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R A Daynes

Publications and source records attributed to R A Daynes.

At least 91 records · Page 5Linked to original sources
PubMed1986

Immunological consequences of ultraviolet radiation exposure.

Depending on the dose and conditions of administration, ultraviolet radiation (UVR) can function as either a complete carcinogen, a co-carcinogenic agent, or an immunologic modulator. Although much is known about its carcinogenic properties, only recently have investigations been aimed at defining the mechanisms by which UVR mediates its effect on the immune system. The objective of this article is to present the necessary background and results of recent studies that provide the basis for defining some of the local and systemic effects that UVR has on an individual's immunologic potential. This discussion focuses on: the histologic alterations in the skin and draining lymph nodes, the changes in lymphocyte localization, the increased release of the immunologic (and physiologic) mediator ETAF/IL-1, and the induction of antigen-specific immunoregulatory circuits that occur subsequent to UVR exposure. It is our hypothesis that the detrimental effects that UVR has on the host's immunologic competence may represent a normal defense mechanism to protect the individual against the adverse consequences of chronic inflammatory stimuli. In this regard, a better understanding of photoimmunology may lead to the development of more effective means of immunologic modulation for altering the clinical course of various human diseases that are either immunologically mediated, photoinduced, or responsive to phototherapy.

Cell Transformation, Neoplastic↗
PubMed1986

Clonal origin of tumors induced by ultraviolet radiation.

Skin tumors were induced in (C3H/HeN X C3H/HeN-PGK-1a)F1 female mice, heterozygous at the X-linked phosphoglycerate kinase-1 (PGK-1) locus, by exposure to the carcinogenic influence of ultraviolet radiation (UVR), 3-methylcholanthrene [(MCA) CAS: 56-49-5], or benz[a]pyrene [(BP) CAS: 50-32-8]. An assessment of the clonal origin of these tumors was accomplished through an analysis of the PGK-1 enzyme phenotype expressed by the transformed cells. In vitro culture was employed as a means of depleting nontransformed cells of host origin from the induced tumors. Cultured lines derived from tumors induced by each of the above agents were found to express only one of the two enzyme forms encoded by the host genotype, consistent with the probability that all the UVR-, MCA-, and BP-induced tumors examined in this study were monoclonal in origin. For further substantiation of the monoclonality of UVR-induced tumors, 2 UVR-induced tumors were enzymatically dissociated immediately following excision from the primary hosts, and the resulting cell suspensions were cloned in soft agar. Upon analysis, each set of clones selected in soft agar expressed only a single PGK-1 enzyme form. To rule out the possibility that the apparent monoclonality of culture-adapted tumor lines was due to in vitro selection, tumors that arose in UVR-treated PGK-1a/b female heterozygote mice were transplanted into PGK-1a and PGK-1b homozygous recipients. These transplanted tumors expressed a single PGK-1 allozyme following growth in recipients that were genetically homozygous for the major PGK-1 enzyme form expressed by the tumor prior to transplantation. These data strongly support the concept that most, if not all, UVR-induced tumors are derived from the progeny of a single transformed cell. This observation is important to the understanding of the nature of tumor-specific transplantation antigens expressed by individual UVR-induced tumors and indicates that such antigens also are clone specific. In addition, the results of this study indicate that polyclonality does not play a significant role in the generation of cellular and phenotypic heterogeneity known to be present within individual UVR-induced tumors.

Animals↗
PubMed1985

Characterization of the in vitro interaction of PNAhi lymphocytes with the bone marrow and hepatic asialoglycoprotein receptors.

We have previously identified an in vivo interaction between circulating PNAhi lymphoid cells and the hepatic asialoglycoprotein receptor, which results in a protracted liver sequestration of these cells. An in vitro frozen section binding assay was developed to study the interaction of PNAhi cells with the receptor in more detail. This assay confirmed that the sequestration of PNAhi lymphoid cells by the liver was mediated by the asialoglycoprotein receptor, as binding was inhibitable by coincubation with galactose, asialoglycoproteins, chelation of divalent cations, or a specific anti-asialoglycoprotein receptor antiserum. This frozen section binding assay was utilized to demonstrate the existence of a bone marrow asialoglycoprotein receptor which was found to be capable of binding to PNAhi lymphocytes or asialoglycoproteins bound to synthetic substrates. We further established that the bone marrow receptor differed both functionally and antigenically from its hepatic analogue.

Animals↗
PubMed1985

Bone marrow engraftment efficiency is enhanced by competitive inhibition of the hepatic asialoglycoprotein receptor.

