CD markers of camel (Camelusdromedarius) intestine naturally infected with Mycobacteriumavium subsp. paratuberculosis: Distinct expression of Madcam-1 and CX3CR1

Abstract

Mycobacteriumavium subsp. paratuberculosis (MAP) infection in camel requires extensive research, particularly the immune responses in the intestine. This study aimed to investigate the nature of the cellular populations that are driven by the immunopathological responses in the camel intestine infected with MAP at different ages. Immunohistochemical staining was carried out on tissues obtained from naturally infected young (5–10 years old) and older (12–15 years old) camels. The staining of the tissues, ileum, mesenteric lymph node, jejunum, and supramammary lymph nodes, with anti-CD3+, CD4+, CD8+, CD25+, CD11c+, CD14+, WC1+, CX3CR1, and Madcam-1 monoclonal antibodies revealed high expression of the molecules CD8+, CD25+, CD11c+, CD14+, WC1+, CX3CR1, and Madcam-1 in the ileum and mesenteric lymph node of the infected older camels. The results indicated the recruitment of CD8+lymphocytes, CD14+ macrophages, and CD11c+ dendritic cells to the ileal lamina propria. High expression of CX3CR1 could indicate a vital role for this special macrophage phenotype in the ileal lamina propria in maintaining intestinal homeostasis. Madcam-1 expression could have an essential role in defining the nature of the recruited cells to the site of the infection. Expression of CX3CR1 and Madcam-1 is a novel finding that merits further attention and pursuit to reveal their significance in the immune responses to MAP in the camel’s intestine.