Pathogenesis of cerebral infarction and hemorrhage induced by a murine leukemia virus

BACKGROUND

Inoculation of neonatal BALB/c mice with the Friend murine leukemia virus TR1.3 uniformly induces cerebral infarctions and hemorrhages within 18 days. The primary target of TR1.3 infection are endothelial cells of capillaries and small vessels. Preliminary post-mortem histologic analysis revealed multifocal endothelial cell pathology associated with the presence of thrombi and extravasation of red blood cells into the brain parenchyma. The consequences of viral infection on endothelial cell integrity and its relevance to hemorrhagic and ischemic lesions are unclear.

EXPERIMENTAL DESIGN

Neonatal BALB/c mice were infected with TR1.3 murine leukemia virus and were monitored daily for symptoms of tremor, seizure and paralysis. Diseased mice were killed and the brains prepared for histopathologic analysis and electron microscopy studies.

RESULTS

Hematoxylin and eosin-stained sections revealed widespread areas of infarction throughout white and grey matter with numerous scattered thrombi. Endothelial cell pathology was widespread and pronounced. This included enlarged cytoplasm, intracytoplasmic clefts, separation of tight junctions, swollen mitochondria, changes to the basal lamina and in many instances the formation of syncytia. Ultrastructural studies identified numerous viral particles within the endothelial cell cytoplasm and budding from the abluminal and luminal cell surfaces.

CONCLUSIONS

These data confirm that TR1.3 virus replicates within endothelial cells and provides the first direct evidence of retrovirus-induced endothelial cell pathology. These results suggest that hemorrhage may be a direct consequence of this endothelial cell pathology, and that endothelial cell damage initiates the formation of thrombi and vessel occlusion that results in multiple cerebral infarctions.

Intracerebral hemorrhages and syncytium formation induced by endothelial cell infection with a murine leukemia virus

The mechanisms of endothelial cell damage that lead to cerebral hemorrhage are not completely understood. In this study, a cloned murine retrovirus, TR1.3, that uniformly induced stroke in neonatal BALB/c mice is described. Restriction digest mapping suggests that TR1.3 is part of the Friend murine leukemia virus (FMuLV) family. However, unlike mice exposed to other FMuLVs, mice infected with TR1.3 virus developed tremors and seizures within 8 to 18 days postinoculation. This was uniformly followed by paralysis and death within 1 to 2 days. Postmortem examination of TR1.3-inoculated mice revealed edematous brain tissue with large areas of intracerebral hemorrhage. Histologic analysis revealed prominent small vessel pathology including syncytium formation of endothelial cells. Immunohistochemical analysis of frozen brain sections using double fluorescence staining demonstrated that TR1.3 virus specifically infected small vessel endothelial cells. Although infection of vessel endothelial cells was detected in several organs, only brain endothelial cells displayed viral infection associated with hemorrhage. The primary determinant of TR1.3-induced neuropathogenicity was found to reside within a 3.0-kb fragment containing the 3' end of the pol gene, the env gene, and the U3 region of the long terminal repeat. The restricted tropism and acute pathogenicity of this cloned murine retrovirus provide a model for studying virus-induced stroke and for elucidating the mechanisms involved in syncytium formation by retroviruses in vivo.

Function of NAD glycohydrolase in ADP-ribose uptake from NAD by human erythrocytes

The function of the ectoenzyme NAD glycohydrolase (NADase) in ADP-ribose uptake from extracellular NAD was studied in human erythrocytes that express relatively high NADase activity (adult erythrocytes) and erythrocytes expressing very low activity (newborn erythrocytes). The rates of ADP-ribose uptake from NAD in human erythrocytes were correlated with their NADase activities. In contrast, there was no significant difference in the rates of ADP-ribose uptake among these cells when incubated with ADP-ribose. These results indicate that ecto-NADase may have a role as supplier of ADP-ribose for its uptake into the cells and that the cleavage of NAD by NADase is necessary for the ADP-ribose uptake by human erythrocytes. From ADP-ribose uptake studies at 37 degrees C a Km of 0.7 +/- 0.05 microM and a Vmax of 2.04 +/- 0.1 pmol/min per microliter cell water was found for the uptake of [3H]ADP-ribose. The thiol-reactive reagents p-chloromercuribenzene sulfonic acid and N-ethylmaleimide inhibited the uptake ADP-ribose with IC50 values of 50 +/- 4 and 750 +/- 25 mM, respectively. Since efflux of [3H]ADP-ribose was negligible, the ADP-ribose transport system appears to be unidirectional. The unidirectionality was supported by the evidence that transported ADP-ribose was rapidly degraded to AMP which is impermeable to the membrane.