The efficiency of pluripotent stem cell engraftment following bone marrow transplantation is predicated upon many poorly understood factors. These include the processes by which intravenously injected stem cells circulate and localize in microenvironments that contain the stromal elements necessary to facilitate their continued proliferation. We have recently established that lymphoid cells that bind the lectin peanut agglutinin are subject to prolonged sequestration following their interaction with the hepatic asialoglycoprotein receptor. Since bone marrow stem cells are also known to bind peanut agglutinin, we hypothesized that the physiologic function of the asialoglycoprotein receptor might significantly impair their ability to localize in anatomic sites where they are able to proliferate. Competitive inhibition with asialoglycoproteins was employed to establish a temporary receptor blockade during the initial 3-4 hr after transplantation. This procedure resulted in a 5- to 10-fold increase in splenic hematopoietic colony formation. Our findings suggest that inhibition of the liver asialoglycoprotein receptor during murine bone marrow transplantation results in more efficient stem cell localization to hematopoietic-inducing microenvironments. This enhancement in engraftment efficiency was paralleled by a more rapid recovery of peripheral blood leukocyte and platelet counts, an increase in megakaryocytic colony formation, as well as increased recipient survival. Techniques designed to inhibit the liver sequestration of bone marrow stem cells may have direct applicability to human bone marrow transplantation procedures.

Animals↗
PubMed1985

Regulation by the skin of lymphoid cell recirculation and localization properties.

The existence of epidermal Langerhans cells, Ia-positive dermal dendritic cells, lymphocytes which can demonstrate epidermitropism, and keratinocytes capable of secreting Interleukin-1-like molecules, each support the concept that skin can function as an immunologic organ. Such conclusions are further strengthened by the knowledge that both afferent and efferent immune responses can take place exclusively within the skin. The purpose of our study was to evaluate the ability of skin to regulate lymphoid cell recirculation and localization properties. The use of ultraviolet radiation as an exogenous stimulus resulted in a pronounced redistribution of antigen-presenting cells from central (spleen) to peripheral (skin and lymph node) lymphoid tissues as well as marked increase in the rate of lymphocyte entry into skin draining lymph nodes. This latter condition was due to elevations in the quantitative levels of high endothelial venules present within the peripheral lymph nodes. The ability of epidermal keratinocytes to express Class II molecules is known to be associated with a number of skin diseases. However, the functional significance of this phenomenon is unknown. The results of our studies, employing a nude mouse model, indicate that the expression of Class II molecules by keratinocytes facilitates the movement of Langerhans cell precursors into the epidermis and may also function to enhance lymphocyte entry into the skin. We conclude that nonlymphoid components resident within the skin can influence essential aspects of the adaptive immune response through the production of soluble factors (e.g., Interleukin-1 or through the cellular expression of Class II molecules.

Animals↗
PubMed1985

Presence of epidermal-derived thymocyte activating factor/interleukin 1 in normal human stratum corneum.

Keratinocytes produce a molecule, epidermal-derived thymocyte activating factor (ETAF), which is biologically and physiochemically similar to the polypeptide hormone interleukin 1 (IL-1). Because the stratum corneum (SC) is composed of terminally differentiated keratinocytes, we questioned whether ETAF/IL-1 could be isolated from this tissue. The extraction of normal human SC with a physiologic saline solution yielded a large amount of ETAF/IL-1 activity, as measured by the in vitro thymocyte co-stimulator assay. SC-derived ETAF/IL-1 (scETAF/IL-1) eluted from a sizing column with an approximate molecular weight of 15,000, and demonstrated three isoelectric point forms after separation on a chromatofocusing column. By these physiochemical characteristics, scETAF/IL-1 was found to be similar, if not identical to human keratinocyte- and macrophage-derived ETAF/IL-1. Further, a number of biologic effects known to occur in vivo after the administration of ETAF/IL-1, such as fever, neutrophilia, and an increase in plasma levels of acute-phase proteins, were all induced by the injection of scETAF/IL-1 into endotoxin-nonresponsive mice. scETAF/IL-1 was also found to stimulate collagenase production by human fibroblasts in vitro. In summary, our studies have established that normal human SC contains a large quantity of scETAF/IL-1. Whether scETAF/IL-1 integrates into the earliest afferents phases of local inflammatory responses, or merely represents a means of disposal of excessively produced hormone is currently unresolved.

Amyloid↗
PubMed1985

Correlation between the inducible keratinocyte expression of Ia and the movement of Langerhans cells into the epidermis.

