RESUMEN
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.
Asunto(s)
Colagenasas/metabolismo , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Macrófagos/metabolismo , Testículo/citología , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Células Cultivadas , Masculino , Ratones , Ratones Endogámicos CBARESUMEN
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.
Asunto(s)
Endopeptidasas/inmunología , Regulación de la Expresión Génica/fisiología , Interleucina-6/biosíntesis , Macrófagos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Animales , Células Cultivadas , Colagenasas/inmunología , Endopeptidasas/metabolismo , Homeostasis/fisiología , Inflamación/enzimología , Macrófagos Peritoneales/metabolismo , Masculino , Ratones , Ratones Endogámicos CBA , Tripsina/inmunologíaRESUMEN
Systemic and topical administration routes of tacrolimus and cyclosporin A (CsA) were compared in effects on early and late phases of elicited T-cell-mediated contact sensitivity (CS), and effects on early and late phases of cutaneous immunoglobulin E (IgE) antibody-mediated hypersensitivity responses in mice. Thus, both CS and IgE responses in the skin have an early mast-cell-dependent phase, and also a late inflammatory phase. We measured the effects of both immunosuppressants on both phases of the respective T cell versus IgE responses. Systemic administration of both agents completely suppressed CS and IgE late-phase responses, but failed to affect either early phase. In contrast, when topical CsA was used, low doses abolished the early phase of IgE responses, but even high doses did not inhibit the early phase of CS. Conversely, topical tacrolimus inhibited the early phase of CS more potently than the early phase of cutaneous IgE hypersensitivity responses. Thus, topical treatment was needed to inhibit the early phases and the two agents acted differentially, suggesting differing susceptibility of the early phases, that are probably due to different signalling mechanisms. These studies underscore the potential value of topical administration of these powerful immunosuppressive agents in the treatment of allergic diseases that exhibit features of early-phase mast-cell-dependent inflammation, and late inflammation due to mast cells or to T cells, such as atopic dermatitis or asthma, since the early phase is predominantly susceptible to topical application, while the last phase of both IgE and T-cell inflammation responds to systemic treatment with both agents.
Asunto(s)
Ciclosporina/uso terapéutico , Dermatitis Alérgica por Contacto/prevención & control , Dermatitis Atópica/prevención & control , Inmunosupresores/uso terapéutico , Tacrolimus/uso terapéutico , Administración Cutánea , Animales , Dermatitis Alérgica por Contacto/inmunología , Dermatitis Atópica/inmunología , Femenino , Inmunoglobulina E/biosíntesis , Inmunoglobulina E/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBA , Cloruro de Picrilo/inmunología , Linfocitos T/inmunologíaRESUMEN
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.
Asunto(s)
Colitis/diagnóstico , Enfermedad Crónica , Humanos , Proctocolitis/diagnósticoRESUMEN
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.
Asunto(s)
Colitis/inmunología , Linfocitos T/inmunología , Animales , Linfocitos T CD4-Positivos/fisiología , Linfocitos T CD8-positivos/fisiología , Trasplante de Células , Colitis/inducido químicamente , Colitis/metabolismo , Colitis/patología , Relación Dosis-Respuesta a Droga , Predisposición Genética a la Enfermedad , Ganglios Linfáticos/citología , Ganglios Linfáticos/inmunología , Subgrupos Linfocitarios/inmunología , Masculino , Mesenterio , Ratones , Ratones Endogámicos/genética , Ratones Endogámicos/inmunología , Especificidad de la Especie , Ácido TrinitrobencenosulfónicoRESUMEN
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.
Asunto(s)
Antígenos CD/biosíntesis , Antígeno B7-1/biosíntesis , Interleucina-12/metabolismo , Macrófagos Peritoneales/inmunología , Glicoproteínas de Membrana/biosíntesis , Regulación hacia Arriba , Animales , Antígeno B7-2 , Células Cultivadas , Haptenos/inmunología , Calefacción , Inmunoglobulinas/inmunología , Macrófagos Peritoneales/citología , Masculino , Ratones , Ratones Endogámicos CBARESUMEN
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.
Asunto(s)
Citocinas/biosíntesis , Macrófagos Peritoneales/metabolismo , Oxígeno/metabolismo , Receptores de Antígenos de Linfocitos T/fisiología , Animales , Antígenos de Superficie/biosíntesis , Línea Celular , Células Cultivadas , Indicadores y Reactivos , Mediciones Luminiscentes , Luminol/metabolismo , Ratones , Ratones Endogámicos AKR , Ratones Endogámicos CBA , Óxido Nítrico/biosíntesis , SolubilidadRESUMEN
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.
