Milena Kataranovski

Immunomodulatory effects of low‐intensity near‐infrared laser irradiation on contact hypersensitivity reaction

Background/Purpose: Contact hypersensitivity (CHS) reaction is a useful model for studying the skin immune system and inflammatory reactions in the skin. In this study, an experimental model of CHS reaction was employed to assess immunomodulatory effects of near‐infrared (near‐IR) low‐intensity laser (LIL) irradiation, which is used as adjuvant therapy in dermatology, physical medicine, rheumatology, etc., because of its declared anti‐inflammatory, biostimulative and analgesic effects.

Immunotoxicity of epicutaneously applied anticoagulant rodenticide warfarin: evaluation by contact hypersensitivity to DNCB in rats

The immunotoxicity of epicutaneously administered anticoagulant rodenticide warfarin (WF) was examined in this work by using experimental contact hypersensitivity (CHS) reaction to hapten dinitrochlorobenzene (DNCB). WF (0.05 and 0.5 mg/kg) administration 24 h before the induction of CHS does not change expression of CHS evaluated by ear swelling assay. Regional draining lymph node response during sensitization phase was characterized by decreased cellularity but increased spontaneous and IL-2 stimulated proliferation of draining lymph node cells (DLC). No changes in IL-2 production and in numbers of CD25(+) cells were noted and even decreased proliferative index (ratio of IL-2 stimulated to unstimulated DLC proliferation) was detected. Increase in granulocyte activity (MTT reduction and adhesion to plastic) was noted following application of WF solely with further increase following subsequent application of DNCB, when granulocyte activation (NBT reduction) was noted also. Access of WF into general circulation might be responsible for observed changes, what was supported by ex vivo changes in DLC and granulocyte functions assessed before initiation of sensitization and by in vitro effect of exogenous WF as well. Differential effects of WF on lymphocytes and granulocytes noted in this study highlight the need for simultaneous testing of both cell type activity what might constitute a more integrated approach in immunotoxicity studies.

Interferon gamma alters the phenotype of rat thymic epithelial cells in culture and increases interleukin-6 production.

Rat thymic epithelial cells (TEC) in long-term culture were characterized by anticytokeratin monoclonal antibodies (mAbs) and electron microscopy. Phenotypic analysis performed by a large panel of mAbs showed that the highest percentage of these cells was of the subcapsular/medullary type. Recombinant rat interferon (IFN)-gamma up-regulated class-I and class-II MHC expression by TEC in culture as confirmed by immunohistochemistry and flow cytometry, but did not significantly alter other cell markers. TEC supernatants of IFN-gamma-treated cultures showed higher interleukin-6 (IL-6) activity, compared to the control, as determined by proliferation of the IL-6-sensitive B9-cell line. Increased IL-6 activity was probably not a consequence of increased TEC number in IFN-gamma-treated cultures because IFN did not significantly stimulate TEC proliferation in vitro. In contrast, IL-6 significantly stimulated TEC proliferation, indicating that this cytokine is not only a regulatory molecule for T-cell proliferation, but could also be an autocrine growth factor for thymic epithelium.

Peripheral blood granulocyte activity following contact sensitization of rats with dinitrochlorobenzene

Contact hypersensitivity (CHS) reaction is a classic example of a cell-mediated reaction. As the afferent phase of the reaction includes inflammation, CHS is a suitable model for investigating non-specific immunity. Some aspects of granulocyte activity in the afferent phase of experimentally induced CHS to dinitrochlorobenzene (DNCB) in two genetically different rat strains, AO and DA were examined in this study. A shift in the ratio of granulocytes to lymphocytes in favour of granulocytes and an increase in granulocyte survival were noted in DA rats. Granulocytes from both strains demonstrated increased levels of NBT reduction and an increase in their adhesion to plastic. Decreased granulocyte adhesion in the presence of monoclonal antibodies to beta2 integrins (anti-CD11b/c and anti-CD18) points to the contribution of these molecules to granulocyte adhesiveness during the sensitization phase of CHS. Stimulation of adhesion in the presence of anti-CD11a antibody, points to a differential modulation of adhesion molecule activity during the afferent phase of CHS. Changes in functional activity of granulocytes demonstrated in this study might contribute to the development of CHS in rats.