A direct correlation between the induced expression of Ia by the host keratinocytes and the infiltration of donor Langerhans cells (LC) into the epidermis was demonstrated in athymic (nude) BALB/c mice that received an adoptive transfer of lymphoid cells from normal semi-syngeneic donors. Neither keratinocyte expression of Ia nor donor LC movement into the epidermis was observed in BALB/c recipients of lymphoid cells from allogeneic C3H nude mice. Further evidence for this relationship was provided by experiments in which the keratinocytes of BALB/c nude mice were induced to express Ia by the injection of normal mouse serum (NMS). By this procedure it was shown that LC precursors derived from allogeneic C3H nude donors were able to infiltrate the epidermis when adoptively transferred into BALB/c nude recipients whose keratinocytes had been induced to express Ia by the simultaneous injection of NMS. These findings suggest that keratinocytes through their expression of Ia may function to facilitate the movement of LC into the epidermis.

Animals↗
PubMed1985

Inhibition of lymphocyte and neutrophil chemotaxis by pertussis toxin.

The cells of the mammalian immune system possess special migratory properties within their in vivo environment, a surveillance characteristic that is thought to be important in the protection of the organism from transformants and exogenous pathogens. Pertussis toxin (PT) has been shown to disrupt the intensity of this process by seriously affecting lymphocyte recirculation in vivo. The mechanisms responsible for this inhibition were investigated by using the in vitro model systems of polymorphonuclear leukocyte and lymphocyte chemotaxis. The type of inhibition that was observed in these in vitro assay systems was quite similar to that observed in vivo, because PT could depress chemotaxis in vitro as well as the accumulation of radiolabeled lymphocytes and neutrophils within a peripheral site of inflammation in vivo. The alterations in neutrophil motility were found to be associated with a stimulus-specific inhibition of the triggering of superoxide anion generation and lysosomal secretion. Some inhibition of neutrophil adherence to plastic surfaces was also observed, most notably after augmentation of adherence with the chemoattractant fMLP. The observed alterations in cellular function after PT treatment occurred in the absence of defects in chemoattractant binding to the neutrophil cell surface, or of membrane potential changes stimulated by ligand binding. The effect of PT in this system was found to be associated with an abnormality in the regulation of intracellular free calcium, suggesting that the substrate for PT in neutrophils is involved in the regulation of calcium ion channels.

Animals↗
PubMed1985

Correlation between keratinocyte expression of Ia and the intensity and duration of contact hypersensitivity responses in mice.

Langerhans cells are the only cells within the epidermis that normally express immune response-associated antigens (referred to as Ia in mice and HLA-D in humans). However, in the epidermis of patients with allergic contact dermatitis or individuals undergoing a delayed-type hypersensitivity response, the keratinocytes at the reaction site are induced to express HLA-DR. In this study the inducible expression of Ia by the keratinocytes of mice was found to be directly correlated with the intensity and duration of experimentally induced contact hypersensitivity (CH) responses. During a CH response in animals that were sensitized on the belly and challenged on the ear with the contact-sensitizing (CS) agent oxazolone, the keratinocytes in the challenged, but not the unchallenged, ear were induced to express Ia. In comparison with animals that were sensitized and challenged at different sites, an intensified expression of Ia by the keratinocytes was associated with a twofold increase in ear swelling in mice that were sensitized and challenged with oxazolone at the same site. Curiously, the challenge of oxazolone-sensitized ears with dinitrofluorobenzene (an unrelated CS agent), croton oil (a nonspecific inflammatory agent), or acetone/olive oil (a noninflammatory agent) also induced both a marked keratinocyte expression of Ia and an enhanced CH response. These results suggest that residual antigen at the original sensitization site may be mobilized to function as the challenge stimulus to elicit a CH response, in association with keratinocyte expression of Ia, when CS-sensitized skin is perturbed with a nonspecific agent. Further evidence of an association between CH responsiveness and keratinocyte expression of Ia came from the following observations. First, the magnitude and duration of a CH response was markedly increased in pertussis toxin (PT)-treated mice. These enhanced responses were associated with intense Ia expression by the keratinocytes in the epidermis at the reaction site. Because PT is known to have an adjuvant effect on delayed-type hypersensitivity reactions, as well as to alter the normal regulatory mechanisms associated with this type of response, it is possible that Ia+ keratinocytes play a synergistic role in the enhanced CH responses that are observed in PT-treated animals. Second, a direct correlation between keratinocyte expression of Ia and CH responsiveness was observed in athymic nude mice that were challenged with oxazolone after receiving an adoptive transfer of lymphoid cells from oxazolone-primed normal syngeneic donors.(ABSTRACT TRUNCATED AT 400 WORDS)

Adjuvants, Immunologic↗
PubMed1985

Site-selective homing of antigen-primed lymphocyte populations can play a crucial role in the efferent limb of cell-mediated immune responses in vivo.

