We investigated whether phagocytosis participates in the protection of insects from viral infection using the natural host–virus interaction between Drosophila melanogaster and Drosophila C virus (DCV). Drosophila S2 cells were induced to undergo apoptotic cell death upon DCV infection. However, UV-inactivated virus was unable to cause apoptosis, indicating the need for productive infection for apoptosis induction. S2 cells became susceptible to phagocytosis by hemocyte-derived l(2)mbn cells after viral infection, and the presence of phagocytes in S2 cell cultures reduced viral proliferation. Phagocytosis depended, in part, on caspase activity in S2 cells, as well as the engulfment receptors Draper and integrin βν in phagocytes. To validate the in vivo situation, adult flies were abdominally infected with DCV, followed by the analysis of fly death and viral growth. DCV infection killed flies in a dose-responding manner, and the activation of effector caspases was evident, as revealed by the cleavage of a target protein ectopically expressed in flies. Furthermore, hemocytes isolated from infected flies contained DCV-infected cells, and preinjection of latex beads to inhibit the phagocytic activity of hemocytes accelerated fly death after viral infection. Likewise, viral virulence was exaggerated in flies lacking the engulfment receptors, and was accompanied by the augmented proliferation of virus. Finally, phagocytosis of DCV-infected cells in vitro was inhibited by phosphatidylserine-containing liposome, and virus-infected flies died early when a phosphatidylserine-binding protein was ectopically expressed. Collectively, our study demonstrates that the apoptosis-dependent, phosphatidylserine-mediated phagocytosis of virus-infected cells plays an important role in innate immune responses against viral infection in Drosophila.

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The cellular localization of inhibin alpha, betaA, and betaB subunits, 3beta-hydroxysteroid dehydrogenase (3beta-HSD), and cytochrome P450 aromatase (aromatase) in stallion testes was investigated. In addition, detailed seasonal changes in circulating immunoreactive (ir)-inhibin were investigated in correlation with testosterone, estradiol, LH, and FSH. Inhibin alpha subunit-positive staining was observed in Sertoli cells, and more clearly positive staining was noted in Leydig cells. Inhibin betaA and betaB subunits were also stained in both types of cells. Immunoreactivity of 3beta-HSD and aromatase was confined to the Leydig cells. There was no seasonal effect on the percentage of the areas within seminiferous tubules and interstitial tissues that stained positive for the inhibin alpha subunit. The highest plasma concentrations of ir-inhibin were observed in the breeding season, and the lowest levels were noted during the nonbreeding season. The circulating concentrations of ir-inhibin, steroid hormones, and gonadotropins were positively correlated with each other throughout the 2 years studied. The presence of the inhibin alpha and beta subunits in Leydig cells and Sertoli cells in the equine testis suggests that these cells may secrete dimetric (bioactive) inhibin in circulation of stallions, and that the circulating ir-inhibin may be a useful indicator of the testicular function of stallions.

To determine the source of circulating inhibin and estradiol-17beta during the estrous cycle in mares, the cellular localization of the inhibin alpha, betaA, and betaB subunits and aromatase in the ovary was determined by immunohistochemistry. Concentrations of immunoreactive (ir-) inhibin, estradiol-17beta, progesterone, LH, and FSH in peripheral blood were also measured during the estrous cycle in mares. Immunohistochemically, inhibin alpha subunits were localized in the granulosa cells of small and large follicles and in the theca interna cells of large follicles, whereas inhibin betaA and betaB subunits were localized in the granulosa cells and in the theca interna cells of large follicles. On the other hand, aromatase was restricted to only the granulosa cells of large follicles. Plasma ir-inhibin concentrations began to increase 9 days before ovulation; they remained high until 2 days before ovulation, after which they decreased when the LH surge was initiated. Thereafter, a further sharp rise in circulating ir-inhibin concentrations occurred during the process of ovulation, followed by a second abrupt decline. After the decline, plasma concentrations of ir-inhibin remained low during the luteal phase. Plasma estradiol-17beta concentrations followed a profile similar to that of ir-inhibin, except during ovulation, and these two hormones were positively correlated throughout the estrous cycle. Plasma FSH concentrations were inversely related to ir-inhibin and estradiol-17beta. These findings suggest that the dimeric inhibin is mainly secreted by the granulosa cells and the theca cells of large follicles; granulosa cells of small follicles may secrete inhibin alpha subunit, and estradiol-17beta is secreted by the granulosa cells of only large follicles in mares.

The platelet counting performance of the PLT-F channel of the XN Series had improved accuracy and precision in the low range and in abnormal samples, avoiding the interference by nonplatelet particles.