Purification and characterization of NAD glycohydrolase from rabbit erythrocytes

The NAD glycohydrolase (NADase) was solubilized from intact erythrocytes with bacterial phosphatidylinositol-specific phospholipase C and purified to homogeneity by affinity chromatography on Cibacron blue-agarose. This purification procedure resulted in an approximately 85-fold purification with an overall recovery of 75%. The purified NADase has a molecular weight of 65,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 63,000 as determined by gel permeation column chromatography at pH 7.0. Two hybridoma cell lines secreting antibodies against NADase were established and the antibodies recognized the purified enzyme as well as a 65-kDa band from the extracts of rabbit erythrocyte ghost. The enzyme displayed a Km of 43 microM for beta-NAD, a Vmax of 23 mumol/min/mg, a broad pH optimum around pH 7.0, and pI of 5.0. Nicotinamide and isoniazid are inhibitors (Ki values, 2.5 and 3.5 mM, respectively) of the noncompetitive type. Adenosine diphosphoribose acts as a competitive inhibitor (Ki = 2.0 mM). Cibacron blue 3GA is a potent competitive inhibitor of NADase (Ki = 96 nM). The purified enzyme splits beta-NAD, NADP, and nicotinamide hypoxanthine dinucleotide among the compounds tested and does not exhibit transglycosidase activity. Amino acid composition of the rabbit erythrocyte enzyme differed from that of NADases of other species, and the purified NADase contains 8% carbohydrate and a stoichiometric amount of inositol.

CD4-positive and B lymphocytes in transplantation immunity. I. Promotion of tumor allograft rejection through elimination of CD4-positive lymphocytes

The elimination of CD4+ cells by anti-CD4 antibody caused regression of a malignant solid tumor allograft that does not lose a cytotoxic T lymphocyte-defined target antigen during tumor progression and requires specific CD8+ CTL for tumor rejection. Treatment with anti-CD4 antibody was effective when started 1-2 weeks after tumor challenge and was at least as effective as treating with anti-CD3 antibody or specific immunization with the antigen expressed on malignant or nonmalignant cells. None of these treatments caused rejection of tumors that were larger than 1 cm3 or had been growing for 3 weeks or longer in the host. Mice bearing large and long-established tumors treated with anti-CD4 antibody rejected a new tumor challenge but failed to reject the long-established tumor. Similarly, mice with established tumors mounted effective CTL responses to reject skin grafts but failed to reject tumors which expressed the same antigen. Treatment with anti-CD4 antibody eliminated primary T lymphocyte dependent antibody responses but failed to suppress ongoing antibody responses to continuous antigenic stimulation. Possibly, the effectiveness of early treatment and the failure of later treatment with anti-CD4 antibody results indirectly from the effect treatment has on B lymphocytes.

Inhibition of the tetracycline efflux antiport protein by 13-thio-substituted 5-hydroxy-6-deoxytetracyclines

A series of 13-(alkylthio) and 13-(arylthio) derivatives of 5-hydroxy-6-deoxytetracycline (tetracycline, Tc) were synthesized and compared to the clinically used antibiotics tetracycline, methacycline, and minocycline for their ability to inhibit tetracycline efflux in an everted membrane vesicle assay of bacterial resistance to tetracyclines. The assay screened for the ability of tetracycline analogues to inhibit [3H]tetracycline uptake into everted membrane vesicles, thereby evaluating the molecular prerequisites for inhibition of an efflux-dependent resistant bacterial system. Thiol adducts attached at the exocyclic C13 carbon of methacycline led to an increase in inhibitor potency as compared to the reference antibiotics. The most potent inhibitors of [3H]tetracycline uptake into everted vesicles among these analogues, particularly members of the alkyl series, revealed important structure-activity relationships between inhibitor potency, steric parameters, and lipophilicity at the C13 sulfur position.