Lymphoid cells of the mammalian immune system exhibit special migratory properties within their in vivo environment. This fundamental characteristic is important to the protection of the organism from infection and neoplastic transformation by a process termed immunologic surveillance. The importance of lymphocyte recirculation was addressed by investigating the role of site-selective homing of lymphocytes during the efferent phase of an in vivo adoptively transferred immune response. We approached this problem by using pertussis toxin (PT), a known inhibitor of lymphoid cell migration in vivo. PT is a protein secreted by the bacterium Bordetella pertussis, which induces a selective and long-lasting inhibition of the emigration of lymphocytes from the bloodstream into solid tissue. In this study, we demonstrate that the blockade of lymphocyte extravasation potential mediates inhibition of certain cell-mediated immune responses in vivo. We investigated the effect of PT on the extravasation of antigen-primed lymphocytes into solid tissue. The results show that the loss of lymphocyte homing potential after in vitro treatment of the primed cells with PT is accompanied by an inhibition of antigen-specific contact hypersensitivity after adoptive transfer. This result suggests that the process of lymphocyte extravasation into nonlymphoid tissue sites such as the skin shares fundamental similarities to the selective localization of circulating lymphocytes to lymph nodes. Furthermore, the inhibition of contact hypersensitivity observed after the i.v. adoptive transfer of PT-treated antigen-primed cells could be circumvented by transferring the PT-treated cells directly into a tissue site with the relevant antigen. In contrast, no inhibition in the number of antibody-forming cells present within the spleen was observed after an adoptive transfer of PT-treated sheep red blood cell-primed lymphocytes, a result that is in agreement with radiotracer data. Thus, the inhibitory effect of PT on the adoptive transfer of contact hypersensitivity was established to be a direct result of the PT-mediated alteration of cellular migration, because PT inhibits the entrance of lymphocytes into specific tissue sites without inhibiting other cellular functions. This conclusion is additionally supported by experiments that showed that lymphocytes that have been pretreated with PT exhibit normal in vitro responses, as assayed by mitogenesis in response to concanavalin A and by the differentiation and function of alloantigen stimulated or hapten-specific cytotoxic T lymphocytes.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Studies on the liver sequestration of lymphocytes bearing membrane-associated galactose-terminal glycoconjugates: reversal with agents that effectively compete for the asialoglycoprotein receptor.

The removal of "effete" glycoproteins from the circulation represents a proposed physiologic role for the hepatocyte asialoglycoprotein receptor. Our experiments support the hypothesis that this receptor may also be directly involved in the removal from the circulation of cells bearing asialoglycoconjugates. We report that the enhanced liver localization of neuraminidase-treated lymphocytes can be competitively inhibited by the coinjection of asialofetuin (ASF). Fetuin itself was without effect. Competitive inhibition of the liver receptor allowed normal localization to lymphoid tissues of the enzyme-treated lymphocytes, a condition which persisted as long as free ASF was present in the circulation. Our studies support the concept that cell surface carbohydrates play an important role in the tissue distribution of circulating lymphocytes. The process of thymocyte maturation, bone marrow transplantation, and the adoptive immunotherapy with continuous T-cell lines represent conditions where recirculation potential may be influenced by the presence of galactose terminal glycoconjugates.

Animals↗
PubMed1984

Cross-reactive transplantation antigens between UV-irradiated skin and UV-induced tumors.

The fate of ultraviolet (UV) light-induced tumors transplanted into syngeneic hosts bearing skin grafts from UV-irradiated donors was studied. Our results suggest that UV-irradiated skin and UV-induced tumors express common antigens. Further, these results may bear on the question of how subcarcinogenic doses of UV radiation can effect the generation of tumor antigen-specific T suppressor cells prior to the existence of UV-induced tumors. Specifically, normal C3Hf/HeJ mice were grafted with UV-irradiated, or normal skin and subsequently implanted with either regressor, progressor, or conversion type UV-induced tumors. Animals bearing UV skin grafts were: a) effectively immunized against conversion type tumors, b) exhibited no differences against regressor type tumors, and c) allowed progressor type tumors to grow at an accelerated rate.

Animals↗
PubMed1984

Experimental ultraviolet radiation carcinogenesis: I. Relationship of the major histocompatibility complex to tumor latency and immunogenecity.

