T cell subsets in allograft rejection. In situ characterization of T cell subsets in human skin allografts by the use of monoclonal antibodies

We have provided evidence that both major T cell subsets, T4-positive (helper/inducer) and T8-positive (cytotoxic/suppressor), infiltrate human skin allografts. Overall, and in the graft dermis and graft bed, T4-positive cells were predominant (1.5 to 3 times more numerous than T8-positive cells). In contrast, T8-positive cells were relatively more numerous in the epidermis and hair follicles. Rejection probably proceeded by two apparently independent pathways: 1) direct contact killing of graft epithelial cells, presumably by immunologically specific T8-positive cytotoxic cells, and 2) injury of microvascular endothelium of both the graft and graft bed with secondary graft infarction. Although important in first set skin allograft rejection, the mechanism of the second type of killing is uncertain. T4-positive cells were probably involved, as evidenced by their greater numbers; furthermore, studies in mice have shown that transfused helper/inducer cells are able to effect first-set skin graft rejection. It remains to be determined whether T4-positive cells act alone or cooperate with other cells to destroy vessels and bring about graft rejection. Langerhans cells were recognized in epithelial and dermal compartments of both allografts and autografts by their reactivity with anti-T6 and anti-Ia antibodies. We could not determine whether such cells in allografts were of host or donor origin.

T cell subsets in allograft rejection. In situ characterization of T cell subsets in human skin allografts by the use of monoclonal antibodies

We have provided evidence that both major T cell subsets, T4-positive (helper/inducer) and T8-positive (cytotoxic/suppressor), infiltrate human skin allografts. Overall, and in the graft dermis and graft bed, T4-positive cells were predominant (1.5 to 3 times more numerous than T8-positive cells). In contrast, T8-positive cells were relatively more numerous in the epidermis and hair follicles. Rejection probably proceeded by two apparently independent pathways: 1) direct contact killing of graft epithelial cells, presumably by immunologically specific T8-positive cytotoxic cells, and 2) injury of microvascular endothelium of both the graft and graft bed with secondary graft infarction. Although important in first set skin allograft rejection, the mechanism of the second type of killing is uncertain. T4-positive cells were probably involved, as evidenced by their greater numbers; furthermore, studies in mice have shown that transfused helper/inducer cells are able to effect first-set skin graft rejection. It remains to be determined whether T4-positive cells act alone or cooperate with other cells to destroy vessels and bring about graft rejection. Langerhans cells were recognized in epithelial and dermal compartments of both allografts and autografts by their reactivity with anti-T6 and anti-Ia antibodies. We could not determine whether such cells in allografts were of host or donor origin.

A cloned cell with NK function resembles basophils by ultrastructure and expresses IgE receptors

Natural killer (NK) cells are defined by their ability to lyse certain tumour cells in vitro without previous exposure to them, and have been postulated as effectors of immune surveillance against spontaneous neoplasms. Because they kill some non-neoplastic lymphoid cells, they may also have a role in immunoregulation. NK cell activity resides in a small proportion of normal mouse spleen cells (less than 5%) that have been difficult to characterize completely. They may represent a heterogeneous group of effector cells whose precise relationship to other myelopoietic or immunological cells has remained obscure. We have previously described a cloned mouse cell line (Cl. Ly 1-2-NK-1+/11) with the functional characteristics of natural killer cells activated by interferon or other factors. We now find that this cloned line, like basophils and mast cells, expresses high-affinity plasma membrane receptors (Fc epsilon R) specific for IgE antibody. In addition, the clone contains cytoplasmic granules similar by ultrastructure to those of basophils of the mouse and other species. Our findings indicate that cells sharing morphological and biochemical features of basophilic granulocytes can mediate NK lysis.

Fibrin deposits in Hodgkin's disease

Fibrin deposits were observed in the involved lymph nodes and/or spleens of 15 patients with Hodgkin's disease by specific immunofluorescence and by electron microscopy. Two basic patterns of fibrin deposition were observed: 1) intercellular deposits, chiefly associated with nonneoplastic-appearing lymphoid cells and 2) deposits associated with the collagen fibers of young connective tissue. In addition, coarse fibrin deposits were observed in areas of necrosis, presumably a non-specific finding. Fibronectin was also observed in intercellular areas, but staining was less intense than for fibrin. Fibrin deposits were also observed in 3 of 6 cases of non-Hodgkin's lymphoma, indicating that the finding is not an exclusive feature of Hodgkin's disease. The pathogenesis and possible significance of fibrin deposition in Hodgkin's disease are related to earlier observations of activation of the coagulation system on neoplasia and cell-mediated immunity and to the possible role of fibrin, fibronectin, and their breakdown products in angiogenesis and fibroplasia.