Hemolytic mechanism of cytolysin produced from V. vulnificus

The characteristics of hemolytic action of cytolysin produced from V. vulnificus were investigated in mouse erythrocytes. The cytolysin bound erythrocyte membranes in temperature-independent manner and then lysed cells temperature-dependently. Hemoglobin release by the cytolysin was completely inhibited by the presence of raffinose or melezitose, but K+ release was not affected. The cytolysin-induced hemolysis was always accompanied with the conversion of membrane-bound cytolysin into an oligomer of 210 kDa, corresponding to a tetramer of native cytolysins. Nonesterified cholesterol inactivated the cytolysin by converting active monomeric cytolysin into inactive oligomer. The results suggest that the cytolysin lyses erythrocytes due to the formation of small pores on erythrocyte membrane by cholesterol-mediated oligomerization of the cytolysin.

Long-term inhibition of tumor growth by tumor necrosis factor in the absence of cachexia or T-cell immunity

The relationship between detrimental (cachectic) and beneficial (antitumor) effects of tumor necrosis factor (TNF) was studied in mice bearing murine tumors transfected to secrete human TNF. In vitro, the TNF-producing transfectants were resistant to the secreted TNF and grew at rates similar to those of untransfected cells or transfected cells that did not secrete TNF. However, tumors formed by the TNF-secreting cells in vivo remained much smaller than the nonsecreting (transfected and untransfected) tumors. This inhibition of tumor growth required only relatively low serum levels of TNF, persisted for many weeks, and was independent of T cells since it occurred in nude mice. Growth of the TNF-secreting tumors increased dramatically after treatment with anti-human TNF antibody, indicating that extracellular TNF secreted by the tumor cells was necessary for the tumor inhibition. Severe weight loss characteristic of cachexia only occurred in animals with very high serum TNF levels (250 pg/ml) and could be prevented or reversed by anti-TNF antibody treatment. These data are consistent with the existence of a therapeutic window in which persistent exposure to human TNF can lead to prolonged inhibition of tumor growth in the absence of T-cell immunity or severe weight loss and without development of resistant tumor variants.

A highly immunogenic tumor transfected with a murine transforming growth factor type beta 1 cDNA escapes immune surveillance

A highly immunogenic C3H-derived UV-induced tumor was cotransfected with a murine transforming growth factor type beta 1 (TGF-beta 1) cDNA and a neomycin-resistance gene. Stable clones were isolated and used in vitro and in vivo to determine the effects of endogenously produced TGF-beta on cytolytic T-lymphocyte (CTL) responses. Tumor cells producing TGF-beta, though retaining expression for class I major histocompatibility complex molecules and the tumor-specific antigen, did not stimulate primary CTL responses in vitro and were not effective in vivo for directly stimulating primary CTL or in priming for CTL responses. Furthermore, TGF-beta-producing tumors grew progressively in transiently immunosuppressed mice without losing the tumor antigen; thus, TGF-beta produced by tumors may promote escape from immune surveillance.

The cryptic tetracycline resistance determinant on Tn4400 mediates tetracycline degradation as well as tetracycline efflux

Escherichia coli containing the cryptic tetracycline resistance determinant (class F) from the Bacteroides fragilis transposon Tn4400 on plasmid pGAT400 expressed a detoxification of tetracycline as well as an active efflux of tetracycline. This finding concurs with the report of detoxification for a related tetracycline resistance determinant from B. fragilis on Tn4351 (B. S. Speer and A. Salyers, J. Bacteriol. 170:1423-1429, 1987), which specifies a 10-fold-higher resistance than Tn4400. Inactivation of tetracycline occurred at an initial rate of congruent to 0.7 micrograms of tetracycline per h per 10(8) cells, as determined by biologic assay and chromatographic analysis. The detoxification is a chemical degradation which can occur in the absence of energy-dependent efflux. The products of this degradation were not substrates for active transport into susceptible cells or out of pGAT400-containing E. coli. These results indicate that Tn4400 mediates two functionally different mechanisms for tetracycline resistance: an active efflux of tetracycline and a degradation of tetracycline.

Cryptic tetracycline resistance determinant (class F) from Bacteroides fragilis mediates resistance in Escherichia coli by actively reducing tetracycline accumulation

Escherichia coli bearing a cryptic tetracycline resistance determinant from Bacteroides fragilis expressed low-level constitutive resistance to tetracycline under aerobic, but not anaerobic, growth conditions and accumulated less tetracycline aerobically than did isogenic susceptible cells. This decreased uptake was energy dependent and reversible by increased concentrations of tetracycline, suggesting a saturable carrier-mediated active efflux mechanism. Decreased uptake was not seen when the cells were grown and assayed anaerobically. Other tetracycline resistance determinants (classes A to E) isolated from gram-negative enteric bacteria expressed resistance and generated active efflux of tetracycline under anaerobic as well as aerobic conditions. When the Bacteroides determinant was placed in the same cell with any of the class A to E tetracycline resistance determinants, there was an increase in resistance under aerobic conditions of as much as 48% more than was projected by adding the resistances expressed by the determinants individually. In cells bearing the class A determinant together with the Bacteroides determinant, saturation of the active efflux system required over twofold more exogenous tetracycline than did cells bearing the class A determinant alone. We have designated this new tetracycline resistance determinant class F.

