Antigens expressed by human B lymphocytes and myeloid stem cells.

Antisera prepared against papain-digested spleen cell membranes were known to by cytotoxic for normal and neoplastic human B lymphocytes and for a majority of acute and chronic myeloid leukemic cells. It is now shown that these antisera are also cytotoxic for normal myeloid stem cells (CFU-C), thus providing a probable explanation for their occurrence in myeloid neoplasia.

The interaction of human monocytes and lymphocytes.

Monocytes isolated from the peripheral blood of tuberculin-positive and tuberculin-negative donors were exposed to PPD, extensively washed, and incubated with autologous or homologous lymphocytes. Lymphocyte transformation was measured morphologically and by incorporation of (14)C-labeled thymidine. Monocytes from tuberculin-positive subjects induced transformation of autologous lymphocytes in 19 of 29 experiments. Studies to define the optimal conditions of exposure to monocytes to PPD and to autologous lymphocytes showed that viable, metabolically intact monocytes are required. A ratio of only 1 monocyte to 100 lymphocytes sufficed to induce transformation; neutrophils were inactive. In general, PPD-sensitized monocytes failed to induce transformation of homologous lymphocytes from either tuberculin-positive or tuberculin-negative subjects. Direct contact between monocytes and lymphocytes was required for consistent transformation, and islands of transforming lymphocytes were observed around a central core of monocytes.

Human monocytes and macrophages. Interaction with antigen and lymphocytes.

PPD-sensitized monocytes and macrophages from tuberculin-positive subjects are both capable of inducing blastogenic transformation of autologous lymphocytes. Incorporation of thymidine-(3)H and morphological transformation were always greater in lymphocyte cultures containing macrophages than in those containing monocytes. More lymphocytes entered the first detectable S phase in cultures containing macrophages. Lymphocyte DNA synthesis occurred as early as 40 hr of culture and always in cells in contact with mononuclear phagocytes. By 120-144 hr, many transformed lymphocytes were free in suspension; at the same time, the "immunological cluster" had increased greatly in size and contained transformed and untransformed lymphocytes. The greater effectiveness of macrophages at induction of lymphocyte transformation may be related to the efficiency of this cell type at trapping antigen and its effectiveness at making contact with and binding lymphocytes.

Plasma kinins and cortisol: a possible explanation of the anti-inflammatory action of cortisol.

Kinins are naturally occurring vasoactive polypeptides thought to be mediators of acute inflammatory responses. Kinins are released from a plasma protein substrate by glass-activated plasma enzymes (kallikreins) or by isolated intact granulocytes. Cortisol in concentrations of 2.5 x 10(-6) to 2.5 x 10(-5)M prevented the release of active kinin from substrate by granulocytes or contact with glass. Deoxycorticosterone, progesterone, and etiocholanolone in comparable concentrations were significantly less effective in preventing kinin release. Plasma obtained from patients receiving prednisone released no kinin after activation by glass and less kinin than control plasma when exposed to granulocytes. Cortisol also partially inhibited the release of kinin by purified urinary kallikrein. Certain adrenocorticosteroids may exert their anti-inflammatory effect by inhibiting the release of plasma kinins. Steroids may act in part by preventing interaction between the activated kallikrein and its substrate.

Insertion of a new gene of viral origin into bone marrow cells of mice.

DNA containing the herpes simplex virus thymidine kinase (HSVtk) gene was used to transform wild-type tk+ mouse L cells to a tk++ status in vitro using methotrexate as a selective agent. HSVtk DNA was also used to transform mouse bone marrow cells in vitro. Transformed marrow cells injected into irradiated and methotrexate-treated recipient mice gave rise to proliferating cells which in some cases dominated the marrow population and which contained HSVtk gene sequences.

Alterations of myc, myb, and rasHa proto-oncogenes in cancers are frequent and show clinical correlation.

Alterations of c-myc, c-rasHa, or c-myb oncogenes were found in more than one-third of human solid tumors. Amplification of c-myc occurred in advanced, widespread tumors or in aggressive primary tumors. Apparent allelic deletions of c-rasHa and c-myb can be correlated with progression and metastasis of carcinomas and sarcomas.

