Extracellular NK histones promote immune cell anti-tumor activity by inducing cell clusters through binding to CD138 receptor.

BACKGROUND: Natural killer (NK) cells are important anti-tumor cells of our innate immune system. Their anti-cancer activity is mediated through interaction of a wide array of activating and inhibitory receptors with their ligands on tumor cells. After activation, NK cells also secrete a variety of pro-inflammatory molecules that contribute to the final immune response by modulating other innate and adaptive immune cells. In this regard, external proteins from NK cell secretome and the mechanisms by which they mediate these responses are poorly defined. METHODS: TRANS-stable-isotope labeling of amino acids in cell culture (TRANS-SILAC) combined with proteomic was undertaken to identify early materials transferred between cord blood-derived NK cells (CB-NK) and multiple myeloma (MM) cells. Further in vitro and in vivo studies with knock-down of histones and CD138, overexpression of histones and addition of exogenous histones were undertaken to confirm TRANS-SILAC results and to determine functional roles of this material transferred. RESULTS: We describe a novel mechanism by which histones are actively released by NK cells early after contact with MM cells. We show that extracellular histones bind to the heparan sulfate proteoglycan CD138 on the surface of MM cells to promote the creation of immune-tumor cell clusters bringing immune and MM cells into close proximity, and thus facilitating not only NK but also T lymphocyte anti-MM activity. CONCLUSION: This study demonstrates a novel immunoregulatory role of NK cells against MM cells mediated by histones, and an additional role of NK cells modulating T lymphocytes activity that will open up new avenues to design future immunotherapy clinical strategies.

The prevalence of soil-transmitted helminthiasis among Filipino pregnant women determined by fecalysis / Philippine Journal of Obstetrics and Gynecology

Background@#The Philippines is endemic to soil-transmitted helminthiasis, a neglected tropical disease which is inadequately diagnosed and treated especially in the pregnant and lactating population. It is important that the prevalence of STH is monitored routinely to assess the effectiveness of control programs and the provision of adequate treatment, hence decreasing its associated adverse outcomes.@*Objective@#To determine the prevalence of STH among pregnant patients consulting for antenatal care in a tertiary provincial hospital using microscopic stool analysis. @*Methods@#This is a cross-sectional study performed on 270 patients attending antenatal care from a tertiary provincial hospital. Microscopic stool analysis using the Kato-Katz technique was the diagnostic tool used to identify presence of intestinal parasites. Data were analyzed using Stata 15. Chi Square and Mann U Whitney Tests were utilized to determine statistical significance. Variables under the adverse perinatal outcomes were subjected to odds ratio to determine correlation among those tested positive for STH. @*Conclusion@#The cumulative prevalence rate of STH is 20.7% and the most common organism identified is A. lumbricoides. Factors related to a high suspicion of STH are: older individuals; higher obstetric score; greater number of living children; increased maternal weight; anemic; underweight; lived in a family with higher number of household members; lived in a family with member treated with antihelminthics; lived in houses without water and toilet; lived in the areas of Maragondon, Mendez, Bailen, Cavite City, Noveleta and Bacoor. Moreover, preterm labor and small for gestational age fetus are the adverse perinatal outcomes identified suggestively related to STH.

Recurrent hydatidiform mole with NLRP7 mutation: The first confirmed case in the Philippines / Philippine Journal of Obstetrics and Gynecology

High gravidity hydatidiform mole (HM) without normal pregnancy is very rare. The challenge of managing such cases will dwell on the concern of having normal conception versus having another molar gestation and its neoplastic sequelae. Presented in this paper is a case of a 32-year-old, gravida 5 para 0 (0040) who was admitted for the management of her fifth molar pregnancy. She underwent suction curettage and administration of methotrexate chemoprophylaxis. Genetic testing was done, which revealed a homozygous mutation in NLRP7, the gene implicated in recurrent molar gestations. This paper discusses the proper approach to determine the cause of recurrent molar pregnancies, as well as the management and prognosis of such cases.

Recurrent hydatidiform mole with NLRP7 mutation: The first confirmed case in the Philippines / Philippine Journal of Obstetrics and Gynecology

High gravidity hydatidiform mole (HM) without normal pregnancy is very rare. The challenge of managing such cases will dwell on the concern of having normal conception versus having another molar gestation and its neoplastic sequelae.Presented in this paper is a case of a 32-year-old, gravida 5 para 0 (0040) who was admitted for the management of her fifth molar pregnancy. She underwent suction curettage and administration of methotrexate chemoprophylaxis. Genetic testing was done, which revealed a homozygous mutation in NLRP7, the gene implicated in recurrent molar gestations. This paper discusses the proper approach to determine the cause of recurrent molar pregnancies, as well as the management and prognosis of such cases.

Transmissible cytotoxicity of multiple myeloma cells by cord blood-derived NK cells is mediated by vesicle trafficking.