Energy-dependent efflux mediated by class L (tetL) tetracycline resistance determinant from streptococci

The class L (TetL) tetracycline resistance determinant from streptococci specified resistance and an energy-dependent decreased accumulation of tetracycline in both Streptococcus faecalis and Escherichia coli. Using E. coli, we showed that the reduced uptake resulted from active efflux. The streptococcal class M determinant, known to render the protein synthesis machinery of S. faecalis resistant to tetracycline inhibition, did not alter tetracycline transport in either host.

Serum antibodies to cow's milk proteins in ulcerative colitis and Crohn's disease

Serum antibodies of immunoglobulin G, immunoglobulin M, and immunoglobulin A isotypes to five major proteins of cow's milk, casein, bovine serum albumin, alpha-lactalbumin, beta-lactoglobulin A, and beta-lactoglobulin B, were measured using enzyme-linked immunosorbent assay in 51 patients with ulcerative colitis, 49 with Crohn's disease, and 20 age-matched controls. Immunoglobulin G and immunoglobulin M antibodies to cow's milk proteins were significantly elevated in patients with inflammatory bowel disease as compared to controls. In contrast, no significant increase in immunoglobulin A antibodies to 3 of 5 proteins was noted. The increased titers of antibodies to milk proteins seem to be specific and not due to a polyclonal immunoglobulin activation, as naturally occurring blood group antibodies were not elevated in patients with ulcerative colitis and Crohn's disease. A good correlation of disease activity, as measured by serum alpha 1-acid glycoprotein concentrations, and immunoglobulin G and immunoglobulin A antibody titers against certain cow's milk proteins could be demonstrated in Crohn's disease, but not ulcerative colitis. These findings suggest that production of antibodies to cow's milk proteins reflects specific immunization with these antigens. The study of antibody isotypes and correlation with disease activity may provide better insight into the immune response to dietary antigens and its possible role in the pathogenesis of inflammatory bowel diseases.

Defective immunoregulation in children with chronic otitis media with effusion

Otitis media and middle ear effusions (MEE) are most common clinical problems in early childhood, for which an estimated one million tympanostomies are performed each year in the United States. Although many factors have been associated with MEE (age, sex, genetics, otitis media, socioeconomic status, feeding style, atopy or hypersensitivity, certain bacteria and viruses), a defective immunoregulatory mechanism in the host may also contribute to the pathogenesis. During the past 2 years, we have evaluated immune function in 90 randomly selected children who underwent repeated tympanostomy for persistent MEE. The T-cell subset ratio (OKT-4/OKT-8) was reduced (below 1.25) in 16%. In 33 children, generation of T-cell growth factor (IL-2) by peripheral blood lymphocytes (PBL) was evaluated and found to be decreased in 11. The mitogenic response of PBL to phytohemagglutinin (PHA) and pokeweed mitogen (PWM) stimulation was abnormal in almost half of the cases. Imbalance of T-cell subsets and decreased production of IL-2 indicate defective immunoregulatory function in some of these children, which may play a role in the pathogenesis of persistent MEE.

Adenovirus type 2 encephalitis and concurrent Epstein-Barr virus infection in an adult man

A 30-year-old bisexual male prisoner with a history of intravenous drug abuse manifested encephalitis. Adenovirus type 2 was isolated from brain tissue obtained by a biopsy and there was a concurrent fourfold rise in the antibody titer. In addition, an initial negative result from a slide test for infectious mononucleosis heterophil antibodies (Monospot) test converted to positive and there was an increase in the IgG antibody titer to Epstein-Barr virus (EBV) viral capsid antigen. Although he was anergic to skin test antigens, T-cell subsets and lymphocyte transformation study results were normal. This case demonstrated a rare adenovirus encephalitis with a simultaneous EBV infection in a patient at risk for acquired immunodeficiency syndrome, who had minimal evidence of T-cell deficiency.