Expression of cellular oncogenes in human malignancies.

Cellular oncogenes have been implicated in the induction of malignant transformation in some model systems in vitro and may be related to malignancies in vivo in some vertebrate species. This article describes a study of the expression of 15 cellular oncogenes in fresh human tumors from 54 patients, representing 20 different tumor types. More than one cellular oncogene was transcriptionally active in all of the tumors examined. In 14 patients it was possible to study normal and malignant tissue from the same organ. In many of these patients, the transcriptional activity of certain oncogenes was greater in the malignant than the normal tissue. The cellular fes (feline sarcoma) oncogene, not previously known to be transcribed in mammalian tissue, was found to be active in lung and hematopoietic malignancies.

Identification of the putative transforming protein of the human T-cell leukemia viruses HTLV-I and HTLV-II.

The human T-cell leukemia viruses HTLV-I and HTLV-II are unique among the transforming retroviruses of vertebrates in their ability to transform human T cells in vitro and in their close association with human malignancies (T-cell lymphomas and leukemia). Their genomes are relatively simple, containing the genes gag, pol, env, and a 3' region termed "X." This 3' region may be responsible for the transforming potential of the viruses. The existence of proteins encoded by the 3' region has been postulated on the basis of multiple open reading frames. In the present study this region is shown to contain a gene encoding a protein of 40 kilodaltons in HTLV-I and 37 kilodaltons in HTLV-II. It is proposed that these proteins be called, respectively, p40xI and p37xII.

Studies of the putative transforming protein of the type I human T-cell leukemia virus.

The putative transforming protein of the type I human T-cell leukemia virus (HTLV-1) is a 40-kilodalton protein encoded by the X region and is termed p40XI. On the basis of both subcellular fractionation techniques and immunocytochemical analysis, it is now shown that p40XI is a nuclear protein with a relatively short half-life (120 minutes). It is synthesized de novo in considerable quantities in a human T-cell line infected with and transformed by the virus in vitro, and it is not packaged in detectable amounts in the extracellular virus.

Nerve growth factor acts through cAMP-dependent protein kinase to increase the number of sodium channels in PC12 cells.

cAMP-dependent protein kinase (PKA) and phospholipid-dependent protein kinase (PKC) play a role in nerve growth factor (NGF)-mediated differentiation. In PC12 cells, NGF causes neurite outgrowth and increases the number of voltage-gated Na+ channels. Neurite outgrowth involves in part activation of PKC. How NGF regulates Na+ channel number is unknown. Using patch-clamp techniques, we find that agents activating PKC, including phorbol esters and a ras oncogene product (p21) that induces neurites, caused little increase in channel number. In contrast, agents increasing intracellular cAMP were as effective as NGF. A specific protein inhibitor of the PKA catalytic subunit blocked increases by NGF or cAMP. Thus, NGF increases Na+ channel number in PC12 cells in part by activating PKA but apparently not PKC.

Defective mononuclear phagocyte function in patients with myelomonocytic leukemia and in some patients with lymphoma.

Mononuclear phagocytes from 8 of 10 patients with myelomonocytic leukemia and 2 of 9 patients with lymphoma phagocytized several species of bacteria but did not inhibit intracellular bacterial replication normally. Intracellular organisms were protected from the lethal effects of antibiotics in the medium. This defect of microbicidal function of malignant monocytes may explain in part the frequency of infection and the mechanism of antibiotic-resistant infection in some patients with malignant myeloproliferative and lymphoproliferative diseases.

Identification of the colony-stimulating cell in human peripheral blood.

Bone marrow colony formation in soft gel culture may be stimulated by substances elaborated by human peripheral blood leukocytes. In order to determine the cell type responsible for colony stimulation, peripheral leukocytes were separated by Ficoll-Hypaque gradients and differential glass adhesion. Morphologic, histochemical, and functional criteria were applied to determine the purity of the monocyte, lymphocyte, and neutrophil fractions. Using these cells as feeder layers and as a source of conditioned medium, evidence was obtained that the monocyte is the colony-stimulating cell of human peripheral blood. Activity greater than that of mixed white cells was obtained with monocyte underlayers, and only monocyte- and macrophage-conditioned media were shown to have significant colony-stimulating activity.