Anaphylactic degranulation of guinea pig basophilic leukocytes. II. Evidence for regranulation of mature basophils during recovery from degranulation in vitro

Mature circulating granulocytes have been considered functionally end stage cells unable to reconstitute their specific cytoplasmic granules. We have reevaluated this assumption by studying guinea pig peripheral blood basophils maintained in vitro for periods up to 72 hours after anaphylactic degranulation. Guinea pig basophils degranulated in vitro by exposure to either specific antigen (sheep serum) or lectin (Concanavalin A) synthesized new cytoplasmic granules. This process was characterized by the appearance of abundant rough endoplasmic reticulum, activation of the Golgi zone, interiorization of plasma membrane, and successive formation of empty vacuoles, multivesicular bodies, immature granules, and, finally, typical mature basophil granules. Although basophil neogranulogenesis in vitro was similar in most respects to that occurring in the bone marrow, it differed significantly in that regranulating basophils retained the nuclear characteristics of mature granulocytes. New basophil granule formation was more prominent and developed earlier when sheep serum was employed as the degranulation stimulus. Cultures degranulated with Concanavalin A, and, less commonly, sheep serum, also contained small numbers of basoblasts, large bizarre basophils with immature nuclear and cytoplasmic features, cytoplasmic lipid droplets, and mature, immature, and fused granules. These cells may arise by a process analogous to lymphocytes blast transformation.

Dermal hypersensitivity reactions to insulin: correlations of three patterns to their histopathology

Fifteen diabetics with recurrent painful local reactions to insulin were studied. Reactions occurring after intradermal insulin injection were observed in nine patients over 48 hr and biopsies were taken at intervals for microscopic study using the 1 mu Giemsa technique. Insulin-specific IgE and IgG levels were measured on all patients. Five patients had biphasic reactions in which wheal and flare (WFR) were followed by an indurated lesion 4 to 6 hr later. These reactions lasted up to 24 hr and were histopathologically identical to similar "late-phase reactions" seen with ragweed. They were transferable with Prausnitz-Küstner (P-K) testing. Three patients had reactions that developed 8 to 12 hr after injection, peaked around 24 hr, and were not preceded by WFR. These reactions were morphologically delayed hypersensitivity reactions and were not transferred by P-K testing. One patient had a reaction that developed in 4 to 6 hr after injection and peaked by 12 hr. Histologically, this reaction was "Arthus" in type and was not transferred by P-K testing. Specific insulin antibody determinations were not helpful in distinguishing patients with different types of reactivity. These data show that recurrent local reactions to insulin may be of three distinct types: "late-phase reactions" (which are IgE dependent), "Arthus" local vasculitic reactions, or tuberculin-type delayed hypersensitivity reactions. These findings may influence the approach to management of these reactions.

Ultrastructural localization of nonspecific esterase activity in guinea pig and human monocytes, macrophages, and lymphocytes

Using either hexazotized pararosaniline or new fuchsin as coupling agents, we investigated the ultrastructural localization of alpha-naphthyl acetate esterase (ANAE) activity in guinea pig bone marrow and peritoneal exudates, and in human peripheral blood cells. DFP-inhibitable ANAE activity was present on the cell surface of lymphocytes, monocytes, macrophages, neutrophils, eosinophils, basophils, megakaryocytes, platelets, and blasts. Demarcation lines in megakaryocytes and the perinuclear cisternae in normoblasts were also positive. In addition, lymphocytes, monocytes, and macrophages displayed ANAE activity associated with cytoplasmic-vesicle clusters (CVC). Reaction product was always present on the cytoplasmic surfaces of these vesicles and in the adjacent cytoplasm; vesicle interiors were invariably ANAE-negative. Small lymphocytes generally had a single large paranuclear ANAE-positive CVC, whereas mononuclear phagocytes had multiple discrete foci of similar appearing ANAE-positive CVC that sometime became confluent. ANAE activity was also found in the Gall bodies of human lymphocytes and in coated vesicles of macrophages. Cytoplasmic ANAE activity was increased in oil-induced guinea pig peritoneal macrophages. Both surface and cytoplasmic esterase activities had a neutral pH optimum. An identical distribution of reaction product was observed when alpha-naphthyl butyrate was employed as substrate. The function of these esterases, and their relation to known surface and cytoplasmic neutral proteases, awaits further investigation.

