The anti-My-10 mouse monoclonal antibody was raised against the immature human myeloid cell line KG-1a and was selected for nonreactivity with mature human granulocytes. Anti-My-10 immunoprecipitated a KG-1a cell surface protein with an apparent Mr of approximately 115 kD. We describe the binding of this antibody to human hematopoietic cell types and show that My-10 is expressed specifically on immature normal human marrow cells, including hematopoietic progenitor cells. My-10 is also expressed by leukemic marrow cells from a subpopulation of patients. Thus, this antibody allows the identification and purification of hematopoietic progenitor cells from normal human marrow and the subclassification of leukemia.
The synchronous occurrence of neurofibromatosis and neuroblastoma has been labeled in the recent literature as a chance event. We report 2 cases of newborn infants with congenital neurofibromatosis and a similar midline pattern of multiple Schwann cell and neuroblastic tumors; other types of ectomesenchymal tumor differentiation are documented, along with supportive ultrastructural and immunohistochemical studies. The tumors may take an aggressive, fatal course despite maximal multimodality antitumor therapy. These 2 cases are reported, with additional literature review, to document a clinically recognizable neurocristopathy that links neuroblastic tumors and neurofibromatosis.
A B S T R A C T Recent studies of cartilage-hair hypoplasia (CHH), a form of short-limbed dwarfism, have shown that all affected individuals have a cellular proliferation defect that results in a cellular immunodeficiency. However, only a minority of CHH individuals suffer from severe, life-threatening infections. For this reason, relevant immune defense mechanisms that may be responsible for maintaining intact host defenses in the majority of CHH individuals were studied. Spontaneous and allogeneic culture-induced (mixed lymphocyte response-MLR) specific and nonspecific (NK-like) cytotoxic mechanisms were analyzed and correlated with lymphocyte subpopulations present in CHH and normal individuals. Spontaneous naturalkiller (NK) activity was present at or above normal levels, but culture-induced specific cytotoxicity and NK-like cytotoxicity as well as NK-like activity by T cell lines were significantly reduced in CHH individuals. The generation of radiation-resistant cytotoxicity, which normally occurs during allogeneic MLR, was markedly diminished in CHH, and was correlated with the decreased proliferation observed in CHH cultures. Preservation of spontaneous NK activity and loss of all forms of culture-induced cytotoxicity was associated with an increase in the proportion of lymphocytes bearing a thymic independent NK phenotype (OKM1+ OKT3-Fcy+ low-affinity E+), and a significant decrease in thymic derived OKT3+ cytolytic T cell subpopulations in CHH individuals. Therefore, an intact cellular cytotoxic effector mechanism has been identified in CHH (i.e., NK activity). Natural cytotoxicity may be of importance in maintaining host resistance to viral infections despite diminished thymic-derived effector mechanisms in cartilage-hair hypoplasia.
The sensitivity of human natural killer cell activity after exposure of peripheral blood mononuclear cells to different doses of gamma irradiation was examined in a group of healthy adults and several families. Three patterns of radiation sensitivity were observed: 1) loss of all NK activity after 3000 rads irradiation; 2) loss of approximately 50% of the NK activity; and 3) maintenance of activity after this dose of irradiation. Low dose irradiation (500 to 2000 rads) resulted in an enhancement of activity. The radiation dose giving low dose activation reflected the individual's sensitivity to 3000 rads. Population studies and the segregation in two informative families indicate that radiation sensitivity of NK activity is controlled by X-linked codominant gene.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.