Biomedical subjects

M Szczepanik

Publications and source records attributed to M Szczepanik.

At least 19 recordsLinked to original sources

PubMed2006

Interplay between Helicobacter pylori and the immune system. Clinical implications.

Helicobacter pylori (H. pylori) is a gram-negative bacteria infecting more than 50% of human population. H. pylori selectively colonizes gastric mucosa and represents the major cause of gastroduodenal pathologies, such as gastric ulcer, autoimmune gastritis, gastric cancer and B cell lymphoma of mucosa associated lymphoid tissue (MALT). In this review interplay between H. pylori and both innate and adaptive immune responses is discussed. The second part of this article presents current knowledge about the relationship between H. pylori infection and neoplasia.

Animals↗

PubMed2005

The influence of collagenase treatment on the production of TNF-alpha, IL-6 and IL-10 by testicular macrophages.

Testicular macrophages (TMf) are located in the interstitial tissue of the male gonad. Highly purified TMf populations can be prepared either by the mechanical shaking of dispersed testicular tissues or by enzymatic digestion with collagenase followed by cell adherence, rosetting and gradient centrifugation. TMf obtained by the enzymatic procedure produced significantly more cytokines (IL-6, IL-10 and TNF-alpha) than TMf isolated by the mechanical method and this effect is long-lasting. Our results indicate that isolation of tissue macrophages by enzymatic digestion may influence their functional activity, and suggest that critical evaluation of the method used to obtain these cells should be the regular practice.

Animals↗

PubMed2003

Modulation of macrophage activity by proteolytic enzymes. Differential regulation of IL-6 and reactive oxygen intermediates (ROIs) synthesis as a possible homeostatic mechanism in the control of inflammation.

Inflammatory foci are rich in proteases released by neutrophils (serine proteases) and macrophages (metalloproteases). These enzymes can degrade extracellular matrix proteins and cell membrane bound proteins thus contributing to the development and progression of inflammatory reaction. In this study we have investigated the influence of collagenase (metalloprotease) and trypsin (serine protease) on murine resident and oil-induced peritoneal macrophages (Mf). Short in vitro treatment of Mf, not affecting cell viability, significantly reduced the release of reactive oxygen intermediates (ROIs) and at the same time triggered the increase of IL-6 production and to lesser extent of TNF-alpha production. Both these effects were dependent on enzyme concentration used and were particularly well pronounced in resident macrophages. In addition both enzymes cleaved a number of cell-membrane molecules, including CD23, CD14, CD95L, and Mac-3. We hypothesize that the enzymatic digestion of certain Mf surface receptor proteins in inflammatory foci may be responsible for modification of cell behaviour either by preventing the generation of specific signal or alternatively by delivering a mock substitute signal to the cell interior. In effect inhibition of ROIs production limits their destructive effects and the increase in the secretion of IL-6 stimulates the synthesis of acute phase proteins and triggers other anti-inflammatory mechanisms thus directing Mf present in inflammatory foci into regulatory pathway rather than allowing them to perform solely the effector function.

Animals↗

PubMed2000

Heat-aggregated immunoglobulins increase in vivo immunogenicity of mouse hapten (TNP)-derivatized macrophages by upregulation of interleukin-12 secretion and expression of B7-1 and B7-2 costimulatory molecules.

Antigen-antibody complexes (IC) can up or down regulate immune responses by induction of immunoregulatory cells. We have studied the effect of mouse heat-aggregated immunoglobulin (Ig) (HA) which have many biological activities similar to IC on immunogenicity of TNP-substituted macrophages (TNP-Mphi). Our results show that: (1) mouse oil-induced peritoneal macrophages treated with HA produce in vitro significantly higher levels of interleukin (IL-1beta), tumor necrosis factor (TNF)-alpha, IL-6, IL-10 and particularly IL-12 and express more B7-1 and B7-2 and ICAM-1 cell surface costimulatory molecules than Mphi treated with monomeric Ig (MM); (2) Mphi derivatized with TNP, treated or not with MM, induce in vivo antigen-specific unresponsiveness. In contrast TNP-Mphi treated with HA induce significant contact sensitivity reaction even when injected into previously tolerized recipient animals. Treatment of recipients with anti-IL-12 Ab prevents immunization by TNP-Mphi-HA. These results indicate that bypass of tolerance by treatment of TNP-Mphi with HA is a result of an increased production of IL-12 by these cells and an enhanced expression of costimulatory molecules important in T cell-Mphi interactions. We suggest that a similar overcoming of tolerance through the action of IC may be responsible for the generation of autoantibodies of heterologous specificity in pathological conditions in which such complexes are formed.