Acute sterile inflammation — correlation between cellular changes and extramedullary-produced regulators in vivo

SummaryRats with polyvinylpyrrolidone (PVP)-induced sterile inflammation were used as a model in vivo for investigation of granulopoiesis and extramedullary-produced regulators. The data obtained demonstrated the invasion of massive numbers of granulocytes at the site of inflammation (peritoneal cavity) during the first 24 h of the acute phase of inflammation. To meet the organisms needs for granulocytes the activation of granulopoiesis in bone marrow occurred simultaneously. Accelerated production of granulocytic cells is manifested by involvement of granulocytic proliferative compartment in various stages of differentiation (CFU-GM and morphologically recognizable proliferative granulocytes — PG). Together with cellular changes within the granulocytic cells line, the changes in the content of investigated regulators influencing granulopoiesis were observed. At different time intervals the levels of interleukin-6 (IL-6), colony-stimulating activity (CSA), and granulocytic stimulating activity (GSA) were increased locally at the site of inflammation as well as in serum. The data obtained provide evidence that inducible granulopoiesis during the acute phase of inflammation is under the control of extramed-ullary-produced regulators, thus confirming their role in the regulation of granulocytic production in vivo.

Post-traumatic activation of draining lymph node cells. II. Proliferative and phenotypic characteristics.

Proliferative and phenotypic characteristics of cells in regional lymph nodes that drain burn injury were examined in rats on day 3 postburn, i.e. at the time of maximal spontaneous proliferation and of interleukin-2 and accessory cytokine (IL-1 and IL-6) production. The importance of IL-1 in spontaneous proliferation of draining lymph node cells was demonstrated by stimulation of IL-2-driven proliferation by recombinant IL-1 in vitro and by susceptibility of unstimulated proliferation to anti-IL-1 antibodies, while requirements for IL-6 in draining lymph node cell proliferation were less pronounced. Cell surface phenotyping revealed a slightly increased percentage of CD25+ cells in the blast cell population of freshly isolated draining lymph node cells after injury, which increased further during cultivation. Enrichment in CD8+ cells on day 3 following burn injury was demonstrated, while no changes in total cell population and CD4+ cells was noted. This was however preceded by pronounced percentual decrease of total T cells and CD4+ cells and by increases of B cells and MHC class II+ cells on day 1 postburn. Inhibition of draining lymph node cell proliferation by anti-MHC class II antibodies suggested that this proliferation was class II MHC dependent. The contribution of cell proliferation and/or cell influx to day 3 postburn draining lymph node cell activity is discussed.

Presence of interleukin-8 and the IL-1 receptor antagonist in the cervical mucus of fertile and infertile women.

BACKGROUND Cytokines are involved in almost every aspect of reproduction, and recent studies suggested a relationship between cytokines and male/female infertility. In the present study, the levels of interleukin-8 (IL-8) and interleukin-1 receptor antagonist (IL-1Ra) were determined in the cervical mucus of fertile and infertile women. METHODS Groups of patients were formed according to the results of the standard procedure for infertility investigation, including postcoital test and the presence of antispermatozoid antibodies in the sera of both partners and in seminal plasma, by mixed antiglobulin reaction (MAR) test and Kibrick agglutination test. IL-8 and IL-1Ra levels were determined in solubilized (ultrasonographic sonication) cervical mucus sampled in the midcycle by commercial ELISA kits and expressed as pg/mg proteins. RESULTS The groups were designated as fertile (n=20) and infertile (n=48). The latter was divided into two subgroups, one consisting of infertile women with positive postcoital test and without antispermatozoid antibodies (n=30), and the other designated as infertile women with negative postcoital test (n=18). This subgroup was composed of women with negative postcoital test and without antibodies (n=10) and the women with negative postcoital test with antibodies (n=8). Similar levels of IL-8 and IL-1Ra were noted in the cervical mucus of infertile women and women with positive postcoital test and without antispermatozoid antibodies. A tendency of decrease (p=0.052) and significant decrease in IL-8 levels (p<0.05) was noted in negative postcoital test group and negative postcoital test group without antibodies, respectively, compared to the levels in the fertile examinees. A significant rise in IL-1Ra levels (p<0.05) was detected in the mucus of negative postcoital test group with further increase in negative postcoital test group with antibodies (p<0.02). CONCLUSION Changes in IL-8 and IL-1Ra levels in the cervical mucus of infertile patients with negative postcoital test suggested the existence of the relationship between cervical cytokines and infertility in these women.