Human breast carcinoma: fibrin deposits and desmoplasia. Inflammatory cell type and distribution. Microvasculature and infarction

Study of 14 human infiltrating breast carcinomas revealed new features that shed light on the pathogenesis of tumor stroma formation and on host immunologic defense mechanisms. Fibrin deposits were observed in the stroma of all tumors, particularly at their growing edge. Fibrin may have contributed both to tumor angiogenesis and, with organization, to the formation of the fibrous stroma characteristic of these and other scirrhous carcinomas. We previously proposed similar mechanisms for several animal tumors. All breast carcinomas studied elicited some degree of lymphocytic response at the tumor periphery; lymphocytes penetrated the fibrous tumor stroma poorly, did not exit in significant numbers from central tumor vessels, and, even when greatly outnumbering tumor cells locally, appeared relatively ineffective at tumor cell killing. Microvascular endothelial cell damage was frequently observed and may have been responsible for zones of tumor infarction. Similar observations have been made in skin allografts and animal tumors where rejection was effected principally by microvascular damage and subsequent tissue infarction, not by lymphocyte contact with individual epithelial target cells.

Surface membrane alterations in guinea pig basophils undergoing anaphylactic degranulation. A scanning electron microscopic study

Purified guinea pig blood basophils in short-term tissue culture were studied by scanning and transmission electron microscopy and by 1-micrometer. light microscopic Epon sections after exposure to specific antigen (sheep serum), to guinea pig serum, or to serum-free medium at intervals from 1 minute to 48 hours. Basophils fixed before culture, or after culture in serum-free medium, were spherical cells with uniformly distributed microvilli, ridges, and folds. In cultures with guinea pig serum, basophils frequently assumed a hand mirror configuration, characteristic of motile cells, with a single posterior, microvilli-bearing uropod and anterior ruffles. Specific antigen induced basophils to become rounded, regardless of the culture medium, and resulted in basophil degranulation and histamine release within 5 to 20 minutes. Exposure of cytoplasmic granules to the external medium was initiated by the development, early in degranulation, of a single, 1 to 2 micrometer. in diameter, opening (degranulation pore) in the plasma membrane. The degranulation pore enlarged progressively over 24 to 36 hours, ultimately permitting the egress of membrane-free cytoplasmic granules. The cell pole opposite the degranulation orifice bore numerous prominent folds and ruffles, changes that persisted for at least 24 hours. By 48 hours after exposure to specific antigen (sheep serum), the surface features of basophils had reverted to those exhibited by unstimulated control cells.

Tumor shedding and coagulation

Three syngeneic carcinomas from two species shed plasma membrane vesicles when cultured in vitro or grown in the ascites tumor form in vivo. Shed vesicles carry procoagulant activity that can account for the activation of the clotting system and the fibrin deposition associated with these and many other types of malignancy in animals and man.

Anaphylactic degranulation of guinea pig basophilic leukocytes. I. Fusion of granule membranes and cytoplasmic vesicles formation and resolution of degranulation sacs

Anaphylactic degranulation of guinea pig basophilic leukocytes, induced in vitro either with Concanavalin A or sheep serum (antigen), was resolved by transmission electron microscopy into two phases: (1) fusion of cytoplasmic granule membranes to form degranulation sacs communicating with the extracellular space by narrow pores and (2) resolution of degranulation sacs with concomitant granule matrix extrusion. Fusion of granule membranes occurred in the absence of obvious alterations of cytoplasmic filaments or microtubules but was preceded by a rapid increase in the number of 50- to 70-nm. cytoplasmic vesicles, a process evident 1 minute after exposure to lectin. By 5 minutes and at later intervals up to 20 minutes, as individual granule membranes fused to form degranulation sacs, vesicle frequency plunged to values one-half or less of control levels. Cytoplasmic vesicles were apparently incorporated into degranulation sacs and may have had a role in joining together the membranes of adjacent granules. Histamine release, detected at 5 minutes and maximal at 20 minutes, occurred at times when communications between degranulations sacs and the extracellular space were so narrow as to retain most recognizable granule matrix material. Resolution of degranulation sacs proceeded over a period of a day in culture and, in Concanavalin A-induced anaphylaxis, was sometimes incomplete even after 36 hours. During this phase, the frequency of cytoplasmic vesicles returned to normal or supernormal values, and the thin cytoplasmic processes forming the walls of degranulation sacs developed prominent, longitudinally disposed cytoplasmic filaments and ultimately retracted into the main cell body, depositing the membrane-free cytoplasmic granule matrix material outside the perimeter of the cell. Guinea pig basophil anaphylactic degranulation thus differs morphologically and kinetically from mast cell and basophil degranulation in other species in which granule membrane fusion and granule matrix extrusion occur nearly stimultaneously and are complete within minutes. The guinea pig basophil provides a useful model for dissociating these two intrinsic components of the degranulation process.

