by electron microscopic studies and quantitatively by measurement of activity associated with radiolabeled HSV-antibody complexes. Virus used for immune complex formation was labeled with either 125 Iodine or 35 S-methionine. In some experiments, anti-HSV IgG used for immune complex formation was labeled with 125 Iodine before incubation with virus. Use of all three radiolabeling approaches resulted in the same general pattern of binding, indicating a requirement for both antibody and virus for interaction with PMN. The activity associated with PMN was increased by preincubation with complement. The results suggest an active role for PMN in controlling HSV infection through their ability to bind and ingest virus-antibody complexes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38230/1/1890200207_ftp.pd

Comparison of cytotoxic properties of neonatal and adult neutrophils and monocytes and enhancement by cytokines.

We studied cytotoxic capabilities of newborn polymorphonuclear leukocytes (PMNs) and monocytes and their enhancement by cytokines and antibodies. Umbilical cord PMNs were assessed for their ability to kill various target cells spontaneously, after activation with phorbol myristate acetate, in the presence of antiserum (antibody-dependent cellular cytotoxicity), and in the presence of dually specific antibody (heteroantibody-mediated cytotoxicity). Target cells included the K562 cell line (natural killer cell target), chicken erythrocytes (CRBCs), and herpes simplex virus-infected CEM cell lines. Newborn PMNs were equivalent to adult PMNs in their cytotoxic capacity in several cytotoxicity assays. Neither adult nor newborn PMNs lyse tumor cell targets (i.e., K562 cells) spontaneously, but both lyse K562 cells following activation with phorbol myristate acetate. Both adult and newborn PMNs lyse CRBCs and herpes simplex virus-infected CEM cells in antibody-dependent cellular cytotoxicity assays, and this lysis could be enhanced by the cytokines granulocyte-macrophage colony-stimulating factor and gamma interferon. PMN heteroantibody-mediated cytotoxicity, resulting from the use of an antibody with dual specificity to CRBCs and immunoglobulin G FcRII, was greater in newborn PMNs than in adult PMNs; however, monocyte heteroantibody-mediated cytotoxicity, resulting from the use of an antibody to CRBCs and monocyte immunoglobulin G FcRI, was lower in newborn monocytes than in adult monocytes. The percentage, but not the density, of PMNs expressing FcRII was significantly reduced in newborn PMNs compared with that in adult PMNs, while the percentages and densities of FcRI expression were equivalent in newborn and adult monocytes. We conclude that the cytotoxic capability in term newborn PMNs is equivalent to that in adult PMNs, that the activity of newborn PMNs can be enhanced by antibody and/or cytokines, and that PMNs can contribute to the newborn's ability to kill virus-infected cells