Bone marrow (BM) niches are special microenvironments that work in harmony with each other for the regulation and maintenance of hematopoiesis. Niche investigations have thus far been limited to various model organisms and animal studies; therefore, little is known about different niches in healthy humans. In this study, a special harvesting method for the collection of BM from two different anatomical regions in the iliac crest of humans was used to investigate the presence of different niches in BM. Additionally, metabolomic and transcriptomic profiles were compiled using comparative ‘omics’ technologies, and the main cellular pathways and corresponding transcripts and metabolites were identified. As a result, we found that the energy metabolism between the regions was different. This study provides basic broad data for regenerative medicine in terms of the design of the appropriate microenvironment for in vitro hematopoietic niche modeling, and identifies the normal reference values that can be compared in hematological disease.

This study aimed to investigate the immunogenicity of the hepatitis B virus (HBV) vaccine by applying a normal and high-dose hepatitis B virus vaccination program in the mice modeling of non-alcoholic fatty liver disease (NAFLD). NAFLD was induced in mouse livers via diet. At the 10-week mark, both groups were divided into 3 subgroups. While the standard dose vaccination program was applied on days 0, 7, and 21, two high-dose programs were applied: one was applied on days 0 and 7, and the other was applied on days 0, 7, and 21. All mice were euthanized. Blood samples from anti-HB titers; T follicular helper, T follicular regulatory, CD27⁺, and CD38⁺ cells; and the liver, spleen, and thymus were taken for histopathologic evaluation. NAFLD subgroups receiving high doses showed higher hepatocyte ballooning scores than normal-dose subgroup. There were differences in CD27⁺ and CD27⁺CD38⁺ cells in animals fed on different diets, without any differences or interactions in terms of vaccine protocols. In the NAFLD group, a negative correlation was observed between anti-HB titers and T helper and CD27⁺ cells, while a positive correlation was observed with CD38⁺ cells. NAFLD induced changes in immune parameters in mice, but there was no difference in vaccine efficacy among the applied vaccine protocols. Based on this study’s results, high-dose vaccination protocols are not recommended in cases of NAFLD, as they do not enhance efficacy and may lead to increased liver damage.