The regulatory role of divalent cations in human granulocyte chemotaxis. Evidence for an association between calcium exchanges and microtubule assembly

Optimal human granulocyte chemotaxis has been shown to require both calcium and magnesium. Exposure of granulocytes to three different chemotactic factors (C5a, kallikrein, and dialyzable transfer factor) yielded a rapid calcium release, depressed calcium uptake, and was associated with a shift of calcium out of the cytoplasm and into a granule fraction. Colchicine, sodium azide, and cytochalasin B, in concentrations that inhibited chemotaxis, also inhibited calcium release while low concentrations of cytochalasin B, which enhanced chemotaxis, also enhanced calcium release. Microtubule assembly was visualized both in cells suspended in C5a without a chemotactic gradient and in cells actively migrating through a Micropore filter. The data suggest microtubule assembly is regulated, at least, in part, by the level of cytoplasmic calcium. It is proposed that asymmetric assembly of microtubules may be instrumental in imparting the net vector of motion during chemotaxis.

Renal biopsy pathology in Wegener's granulomatosis

Eighteen renal biopsies from 10 patients with active generalized Wegener's granulomatosis (GWG), with GWG in remission on therapy, and with active localized Wegener's granulomatosis (LWG) have been examined by light and electron microscopy. In all 9 patients with active GWG, light microscopy revealed focal and segmental glomerulonephritis. Electron microscopy revealed subepithelial basement membrane densities resembling immune complex deposits in two biopsies from patients with active GWG. In biopsies from patients on cytotoxic therapy, there was no active inflammatory process, but focal glomercular obsolescence and segmental tuft sclerosis provided evidence of prior focal and segmental glomercular disease. Discrete zones of basement membrane crimping and increased mesangial material along the capillary wall were observed in some patients with apparent LWG, as well as proven GWG, possibly representing foci of previous glomerular injury. The appearance of dense deposits on the epithelial side of the basement membrane suggests that immune complex deposition in the glomeruli may be at least partially responsible for the renal injury in Wegener's granulomatosis.

Function of macrophages in antigen recognition by guinea pig T lymphocytes. I. Requirement for histocompatible macrophages and lymphocytes

Antigen activation of DNA synthesis in immune thymus-derived lymphocytes of guinea pigs requires the cooperation of macrophages and lymphocytes. We have investigated the role of histocompatibility determinants in this macrophage-lymphocyte interaction using cells from inbred strain 2 and 13 guinea pigs. The data demonstrate that efficient presentation of macrophage-associated antigen to the lymphocyte requires identity between macrophage and lymphocyte at some portion of the major histocompatibility complex. The failure of allogeneic macrophages to effectively initiate immune lymphocyte proliferation was not the result of the presence of an inhibitor of blastogenesis released in mixtures of allogeneic cells, peculiarities of the antigen or lymphoid cells employed, nor differing kinetics of activation by allogeneic macrophages. In addition, data were presented that demonstrated that alloantisera inhibit lymphocyte DNA synthesis by functional interference with macrophage-lymphocyte interaction.

Function of macrophages in antigen recognition by guinea pig T lymphocytes. II. Role of the macrophage in the regulation of genetic control of the immune response

A number of recent studies have suggested that the main functional role of the product of the immune response (Ir) genes is in the process of antigen recognition by the T lymphocyte. The observation in the accompanying report that the interaction of macrophage-associated antigen with immune T lymphocytes requires that both cells share histocompatibility antigens raised the question as to whether the macrophage played a role in the genetic control of the immune response or even if the macrophage were the primary cell in which the product of the Ir gene is expressed. In the current study, parental macrophages were pulsed with an antigen, the response to which is controlled by an Ir gene lacking in that parent; these macrophages were then mixed with T cells derived from the (nonresponder x responder)F(1) and the resultant stimulation was measured. No stimulation was seen when column-purified F(1) lymph node lymphocytes were mixed with antigen-pulsed macrophages from the nonresponder parent. However, when the highly reactive peritoneal exudate lymphocyte population was used as the indicator cells, parental macrophages pulsed with an antigen whose Ir gene they lacked were capable of initiating F(1) T-cell proliferation. The magnitude of stimulation was approximately 1/10 that seen when macrophages from either the responder parent or the F(1) were used. In order to explain this observation, we hypothesize that antigen recognition sites on the T lymphocyte are physically related to a macrophage-binding site and both are linked to the serologically determined histocompatibility antigens. Thus, parental macrophages pulsed with an antigen, whose Ir gene they lack, activate F(1) cells poorly because the recognition sites for the antigen are physically related to the macrophage-binding site of the responder parent while the main contacts between the cells are at the nonresponder binding sites. Experiments performed with alloantisera lend support to this hypothesis. Thus, when parental macrophages are pulsed with any antigen and added to F(1) T cells, an alloantiserum directed against parental histocompatibility antigens reacts with both the lymphocyte and the macrophage and thereby inhibits macrophage-lymphocyte interaction and abolishes antigen-induced lymphocyte transformation. When the alloantisera are directed at determinants present solely on the T lymphocyte, they only inhibit the recognition of antigens controlled by the Ir gene linked to the histocompatibility antigen against which they are directed. We conclude from these studies that antigen recognition by the T lymphocyte is a complex multicellular event involving more than simple antigen binding to a specific lymphocyte receptor.

