Potential role of heat-shock protein 70 and interleukin-15 in the pathogenesis of threatened spontaneous abortions

The role of HSP70 and both its constitutive (Hsc) and inducible (Hsp) forms in the pathogenesis of threatened spontaneous abortions was investigated. Immunohistology and/or immunofluorescence was used to analyze paraffin- embedded tissue sections, and reverse transcriptase-quantitative polymerase chain reaction and flow cytometry were used for analyses of decidual mononuclear cells (DMCs) and confocal microscopy for the detection of perforin, granulysin, and lysosome-associated membrane protein-1 (LAMP-1) in decidual lymphocytes (DLs). The percentage of single Hsp70+, Hsc70+, and IL-15+ cells and mRNA levels of HSP70, CD91, and TLR4 were lower in the decidua basalis in cases of threatened miscarriages compared to that in cases of normal pregnancy. In a suspension of normal DMCs, IL-15 significantly decreased the HSP70 members and TLR4 in dendritic cells, T cells, and NK cells while increasing CD91 in NK cells alone. Downregulation of Hsc70, Hsp70, and IL-15 expression at gene and/or protein levels might support the retention of fertilization products in cases of missed abortion and blighted ovum