{'fraction_non_alphanumeric': 0.041422782530391715, 'fraction_numerical': 0.041422782530391715, 'mean_word_length': 4.527363184079602, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
DECREASED INTERLEUKIN-15 (IL-15) mRNA EXPRESSION FROM ACTIVATED CORD (C) VS. ADULT (A) PERIPHERAL BLOOD (PB) MONONUCLEAR CELLS (MNC): IMPLICATION IN THE IMMATURITY OF NEONATAL IMMUNE FUNCTION AND DECREASED GRAFT-V

The increased susceptibility of neonates to infection may be due to defects in CB cellular immunity and cytokine production (Cairo, Blood 82:2269, 1993; Cairo, et al, Pediatr Res 30:362, 1991; and 31:574, 1992). These alterations may additionally account for the low incidence of GvHD post related and unrelated CBT (Wagner, et al, Blood 82:86a, 1993, Sweetman, et al, Blood 86: 388a, 1995). IL-15 is a novel cytokine that shares many biological properties with IL-12 in regulating many of the biologic functions of NK and T cells. In this study, we investigated the IL-15 gene expression in C and A MNC in order to examine the role of IL-15 in neonatal immunity. MNC were isolated from C and A PB with Ficoll-hypaque and stimulated with LPS (10 μg/ml, 6-48 hrs). Northern blots containing poly A+ RNA were hybridized with an antisense probe made by transcription of a human cDNA (kindly provided by Immunex) to detect IL-15 mRNA expression. Unstimulated C and A MNC did not constitutively express significant levels of IL-15 mRNA. Upon stimulation of cells with LPS (10μg/ml, 12 hrs), IL-15 mRNA expression was significantly induced in both C and A MNC. However, IL-15 mRNA expression in C MNC was only 25 ± 2.0% of that in A MNC. We next determined the relative rates of transcription of the IL-15 gene by nuclear run-on assays. The nuclei from unstimulated and LPS-stimulated cells were isolated and incubated with 32P-UTP. Newly elongated 32P-labeled transcripts were hybridized to slot blots of target DNA (0.5 kb IL-15 cDNA). The basal and stimulated levels of transcription were the same in C and A MNC. These preliminary data suggest that C MNC express less IL-15 mRNA compared to A in response to stimulation and this discrepancy is not secondary to the transcriptional regulation. Reduced expression of IL-15 mRNA from activated CB MNC may contribute to the immaturity of CB cellular immunity and to a decreased incidence of GvHD following both related and unrelated CB stem cell transplantation.