Natural killer cells (NK) are important effectors of anti-tumor immunity, activated either by the downregulation of HLA-I molecules on tumor cells and/or the interaction of NK-activating receptors with ligands that are overexpressed on target cells upon tumor transformation (including NKG2D and NKP30). NK kill target cells by the vesicular delivery of cytolytic molecules such as Granzyme-B and Granulysin activating different cell death pathways, which can be Caspase-3 dependent or Caspase-3 independent. Multiple myeloma (MM) remains an incurable neoplastic plasma-cell disorder. However, we previously reported the encouraging observation that cord blood-derived NK (CB-NK), a new source of NK, showed anti-tumor activity in an in vivo murine model of MM and confirmed a correlation between high levels of NKG2D expression by MM cells and increased efficacy of CB-NK in reducing tumor burden. We aimed to characterize the mechanism of CB-NK-mediated cytotoxicity against MM cells. We show a Caspase-3- and Granzyme-B-independent cell death, and we reveal a mechanism of transmissible cell death between cells, which involves lipid-protein vesicle transfer from CB-NK to MM cells. These vesicles are secondarily transferred from recipient MM cells to neighboring MM cells amplifying the initial CB-NK cytotoxicity achieved. This indirect cytotoxicity involves the transfer of NKG2D and NKP30 and leads to lysosomal cell death and decreased levels of reactive oxygen species in MM cells. These findings suggest a novel and unique mechanism of CB-NK cytotoxicity against MM cells and highlight the importance of lipids and lipid transfer in this process. Further, these data provide a rationale for the development of CB-NK-based cellular therapies in the treatment of MM.

A variant in IRF3 impacts on the clinical outcome of AML patients submitted to Allo-SCT.

Allo-SCT has a strong curative potential for AML patients mainly due to a GVL effect. Unfortunately, GvL and GVHD are intimately linked. IFN regulatory factor-3 (IRF3), by modulating innate immune reactions, could impact on the incidence and intensity of GVL and GVHD. We analyzed two gene variants in IRF3 (rs7251 and rs2304205) on the clinical outcome of 249 AML patients submitted to HLA-identical sibling allo-SCT. Patients with a donor carrying the dominant GG gene variant in rs7251 had, as compared with GC and CC variants, a lower acute GVHD (aGVHD) III-IV incidence (4% vs 11% vs 27%; P=0.0078), a higher relapse incidence (49% vs 35% vs 26%; P=0.018), and lower TRM (7% vs 24% vs 18%; P=0.0065). In functional studies, the GG variant was associated with lower production of IFN-γ, decreased lymphocyte proliferation after antigen presentation by DCs, and lower cytotoxic response of mature natural killer cells. Patients carrying the AA dominant variant in rs2304205 had higher relapse incidence (50% vs 39% vs 18%, P=0.0068). The presence of both variants (GG in rs7251 and AA in rs2304205) in donors and patients resulted in a stronger clinical impact.

A constitutional variant in the transcription factor EP300 strongly influences the clinical outcome of patients submitted to allo-SCT.

An adequate response of the innate immune system after allo-SCT is crucial for the clinical outcome of patients submitted to this procedure. EP300 is one of the key genes of the innate immune system (IIS). We evaluated the influence of gene variant A>G rs20551 in EP300 in donor and/or recipient on clinical results after HLA-identical sibling allo-SCT. Patients with AA gene variant had a lower relapse incidence (31 vs 48%, P=0.025; odds ratio (OR)=1.6, P=0.05), attained better disease-free survival (AA: 53% vs AG+GG: 24%, P=0.001; OR=1.8, P=0.01), and better OS (AA: 53% vs AG+GG: 34%, P=0.001; OR=1.9, P=0.007). This beneficial association was more evident when AA gene variant was present in both donor and patient. In healthy individuals, AA gene variant was associated with lower IL2 production after a mitogenic stimuli, higher CD4+ cell response after CMV infection, and higher expression of innate immune genes (IRF-3 and MIF), cell cycle genes (AURKB, CCNA2 and CCNB1), lymphocyte survival genes (NFAT5 and SLC38A2), and with a lower expression of P53 compared with recessive GG gene variant. These findings suggest a beneficial effect of the AA gene variant in rs20551 on clinical outcome after allo-SCT.

Cellular and molecular immune responses of the sea bass (Dicentrarchus labrax) experimentally infected with betanodavirus.

Naïve sea bass juveniles (38.4 + or - 4.5 g) were intramuscularly infected with a sublethal dose of betanodavirus isolate 378/I03, followed after 43 days by a similar boosting. This infection resulted in an overall mortality of 7.6%. At various intervals, sampling of fish tissues was performed to investigate: i) B and T lymphocyte content in organs and tissues; ii), proliferation of leucocytes re-stimulated in vitro with inactivated virus; iii) presence of serum antibody specific for betanodavirus; iv) expression of genes coding for the following immunoregulatory molecules involved in innate and acquired responses: type I IFN, Mx, IL-1, Cox-2; IL-10, TGF-beta, TCRbeta, CD4, CD8alpha, IgM, by using a quantitative PCR array system developed for sea bass. The obtained results showed a detectable increase of T cells and B cells in PBL during betanodavirus infection. Furthermore, leucocytes obtained from blood, head kidney, and gills showed a detectable "in vitro" increase in viability upon addition of inactivated viral particles, as determined by measuring intracellular ATP concentration. ELISA analysis of sera showed that exposure to nodavirus induced a low, but specific antibody titer measured 43 days after infection, despite the presence of measurable levels of natural antibody. Finally, a strong upregulation of genes coding for type I IFN, Mx, and IgM was identified after both infection and boosting. Interestingly, an upregulation of Cox-2 until boosting, and of TGF-beta and IL-10 after boosting was also observed, while the other tested genes did not show any significant variations with respect to mock-treated fish. Overall, our work represents a first comprehensive analysis of cellular and molecular immune parameters in a fish species exposed to a pathogenic virus.