The induction of skin tumors by ultraviolet radiation (UV) was compared concurrently in 3 inbred mouse strains (BALB/c, C3H, and C57BL/10) and 7 related H-2 (major histocompatibility complex) congenic strains of mice. The latency period for UV-tumor induction was observed to be shorter in BALB/c mice compared with that in C3H and C57BL/10 animals. Similarly, tumor latency periods in the different H-2 congenic mouse strains tested were comparable to those of their related background strain. The proportion of squamous cell carcinomas to spindle cell fibrosarcomas, as well as the ratio of progressor and regressor tumors, as determined by their ability to grow when transplanted into normal syngenic mice, were comparable for those strains of mice that shared common genetic backgrounds. Interestingly, for all strains of mice analyzed UV-regressor and UV-progressor tumors were found to arise randomly throughout the latency period. These studies suggest that, at least for the three parameters tested, genes or gene products encoded within the major histocompatibility complex do not influence either latency period, histologic type or immunogenicity of UV-induced skin tumors.

Animals↗
PubMed1984

Molecular mechanisms of lymphocyte extravasation. I. Studies of two selective inhibitors of lymphocyte recirculation.

Pertussigen, a protein toxin purified from Bordetella pertussis, and fucoidin, a high molecular weight sulfated polysaccharide, were analyzed for their ability to inhibit lymphocyte recirculation in vivo. Pertussigen treatment of lymphocytes resulted in a dosage- and time-dependent loss of their ability to localize in lymph nodes or Peyer's patches. This toxin-induced alteration did not reverse after extended lymphocyte culture in toxin-free media, and had no effect on lymphocyte viability or activation by mitogens. Furthermore, pertussigen-treated lymphocytes retained the ability to specifically adhere to high endothelial cells in an in vitro binding assay. Kinetic studies suggested that the toxin's molecular action on lymphocytes is analogous to that reported for pancreatic islets and hormone-responsive cultured cell lines. Inhibition of lymphocyte recirculation by fucoidin was also observed in vivo. Fucoidin-mediated inhibition of lymphocyte localization to peripheral lymph nodes was reversible with time, and could not be effected by pretreatment of lymphocytes with the polysaccharide. Furthermore, we confirmed the observation that fucoidin blocks lymphocyte adhesion to high endothelial cells in vitro. On the basis of these observations, we propose that the mechanism of lymphocyte extravasation involves a specific receptor-mediated binding event followed by an adenylate cyclase-dependent activation of cell motility. Fucoidin is capable of interfering with the primary adhesion event, whereas pertussigen selectively inhibits the second process to block lymphocyte recirculation in vivo.

Adenylate Cyclase Toxin↗
PubMed1984

Molecular mechanisms of lymphocyte extravasation. II. Studies of in vitro lymphocyte adherence to high endothelial venules.

Lymphocyte migration from the blood into the lymph nodes in most species occurs across post-capillary high endothelial venules (HEV). In a previous study, we proposed that lymphocyte extravasation involves receptor-mediated binding followed by adenylate cyclase-dependent activation of lymphocyte motility. This hypothesis was, in part, based on observations of in vitro lymphocyte adherence to HEV by employing pertussigen, which is a known inhibitor of lymphocyte recirculation. In vitro lymphocyte-HEV binding requires a cold (6 degrees C) incubation step and binding is poor to nil if the assay is attempted at room (23 degrees C) or physiologic temperature. We decided to investigate why this assay is temperature restricted, because of the possibility that pertussigen or fucoidin -treated lymphocytes might interact with HEV differently at higher temperatures. We now report that O.C.T. compound (OCT), the embedding matrix generally used to cut frozen lymph node sections, is toxic to lymphocytes at temperatures above 6 degrees C. Exclusion of OCT from the assay system will allow lymphocyte-HEV binding to occur at 23 degrees C and to a lesser extent at 37 degrees C. With this modified protocol, lymphocytes treated with either pertussigen, fucoidin , or neuraminidase were tested for adherence to HEV at 23 degrees C. No essential difference in binding properties was observed from what had been reported at 6 degrees C. In contrast, trypsin-treated lymphocytes that did not bind to HEV with the standard technique at 6 degrees C did adhere to a minimal extent to HEV at 23 degrees C using the modified procedure. We also report some preliminary work, using the modified assay, on in vitro lymphocyte-HEV binding of rat, rabbit, and guinea pig lymphocytes to sections of lymph nodes from the respective species.

Adenylate Cyclase Toxin↗