Increased activity of lymph node cells in experimental thermal injury: changes in accessory cells in injured area-draining lymph nodes

Accessory cell content and some of their functional characteristics were determined in regional lymph nodes which drain burn injury (DLN) in rats. Increase in percentages of non-specific esterase-positive cells and NBT+ macrophages and in numbers of dendritic cells were noted in cytospin preparations of draining lymph node cells (DLC) 24 and 72 h following thermal injury. An accumulation of B cells was also noted in the DLN paracortex region at these time points. Enrichment of ED1+ (rat macrophage marker) cells was noted in the adherent DLC population. Increased activity of interleukin-1 (IL-1) in conditioned medium from adherent DLC population and the increased stimulatory capacity of whole DLC or dendritic cell enriched-DLC fraction were noted in functional assays. Enrichment in accessory cells and an increase in their functional activity could contribute to the endogenous activity of regional lymph nodes which drain burned areas.

The In Vivo Effect of Liposomes on Hematopoiesis

The influence of liposome structure on hematopoiesis in vivo was assessed in relation to the different contents and origins of phospholipids that make up their membrane structures. Changes within different hematopoietic cells and serum tumor necrosis factor alpha (TNF-alpha) levels were estimated up to 14 days following intravenous administration of liposomes made of either pure egg yolk phosphatidylcholine (LEY) or a soybean phospholipid preparation (LSB) into normal CBA mice. In peripheral blood, only transient changes within white blood cells were observed. In bone marrow, a persistent decline in the number of mature granulocytes, monocytes, and lymphocytes was found. The changes within femoral granulocytic proliferative compartments in various stages of differentiation and a maturation compartment pointed out that, parallel with the depletion of the granulocyte-storage pool, stimulation of de novo production of granulocytic cells occurred. Although both types of tested liposomes induced similar cellular changes, only liposomes made of pure egg yolk phosphatidylcholine induced a transient increase in serum TNF-alpha levels.

IL-1, TNF and IL-6 Release by Wound- inflammatory Cells During the Healing Process in Two Strains of Rats

Publisher Summary This chapter presents a study in which the cellular responses during the course of wound healing in two different inbred rat strains, Albino Oxford (AO) and Dark August (DA), are investigated. The rate of wound closure of full-thickness wounds, the type of wound-infiltrating cells, and the time course of interleukin 1(IL-1), interleukin 6 (IL-6), and tumor necrosis factor (TNF) production by wound-derived cells were measured by using a sponge–matrix model. Two round full-thickness wounds were prepared dorsally in both strains with a sharp, round metal blade of 1 cm diameter, and wound diameters were measured during seven days of the healing process. The study demonstrates that DA and AO rats differ in their healing capabilities. The DA rats showed an accelerated wound-healing course that was accompanied by a different pattern of wound cellular infiltration and significantly higher levels of IL-6 and TNF in supernatants of wound-derived cells compared to AO strain. A higher proportion of infiltrating lymphocytes and higher IL-6 and TNF activities in wound-cell supernatants could be one of the mechanisms that underline the accelerated wound-healing course seen in DA rats.