Leukocyte myeloperoxidase deficiency and disseminated candidiasis: the role of myeloperoxidase in resistance to Candida infection.

The neutrophils and monocytes of a patient with disseminated candidiasis were found to lack detectable levels of the lysosomal enzyme myeloperoxidase (MPO), although they had normal levels of other granule-associated enzymes. Leukocytes from one of the patient's sisters also lacked detectable MPO; leukocytes from his four sons contained approximately one-third of mean normal peroxidase levels. Neither the patient nor his affected relatives had experienced frequent or unusual bacterial infections. The phagocytic activity of the patient's MPO-deficient neutrophils was intact, and the cells displayed normal morphologic and metabolic responses to phagocytosis. In contrast to normal leukocytes which killed 30.5+/-7.3% of ingested Candida albicans in 1 hr, however, the patient's neutrophils killed virtually none. His leukocytes also failed to kill the strain of C. albicans recovered from his lesions, as well as other Candida species. These MPO-deficient neutrophils killed Serratia marcescens and Staphylococens aureus 502A at an abnormally slow rate, requiring 3-4 hr to achieve the bactericidal effect attained by normal leukocytes after 45 min. No other abnormalities in his cellular or humoral immune responses were demonstrated. These findings suggest that hereditary MPO deficiency is transmitted as an autosomal recessive characteristic, that the homozygous state conveys enhanced susceptibility to disseminated candidiasis, and that MPO is necessary for candidacidal activity in human neutrophils. Although lending support to the suggested bactericidal role of MPO in leukocytes, the data indicate that alternative bactericidal mechanisms, effective in the absence of MPO, are functionally dominant in the human neutrophil.

The human alveolar macrophage: isolation, cultivation in vitro, and studies of morphologic and functional characteristics.

Human alveolar macrophages were lavaged from surgically resected lungs and from lungs of normal subjects. Macrophages that had been purified by glass adherence were maintained in tissue culture for as long as 54 days. After 3-4 wk in vitro they underwent transformation into multinucleated giant cells. These aged cells had more than 30 times the phagocytic capacity that the same group of cells had had after 1 day in vitro. Phagocytosis of heat-killed Candida albicans was inhibited by iodoacetate, sodium fluoride, potassium cyanide, and low partial pressures of oxygen, suggesting that these cells require both oxidative and glycolytic energy sources for maximal particle ingestion. Alveolar macrophages and monocyte-derived macrophages killed Listeria monocytogenes with similar efficiency, but neutrophils were more efficient than either of the other cell types. Bacterial killing is probably not dependent upon myeloperoxidase in the monocyte-derived macrophage or in the alveolar macrophage since histochemical stains for peroxidase do not stain either cell type. C. albicans blastospores, which are killed by neutrophils and monocytes that contain myeloperoxidase, were not killed by human alveolar macrophages during the 4 hr of observation. Large cells with supernormal phagocytic capacity were recovered from patients with postobstructive pheumonia and from one patient with recurrent bacterial pneumonia, indicating that macrophage function can be altered in certain disease states. Human alveolar macrophages are unique human phagocytes in their dependence on an oxygen tension greater than 25 mm HG for maximal phagocytosis. Carbon dioxide tensions as high as 70 mm Hg did not alter phagocytosis when the pH of the medium was held constant. These data suggest that the increased susceptibility to pneumonia of patients with chronic bronchitis or atelectasis may be in part related to suboptimal phagocytosis by macrophages in areas of the lung with depressed oxygen tension.

Differentiation of subpopulations of human and murine hemopoietic stem cells by hypotonic lysis.