Melanoma. An ultrastructural study of the host inflammatory and vascular responses

Electron microscopic studies of 4 surgically excised human primary superficial spreading melanomas of the skin were done with special emphasis on the host inflammatory and vascular responses to tumor. Host cells participating in the inflammatory response included numerous small lymphocytes, activated macrophages, and mast cells. Some mast cells had lost local portions of granule content, but complete degranulation of mast cells was not seen. Activated macrophages had avidly ingested melanin granules and cellular debris and often were close to dying tumor cells. Lymphocytes, many displaying motile forms, were actively invading the epidermis; formed perivascular cuffs around damaged vessels; and were in intimate contact with living, damaged, and dead melanoma cells. Basophils, eosinophils, and neutrophils were absent from inflammatory infiltrates. Changes of the microvasculature included focal endothelial necrosis and hypertrophy as well as basal lamina changes indicative of repeated episodes of endothelial injury, necrosis and regeneration. These findings are discussed in relationship to a number of recent studies of the immunologically-mediated inflammatory responses to contact allergy, graft rejection, and syngeneic tumor rejection, in man and animals.

Antigen-induced IgE-mediated degranulation of human basophils

The events associated with antigen-induced, IgE-mediated degranulation of human basophils from allergic donors were studied ultrastructurally. Partially purified cells were examined prior to addition of antigen and after incubation with antigen or control buffer for 15 seconds to 60 minutes. Reactions were stopped instantaneously by adding fixative directly to the cell suspension. After fixation the cells were exposed to cationized ferritin as a sensitive probe for demonstrating possible continuities between the cytoplasmic granules and the cell surface. Ficoll-Hypaque-isolated basophils were of three types: Type I, cells containing basophil granules with a full complement of particles; type II, cells containing some full granules but also variable numbers of cytoplasmic vacuolar structures having the size and shape of basophilic granules but having reduced or no particle content (partially fixed or empty granules); and type III, basophils containing only empty granules. Following exposure to specific antigen, basophils of all three types underwent degranulation characterized by the fusion of the membranes bounding single basophilic granules with the plasma membrane and leading to extrusion of content. Cells in the process of degranulation (type IV and V basophils) were characterized by communications between individual granules and the cell exterior. Identification of such communications was facilitated by cationized ferritin which entered granules having open communications with the cell surface. Without this marker, the number of such communications would have been seriously underestimated, either because they were extremely narrow, tortuous, or outside the plane of section. The majority of individual basophilic granules fused singly and separately with the plasma membrane, in contrast to guinea pig basophil and rat mast cell degranulation where intercommunicating clusters of granules fused with the plasma membrane at a single point. The particle and membrane contents of extruded granules frequently remained adherent to the surface of type IV and V basophils and were not immediately solubilized. Morphologic evidence of degranulation progressed with time of exposure to antigen, exhibiting kinetics that paralleled histamine release. Cells in control incubations, and rare basophils that had been exposed to antigen E, failed to degranulate. Fully degranulated (type VI) basophils were viable cells that had a markedly irregular surface and were devoid of basophilic granules but retained the minor population of small perinuclear granules.

The microvasculature is the critical target of the immune response in vascularized skin allograft rejection

Vascularized first set human skin allografts were rejected largely by a process of extensive and progressive microvascular damage leading to ischemia and infarction. Microvascular injury was associated with a cellular immune response. However, vessel damage was at least in part immunologically nonspecific because vessels of the graft bed (host tissue) were damaged as well as those of the graft itself. We conclude that the microvascular endothelium is the critical target of the immune response in vacularized skin allografts in man, and that this sequence of events--primary vascular damage followed by ischemic infarction--may have significance in a variety of experimental and clinical settings.

The basophil. Its morphology, biochemistry, motility, release reactions, recovery, and role in the inflammatory responses of IgE-mediated and cell-mediated origin

The current state of our knowledge of basophils is reviewed. Much has recently been learned about these cells-their morphology, biochemical contents, interactions with homocytotropic antibodies, release of mediators in anaphylaxis, capacity for ingesting and releasing exogenous tracers, motility, participation in and progressive degranulation in cell-mediated hypersensitivity reactions, and their recovery from degranulation. It seems unlikely that basophils exist to destroy the organism by anaphylactic shock. Nonetheless, basophil function is probably closely related to the potent chemicals stored in their cytoplasmic granules. Perhaps small amounts of these chemicals are required for homeostasis and these cells function by releasing such substances as they are needed. This hypothesis requires that basophils be capable of releasing their contents slowly and piecemeal, which apparently occurs. This hypothesis also requires that physiological, rather than pharmacological, roles be found for histamine.