Animals↗

PubMed2000

IL-12 is produced by antigen-presenting cells stimulated with soluble alphabeta TCR and restores impaired T(h)1 responses.

Contact sensitivity (CS) is a cutaneous T(h)1 response that is induced by skin painting with reactive hapten. In prior in vivo studies of CS, we showed that recombinant soluble alphabetaTCR (sTCR) acted non-specifically to protect CS-effector T cells from suppression, but no molecular mechanism was determined. In the current study, we employed an in vitro system to investigate the mechanism of how sTCR protect CS-effector T cells from suppression. Immune CS-effector cells and appropriate hapten-conjugated antigen-presenting cells (APC) were incubated together with down-regulatory culture supernatant produced by suppressive spleen cells from mice tolerized i.v. with specific hapten, which produced strong inhibition of IFN-gamma production by the CS-effector cells. Importantly, addition of two different sTCR, of unrelated specificity, reversed this down-regulation and thus restored IFN-gamma production. We found that the APC, and not the CS-effector T cells, were the locus of the sTCR-mediated protection and showed direct binding of sTCR to APC by flow cytometry. Further, addition of anti-IL-12 showed that sTCR protection was due to IL-12 induced by sTCR and released by the APC, and was confirmed by ELISA measurement of IL-12 induced in APC supernatants by sTCR incubation. These results indicated a possible new regulatory loop in which suppression was reversed by IL-12 derived from APC, following direct surface binding of sTCR, and enhanced by IFN-gamma production from the T(h)1 CS-effector cells.

Animals↗

PubMed2000

Cross-reactivity of TNP immune effector T cells that mediate contact hypersensitivity and inflammatory bowel disease in the mouse.

BACKGROUND: Experiments were aimed to test the cross-reactivity of immune Th1 cells that mediate contact hypersensitivity (CHS) or inflammatory bowel disease (IBD) to TNP in the mouse. METHODS: CBA/J mice were immunized either epicutaneously or intrarectally with TNP and after appropriate time intervals were challenged with antigen in a crossed manner. The CHS reaction was measured by the ear swelling test. IBD was quantified by increase of colon weight and myeloperoxidase level. Both reactions were confirmed histologically. In passive-transfer experiments, mesenteric lymph node cells of animals sensitized intrarectally and peripheral lymph node and spleen cells of mice immunized epicutaneously were used. In some experiments, before being immunized mice were made either unresponsive to the TNP hapten by induction of suppressor T cells, or resistant to suppression after induction of upregulatory T cells. RESULTS: Irrespective of the mode of sensitization upon appropriate challenge with antigen all mice developed a good CHS reaction as well as significant IBD. This cross-reactivity could be passively transferred by immune cells. In mice in which antigen-specific down- or upregulatory cells were induced before sensitization both CHS and IBD to TNP were modulated accordingly. CONCLUSION: TNP hapten deposited on skin or on mucosal surfaces induces effector cells that recognize antigen independent of its tissue localization, and produce a local inflammatory reaction. TNP-specific up- and downregulatory cells, shown before to regulate the CHS reaction, similarly modulate the generation and development of hapten-induced IBD.

Animals↗

PubMed2000

IL-12 reverses established tolerance mediated by TCRalphabeta+ but not by TCRgammadelta+ suppressor T cells.

