ABSTRACT Objective To determine the role of the AKT pathway in the regulating of natural Killer-induced apoptosis of acute myeloid leukemia cells and to characterize the associated molecular mechanisms. Methods BALB/c nude mice were injected with HL60 cells to induce a xenogenic model of subcutaneous leukemic tumors. Mice were treated with perifosine, and their spleens were analyzed using biometry, histopathology, and immunohistochemistry. Gene expression analysis in leukemia cells was performed by real-time PCR. Protein analysis of leukemia and natural Killer cells was performed by flow cytometry. AKT inhibition in HL60 cells, followed by co-culture with natural Killer cells was performed to assess cytotoxicity. Apoptosis rate was quantified using flow cytometry. Results Perifosine treatment caused a reduction in leukemic infiltration in the spleens of BALB/c nude mice. In vitro , AKT inhibition reduced HL60 resistance to natural Killer-induced apoptosis. AKT inhibition suppressed the immune checkpoint proteins PD-L1, galectin-9, and CD122 in HL60 cells, but did not change the expression of their co-receptors PD1, Tim3, and CD96 on the natural Killer cell surface. In addition, the death receptors DR4, TNFR1, and FAS were overexpressed by AKT inhibition, thus increasing the susceptibility of HL60 cells to the extrinsic pathway of apoptosis. Conclusion The AKT pathway is involved in resistance to natural Killer-induced apoptosis in HL60 cells by regulating the expression of immune suppressor receptors. These findings highlight the importance of AKT in contributing to immune evasion mechanisms in acute myeloid leukemia and suggests the potential of AKT inhibition as an adjunct to immunotherapy.

RESUMO Objetivo Analisar e comparar a expressão de receptores do tipo Toll por células T reguladoras presentes no líquido peritoneal de pacientes com endometriose. Métodos Células T reguladoras foram isoladas do líquido peritoneal de mulheres com e sem endometriose, coletadas durante a cirurgia, e o RNAm foi extraído para análise da expressão de receptores do tipo Toll por reação em cadeia da polimerase com transcriptase reversa. Resultados Pacientes com endometriose apresentaram células T reguladoras expressando maior número e variedade de Toll por células quando comparadas com T reguladoras de pacientes do Grupo Controle. Receptores do tipo Toll-1 e receptores do tipo Toll-2 foram expressos em ambos os grupos. Todos os outros tipos de receptores Toll foram encontrados expressos apenas em células T reguladoras do grupo com endometriose. Conclusão Pacientes com endometriose apresentaram células T reguladoras peritoneais expressando vários tipos de receptores tipo Toll.

ABSTRACT Objective To analyze and compare the expression of Toll-like receptors by regulatory T cells present in the peritoneal fluid of patients with and without endometriosis. Methods Regulatory T cells were isolated from peritoneal fluid of women with and without endometriosis, collected during surgery, and mRNA was extracted for analysis of Toll-like receptors expression by reverse-transcriptase polymerase chain reaction. Results Patients with endometriosis presented regulatory T cells expressing a larger number and variety of Toll-like receptors when compared to regulatory T cells from patients in the Control Group. Toll-like receptor-1 and Toll-like receptor-2 in regulatory T cells were expressed in both groups. All other expressed Toll-like receptors types were only found in regulatory T cells from the Endometriosis Group. Conclusion Patients with endometriosis had peritoneal regulatory T cells expressing various Toll-like receptors types.