The online version of this article has a Supplementary Appendix. BackgroundTo understand how myelodysplastic syndrome cells evolve from normal stem cells and gain competitive advantages over normal hematopoiesis, we established a murine xenograft model harboring bone marrow cells from patients with myelodysplastic syndromes or acute myeloid leukemia with myelodysplasia-related changes. Design and Methods Bone marrow CD34+ cells obtained from patients were injected, with or without human mesenchymal stem cells, into the bone marrow of non-obese diabetic/severe combined immunodeficient/IL2Rγ null hosts. Engraftment and differentiation of cells derived from the patients were investigated by flow cytometry and immunohistochemical analysis. ResultsCo-injection of patients' cells and human mesenchymal stem cells led to successful engraftment of patient-derived cells that maintained the immunophenotypes and genomic abnormalities of the original patients. Myelodysplastic syndrome-originated clones differentiated into mature neutrophils, megakaryocytes, and erythroblasts. Two of the samples derived from patients with acute myeloid leukemia with myelodysplasia-related changes were able to sustain neoplastic growth into the next generation while these cells had limited differentiation ability in the murine host. The hematopoiesis of mice engrafted with patients' cells was significantly suppressed even when human cells accounted for less than 1% of total marrow mononuclear cells. Histological studies revealed invasion of the endosteal surface by patient-derived CD34 + cells and disruption of extracellular matrix architecture, which probably caused inhibition of murine hematopoiesis. ConclusionsWe established murine models of human myelodysplastic syndromes using cells obtained from patients: the presence of neoplastic cells was associated with the suppression of normal host hematopoiesis. The efficiency of engraftment was related to the presence of an abnormality in chromosome 7.Key words: xenograft, MDS, NOG mouse, niche, MSC. syndromes. Haematologica 2011;96(4):543-551. doi:10.3324/haematol.2010 This is an open-access paper. Citation: Muguruma Y, Matsushita H, Yahata T, Yumino S, Tanaka Y, Miyachi H, Ogawa Y, Kawada H, Ito M, and Ando K. Establishment of a xenograft model of human myelodysplastic Establishment of a xenograft model of human myelodysplastic syndromes

The present study compares immune reconstitution after allogeneic cord blood transplantation (CBT) and CD34+ stem cell transplantation (CD34-SCT) with that after bone marrow transplantation (BMT). Eighty-eight children who underwent CBT (20 patients), BMT (58), and CD34-SCT (10) were enrolled, and lymphocytes and T-, B-, and natural killer-lymphocyte subsets were monitored for more than 5 years after transplantation. CBT recipients showed significant ircreases in (1) total lymphocyte counts (P < .001), (2) CD4+/CD8+ cell ratios (P < .01), (3) CD4+ and CD4+CD45RA+ cells (P < .001), (4) CD8+CD11b+ cells (P < .001), and (5) CD19+ and CD19+CD5+ cells (P < .0001) and marked decreases in the frequencies of CD8+ and CD8+CD11b- cells (P < .0001). CD34-SCT recipients showed lower lymphocyte counts in the first 6 months and an emergence of lymphocyte and CD4+CD45RA+ cells at approximately 9 months and 1 year. Both CBT and CD34-SCT recipients showed increased frequencies of CD56+ cells at 1 month (CD34-SCT versus BMT, P < .001) but decreased frequencies after 6 months (CBT versus BMT, P < .001). Lymphoproliferative responses to exogenous interleukin 2 were constantly lower in CBT and CD34-SCT recipients than in BMT recipients. These results suggest that the delay in immune reconstitution after CBT in the early phase was mainly qualitative and related to the immaturity of cells, whereas the delay in CD34-SCT was mainly quantitative in the first several months.

Immunohistochemical detection of inhibin-alpha, -betaA and -betaB chains and 3beta-hydroxysteroid dehydrogenase (HSD) was carried out on primary testicular tumors from 15 dogs and normal testes from three adult dogs. Histopathologically, the tumors were composed of three types: Leydig cell tumors in five dogs, Sertoli cell tumors in five dogs, and seminoma in five dogs. In normal testes, immunostaining against inhibin-alpha, -betaA, and -betaB chains and 3beta-HSD revealed positive reactivity in the cytoplasm of Leydig cells. In testicular tumors, immunoreactive cells against inhibin-alpha, -betaA, and -betaB chains and 3beta-HSD were localized in all Leydig cell tumors but not in any Sertoli cell tumors or seminomas. The results of radioimmunoassay for plasma inhibin in dogs with Leydig cell tumors showed higher concentrations than those in dogs with Sertoli cell tumors and seminomas and those in normal dogs. The concentration of inhibin in the plasma was markedly decreased by the surgical removal of the Leydig cell tumor in one dog. Our findings suggest that inhibin is synthesized by normal and neoplastic Leydig cells in the canine testis, and the secreted inhibin may be inhibin A and inhibin B.