Rejection of first-set skin allografts in man. the microvasculature is the critical target of the immune response

Recent reports of microvascular injury in delayed hypersensitivity skin reactions prompted us to reexamine the pathogenesis of first-set skin allograft rejection in man using morphologic techniques that allowed both extensive vessel sampling and unequivocal evaluation of microvascular endothelium. We here report that widespread microvascular damage is a characteristic, early consequence of the cellular immune response to first-set human skin allografts and is qualitatively similar to, but substantially more extensive than, that occurring in delayed hypersensitivity reactions. Microvascular damage in invariably preceded significant epithelial necrosis and affected initially and primarily those venules, arterioles, and small veins enveloped by lymphocytes. Vessels of both the allograft itself and the underlying graft bed (recipient tissue) were equally affected. These data suggest that endothelial cells of the microvasculature are the critical target of the immune response in first-set vascularized skin allograft rejection in man and that rejection can be attributed largely to ischemic infarction resulting from extensive microvascular damage. Other mechanisms, such as direct cellular contacts between infiltrating lymphocytes and epithelium, apparently played only a minor role. The findings presented here indicate that the rejection of first-set vascularized skin allografts, though induced by immunologically specific mechanisms, is primarily effected by final pathways that are relatively nonspecific and that may cause damage to both foreign and host vessels and cells. Rather than contradicting studies demonstrating the exquisite specificity of allograft rejection in other systems, these findings provide a further example of the heterogeneity of the cellular immune response. Recognition of the critical role of immunologically mediated microvascular injury may prove important both for an understanding of the biology of allograft rejection and for strategies aimed at prolonging allograft survival.

Fibrin gel investment associated with line 1 and line 10 solid tumor growth, angiogenesis, and fibroplasia in guinea pigs. Role of cellular immunity, myofibroblasts, microvascular damage, and infarction in line 1 tumor regression

Line 1 and line 10 tumors became invested in a fibrin-gel cocoon within hours after transplantation to the subcutaneous spaces of unsensitized syngeneic inbred Sewall Wright strain 2 guinea pigs. The fibrin gel comprised more than 80% of the line 1 tumor mass and, after day 3, became organized and was subsequently replaced by fibrous connective tissue, which gave the tumor the appearance of a scirrhous carcinoma. A cellular infiltrate of lymphocytes and basophils developed at the periphery of line 1 tumors after day 8, and tumors regressed by day 13. The fibrin gel investing the highly malignant line 10 tumors accounted for less than 10% of the tumor mass and persisted without fibrous organization as a tumor grew progressively and invaded adjacent tissues. These data provide new and potentially important insights into the biology of solid tumor growth and the mechanisms of immunologic tumor rejection. Envelopment of tumors in a fibrin gel created an anatomic barrier separating the tumors from the host. Neovascularization mimicking that about line 1 and line 10 tumors was induced by sc fibrin implants; these data suggest that activation of the clotting and/or fibrinolytic systems by tumor cells may itself provide sufficient stimulus for induction of tumor angiogenesis without requiring a separate tumor angiogenesis factor. The scirrhous pattern of growth characteristic of line 1 tumors apparently was achieved by organization of an abundant fibrin gel. Line 1 tumor regression did not for the most part involve direct contacts between tumor cells and any type of inflammatory cell, including macrophages; rather, tumor destruction was effected by ischemic necrosis secondary to widespread microvascular injury. The mechanisms of such injury are uncertain, but tumor rejection was correlated with evidence of developing cellular immunity and anatomic associations between lymphocytes and myofibroblasts. Further experiments will be necessary before these findings can be generalized to other tumor systems.

Delayed-type hypersensitivity skin reactions in congenital afibrinogenemia lack fibrin deposition and induration

Induration is a characteristic feature of delayed-type hypersensitivity skin reactions and is the usual measure of their intensity. The precise basis of induration has not been established, although activation of the clotting system with consequent fibrin deposition has been clearly implicated. In this study, two subjects with congenital afibrinogenemia, a genetic defect in fibrinogen synthesis, were skin tested with standard microbial antigens: streptokinase-streptodornase, monilia, mumps, and tuberculin purified protein derivative. One positive delayed reaction from each subject was biopsied at 40-48 h and compared with 23 biopsies of similar skin tests in normal volunteers. The eight skin tests in the afibrinogenic subjects lacked induration, although the erythema was similar in size (10-34 mm in diameter), intensity, and time-course to those in normals. Biopsies from the two strongest reactions from the afibrinogenemic subjects showed a typical perivascular mononuclear infiltrate. No more than traces of fibrin/fibrinogen were detected by immunofluorescence, in striking contrast to the abundant fibrin/fibrinogen deposition in 23 positive, indurated reactions in normal subjects. These findings indicate that fibrinogen itself is essential for the development of induration in delayed-type skin reactions in man. As judged by 1-mum sections and fluorescence, this is probably a result of the formation of an extravascular fibrin gel.