Increased serum antibody levels against cow's milk proteins in children with chronic liver disease

We measured IgG, IgM and IgA antibodies to cow's milk proteins: alpha-casein, alpha-lactalbumin, bovine serum albumin, beta-lactoglobulin-a and beta-lactoglobulin-b in the sera of 29 pediatric patients with liver disease. IgG antibodies to bovine serum albumin, beta-lactoglobulin-a and beta-lactoglobulin-b and IgA antibodies to alpha-casein were elevated in most of the patients compared to age-matched controls. We postulate that, in patients with liver disease either increased intestinal uptake resulting in increased humoral response, or decreased hepatic clearance of food antigens intensifying a humoral response to these foreign antigens, may occur.

The periodontal microflora of juvenile diabetics. Culture, immunofluorescence, and serum antibody studies

These studies demonstrate a unique constellation of organisms populating the subgingival area in periodontitis lesions of patients with juvenile or insulin-dependent diabetes mellitus (IDDM). The cultivable microflora was predominated by Capnocytophaga and anaerobic vibrios in the patients studied. In some patients, Actinobacillus actinomycetemcomitans were also found. This distinguishes the subgingival flora of IDDM patients suffering from periodontitis from that of patients with localized juvenile periodontitis (LJP), and that of adult periodontitis patients. In LJP most patients harbor both A actinomycetemcomitans and Capnocytophaga subgingivally; and in periodontitis lesions from nondiabetic adults, black-pigmented Bacteroides such as B gingivalis or B melaninogenicus subspecies intermedius are often found. Antibiotic susceptibility patterns suggest that penicillin or tetracycline or its analogs such as minocycline may be effective against the predominant cultivable microflora in periodontal lesions of IDDM patients; however, individual patients may harbor flora with significant resistance to these antibiotics.

IgE and IgD antibodies to cow milk and soy protein in duodenal fluid: effects of pancreozymin and secretin

Duodenal fluid IgE was reported to be increased in food allergy and in inflammatory conditions of the bowel. We studied the presence and specificity of IgE and IgD antibodies against alpha-casein, beta-lactoglobulin A, alpha-lactalbumin, bovine serum albumin and soy bean agglutinin using an enzyme-linked immunoassay (ELISA). Thirteen children with various intestinal diseases and thirteen normal adult volunteers were examined. In resting duodenal fluids, 8/13 of the children had IgE and 5/13 had IgD, while only 1/13 of the adults showed detectable IgE and IgD. After pancreozymin, 4/6 of the children and 4/8 of the adults showed detectable IgE and IgD in their duodenal fluids. After secretin, the duodenal fluids from 1/8 of the children and 2/8 of the adults had detectable IgE, while 6/13 children and 1/10 of the adults had IgD. The results indicate an increase in duodenal contents of IgE and IgD antibodies specific to cow's milk and soy protein after pancreozymin. Since this mediator is normally released during digestion, it is suggested that IgE and IgD antibodies specific for food proteins, may be involved in the physiological processing of foods in the intestine. In infants and children with gastrointestinal disease, the incidence of IgE and IgD antibodies specific for milk and soy proteins is higher in basal and pancreozymin-stimulated duodenal fluid when compared with control adults.

Pancreozymin and secretin enhance duodenal fluid antibody levels to cow's milk proteins

Duodenal fluid was collected from normal volunteers before and after stimulation with pancreozymin-cholecystokinin and secretin. Protein content, proteolytic enzyme activities, and antibody activities against cow's milk proteins, alpha-casein, and beta-lactoglobulin B, were measured in the duodenal fluid. After pancreozymin-cholecystokinin stimulation, immunoglobulin A and immunoglobulin M antibody activities rose to peak levels in 5-10 min. The increase in protein content and proteolytic enzyme activities after pancreozymin-cholecystokinin stimulation paralleled the increase in antibody activity against the two cow's milk proteins. Secretin, in spite of its known dilutional effect on duodenal fluid enzyme concentration, also produced a rise in immunoglobulin M and immunoglobulin A antibody activities. Only a slight increase in immunoglobulin G antibody activity was noted after both pancreozymin-cholecystokinin and secretin. It is suggested that, pancreozymin-cholecystokinin and secretin, in addition to their well-established effects on the release of digestive enzymes, also stimulate release of specific antibodies against food proteins. Release of antibody coincident with food intake may act in preventing the inadvertent absorption of antigenic food proteins.