Asunto(s)
Dermatitis por Contacto/etiología , Enfermedades Inflamatorias del Intestino/etiología , Células TH1/inmunología , Trinitrobencenos/inmunología , Animales , Antígenos/administración & dosificación , Reacciones Cruzadas , Dermatitis por Contacto/inmunología , Dermatitis por Contacto/patología , Haptenos/administración & dosificación , Inmunización Pasiva , Enfermedades Inflamatorias del Intestino/inmunología , Enfermedades Inflamatorias del Intestino/patología , Masculino , Ratones , Ratones Endogámicos CBA , Trinitrobencenos/administración & dosificaciónRESUMEN
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.
Asunto(s)
Dermatitis por Contacto/inmunología , Regulación hacia Abajo , Tolerancia Inmunológica , Interleucina-4/fisiología , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Células TH1/inmunología , Traslado Adoptivo , Animales , Anticuerpos Monoclonales/farmacología , Citocinas/inmunología , Femenino , Ratones , Ratones Endogámicos BALB C , Receptores de Antígenos de Linfocitos T alfa-betaRESUMEN
The increased incidence of bacterial and mycotic infections in poorly controlled diabetic patients or animals is frequently attributed to impaired activities of professional phagocytes (granulocytes, macrophages) in hypoinsulinaemic milieu. We measured production of monokines (IL-6 and tumour necrosis factor-alpha (TNF-alpha)), active NO and reactive oxygen intermediates (ROIs), as well as expression of several cell surface adhesion molecules (Mac-1, -2 and -3, intercellular adhesion molecule-1 (ICAM-1) and Fc gammaRII), by thioglycollate medium-induced peritoneal macrophages of normoglycaemic and alloxan diabetic CBA/J mice (blood glucose level in the range 300 or 500 mg/dl). Macrophages of animals with moderate diabetes (300 mg/dl) produced significantly more IL-6 and TNF-alpha and ROIs than cells of control mice and showed an increased expression of all cell surface molecules, except Mac-3. NO/NO2 production was not affected. Administration of insulin restored enhanced values to normal levels, except for the production of ROIs which remained unusually high. We conclude that two separate mechanisms influence macrophage physiology in diabetes--lack of saturation of insulin receptors on macrophages and an indirect effect due to formation of advanced glycosylation endproducts (AGE) on their surfaces. The latter is possibly responsible for increased generation of ROIs, since it cannot be down-regulated by prolonged insulin treatment. How the increased activity of macrophages of moderately diabetic mice (enhanced production of proinflammatory monokines and oxygen radicals as well as expression of molecules) is related to their ability to kill bacteria is now under investigation.
Asunto(s)
Moléculas de Adhesión Celular/biosíntesis , Diabetes Mellitus Experimental/metabolismo , Interleucina-6/biosíntesis , Macrófagos/metabolismo , Óxido Nítrico/metabolismo , Oxígeno/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Aloxano , Animales , Biomarcadores , Membrana Celular/metabolismo , Células Cultivadas , Ratones , Ratones Endogámicos CBA , Especies Reactivas de Oxígeno/metabolismoRESUMEN
We have previously reported that T lymphocytes proliferating in vitro to the hapten trinitrochlorobenzene (TNCB) exhibit a very restricted V beta gene usage and response to TNCB is limited to T-cell receptors (TCR) composed of V beta 8.2 in combination with V alpha 3.2, V alpha 8 and V alpha 10. This paper investigates the role played by T lymphocytes expressing the V beta 8.2 gene segment in the contact sensitivity (CS) reaction to TNCB in the intact mouse and in its passive transfer into naive recipient mice. Mice injected with monoclonal antibodies to V beta 8 are unable to develop CS upon immunization with TNCB and 4-day TNCB-immune lymph node cells from mice that had been depleted in vivo or in vitro of V beta 8+ T lymphocytes fail to transfer CS. However, when separated V beta 8+ and V beta 8- cells were used for passive transfer, it was found that V beta 8+ T lymphocytes failed to transfer CS when given alone to recipient mice and a V beta 8- population was absolutely required. Further analysis revealed that within the V beta 8- population, T lymphocytes expressing the gamma delta TCR were fundamental to allow transfer of the CS reaction. These gamma delta cells were found to be antigen non-specific, genetically unrestricted and to rearrange the V gamma 3 gene segment. This indicates that transfer of the CS reaction requires cross-talk between V beta 8+ and gamma delta+ T lymphocytes, thus confirming our previous results