Characterization of natural killer and antibody-dependent cellular cytotoxicity of preterm infants against human immunodeficiency virus-infected cells

Abstract

The odds risk of vertical Iransmission of human immunodeficiency virus (HIV) to preterm infants is almost four times that of lernt infants and may relate to maternal and neonatal factors. We characterized the competence of early nonspecific cellular immunity, namely natural killer cytotoxicity (NKC) and antibody-dependent cellular cytotoxiciry (ADCC), of peripheral blood mononuclear cells (PBMC) from preterm neonates (Group II: 30-35 weeks gestation, n=13; Group III: < 30 weeks gestation, n=7) vs. term neonates (Group I: > 36 weeks gestation, n=28)end adults against a T cell line infected with the human T-cell lymphotrophic virus-HI using a Slchromium release assay. PBMC from term neonates exhibited levels of NKC activity equal to adults against HI V-infccicd targets, yet the NKC capacity of preterm neonatal PBMC was significantly diminished (p <03). Overnight stimulation of a subset of samples with intcrlcukin-12 (IL-1Ü) augmented the NKC activity of both infant groups and adults (p <001), while the ADCC activity remained unchanged These findings demonstrate that term neonales are deficient in ADCC against HIV-infected targets while preterm infants are deficient in both NKC and ADCC which may relate, in pan, to the increased risk of transmission of HIV with preterm delivery. In addition, IL12 has the potential to augment both term and preterm neonatal antiviral defense.