Macrophage-lymphocyte interaction. I. Characteristics of the antigen-independent-binding of guinea pig thymocytes and lymphocytes to syngeneic macrophages

The nature of the physical interaction between guinea pig non-glass-adherent lymphoid cells and syngeneic macrophages in vitro was investigated. This cellular interaction was found to require the presence of metabolically intact macrophages but neither serum nor antigen. Peritoneal, splenic, or alveolar macrophages were significantly more capable of interacting with thymocytes than either polymorphonuclear leukocytes or fibroblasts. The role of the non-glass-adherent cell was passive in that heat-killed or metabolically poisoned thymocytes were bound by normal macrophages. Two normal lymphoid cell populations, thymocytes, and lymph node lymphocytes, were bound to macrophages in significantly larger numbers than either L(2)C leukemia cells or erythrocytes. Thus, specificity for each of the participant cell types was demonstrated. These data indicate that macrophages possess a unique ability to recognize and bind lymphocytes and thymocytes by a mechanism which is distinguishable from other known macrophage receptors.

Functional heterogeneity of murine lymphoid cells. V. Lymphocytes lacking detectable surface theta or immunoglobulin determinants

An appreciable percent (3-14%) of the lymphocyte-like cells of the mouse spleen lack both the theta-isoantigen and sufficient surface immunoglobulin to be detected by conventional immunofluorescence or autoradiographic procedures. These theta(-),Ig(-) cells are increased in frequency after treatment of mice with antithymocyte serum or in mice that have been thymectomized, irradiated (850 R), and reconstituted with bone marrow cells. Moreover, in chimeric C57BL/6 mice in which the T cells are derived from (BALB/c x C57BL/6)F(1) donors, theta(-),Ig(-) cells also lack BALB/c histocompatibility antigens. These experiments indicate that theta(-),Ig(-) cells are not theta(-) T lymphocytes. Removal of complement receptor lymphocytes from spleen cell populations increases the frequency of theta(-),Ig(-) cells, indicating that such cells lack the complement receptor. Partially purified populations of theta(-),Ig(-) cells have been obtained by cytolysis by anti-theta- and anti-kappa-antibody and complement and by density gradient ultracentrifugation. These cells closely resemble lymphocytes in morphology. The only exceptional feature is the existence of prominent nucleoli. The theta(-),Ig(-) cells lack hemoglobin and endogenous peroxidases, are not actively phagocytic, and do not adhere to glass. This suggests they are not of the erythroid, myeloid, or monocytoid lines. [(3)H]Thymidine labeling studies indicate that theta(-),Ig(-) cells are members of a relatively slowly dividing cell pool. Whether theta(-),Ig(-) cells are members of the "classical" B lymphocyte line or belong to another, as yet undescribed, lineage is not yet certain.

Glucocorticoid suppression of macrophage migration inhibitory factor

The ability of hydrocortisone to modify antigen-mediated inhibition of macrophage migration, an in vitro correlate of cellular immunity in the guinea pig, was investigated. Only the glucocorticoids, hydrocortisone and dexamethasone, significantly blocked migration inhibitory factor (MIF) activity in pharmacologic concentrations. Hydrocortisone had no effect on antigen "processing" by macrophages, nor on the ability of antigen-stimulated peritoneal exudate lymphocytes to produce MIF. Rather, hydrocortisone antagonized directly the inhibitory effect of MIF on the macrophage.

Evidence for a nonprecipitating antibody in the guinea pig

Guinea pigs immunized with horseradish peroxidase (HRPO) in complete Freund’s adjuvant develop significant delayed hypersensitivity as measured <i>in vivo </i>and <i>in vitro, </i>while sera from these same guinea pigs do not contain detectable amounts of precipitating antibody. Sera from HRPO-immunized guinea pigs will, however, inhibit the precipitation of HRPO and agglutination of sheep erythrocyte HRPO conjugates by specifically purified rabbit IgG anti-HRPO. Initial characterization suggests that these immune sera contain a nonprecipitating antibody.

The uropod-bearing lymphocyte of the guinea pig. Evidence for thymic origin

In this study, the frequency of uropod formation and the type of lymphocyte bearing the uropod was investigated in various guinea pig lymphocyte populations. Without prior in vitro stimulation, almost 40% of peritoneal exudate lymphocytes (PELS) form uropods, while thymocytes and lymph node cells form far fewer. Subsequent stimulation in vitro with purified protein derivative demonstrated that there is an association between antigen reactivity and frequency of uropod formation in these populations. The ultrastructure of these uropods is identical to that described for human lymphocytes stimulated with phytohemagglutinin. In the populations studied, all the lymphocytes forming uropods lack easily detectable surface membrane immunoglobulin and are therefore most likely thymus-derived or T lymphocytes.

