Neem leaf glycoprotein reverses tumor-induced and age-associated thymic involution to maintain peripheral CD8+ T cell pool.

Aim: As tumor causes atrophy in the thymus to target effector-T cells, this study is aimed to decipher the efficacy of neem leaf glycoprotein (NLGP) in tumor- and age-associated thymic atrophy. Materials & methods: Different thymus parameters were studied using flow cytometry, reverse transcriptase PCR and immunocyto-/histochemistry in murine melanoma and sarcoma models. Results: Longitudinal NLGP therapy in tumor hosts show tumor-reduction along with significant normalization of thymic alterations. NLGP downregulates intrathymic IL-10, which eventually promotes Notch1 to rescue blockade in CD25+CD44+c-Kit+DN2 to CD25+CD44-c-Kit-DN3 transition in T cell maturation and suppress Ikaros/IRF8/Pu.1 to prevent DN2-T to DC differentiation in tumor hosts. The CD5intTCRαβhigh DP3 population was also increased to endorse CD8+ T cell generation. Conclusion: NLGP rescues tumor-induced altered thymic events to generate more effector T cells to restrain tumor.