Tumor-basophil interactions in vitro--a scanning and transmission electron microscopic study

Purified guinea pig basophils, or basophils either specifically degranulated with antigen or nonspecifically degranulated with lectin, were cultured with guinea pig line 1 hepatoma cells for 1 to 24 hr and studied ultrastructurally. As early as 1 hr of culture, degranulated or nongranulated basophils and tumor cells formed close contacts by mutually intertwined elongated cell processes and also in cultures containing degranulated basophils, extruded membrane-free basophil cytoplasmic granules became firmly attached to tumor cells. At later intervals, some tumor cells cultured with basophils exhibited cytostatic and cytopathic changes, including dense mitochondria, centralization of organelles, dilated perinuclear and rough endoplasmic cisternae, cell swelling and cytoplasmic lucency, disrupted cytoplasmic organelle and plasma membranes, nuclear pyknosis and fragmentation. Some tumor cell specialized surface attachments were either disrupted or damaged at points of basophil or basophil granule adhesion. Tumor damage was most extensive in cultures containing degranulated basophils, although only a minority of tumor cells (less than 10%) was affected. Tumor injury was seen much less frequently in the presence of nondegranulated basophils, and was absent in control cultures of tumor alone. The occasional viable tumor cells that phagocytosed basophil granules were apparently unharmed, suggesting that internalization of basophil granules by tumor cells is not cytotoxic.

Nerve growth factor: a protease that can activate plasminogen

The single, highly stable form of mouse submandibular gland nerve growth factor (NGF), prepared as described by Young et al. [(1978) Biochemistry 17, 1490--1498] is a protease of restricted specificity that can convert plasminogen to plasmin. In the absence of plasminogen, NGF is not fibrinolytic, nor does it hydrolyze casein at a measurable rate. Treatment of NGF with diisopropyl fluorophosphate inhibits its ability to activate plasminogen as well as its capacity to hydrolyze certain synthetic arginine esters. These results indicate that NGF is a member of the class of serine proteases. Since NGF is known to be secreted at high concentrations in mouse saliva, it may serve to activate plasminogen (with subsequent fibrinolysis) somewhere in the alimentary tract. Plasminogen activation is the only known action of NGF upon a biologically important non-neural substrate.

Sulfated glycosaminoglycans of guinea pig basophilic leukocytes

Cytoplasmic granules of basophilic leukocytes stain metachromatically and have been thought to contain sulfated glycosaminoglycans, presumably heparin. To test this hypothesis, we identified the [35S]glycosaminoglycans synthesized by guinea pig blood basophils in culture and in vivo. Basophils isolated from guinea pig blood were cultured for 20 hr in F12 medium--10% guinea pig serum containing sodium [35S]sulfate. Alternatively, basophils were purified from animals receiving repeated i.v. injections of sodium [35S]sulfate. Glycoaminoglycans were isolated from these basophils after pronase digestion and identified by the use of selective glycosaminoglycan-degrading enzymes. Approximately 55% of the [35S]glycosaminoglycans was degraded by chondroitinase AC, indicating the presence of chondroitin sulfate; an additional 30 to 35% could be degraded by chondroitinase ABC, indicating that dermatan sulfate was also present. The 15% glycosaminoglycan remaining after chondroitinase ABC digestion was degraded by purified heparitinase (heparanase), which has no effect on authentic heparin but degrades heparan sulfate. Thus, the glycosaminoglycan content of guinea pig basophils is a mixture of chondroitin sulfate, dermatan sulfate, and smaller amounts of heparan sulfate. No heparin was detected.

Cutaneous necrotizing venulitis: a sequential analysis of the morphological alterations occurring after mast cell degranulation in a patient with a unique syndrome

An unusual patient, with dermal nodules, flexion contractures of the fingers and toes, cold-induced urticaria, dermographism and serum hypocomplementaemia, had necrotizing cutaneous venulitis underlying the spontaneous lesions. Since necrotizing cutaneous venulitis could be experimentally induced by the physical stimuli of cold or trauma, the time-course of histopathological events was documented in the skin of this patient. The histopathological alterations were studied in 1 micron thick, Epon-embedded skin biopsy specimens over an interval of 6 days. The early massive degranulation of the mast cells was followed by the sequential infiltration of neutrophilic, eosinophilic and basophilic polymorphonuclear leucocytes, by the development of venular endothelial cell necrosis and by the deposition of fibrin. The persistent serum hypocomplementaemia involved the classic activating and amplification pathways. It seems possible that the unusual combination of pathobiological processes involving the mast cells and the complement system in this patient has created a unique syndrome, in which venules are damaged and the sheaths of the extensor tendons of the hands and feet become affected in time.

Plasminogen activator of guinea pig basophilic leukocytes: probable localization to the plasma membrane

The plasminogen activator (PA) activity of guinea pig basophil-enriched leukocyte preparations was localized to basophils, and not to contaminating lymphocytes and eosinophils, by correlating PA activity with basophil frequency and, more directly, by means of an improved cytochemical method here described. PA activity was fully expressed in living cells in the absence of immunologic stimuli and was suppressed/lost to a variable extent by different techniques of cell disruption. Conversely, killed, but not living, basophils expressed significant plasminogen-independent fibrinolytic activity, presumably reflecting access of cytoplasmic proteases of broken basophils to fibrin substrate. The PA activity of intact cells was destroyed by gentle trypsinization under conditions that did not impair cell viability. When disrupted cells were ultracentrifuged on a sucrose density gradient, PA activity was absent from purified granules and was confined to fractions containing cell membranes. The simplest explanation of these data is that guinea pig basophils have PA activity associated with their plasma membranes. This conclusion has several important implications for basophil functions in cell-mediated and other immunologic reactions in vivo.