Abnormal bactericidal, metabolic, and lysosomal functions of Chediak-Higashi Syndrome leukocytes

Phagocytic, antimicrobial, and metabolic functions were studied in leukocytes obtained from three patients with the Chediak-Higashi syndrome (CHS) and compared to normals, individuals, heterozygous for Chediak-Higashi syndrome, and two subjects with chronic granulomatous disease of childhood (CGD). Chediak-Higashi syndrome leukocytes showed normal ingestion of a variety of bacteria, Candida albicans, and polystyrene latex particles. Intracellular destruction was significantly impaired for Staphylococcus aureus, Group D streptococci, and a rough strain of Type II pneumococci over a 2 hr incubation. Killing of Serattia marcescens was consistently delayed at 1 hr whereas that of Escherichia coli and C. albicans appeared normal, unless the incubations were shortened to 20 min. Examination of the rates of killing indicated that the greatest defect occurred in the first 20 min of contact between Chediak-Higashi syndrome cells and bacteria. Separation of Chediak-Higashi syndrome granulocytes from monocytes revealed that the former were most defective in bactericidal activity. After phagocytosis, Chediak-Higashi syndrome granulocytes displayed a normal burst in oxygen consumption and oxidation of glucose-1-(14)C and glucose-6-(14)C and formate-(14)C. Oxidation of glucose-1-(14)C by non-phagocytizing Chediak-Higashi syndrome granulocytes and monocytes averaged 2-3 times normal, whereas glucose-6-(14)C and formate-(14)C oxidation were not significantly increased by resting cells. Iodination of intracellular protein by Chediak-Higashi syndrome leukocytes was significantly increased above normal in both the resting and phagocytizing state. Electron microscopic histochemistry revealed that almost all peroxidase activity was localized to the giant granules in Chediak-Higashi granulocytes, and after bacterial ingestion there was a failure of delivery of peroxidase to many phagosomes. Upon longer incubation more phagosomes acquired peroxidase activity, presumably through a fusion process, although many giant granules remained intact. The contrasting patterns and kinetics of the killing defects and the differing metabolic properties of Chediak-Higashi syndrome and chronic granulomatous disease leukocytes emphasize the pleiomorphic nature of inherited disorders of leukocyte function.

The peritoneal exudate lymphocyte. I. Differences in antigen responsiveness between peritoneal exudate and lymph node lymphocytes from immunized guinea pigs

Peritoneal exudate lymphocytes from guinea pigs immunized with horse radish peroxidase, dinitrophenyl guinea pig albumin, or ferritin in complete Freund's adjuvant have been shown to be significantly more reactive than other lymphocytes in two in vitro assays of cellular immune function: production of macrophage migration inhibitory factor and antigen-induced lymphocyte proliferation. The enhanced reactivity of peritoneal exudate lymphocytes cannot be accounted for by artifacts introduced by column purification or by the presence of nonlymphoid accessory cells. These observations suggest that the peritoneal exudate lymphocyte pool is a highly enriched source of cellular immune effector cells with specificity directed towards those antigenic determinants to which an animal has been recently exposed.

The influence of postnatal development on drug-induced hepatic porphyria and the synthesis of cytochrome P-450. A biochemical and morphological study

The mitochondrial enzyme delta-aminolevulinate synthetase (ALAS) controls the rate-limiting step in the synthesis of porphyrins and heme. An experimental form of hepatic porphyria can be readily elicited in laboratory animals, such as the rat, by drugs and foreign chemicals which are known to enhance the de novo formation of this enzyme in the liver. The present study shows that there is a striking refractoriness to the induction of ALAS during the perinatal period in the rat. Chemicals which have potent porphyria-inducing activity in adult animals have no significant inducing effect on hepatic ALAS in neonates. The ultrastructural changes which accompany the induction of ALAS by drugs and chemicals in adult liver also fail to take place in the livers of neonates. A progressive capacity for responding to the action of chemical inducers of hepatic ALAS does, however, develop in neonatal animals so that by approximately 5-6 wk of age experimental porphyria can be elicited as effectively in them as in adults. The reasons for the refractoriness of hepatic ALAS to induction in the perinatal period are not known; but the findings of this study make it clear that ALAS belongs to that increasingly large group of liver enzymes in mammals whose appearance, increase of activity, or inducibility is developmentally determined. The occurrence of developmental changes in the indicibility of ALAS in the liver of neonates also provided an opportunity to study the relationship of this enzyme activity to the drug-mediated induction of the hepatic hemoprotein cytochrome P-450. This inducible hemoprotein serves as the terminal oxygenase in the microsomal mixed-function oxidase system in the liver. The results of this study indicate that, in contrast to the refractoriness of ALAS to induction, significant drug-induced changes of hepatic P-450 content and of hemeprecursor incorporation into this cytochrome do take place in neonates. The synthesis of P-450 thus appears to be under a regulatory control different from that of ALAS in neonates, and the relation between ALAS activity and P-450 formation is not therefore a direct one.