Neem leaf glycoprotein mediated immunomodulation and epigenetic regulation in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is associated with impaired antitumor immunity and defective activation of protective immune cells. Neem leaf glycoprotein (NLGP), an immunomodulatory component of neem leaf preparation, has demonstrated antitumor activity in several experimental models without apparent toxicity. This study investigated the immunomodulatory and epigenetic effects of NLGP on immune cells involved in tumor protection in AML.

Peripheral immune cells from healthy individuals and AML patients were treated with NLGP. CD33 negative lymphocytes from AML patients were evaluated for lymphocyte proliferation, immune-cell activation, and secretion of the Th1-associated cytokines IFN-γ and TNF-α. Nitric oxide (NO₂⁻) release and reduced glutathione (GSH) content were also measured. The expression of Th1- and tumor-suppression-associated genes was analyzed. Chromatin immunoprecipitation was used to assess enrichment of active histone marks, including H3K4me3 and H3K14Ac, and repressive or regulatory markers, including H3K27me3, HDAC1, p53, Notch1, and c-Myc, at the IFNG and TBX21 loci. Cytotoxic T-lymphocyte (CTL)-mediated killing of AML cells was also examined.

NLGP enhanced lymphocyte proliferation and activated multiple immune-cell populations in normal subjects and AML-derived CD33 negative lymphocytes. It increased IFN-γ, TNF-α, and NO₂⁻ production while reducing GSH content. NLGP upregulated genes associated with Th1 immunity and tumor suppression. At the IFNG and TBX21 loci, it increased enrichment of H3K4me3, H3K14Ac, and p53, while reducing H3K27me3, HDAC1, Notch1, and c-Myc enrichment. NLGP also stimulated CTLs and enhanced their ability to eliminate AML cells.

NLGP promotes tumor-protective immunity in AML through coordinated immune activation and epigenetic regulation, supporting its potential as a novel adjunctive immunotherapeutic strategy.