Complement regulation in ovine lymph nodes during early pregnancy.

Leying Zhang,Xu Han,Ling Yang,Pengfei Feng,Lidong Cao

doi:10.3892/etm.2021.11089

Leying Zhang, Xu Han + Show 3 more

Open Access

https://doi.org/10.3892/etm.2021.11089

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Abstract

A fetus changes immune responses in the uterus and the maternal immune system, and lymph nodes are associated with regulating maternal adaptive immunity. Complement activation is associated with abnormal pregnancy in mice and humans. The aim of the present study was to explore the expression levels of complement components in maternal lymph nodes during early pregnancy in sheep. Maternal inguinal lymph nodes were sampled on day 16 of the estrous cycle, and days 13, 16 and 25 of gestation in ewes. Reverse transcription-quantitative PCR, western blotting and immunohistochemical analyses were used to detect the expression levels of complement components C1q, C1r, C1s, C2, C3, C4a, C5b and C9 in the lymph nodes. The results revealed that the protein and mRNA levels of C1q, C1s and C5b were enhanced during early pregnancy, and that C1r and C4a were upregulated at day 25 of pregnancy. The mRNA and protein levels of C2 and C9 peaked at day 16 of pregnancy, but C3 was decreased at day 25 of pregnancy. C3 protein was located in the subcapsular sinuses and lymph sinuses of the maternal lymph node. In summary, the present study detected changes in the expression levels of complement components in maternal lymph nodes, which may be associated with maternal immune regulation during early pregnancy in sheep.

Highlights

During pregnancy, the fetus evades and provokes immune responses in the uterus, maternal peripheral tissues and immune system, which are essential for the success of pregnancy [1]
It has been reported that early pregnancy induces increases in the expression levels of progesterone (P4) receptor, P4‐induced blocking factor [5], cyclooxygenase 1 (COX‐1), COX‐2, prostaglandin E synthase, Aldo‐keto reductase family 1 member B1 [6], interleukin (IL)‐5 and IL‐10, but TNF‐β and IL‐2 are decreased in the maternal lymph nodes during early pregnancy in sheep [7]
Western blotting indicated that there was almost no expression of C1s protein on day 16 of the estrous cycle, but pregnancy induced the expression of C1q, C1s and C5b proteins in lymph nodes compared with day 16 of the estrous cycle (P

Summary

Introduction

The fetus evades and provokes immune responses in the uterus, maternal peripheral tissues and immune system, which are essential for the success of pregnancy [1]. It has been reported that early pregnancy induces increases in the expression levels of progesterone (P4) receptor, P4‐induced blocking factor [5], cyclooxygenase 1 (COX‐1), COX‐2, prostaglandin E synthase, Aldo‐keto reductase family 1 member B1 [6], interleukin (IL)‐5 and IL‐10, but TNF‐β and IL‐2 are decreased in the maternal lymph nodes during early pregnancy in sheep [7]. There are increases in the protein expression levels of melatonin receptor 1, cluster of differentiation 4, signal transducer and activator of transcription 1, 2',5'‐oligoadenylate synthetase, myxovirus resistance protein 1, C‐X‐C motif chemokine 10 and gonadotropin releasing hormone and its receptor in the maternal lymph nodes during early pregnancy in sheep [8,9,10]. Pregnancy induces changes in maternal lymph nodes, which may be associated with maternal immune tolerance to paternal alloantigens

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