Differences between human male and female neutrophils with respect to which RNAs are present in polysomes.

Background: Human males and females show differences in the incidence of neutrophil-associated diseases such as systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis, and differences in neutrophil physiological responses such as responses to infection, tissue damage, and chemotactic factors. However, little is known about the basis of sex-based differences in human neutrophils. Methods: Starting with human neutrophils from healthy donors, we used RNA-seq to examine total RNA profiles, RNAs not associated with ribosomes and thus not being translated, RNAs in monosomes, and RNAs in polysomes and thus heavily translated. Results: There were sex-based differences in the levels of RNAs across free RNA, monosome, and polysome fractions. Male neutrophils had increased levels of mRNAs encoding mitochondrial proteins in the free RNA fractions, indicating low levels of translation. The polysomes of male neutrophils were enriched for mRNAs encoding cytoskeletal organization, cell motility, and cell activation. The polysomes of female neutrophils were enriched for mRNAs associated the regulation of metabolic processes, cytokine responses, and mitochondrial proteins. Conclusions: These data indicate that male and female neutrophils have different expression patterns and different translation efficiency of some mRNAs. This may contribute to the observed sex-based differences in neutrophil behavior and neutrophil-associated disease incidence and severity.