小牛胸腺多肽通过调节肠道菌群介导的免疫功能抑制结直肠肿瘤生长

Calf thymus polypeptide (CTP), with a molecular mass of <10 kDa, is prepared from the thymus of less than 30-day-old newborn cattle. In the present study, the inhibitory function of CTP in colorectal cancer (CRC) was investigated in B6/JGpt- Apc em1Cin(MinC) /Gpt ( Apc Min/+ ) mice. CTP hampered tumor development and enhanced the ratio of CD3e - NK1. 1 + cells by 113. 0% and CD3e + CD28 + cells by 84.

7% in the peripheral blood of Apc Min/+ mice. CTP improved the richness, diversity, and evenness of the intestinal microbiota of Apc Min/+ mice, particularly by regulating the abundance of immune-related microorganisms. CTP effectively regulated the expression of immune-related cytokines, such as interleukin (IL)-2 (15. 19% increment), IL-12 (17. 47% increment), and transforming growth factor (TGF)-β (11. 19% reduction).

Additionally, it enhanced the levels of CD4 and CD8, as well as the ratio of helper T lymphocytes (Th)1/Th2 in the spleen and tumors of Apc Min/+ mice. In CTP-treated mice, reduced levels of programmed death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), cytotoxic T lymphocyte-associated antigen 4 (CTLA4), activated nuclear factor of activated T cells 1 (NFAT1), and nuclear factor κB (NF-κB) p65 signaling were noted.

Collectively, the anti-CRC effect of CTP is related to the modulation of intestinal microbiota-mediated immune function, which provides a reference for CTP as a therapeutic drug or a combination drug used in CRC treatment in a clinical setting.