Isolation of the cytoplasmic granules of guinea pig basophilic leukocytes: identification of esterase and protease activities

Procedures were developed for isolating highly purified cytoplasmic granules of basophilic leukocytes from guinea pig peripheral blood. The methods involved disruption of cells in 0.34 M sucrose followed by a series of membrane filtrations and fractionation on sucrose density gradients. These preparations, up to 95% pure basophil granules by electron microscopy, contained a mixture of neutral esterases-proteases including caseinolytic activity; both trypsin- and chymotrypsin-like serine hydrolases were identified by means of appropriate inhibitors. Localization of at least one such activity to the basophil granule was confirmed by a cytochemical method; this activity was absent in contaminating lymphocytes and eosinophils. By contrast, several lysosomal enzymes, lactic dehydrogenase, and plasminogen activator activity, present in cell homogenates, were absent from purified granules. The granule matrix of guinea pig basophils, unlike the cytoplasmic granules of other granulocytes or mast cells, was little altered by high or low salt concentration but was disrupted into insoluble fragments by 0.01 N HCl and by Triton X-100. Granules were solubilized by papain and by urea-SDS but enzyme activity was destroyed. Triton X-100 incubation with freeze-thawing proved to be the optimal method for extracting esterase activities. Esterase activities were not released from basophils under conditions of anaphylactic degranulation that liberated the great majority of basophil granule histamine.

Morphology of delayed-type hypersensitivity reactions in the guinea pig cornea

Guinea pigs sensitized with several soluble protein antigens in incomplete Freund's adjuvant (IFA) and tested at 5 to 7 days developed basophil-rich corneal reactions characterized by minimal edema and fibrin deposition. These lesions resembled the skin reactions of cutaneous basophil hypersensitivity (CBH) in their immunization requirements, time course, and character, but differed in that basophils were relatively less frequent and eosinophils and neutrophils more numerous in ocular than in cutaneous reactions developing simultaneously in the same animal. In contrast, animals immunized with antigens such as ovalbumin in complete Freund's adjuvant (CFA) developed much more severe delayed-type ocular reactions whether tested at early or late intervals after sensitization. These intensely injected, chemotic reactions exhibited an extensive cellular infiltrate of mononuclear cells as well as marked corneal edema accompanied by extensive fibrin deposition. Hence, these ocular reactions were similar to the classic indurated tuberculin-type delayed hypersensitivity (DH) skin reactions except that neutrophils were more numerous. These data indicate that in the eye as in the skin two distinct patterns of delayed-onset, cell-mediated hypersensitivity may occur to the same antigen, depending on the mode of immunization and the time of testing. However, significant differences were found in the frequency with which the various granulocytes infiltrated reactions elicited simultaneously in the eye and skin. Therefore, the character of immune expression may vary in different parts of the body and local factors, such as the local microvasculature, evidently contribute to these differences.

Systemic expression of cutaneous basophil hypersensitivity

Guinea pigs primed for cutaneous basophil hypersensitivity (CBH) with several soluble proteins or with sheep erythrocytes developed a systemic, delayed-onset, maculopapular rash when challenged parenterally with specific antigen. The rash was most readily induced 5 to 7 days after immunization, at a time when local CBH skin test reactivity was also optimal. Miscroscopically, the rash resembled local CBH skin test reactions, being comprised of a papillary dermal infiltrate of basophils and lymphocytes and a striking dilatation and compaction of superficial venules. In addition to the systemic rash, animals expressing systemic CBH (SCBH) exhibited a striking eosinophilia at 24 hr which gave way to basophilia at 48 hr. Focal collections of eosinophils, and of smaller numbers of basophils, were found in the lungs and spleen; both eosinophils and basophils infiltrated the medulla of the thymus. Thus, basophil-rich infiltrations are favored in the skin even after systemic challenge with antigen and occur only to a much smaller extent in other organs where eosinophils may predominate. These differences in the response of various organs to challenge with parenteral antigen suggest that as yet unidentified local factors play a determinative role in regulating the inflammatory response. The pathogenesis of SCBH is not yet established, but it shares many of the properties of local CBH: histology, carrier specificity, development early after sensitization in the absence of detectable antibodies. Passive transfer has not been accomplished with serum alone but has been achieved irregularly with cells plus serum. SCBH may serve as a useful model for several disease states in man characterized by a systemic rash and eosinophilia, including certain types of drug reaction.