Both human and mouse bone marrow contain subpopulations of hemopoietic stem cells that greatly vary in their resistance to water exposure: The cells forming erythroid colonies or bursts in methyl cellulose in vitro are most sensitive to hypotonic conditions and are destroyed within 60 s in the hypotonic milieu. The murine pluripotent stem cells assayed by the spleen colony technique, as well as both murine and human myeloid stem cells assayed by the plasma clot diffusion chamber technique, displayed intermediate sensitivity and were nearly completely eliminated by 120 s of exposure to water. Both human and mouse bone marrow stem cells producing myeloid colonies in agar are most resistant to hypotonic conditions. The addition of monocyte-macrophages and lymphoid cells to water-exposed mouse bone marrow cell populations to compensate for losses did not restore either erythroid or myeloid colony formation.

Leukocyte antimicrobial function in patients with leprosy.

Patients with lepromatous leprosy are unresponsive to lepromin skin-test material and possess defective lymphocyte function in vitro, including impaired mitogenesis in response to antigens of Mycobacterium leprae. It has been claimed that their macrophages cannot digest M. leprae in vitro; such a defect could explain both lepromin nonreactivity and impaired lymphocyte function on the basis of failure of the afferent limb of the immune response (i.e., defective macrophage "processing" of M. leprae). The present studies indicate that macrophages from patients with lepromatous and tuberculoid leprosy and from normal donors do not differ in their ability to digest heat-killed M. leprae in vitro, or in their ability to sustain the viability of M. leprae in tissue culture; that monocytes, macrophages, and polymorphonuclear leukocytes of leprosy patients and controls possess equivalent microbicidal activity against Listeria monocytogenes, Escherichia coli, Proteus vulgaris, Staphylococcus aureus, and Candida albicans; and that polymorphonuclear leukocytes from patients with lepromatous leprosy iodinate ingested bacteria normally. Whether the basic immune defect leading to the development of lepromatous leprosy resides in the lymphocyte or in the macrophage remains to be determined. However, the present study shows that phagocytic cells from patients with either principal form of leprosy function normally in a variety of sophisticated tests of antimicrobial function.

Potentiation of erythropoiesis in vitro by dexamethasone.

The effect of dexamethasone on erythropoiesis was examined in vitro. Hematopoietic cells from 13-day mouse fetal livers were cultured for 48 h in the presence or absence of erythropoietin and erythroid colonies enumerated. Colony formation occurring in cultures containing no added erythropoietin was inhibited by the incorporation of antierythropoietin antibody, suggesting that these colonies formed in response to endogenous hepatic erythropoietin. Maximal colony formation was observed with 0.5 U/ml of sheep erythropoietin. Dexamethasone increased erythroid colony formation with peak stimulation at 10(-9) M. Dexamethasone potentiation was most marked in cultures containing less than maximally stimulating concentrations of erythropoietin. The cells required only a brief exposure to glucocorticosteroid to exhibit the augmented cloning capacity, and dexamethasone stimulation was inhibited by progesterone (10(-6) M). A comparable response to dexamethasone was observed in cultures of adult murine and human bone marrow erythroid progenitors, implying that the phenomenon is not peculiar to fetal cells and is not dependent on the presence of fetal hepatocytes. These data suggest that erythroid progenitor cells possess a glucocorticoid receptor mechanism that can modulate the response to erythropoietin in vitro.

The interaction of human macrophages and lymphocytes in the phytohemagglutinin-stimulated production of interferon.