Topical cutaneous painting with chemically reactive haptens induces the ability to subsequently elicit contact sensitivity (CS) responses in the skin. These CS responses are in vivo examples of acquired, antigen (Ag)-specific T cell immunity, and are a form of delayed-type hypersensitivity (DTH). In contrast, high dose i.v. administration of the hapten can induce Ag-specific tolerance. In some instances this specific immune hyporeactivity is due to suppressor T cells. We investigated the effect of IL-12 on reversal of tolerance due to suppressor T cells that were induced by i.v. administration of hapten in either normal TCRalpha+/+, or in immunodeficient TCRalpha-/- mice. In the TCRalpha+/+ mice, tolerance is mediated by TCRalphabeta+ suppressor T cells, while in the TCRalpha-/- mice the tolerance is due to suppressive TCRgammadelta+ cells. Treatment with IL-12 reversed suppressor mediated by the TCRalphabeta+ cells, but did not affect tolerance due to TCRgammadelta+ suppressor cells. Another difference was that the alphabetaTCR+ suppressor cells produced a soluble suppressor factor that could replace the surppressor cells, while gammadeltaTCR+ suppressor cells did not. We hypothesized that IL-12 may strengthen responses of target CS-effector T cells influenced by the hapten-MHC-specificity of alphabeta suppresssor cells, or suppressor factor. On the other hand, gammadeltaTCR+ suppressive cells likely have specificity for the hapten alone, and are not MHC-restricted, and therefore probably do not operate via peptide-MHC interactions, that could be strengthened by IL-12. The ability of IL-12 to strengthen the resistance of CS-effector T cells to alphabeta TCR suppressor cells, may be due to the ability of IL-12 to increase T cell costimulation mediated by signaling mechanisms acting via B7.1 and B7.2. In contrast, gammadeltaTCR+ suppressor cells, that are largely hapten-specific, probably do not interact with peptide/MHC complexes on APC, and thus are not affected by IL-12 strengthening of co-stimulation.

Animals↗

PubMed2000

Soluble T cell receptors modulate cytokine production and oxygen metabolism by peritoneal macrophages.

Preincubation of peritoneal macrophages and their subsequent culture with recombinant soluble T cell receptor (sTCR) results in significant increase of: TNF-alpha, IL-1beta, IL-6, IL-10, IL-12 production and nitric oxide (NO) synthesis and this phenomenon was dose dependent. Moreover, treatment of macrophages with sTCR showed two to three fold increase of luminol dependent chemiluminescence (LCL) when compared to untreated macrophages (Mf). In contrast, in our study we did not find any influence of sTCR on co-stimulatory (B7.1 and B7.2), adhesion molecule (ICAM-1) or FcRII/III expression by macrophages. However, macrophages treated with control supernatants received after phosphatidylinositol-specific phospholipase C (PI-PLC) treatment of BW1100 cells or thymocytes termed s-BW or s-Th did not influence their biological activity.

Animals↗

PubMed2000

Experimental inflammatory bowel disease--role of T cells.

BACKGROUND: Our experiments were aimed to test: 1. which lymphocyte subpopulations participate in mouse colitis, produced by intrarectal (i.r.) deposition of trinitrobenzene sulphonic acid (TNBSA, TNP hapten); 2. the expression of cell adhesion molecules on lymphocytes draining the site of reaction; 3. the influence of mouse haplotype on the development of colitis. METHODS: CBA/J, BALB/c and C57BI/6 inbred and outbred Swiss Webster strains were used. Mesentheric lymph node (MLN) cells of immunized animals, unseparated or separated into CD4+, CD8+ or gammadelta+ and alphabeta+ T cell subpopulations or depleted of B lymphocytes, were transferred into recipients which were challenged i.r. with TNBSA. Inflammatory reaction in the colon was confirmed macro- and microscopically and by myeloperoxidase (MPO) level. MLN lymphocyte surface markers were tested cytofluorimetrically using appropriate antibodies. RESULTS: Sensitization with TNP results in chronic colitis (hapten dose-dependent colon weight gain and cellular infiltrate, significant increase of MPO level) only in CBA/J and BALB/c strains and can be adoptively transferred in a cell-dose dependent manner into syngeneic recipients by T alphabeta+ cells of both CD4+ and CD8+ subpopulations. T gammadelta+ cells were ineffective and B lymphocytes do not participate in the passive transfer reaction. In MLN the number of T lymphocytes positive for cell adhesion molecules particularly LPAM-1 (V-CAM1) and LPAM-2 increases significantly. CONCLUSIONS: Both CD4+ and CD8+ lymphocytes participate in the development of TNP-induced colitis. High MPO level may suggests that both Th1 and Th2 cells are involved. Colitis is accompanied by a significant accumulation in MLN of T lymphocytes positive for several cell surface adhesion molecules characteristic for memory T cells. Significant differences in susceptibility to develop colitis were found between different strains of mice.

