Polysaccharide of Atractylodes Macrocephala Koidz alleviates Cyclophosphamide induced lymphocytes injury in goslings

The immune system of gosling is not fully developed, making them susceptible to pathogens, stress, and adverse environmental factors, which can lead to compromised immune function. Cyclophosphamide (CTX) is a commonly used immunosuppressive agent, causing DNA strand breaks and cell death, thereby inducing lymphocytes injury and reducing immune function. This study aimed to evaluate whether polysaccharide from Atractylodes macrocephala Koidz (PAMK) can alleviate CTX-induced lymphocyte injury in goslings and to elucidate its underlying mechanisms. One-day-old Magang goslings were divided into control, CTX, PAMK, and PAMK+CTX groups. Thymus morphology, lymphocyte apoptosis, cytokine/chemokine expression, and transcriptome profiles were assessed through histology, TUNEL staining, flow cytometry, RT-qPCR, and Western blot. CCL5 overexpression experiments were conducted in vitro to further validate the mechanistic pathway. PAMK significantly alleviated CTX-induced thymic damage, preserved thymocyte structure, and reduced lymphocyte apoptosis. Transcriptome and KEGG analyses revealed the chemokine signaling pathway as a key target. PAMK downregulated CCL5/CCR5 expression and restored downstream Src, PI3K, Raf, and ERK1/2 activity. In CCL5-overexpressing lymphocytes, PAMK reversed pro-apoptotic effects by modulating the same pathway, confirming its regulatory role. PAMK mitigates CTX-induced thymic injury in goslings by modulating the CCL5/CCR5-mediated chemokine signaling pathway, offering potential for developing immunomodulatory strategies in poultry.