Chemotactic activity in middle ear effusions

A study of chemotactic activity in different middle ear effusions (MEE) was undertaken using a technique that has overcome some of the pitfills of previous chemotactic investigations on MEE. In the present study, neutrophils were made to migrate upwards toward a chemotactic gradient. Chemotactic activity was differentiated from increased random migration by the use of a two-filter paper system. The study indicated that directed migration or chemotaxis was present in 65% of purulent effusions, in approximately 25% to 30% of serous and seromucinous effusions, but in less than 20% of mucoid effusions. Chemotactic agents in MEE have been discussed. Chemotactic activity for neutrophils may be an important part of the inflammatory response in otitis media with effusion (OME) and responsible for the elimination of bacteria and other foreign particles. On the other hand, prolonged chemotactic activity owing to immunologic or nonimmunologic mechanisms may be responsible for the release of lysosomal enzymes and the subsequent maintenance of an inflammatory response in middle ear tissue. The exact mechanism and nature of the underlying chemotactic response for leukocytes in OME remain to be determined.

Effects of DNP on rat thymocyte uptake of 2-deoxyglucose: effects of nutrients

Rat thymocyte glucose transport activity was measured by the uptake of 3H-2-deoxyglucose. In the presence of 5mM glucose, DNP stimulated the uptake of 2-deoxyglucose. In the absence of glucose, DNP inhibited the uptake of 2-deoxyglucose. Both stimulatory and inhibitor effects of DNP were DNP concentration dependent. The incubation of thymocytes with nutrients which are metabolized through mitochondrial oxidation, such as beta-hydroxybutyrate, pyruvate, alanine and glutamine, did not support the stimulatory effects of DNP on 2-deoxyglucose uptake. The incubation of thymocytes with a nutrient which can support glycolysis, such as adenosine, supported the stimulatory effect of DNP on 2-deoxyglucose uptake. Iodoacetate, an inhibitor of glycolysis, inhibited 2-deoxyglucose uptake even in the presence of glucose. The present data suggested that the stimulatory effect of DNP on thymocyte 2-deoxyglucose uptake required intact glycolysis activity.

Prednisolone disposition in steroid-dependent asthmatics

A 40-mg intravenous dose of prednisolone was given as prednisolone phosphate to seven severe steroid-dependent asthmatics and to 13 healthy volunteers to determine if the large prednisone requirements of these patients were a function of the disease, cellular response, or rapid clearance of prednisolone. Plasma concentrations of prednisolone, prednisone, and cortisol were determined by high-performance liquid chromatography over an 8-hr test period. Circulating eosinophil concentrations were monitored concurrently. The apparent half-lifes of prednisolone in the asthmatics and normals were 3.33 +/- 0.71 and 3.25 +/- 0.58 hr (mean +/- SD). The apparent plasma clearances of prednisolone were 201 +/- 54 and 198 +/- 38 ml/min/1.73 m2 and the apparent volumes of distribution were 50.8 +/- 11.7 and 53.5 +/- 13.5 L/1.73 m2 for the asthmatic and normal groups, respectively. When the concentration-dependent binding of prednisolone to plasma protein was examined, no differences in the apparent clearances of unbound drug were found between the two groups. The eosinopenic response to prednisolone was similar in the steroid-dependent asthmatics and healthy normal volunteers. These studies indicate that binding, distribution, and clearance of prednisolone are not responsible for the large prednisone requirement of some steroid-dependent asthmatics. Differences in steroid-receptor sensitivity or in severity or pathophysiology of the disease state more likely account for the need for large prednisone dosages in these patients.

Effect of Aroclor 1254 on leukocyte glucose uptake

Uptake of glucose in human leukocytes was estimated by measuring incorporation of 14C-labeled 2-deoxyglucose (2-DG) into the cells. Exposure of lymphocytes and monocytes, but not neutrophils, to Aroclor 1254 (10 microM) caused a decreased 2-DG uptake. This method of measuring glucose uptake may be useful for detecting potential polychlorinated biphenyl (PCB) target cells.

Chemotaxis of human neutrophils against gravity: a new method

A new method is described in which human neutrophils were made to migrate upward and against gravity. Thus, the possible effect of gravity on cell migration and consequent detachment of cell after migration have been eliminated.

