de Souza Carolina Menezes Suassuna, Lima Ewerton de Souza, Ordonho Raphael Ferreira, Oliveira Bianca Rafaella Rodrigues Dos Santos, Rodrigues Rebeca Cordeiro, de Moura Marquiliano Farias, Lima Daniel Magalhães, Blagitz Maiara Garcia, Ramos Sanchez Eduardo Milton, de Medeiros Isac Almeida, Souza Fernando Nogueira, Fernandes Artur Cezar de Carvalho
Programa de Pós-Graduação em Ciência Animal, Centro de Ciências Agrárias, Universidade Federal da Paraíba, Areia, Brazil.
Núcleo Aplicado à Produção e Sanidade da Glândula Mamária (NAPROSA), Departamento de Ciências Veterinárias, Centro de Ciências Agrárias, Universidade Federal da Paraíba, Areia, Brazil.
Front Vet Sci. 2022 Jul 22;9:928521. doi: 10.3389/fvets.2022.928521. eCollection 2022.
The present study sought to evaluate the expression of PD-1 and CTLA-4 in blood T lymphocytes during the periparturient period and their relationship with uterine health in dairy cows, as determined by endometrial cytology and serum concentrations of β-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFAs), which are indicators of a negative energy balance. The second objective of this study was to investigate whether the expression of PD-1 and CTLA-4 in T lymphocytes is associated with the serum acute phase-protein haptoglobin concentration during the periparturient period. To address these objectives, 26 clinically healthy dairy cows were used. Peripheral blood was collected 14 days prepartum (T-14), at calving (T0), and 30 days postpartum (T30) to measure the expression of PD-1 and CTLA-4 in blood T lymphocytes by flow cytometry. In addition, we collected blood at T0, 10 days after parturition (T10), and T30 to obtain serum and determine the serum concentrations of NEFA, BHB, and Hp. Endometrial cytology was performed at T10, 20 days after parturition (T20), and T30. In the present study, we observed higher expression of CTLA-4 and PD-1 in T lymphocytes at parturition and in the prepartum period, which could indicate a relationship between these immune checkpoints and immunological tolerance during gestation in dairy cattle. In addition, a negative association between the expression of these immune checkpoints prepartum or at parturition and endometrial cytology at T20 and T30 was observed, indicating the negative implications of these immune response regulators in susceptibility to infections. This finding was further corroborated by the relationship between the serum concentration of haptoglobin and the expression of CTLA-4 and PD-1 by T lymphocytes. However, we did not observe a relationship between the indicators of negative energy balance, evaluated by the serum concentrations of BHB and NEFA, and the expression of the immune checkpoint markers studied. Thus, our findings represent an initial step that paves the way for the development of new therapeutic alternatives directed by the host with the objective of increasing the resistance of dairy cattle to infections in this critical period of life.
本研究旨在评估围产期奶牛血液T淋巴细胞中PD-1和CTLA-4的表达，以及它们与子宫健康的关系，子宫健康通过子宫内膜细胞学检查以及作为负能量平衡指标的β-羟基丁酸（BHB）和非酯化脂肪酸（NEFA）的血清浓度来确定。本研究的第二个目的是调查围产期T淋巴细胞中PD-1和CTLA-4的表达是否与血清急性期蛋白触珠蛋白浓度相关。为实现这些目标，使用了26头临床健康的奶牛。在产前14天（T-14）、产犊时（T0）和产后30天（T30）采集外周血，通过流式细胞术测量血液T淋巴细胞中PD-1和CTLA-4的表达。此外，我们在T0、产后10天（T10）和T30采集血液以获取血清，并测定血清中NEFA、BHB和Hp的浓度。在T10、产后20天（T20）和T30进行子宫内膜细胞学检查。在本研究中，我们观察到产犊时和产前T淋巴细胞中CTLA-4和PD-1的表达较高，这可能表明这些免疫检查点与奶牛妊娠期间的免疫耐受之间存在关联。此外，观察到产前或产犊时这些免疫检查点的表达与T20和T30时的子宫内膜细胞学检查之间存在负相关，表明这些免疫反应调节因子对感染易感性具有负面影响。触珠蛋白血清浓度与T淋巴细胞中CTLA-4和PD-1表达之间的关系进一步证实了这一发现。然而，我们未观察到通过血清BHB和NEFA浓度评估的负能量平衡指标与所研究的免疫检查点标志物表达之间存在关联。因此，我们的研究结果是迈出的第一步，为开发以宿主为导向的新治疗方案铺平了道路，目的是提高奶牛在这一生命关键时期对感染的抵抗力。