In studies of 13 normal adults to determine the blood cell types responsible for interferon production induced by phytohemagglutinin, the following observations were made. (a) In cultures containing 96-100% pure macrophages derived from blood monocytes, no interferon was detected in either the presence or the absence of phytohemagglutinin for up to 92 hr. (b) In cultures of 99.5-100% pure lymphocytes, low levels of interferon were detected in the presence, but not in the absence, of phytohemagglutinin. (c) An average fivefold increase in interferon titers occurred when pure lymphocytes were combined with the macrophages in culture with phytohemagglutinin. The peak response of interferon occurred at 68 hr after the initiation of the combined cultures. For maximum response, phytohemagglutinin was required for the duration of the culture, and both cell types in association were necessary. Medium from phytohemagglutinin-stimulated macrophages or lymphocytes could not substitute for the corresponding intact cell. However, frozen-thawed macrophages in combination with lymphocytes and phytohemagglutinin produced an intermediate interferon response. An increase in either cell type produced an increased response in the range studied: lymphocytes, 0.45-1.8 x 10(6) per ml; and macrophages, 0.5-2.1 x 10(5) per ml. Syngeneic fibroblasts, HeLa cells, or mouse macrophages could not substitute for the human macrophages in the combined cultures with phytohemagglutinin. (d) Although all cultures producing interferon showed some degree of transformation (thymidine-(3)H incorporation into deoxyribonucleic acid), no direct correlation between the degree of phytohemagglutinin-induced lymphocyte transformation and the interferon titers was observed.The demonstration of macrophage-lymphocyte interaction in the production of interferon is of interest in view of the known interrelationship of these same cell types in antibody synthesis and cellular immunity.

Cyclic 3',5'-adenosine monophosphate in the human lukocyte: synthesis, degradation, andeffects n neutrophil candidacidal activity.

Prostaglandins E(1) and E(2) (PGE(1) and PGE(2)) stimulate adenyl cyclase activity in broken cell preparations of normal human leukocytes, whereas prostaglandin F(1a) produces no effect. PGE(1) and PGE(2) also cause increased accumulation of cyclic 3',5'-adenosine monophosphate-(3)H ((3)H-labeled AMP) in intact leukocytes which have been preincubated with adenine-(3)H in vitro. Theophylline inhibits leukocyte phosphodiesterase activity and potentiates the stimulatory effect of the prostaglandins on intracellular accumulation of cyclic 3',5'-AMP-(3)H. The ability of human granulocytes in vitro to kill Candida albicans was consistently inhibited by PGE(1) and theophylline. This effect was reproduced by dibutyryl cyclic 3',5'-AMP, a lipid-soluble analogue of the endogenous nucleotide. The inhibition of candidacidal activity could not be accounted for by drug effects on phagocytosis, oxygen consumption, or hexose monophosphate shunt activity. These results are consistent with the hypothesis that increased intracellular concentrations of cyclic 3',5'-AMP impair the granulocyte's ability to kill C. albicans, but the precise mechanism of inhibition has not yet been defined.

Kinins: possible mediators of neonatal circulatory changes in man.

Bradykinin is a potent constrictor of the human umbilical artery and vein and the ductus arteriosus of the lamb in vitro at oxygen tensions above 40 mm Hg (comparable to those in the newborn infant). Bradykinin is also capable of producing remarkable dilatation of the pulmonary vasculature of the lamb. Theoretically, kinins are capable of effecting some of the rapid circulatory changes required of the neonate. The present study was undertaken to investigate the role of kinins as mediators of such changes. The concentration of bradykinin in the cord blood of 56 newborn infants at the time of birth was significantly higher than the blood level in adult subjects (12.8 +/- 4.3 ng/ml compared with 2.0 ng/ml or less). Cord arterial blood contained inactive kinin precursor (kininogen) and inactive kinin-releasing enzyme (kallikrein). Plasma kallikrein was activated, with subsequent kinin formation and kininogen depletion, by exposure to neonatal granulocytes or by a decrease in the temperature of cord blood from 37 to 27 degrees C. A comparable decrease in the temperature of umbilical arterial blood occurs at the time of birth. Activation of kallikrein by neonatal granulocytes was dependent on cell concentration and required oxygen tensions comparable to those in the neonate but above the range in the fetus. Granulocytes of the neonate, unlike those of adult subjects, lacked kininase activity.Thus, bradykinin can constrict and dilate vessels as required for the transition of fetal to neonatal circulation. Bradykinin can be produced in plasma of the newborn by decreases in temperature, such as occur in the umbilical blood at birth, and by exposure to granulocytes which are present in the circulation in increased numbers shortly after birth. We propose that bradykinin is produced at birth and may be a mediator of neonatal circulatory changes.