Polymorphonuclear neutrophil function in malignant lymphomas and effects of splenectomy

Granulocyte (PMN) directional locomotion (migration) in vitro and in vivo, resting nitroblue tetrazolium (NBT)-reduction and adherence to nylon wool of polymorphonuclear neutrophils (PMN) were assayed in 7 patients with Hodgkin's disease (HD) and in 11 patients with non-Hodgkin's lymphoma (NHL) prior to therapy. In most patients with HD, NBT-reduction was increased and in all directional locomotion was markedly decreased both in vitro and in vivo. In addition to being depressed, accumulation of PMN into skin chambers in patients with HD correlated with the peripheral blood count (r = 0.95). In vitro directional migration of PMN in NHL was depressed in half the patients, but increased in the in vivo assay. After splenectomy, PMN-adherence tended to increase and NBT-reduction to decrease. These findings are compatible with a constant cellular defect of PMN in HD, whereas in NHL abnormal PMN function is more likely mediated by extracellular factors. Abnormal PMN function may correlate with clinical susceptibility to infection in malignant lymphomas.

Biochemical basis of aroclor 1254 and pesticide toxicity in vitro. 1. Effects on intracellular ATP concentration

Aroclor 1254 and op'-DDT inhibit lymphocyte mitogenic response to PHA. We use petri dish purified lymphocytes for studying the biochemical basis of chemical toxicity. Aroclor 1254 and DDT decrease lymphocyte intracellular ATP concentration. The inhibitory effect on ATP production is due to the suppression of mitochondrial respiration as judged by decreased oxygen consumption. Lymphocyte glycolysis measured by lactate production is not inhibited by Aroclor 1254 to any significant extent. ATP is required for various biosynthetic reactions following mitogenic stimulation. The inhibition of mitochondrial respiration which leads to decreased ATP concentration may be responsible for Aroclor inhibition of lymphocyte mitogenic response to PHA.

Effects of pesticides on human leukocyte functions

Aroclor 1254 and twelve pesticides of different chemical classes were tested for their in vitro effects on lymphocyte mitogenic responses to PHA, rosette formation with sheep red blood cells (E-rosette) and neutrophil chemotaxis. By using a diluted whole blood culture, butoxide at 10 micrometers inhibit lymphocyte mitogenic response to PHA by 26%. Inhibition by other pesticides were less than 20% (5--20(). Higher degrees of inhibition were observed if the lymphocytes were pretreated with pesticides in the absence of serum: pp-DDT inhibited by 73% trithion by 50% and benzylthiocyanate by 30%. E-rosette formation was less inhibited by these pesticides except DDT, which inhibited the E-rosette formation by 50% at 10(-4)M. Only methyl parathion was found to have some inhibitory effects on neutrophil chemotaxis. These results indicate that insecticides may have direct effects on the leukocyte function and that the presence of serum may alter the interaction of insecticides and leukocyte membranes.

An improved micro-method for enumeration of human B-cell rosettes with mouse red blood cells

A micro-method for enumerating B-lymphocytes in human peripheral blood is described, using formation of rosettes with mouse red blood cells as a B-cell marker. The optimal conditions for the enumeration of mouse red cell rosette forming cells have been defined. By this method, it was possible to utilize less than 1ml of peripheral blood (venous or capillary) for simultaneous enumeration of both T-cell and B-cell rosettes. Our study of human lymphoid cell lines, thymic cells, lymphocytes from agammaglobulinemia, and severe combined immunodeficiency has provided additional evidence that lymphocyte rosetting with mouse red blood cells represent B-lymphocytes.

Immunologic reconstitution in man--present status

Recent advances in immunobiology have shed new light on our understanding of the essential role of immunity as it relates to body economy. Immunity, once thought to be the primary defense mechanism against microbial infection, appears to have a much broader function--recognition and elimination of foreign bodies and preservation of the integrity of the individual. As our understanding of the pathophysiology of the immune system became more clear, immunologic reconstitution emerged as a new, promising mode of treatment for a variety of diseases with immunodeficiency. Bone marrow transplantation, thymus transplanation, transfer factor therapy, infusion of leukocytes, BCG vaccination, and other specific or nonspecific immunostimulants have been tried, with dramatic beneficial results in some instances. Although still in its infant stage, this form of treatment appears to have great potential and wide application in the prevention and treatment, not only of primary immunodeficiency, but also of many other diseases such as cancer, the so-called autoimmune diseases, and even aging.