Hapten-specific delayed hypersensitivity to epsilon-2,4-dinitrophenyl-L-lysine-Ficoll in guinea pigs immunized with 2,4-dinitrophenyl-keyhole limpet hemocyanin

After active immunization with 2,4-dinitrophenyl-keyhole limpet hemocyanin (DNP-KLH), 2,4-dinitropheynl-L-lysine (DNPL)-Ficoll may elicit indurated, erythematous skin reactions lasting 24-72 h. Histological sections of these reactions, examined by microscope techniques, showed they contained polymorphonuclear leukocytes and perivascularly situated lymphocytes and macrophages, but had very few basophils. Consequently, the reaction was interpreted as having an immediate component and a component typical of delayed hypersensitivity; this indicated that the delayed reaction could be specific for the DNP hapten. Although this delayed type of skin reaction was not transferred to recipients with anti-DNP-KLH serum, one pool of that serum did sensitize guinea pigs so that they could respond with a different skin reaction after challenge with DNPL-Ficoll. This reaction was soft, pale pink, and lasted for 24 h. Histologically, it contained only a few polymorphonuclear leukocytes. It differed from the delayed reaction in actively immunized animals in that it lacked induration, and was devoid of lymphocytes and macrophages.

Generation of macrophage migration inhibitory activity by plasminogen activators

Medium from cultures of simian virus 40-transformed mouse 3T3 cells (SV3T3) inhibits the migration in vitro of peritoneal exudate cells (macrophages) from guinea pigs while medium from untransformed 3T3 cultures does not [Hammond, M. E., Robbin, R. D., Dvorak, A. M., Selvaggio, S. S., Black, P. H. & Dvorak, H. F. (1974) Science 185, 955-957]. The present paper describes the generation of migration inhibitory factor (MIF)-like activity for peritoneal exudate cells from guinea pigs after incubation of a serum-free harvest fluid from SV3T3 cells with guinea pig serum. Inhibited macrophages lose a densely staining material from the cell surface coat compared with uninhibited guinea pig peritoneal exudate cells. The factor in SV3T3 harvest fluids which generates the migration inhibitory activity appears to be plasminogen activator, i.e., a serine protease, because (i) plasminogen activator activity and the factor which generates MIF-like activity copurify, and co-chromatograph on Sephadex G-200 columns, and (ii) plasminogen activator activity and capacity to generate MIF-like activity are simultaneously lost upon treatment with [3H]diisopropylfluorophosphate. In addition, a purified preparation of a known plasminogen activator, human urokinase, can also generate MIF-like activity upon reaction with guinea pig serum. Because transformation of 3T3 cells by SV40 increases their plasminogen activator secretion, enhanced secretion of plasminogen activator by SV3T3 cells may explain why formation of MIF-like activity is observed in SV3T3 but not 3T3 cultures. These results reveal a biochemical pathway whereby a product secreted by virus-transformed cells affects one function of a cell central to the host's immunological defense system.

Metabolic studies of guinea pig basophilic leukocytes in short-term tissue culture. I. Measurement of histaminesynthesizing capacity by using an isotopic-thin layer chromatographic assay

Mature circulating guinea pig basophils, purified to comprise 25% or more of leukocytes, have been successfully maintained in short-term tissue culture for up to 72 hr. These cells were found to retain the ability to synthesize histamine, as assayed by a new isotopic-thin layer chromatographic assay which can reliably detect as little as 0.5 pg of 3H-histamine. Cell-associated, newly synthesized histamine was detectable as early as 1 hr of culture, was substantially increased at 6 hr, and reached maximal levels at 24 hr, when it accounted for approximately 6.5% of total cell histamine. Newly synthesized histamine was still detectable at 48 and 72 hr of culture. Histamine synthesis was decreased by lwoering the concentration of histidine in the culture medium, and was markedly reduced by all the specific histidine dedarboxylase (HDC)3 inhibitors tested, but not by alpha-methyl-DOPA, pyrilamine maleate, or metiamide. Increasing the concentration of pyridoxal phosphate, the HDC coenzyme, above that normally present in culture medium resulted in only an equivocal increase in the amount of newly synthesized histamine, whereas aminoguanidine, an inhibitor of histaminase, had no detectable effect. Uptake of exogenous histamine by cultured basophils was trivial compared to histamine synthesis. Both newly synthesized and previously manufactured, nonisotopic, histamine seemed to be stored in the same pool, as the same proportion of both was released by concanavalin A (Con A). Cellular histamine was largely conserved, with little or no spontaneous release into the medium of detectable isotopic or nonisotopic histamine. These techniques provide a model for studying granulocyte metabolic processes in vitro, and should assist in the direct investigation of a variety of their physiologic functions.