Faculty Collaboration Database

The female reproductive tract contains multiple innate sialic acid-binding immunoglobulin-like lectins (Siglecs) that facilitate sperm survival. J Biol Chem 2019 Aug 02;294(31):11910-11919

Date

06/16/2019

Pubmed ID

31201275

Pubmed Central ID

PMC6682739

DOI

10.1074/jbc.RA119.008729

Scopus ID

2-s2.0-85070756446 (requires institutional sign-in at Scopus site)   33 Citations

Abstract

A sperm that fertilizes an egg has successfully survived multiple checkpoints within the female reproductive tract, termed pre-fertilization events. The leukocytic response is a pre-fertilization event in which sperm trigger an immune response that promotes homing of circulating leukocytes to the uterine lumen to destroy most sperm. Various glycoconjugates decorate the sperm surface, including sialic acids, which are abundant at the sperm surface where they cap most glycan chains and regulate sperm migration through cervical mucus, formation of the sperm oviductal reservoir, and sperm capacitation. However, the role of sperm-associated sialic acids in the leukocytic reaction remains unknown. The cognate endogenous binding partners of sialic acids, sialic acid-binding immunoglobulin-like lectins (Siglecs) play a pivotal role in regulating many immune responses. Here we investigated whether sperm-associated sialic acids inhibit activation of neutrophils, one of the major immune cells involved in the leukocytic reaction. We used in vitro interactions between sperm and neutrophils as well as binding assays between sperm and recombinant Siglec-Fc chimeric proteins to measure interactions. Moreover, we examined whether Siglecs are expressed on human and mouse endometria, which have a role in initiating the leukocytic reaction. Surprisingly less sialylated, capacitated, sperm did not increase neutrophil activation in vitro However, we observed expression of several Siglecs on the endometrium and that these receptors interact with sialylated sperm. Our results indicate that sperm sialic acids may interact with endometrial Siglecs and that these interactions facilitate sperm survival in the face of female immunity.

Author List

Tecle E, Reynoso HS, Wang R, Gagneux P

Author

Eillen Tecle PhD Assistant Professor in the Microbiology and Immunology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Endometrium
Female
Immunoglobulin Fc Fragments
Male
Mice
Mice, Inbred C57BL
Neuraminidase
Neutrophil Activation
Neutrophils
Recombinant Fusion Proteins
Sialic Acid Binding Immunoglobulin-like Lectins
Sialic Acids
Spermatozoa