Immune cell-derived exosomes can increase immunity against tumors. In contrast, tumor-derived exosomes can reduce the immunity and can change the tumor microenvironment to further develop and provide metastasis. These effects take place by an alteration in the innate and adaptive immune cell functions. In this experiment, we studied the natural killer (NK) cells' effectiveness on tumor cells after expansion and thereafter incubated it with exosomes. The exosomes were derived from 2 populations of NK cells: (1) naive NK cells and, (2) NK cells previously exposed to neuroblastoma (NB) cells. Moreover, we have studied the NB-derived exosomes on NK cell function. The molecular load of the characterized exosomes (by means of nanoparticle-tracking analysis, flow cytometry, scanning electron microscopy, and western blot) from NK cells exposed to the NB cell revealed their expression of natural killer cell receptors in addition to CD56, NKG2D, and KIR2DL2 receptors. These exosomes were used to treat NK cells and thereafter administered to NB tumor cells both in vitro and in vivo. Our results showed some kind of NK cells' education by the exosomes. This education from NK cells previously exposed to NB cell-derived exosomes caused efficient and greater cytotoxicity against NB tumors, but NB-derived exosomes act as tumor promoters by providing a tumor supporting niche. Hence, this method of preparing the exosomes has a dramatic effect on activation of anti-NK cells against NB cells.

The best donors for hematopoietic SCT (HSCT) are fully-matched siblings. In patients without fully-matched siblings, HLA registries or cord blood banks are alternative strategies with some restrictions. Owing to the high rate of consanguineous marriage in our country, between 2006 and 2013, extended family searches were undertaken in Hematology-Oncology Research Center and Stem Cell Transplantation (HORCSCT), Tehran, Iran, in 523 HSCT candidates with parental consanguinity and no available HLA identical sibling. Fully-matched other-relative donors were found for 109 cases. We retrospectively studied the HSCT outcome in these patients. Median time to neutrophil engraftment was 13 days (range: 9-31days). In 83 patients, full chimerism and in 17 patients, mixed chimerism was achieved. Acute GvHD (aGvHD) grade II-IV appeared in 36 patients (33%). The frequency of aGvHD development in various familial subgroups was NS. Five patients expired before day+100. In the surviving 104 cases, chronic GvHD developed in 20 patients (19.2%). The distantly related subgroup had significantly a higher rate of cGvHD (P = 0.04). The 2-year OS and disease-free survival (DFS) were 76.7 ± 4.5% and 71.7 ± 4.7%, respectively. No significant difference in OS (P = 0.30) and DFS (P = 0.80) was unraveled between various familial relationships. Our considerable rate of fully-matched non-sibling family members and the favorable outcome support the rationale for extended family search in regions where consanguineous marriage is widely practiced.

Although liver biopsy is an invasive procedure, it remains the gold standard technique for the evaluation of hepatic fibrosis in different patients, including those with major thalassemia (MT). Recently, noninvasive imaging techniques, such as transient elastography, have emerged. We investigated the effectiveness of TE, in comparison to liver biopsy, for the evaluation of liver fibrosis in pediatric patients with MT who were candidates for hematopoietic stem cell transplantation (HSCT). Eighty-three pediatric MT patients (48 boys and 35 girls), who were candidates for HSCT, were included in this study. The median age was 8 years. Liver stiffness was assessed for all patients, before transplantation, using both TE, measured in kilopascals (kPa) and liver biopsy, based on the Metavir score. The diagnostic accuracy of TE and liver biopsy were estimated using linear discriminated analysis (the area under the receiver operating characteristic curves [AUROCs]). The median TE score was 4.3 kPa (range, 3.5 to 5.2). The TE value did not differ among patients with different ferritin levels (P = .53). TE increased proportionally to Metavir fibrosis stages (P < .001) and the necro-inflammatory grade (P < .001). The TE score also correlated to liver iron content (P < .001), liver size (P < .003), and Lucarelli risk classification (LRC) (P < .001). ROC curve analysis revealed moderate accuracy of the TE score for the diagnosis of fibrosis (AUROC = 73%) and for distinguishing individuals with a LRC III from those classified as I and II (AUROC = 82%). The TE score was also superior to Fibrosis-4 (AUROC = 61%) for the assessment of liver fibrosis and LRC differentiation. The results of this study demonstrated that TE can be a valuable method for assessing liver fibrosis and differentiating LRC III from the other 2 classes in pediatric patients with MT who have been selected for HSCT.

There are many types of leukocytes reside in subcutaneous adipose tissue (SAT), and among them, natural killer cells (NKs) comprise a major part. We show that the NKs that reside in the SAT (adipose tissue-derived NK cells; ADNKs) of the abdominal region found with phenotypic differences from the NKs circulating in the peripheral blood derived NK cells (PBNKs). In this survey, flow cytometry phenotyping was used to study the differences between the natural cytotoxicity receptor expression on ADNKs and PBNKs of both obese and lean persons. Also, their cytotoxicity and cytokine production patterns were evaluated. The activation experiments on isolated and expanded NKs with IL-2, IL-15, and IL-21 cytokines revealed the main population of the CD56dim within the total ADNKs of obese persons has an under-expression of NKp30 and NKp44 despite the unchanged levels of NKG2D. The data suggest the suppressive condition of the adipose tissue niche on the NKs response against sensitive major histocompatibility complex class I non-expressing neoplastic cells. As the NKs are the first line of the body’s defense vs tumor formation, this change may lead to the development of transformed cells into the tumors.