# Splenocytes and thymocytes migration patterns between lymphoid organs in pregnancy

## TL;DR

The study found that thymocytes and splenocytes migrate similarly in pregnant and non-pregnant mice, but are more retained in pregnant females compared to males.

## Contribution

The study reveals that cell migration patterns in lymphoid organs are not significantly altered by pregnancy, but retention is higher in pregnant females.

## Key findings

- PKH26+ thymocytes are more retained in pregnant females compared to males.
- Thymocyte and splenocyte migration is similar in pregnant and non-pregnant mice.
- Lymphoid organ size in pregnant mice may result from leukocyte retention.

## Abstract

Cell migration is essential for the immune system and is frequently analyzed in adult non-pregnant animals but poorly explored in pregnant animals. However, a physiologic increased size in the spleen and periaortic lymph nodes had been reported in pregnant mice.

Using a mouse model, we transferred PKH26-stained thymocytes and splenocytes from pregnant or non-pregnant animals to receptor mice in the presence or absence of pregnancy. Percentage of PKH-26 cells and Mean Fluorescence Intensity were calculated. Non-parametric ANOVA analysis was performed.

We detected that the percentage of PKH26+ thymocytes in the spleen, lymph nodes, and peripheral blood is higher in females than in males (p = 0.039). Our results showed a similar frequency of thymocytes and splenocytes from pregnant and non-pregnant mice located in receptor lymphoid organs (p > 0.05). Also, the location of marked cells was similar during the perinatal period (p > 0.05).

The mobility of thymocytes and splenocytes in pregnant and non-pregnant mice is similar. Therefore, we suggest that the larger size of the spleen and periaortic lymph nodes noted previously in pregnant mice could result from the retention of leukocytes in the secondary lymphoid organs.

•Transfer cells are more retained in pregnant mice than in male mice.•Despite pregnancy, transfer cells are similar in lymphoid tissue of receptors.•Thymocytes and splenocytes show similar migration with or without pregnancy.

Transfer cells are more retained in pregnant mice than in male mice.

Despite pregnancy, transfer cells are similar in lymphoid tissue of receptors.

Thymocytes and splenocytes show similar migration with or without pregnancy.