Animals↗

PubMed2000

[Chronic inflammation of the colon: a diagnostic problem].

Chronic inflammation of the colon and rectum with associated diarrhea has become more difficult to diagnose recently. Many etiological factors and different therapeutic outlines need to be carefully discussed and summarized. Based on most recent literature, authors present current data on etiology and specific (case-depended) diagnostic procedures in colitis and proctocolitis.

Chronic Disease↗

PubMed1999

Role of interleukin-4 in down-regulation of contact sensitivity by gammadelta T cells from tolerized T-cell receptor alpha-/- mice.

Contact sensitivity (CS) is a classical example of an in vivo T-cell-mediated immune response that is under regulation. Such down-regulation can be mediated by alphabeta T cells in mice that are tolerized by prior exposure to high doses of antigen. In contrast, we demonstrated previously that such high-dose antigen tolerance in T-cell receptor (TCR) alpha-/- H-2d mice induced antigen-specific, apparently major histocompatibility complex-unrestricted, CD4- CD8- gammadelta T cells, that also could down-regulate CS responses antigen-specifically in vivo, and also inhibited in vitro production of IFN-gamma. In the present experiments we employed H-2b-deficient TCRalpha-/- and TCRbeta-/- mice, owing to different molecular constructs than were used previously, and confirmed that tolerized gammadelta T cells in these different H-2b alphabeta TCR-/- mice down-regulated CS. Thus, gammadelta T-cell suppressor function was not limited to mice bearing a special transgenic TCRalpha-/- DNA construct. Furthermore, employing monoclonal antibody and complement depletion in vitro and adoptive transfer in vivo, characterized the phenotype of these gammadelta down-regulatory T cells as: CD3+, CD28+, CD40-ligand+, Fas+, FcgammaR+ and NK1.1-. Also, in vitro antigen desensitization of these trinitrophenyl (TNP)-specific TCRgammadelta+ down-regulatory cells was achieved with soluble TNP-bovine serum albumin (BSA), but not with oxazolone-BSA, showing that these suppressive gammadelta T cells have antigen-specific receptors. Moreover, employing monoclonal antibody blocking of gammadelta suppressors in vitro, and of recipients in vivo, we showed that interleukin-4 (IL-4) was involved in this down-regulation of CS by gammadelta T cells, while IL-10 and transforming growth factor-beta2 were not. In summary, generation of antigen-specific, double-negative, gammadelta suppressor cells, by tolerance of high antigen doses in TCRalpha-/- mice, appears to be a general phenomenon, and IL-4 production is involved in their down-regulation of the T helper type 1 cells that mediate CS.

Adoptive Transfer↗

PubMed1999

[Defense mechanisms in the peritoneum].

There are many specialised defence mechanisms connected with immunity of peritoneal cavity. These are absorbtion of bacteria and their toxins from peritoneum, phagocytosis, opsonization, activation of the complement and separation of infection in the peritoneal cavity. A very important role in defence mechanisms of peritoneal cavity play GALT and PALT. Among many cells of the immune system mastocytes and gamma delta T cells have important role in induction and regulation of immune mechanisms in the peritoneal cavity. Lymphocytes T gamma delta release many cytokines and chemokines what allows them to play their protecting role during peritonitis. Released cytokines (especially IFN-gamma) activate macrophages to produce and secret many proinflammatory cytokines and factors. On the other hand mast cells play their role in defence of peritoneal cavity via TNF-alpha and histamine release and inhibition of fibrynolysis.