Leprosy XII. Quantitative analysis of thymus-derived lymphocyte response to phytohemagglutinin in leprosy

The immune status of various leprosy patients was evaluated by using a micromethod to evaluate lymphocyte responses to phytohemagglutinin (PHA). In our study, whole blood was used and the degree of response to PHA stimulation was expressed in terms of unit volume of blood. A markedly decreased response to PHA stimulation was noted in patients with active lepromatous leprosy. Patients with active lepromatous leprosy who have been proved drug (DDS) resistant showed less response than did those of drug sensitive patients with active lepromatous disease, while the patients with active lepromatous leprosy complicated by erythema nodosum leprosum (ENL) showed higher response than did those of patients with no complicated ENL. Comparing the results obtained to those obtained using other methods for T cell analysis indicates that these results reflect the number of T lymphocytes in the leprosy patient. Thus, this simple method is of value in assaying the presence and responses of T lymphocytes in the leprosy patient.

Cell-mediated and humoral immune responses or renal transplant recipients with cytomegalovirus infections

Cell-mediated and humoral immune responses were determined in immunosuppressed renal transplant recipients. A micro-phytohaemagglutinin (PHA) stimulation test utilizing whole heparinized blood and a macro-PHA test utilizing separated, washed lymphocytes were used to study cell-mediated immunity. Humoral immune status was estimated by determining quantitative immunoglobulins and complement fixing (CF) antibody titres to cytomegalovirus (CMV) infection. Micro-PHA responses were found to be markedly depressed in patients undergoing immunosuppressive therapy and in patients with chronic uraemia. Macro-PHA responses were normal, indicating that serum factors were responsible for the depressed micro-PHA responses. Antibody responses to CMV infections were found to be ten to a hundred times higher than in normal persons. An inverse relationship was demonstrated between micro-PHA responses and peak CF antibody titres to CMV infections. Humoral immune responses appeared to compensate for depressed cell-mediated immunity as measured by the micro-PHA test. Four patients had very low micro-PHA responses, did not respond to their CMV infections with CF antibody, and died of mixed bacterial and viral infections. Serum immunoglobulins of two were studied and were shown to be greater than two standard deviations below the normal mean. These patients appeared more suppressed than other patients receiving similar therapy and thus probably retained higher concentrations of suppressive drugs.

Two separate genes controlling stimulation in mixed lymphocyte reaction in man

The genetic control of strong stimulation in the mixed lymphocyte culture reaction is determined by a separate gene (MLR-S) closely linked to the FOUR-locus of the HL-A chromosomal region. Three additional examples of siblings with recombination between FOUR-locus and MLR-S locus are presented which confirms the independent genetic control of mixed lymphocyte reaction from the control of HL-A antigens. The occurrence of two recombinant children in one family with four other children representing all possible HL-A haplotype-combinations, strongly supports the genetic mapping of the MLR-S determinants outside the HL-A chromosomal region. The experiments presented show that additional genes located within the HL-A region itself contribute with a weak stimulation of allogenic mixtures. These data are discussed in relation to the marginal stimulation of the mixed lymphocyte culture reaction which can be seen between unrelated individuals. It seems that a group of relatively histocompatible individuals can be defined by identity of the MLR-S locus but with differences on the weak MLC-determinants, and that this group for the purpose of clinical transplantation behaves as histocompatible individuals.

B and T lymphocytes in primary immunodeficiency disease in man

B- and T-cell populations in 32 patients with different forms of primary immunodeficiency disease were studied. The B-cells in peripheral blood were investigated with respect to surface immunoglobulins by means of immunofluorescence. The T-cell function was studied utilizing quantitation of proliferative response to phytochemagglutinin (PHA)(1) and delayed allergy to various antigens. In 10 patients lymph node lymphocytes were also evaluated 11 male children with infantile x-linked agammaglobulinemia were divided into two subgroups. One did not show immunoglobulin spots on peripheral blood lymphocytes at all, the other contained a very low percentage of IgM- and occasionally IgA bearing lymphocytes. Eight patients with common variable immunodeficiency had moderately decreased percentages of peripheral blood and lymph node lymphocytes with surface immunoglobulins, but these patients lacked immunoglobulin secreting cells. Four cases of isolated IgA deficiency had normal or high percentages, and two cases of ataxia-telangiectasia had high percentages of lymphocytes with IgA in so called receptor distribution in both peripheral blood and lymph nodes. In three patients with infantile combined immunodeficiency that had been corrected by marrow transplantation, the percentages of Ig-bearing lymphocytes increased to normal or high levels together with establishment of functional T-cell population and ultimate secretion of serum immunoglobulins. One case of Di George syndrome reconstituted by fetal thymus transplant showed gradual decrease of B lymphocytes in circulation parallel to restoration of T-cell population.