Animals↗

PubMed1998

IL-12 reverses established antigen-specific tolerance of contact sensitivity by affecting costimulatory molecules B7-1 (CD80) and B7-2 (CD86).

Cutaneous painting with reactive haptens induces contact sensitivity (CS) responses that are in vivo examples of T cell immunity. In contrast, high dose i.v. administration of the hapten can induce tolerance. We investigated the effect of IL-12 on reversal of this tolerance and attempted to determine in vitro the mechanism of this reversing effect by measuring proliferation and IFN-gamma production by CS effector T cells stimulated with hapten-conjugated APC, and we also measured CS ear swelling in vivo. The in vitro responses of T cells to hapten-APC became absent in tolerized mice, paralleling impaired in vivo CS responses. Addition of IL-12 to cultures manifesting this fully established in vitro tolerance completely restored impaired responses of tolerized T cells. The reversing effects of IL-12 were not blocked by anti-IFN-gamma mAb, but were blocked by mAbs against B7-1, more strongly by anti-B7-2, and by both Abs together. Additional in vivo ear-swelling response experiments confirmed the reversing effects of IL-12 on established tolerance. To examine whether the IL-12 effect depended on stimulation of IFN-gamma, we directly injected IFN-gamma into tolerized mice. This partially mimicked but did not fully reconstitute the effects of IL-12. In summary, IL-12 abrogation of established tolerance of CS may have been partially due to endogenous production of IFN-gamma, but appeared mainly due to direct activation of the tolerized T cells by affecting signaling through costimulatory molecules B7-1 and B7-2.

Animals↗

PubMed1998

Cross-talk between gammadelta T lymphocytes and immune cells in humoral response.

The role of gamma delta T cells in immunoregulation is largely unknown. In the current study we noted that gamma delta T cells play a positive role in the humoral response. These positively acting gamma delta T cells are required for the successful adoptive cell transfer of the humoral response, as well as for in vitro generation of plaque-forming cells (PFC). The presented results show that gammadelta T cells cause an increase in interleukin-10 (IL-10) production, which partly elucidates the mechanism of action of these cells. However, experiments with cell culture inserts strongly suggest that direct cell-cell contact between immune and gamma delta H-2-compatible regulatory T cells is critical to the exertion of the positive immunoregulatory function of gamma delta cells. The mechanism of cross-talk between these two cell populations is still not clear but we regard as most likely that the positively acting gamma delta T cells may interact with a complex of heat-shock protein-non-polymorphic MHC (IB) on the surface of T helper type 2 and/or B cells. This could provide, by direct cell-cell contact, the cognate recognition between gamma delta T-cell receptors and heat-shock protein-MHC that leads to positive internal signalling in the immune cells.

Animals↗

PubMed1998

[Immunogerontology--aging of the immune system and its cause].

Ageing is characterized by declining ability of the individual to adapt to environmental stress. By most parameters tested either in the laboratory or in vivo, immune function is decreased in elderly compared with young individuals. First age-associated changes in the immune system appear at the time of sexual maturity and result in the thymus atrophy. However, more drastic decrease of circulating T lymphocytes is observed in people over 70. Moreover, T cells respond weaker to mitogens, produce lower level of cytokines and cytokine receptors e.g. IL-2, IL-2R. Observed decrease of CD8+ T cells (T cytotoxic & T suppressor cells) results in an increase of CD4/CD8 ratio. Additionally, ageing also affects humoral response what consists in decrease in antibody producing cell number. Moreover, elderly individuals show increased level of serum IgG and IgA with parallel decrease of IgM. Seniors possess increased level of auto-antibodies and auto-anti-idiotopic antibodies. Innate immune responses are less affected with age. Adherence and phagocytosis of polymorphonuclears and macrophages is unchanged or even increased. However, their chemotaxis and synthesis of reactive oxygen metabolites is decreased. Reduced immunological vigor may result in the high incidence of infectious diseases, autoimmune diseases, immune complex diseases, and cancer.

Adaptation, Physiological↗

PubMed1998

[Regulation of the contact sensitivity reaction by suppression of T gamma delta lymphocytes].

Contact sensitivity (CS) is a classical example of in vivo T cell mediated immune response that is under regulation. It is well known that in normal mice suppression of CS can be mediated by T alpha beta cells tolerized by prior exposure to high dose of antigen (Ag). In this paper it was shown that treatment of defective TCR alpha -/- or TCR beta -/- mice with high dose of Ag may result in induction of T gamma delta suppressor cells, that are able to inhibit both adoptive cell transfer of CS in vivo and IFN-gamma production in vitro. These suppressor cells are characterized as: TCR gamma delta+, CD3+, CD4-, CD8-, CD28+, CD40L+, CD95 (Fas)+, Fc gamma R+ and NK1.1-. Suppression mediated by T gamma delta cells showed antigen specificity, but was not restricted by the MHC. T gamma delta suppressor cells express very strong down-regulatory activity where even 2.5 x 10(3) T gamma delta cells could suppress 7 x 10(7) CS-effector cells. Presented data may suggest that IL-4 released by T gamma delta suppressor cells is involved in the mechanism of their down-regulatory function.

Adaptation, Physiological↗

PubMed1997

Different patterns of gamma delta and alpha beta T cell redistribution in the mouse after partial gastrectomy.

BACKGROUND: Stress, including surgical trauma, results in different dysfunctions of the body. In our former experiments on posttraumatic modification of immune response of gastrectomized mice we observed a significant suppression of contact sensitivity. This could be transferred by lymph nodes and spleen T lymphocytes of mice which underwent surgery. MATERIALS AND METHODS: We studied changes in gammadelta and alphabeta T cell numbers in peripheral blood, Peyer's patches, and mesenteric lymph nodes after partial gastrectomy (major operation) and after sham gastrectomy (laparotomy-minor operation) in mice. The number of gammadelta and alphabeta T cells was counted on the FACSTAR cell sorter before and 1, 2, 3, 7, and 14 days after surgery. RESULTS: In our observations there was a significant increase of percentage of gammadelta T cells both in Peyer's patches (1.9 +/- 0.5 to 10.5 +/- 0.3) and in mesenteric lymph nodes (2.7 +/- 0.7 to 8.8 +/- 3.5) on the third day after partial gastrectomy (546 and 322% of control values, respectively). In contrast in gastrectomized mice the number of alphabeta T cells in Peyer's patches (38.4 +/- 6.8 to 21.2 +/- 6.2) and lymph nodes (56.7 +/- 15 to 40.4 +/- 17) was decreased on day 3 (55 and 71% of control values, respectively). There was a decline in both alphabeta (18.1 +/- 8 to 8.2 +/- 1.7) and gammadelta (6.7 +/- 2.8 to 3.9 +/- 2) T cell numbers in peripheral blood on days 1, 3, and 7 (45 and 58% of normal values, respectively). Sham operation had no significant influence on alphabeta and gammadelta T cell numbers. We observed that after leg amputation the number of gammadelta T cells in mesenteric lymph nodes was significantly increased on day 3 (0.8 +/- 0.2 to 7.7 +/- 0.3), 770% of normal. In contrast to this, leg amputation had a negligible effect on T cell counts in Peyer's patches during all periods of observation. CONCLUSIONS: We suggest that the major surgical stress (partial gastrectomy) may disturb the normal cell traffic selectively with increased gammadelta T cell homing in intestinal Peyer's patches and lymph nodes (GALT) and with the cell displacement from peripheral blood to lymphatic organs. The severity and localization of stress may be crucial.

Animals↗

PubMed1997

[Colitis in laboratory experimentation].

Immunological concept of pathogenesis of inflammatory bowel disease (ulcerative colitis and Crohn's disease) is presently most common but it's specific etiology is still unknown. Spontaneous manifestations of these disease in animal are very rare and ad adequate laboratory animal model is needed for research. In this review different animal models of colitis are present in chronological order, displaying the search for the highest similarity to the clinical colitis.

Animals↗