obtained using TNCB-specific T-cell lines. Time-course experiments showed that V beta 8+ lymphocytes taken 4-24 days after immunization with TNCB were able to proliferate and produce interleukin-2 (IL-2) in response to the specific antigen in vitro. Similar time-course experiments were then undertaken using the passive transfer of the CS reaction system. The results obtained confirm that TNCB-specific V beta 8+ T lymphocytes are present in the lymph nodes of immunized mice from day 4 to day 24, and reveal that gamma delta+ T lymphocytes are active for a very short period of time, i.e. days 4 and 5 after immunization. In fact, TNCB-specific V beta 8+ cells are able to transfer CS when taken 4-24 days after immunization, providing the accompanying V beta 8- or gamma delta+ T lymphocyte are obtained 4 days after immunization. In contrast, injection of V beta 8+ T lymphocytes together with V beta 8- or gamma delta+ T lymphocytes that had been taken 2 or 6 days after immunization, failed to transfer significant CS into recipient mice. Taken together, our results confirm that cross-talk between V beta 8+ and gamma delta+ T lymphocytes is necessary for full development of the CS reaction and may explain why the CS reaction in the intact mouse lasts up to 21 days after immunization while the ability of immune lymph node cells to transfer CS is limited to days 4 and 5 after immunization.
Asunto(s)
Dermatitis Alérgica por Contacto/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/análisis , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/análisis , Subgrupos de Linfocitos T/inmunología , Animales , Comunicación Celular/inmunología , Epítopos/inmunología , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/inmunología , Haptenos/inmunología , Inmunización Pasiva , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBA , Cloruro de Picrilo/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Factores de TiempoRESUMEN
Contact sensitivity (CS) responses, induced by skin painting with reactive haptens like picryl chloride or oxazolone, are classical examples of in vivo immunity mediated by alpha beta T cells. Our previous studies showed that gamma delta T cells were required to assist the alpha beta CS-effector T cells in the successful adoptive cell transfer of CS responses. These spleen and lymph node-derived gamma delta+ CS-assisting regulatory cells were CD3+, CD4-CD8+, non-antigen-specific, and non-MHC-restricted, and preferentially expressed V gamma 5 and V delta 4 variable regions. In the current study we show that systemic treatment of mice in vivo with anti-gamma delta mAb, produced a similar positive influence on CS responses in two different systems: i.e. active sensitization, or adoptive cell transfer. In addition to augmented CS responses produced by treatment with pan anti-gamma delta TCR mAb, anti-gamma delta-V region mAb were examined, and augmentation of CS also was produced by anti-V gamma 5 and anti-V delta 4 mAb, the V regions determined previously to be preferentially expressed on gamma delta CS-assisting cells. We speculate that the positive influence of anti-gamma delta mAb was not caused by quantitative changes in gamma delta T cells, because FACS studies demonstrated a lack of in vivo depletion of peripheral blood and lymphoid gamma delta T cells, and also no depletion of epidermal dendritic gamma delta T cells (DETC), in mice treated with anti-gamma delta TCR mAb. Instead, our data favor the hypothesis that CS-assisting gamma delta T cells can be activated in vivo by anti-gamma delta TCR mAb interacting with their gamma delta TCR, at least with the short term protocols we employed, resulting in augmentation of CS responses perhaps by releasing positively-acting factors, such as certain cytokines.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Dermatitis por Contacto/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Traslado Adoptivo , Animales , Relación Dosis-Respuesta a Droga , Citometría de Flujo , Región Variable de Inmunoglobulina/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBARESUMEN
We determined the regulatory properties of heat-aggregated immunoglobulins (HA-Ig) that possess many activities of immune complexes (IC), such as binding and activation of cells via immunoglobulin Fc gamma receptors (FcgammaR). HA-Ig protected contact sensitivity (CS) effector T cells from antigen-specific immunosuppression, while monomeric IgG were inactive. This anti-suppressive activity of HA-Ig was antigen non-specific, and depended on the species from which Ig was derived, i.e. mouse and rat HA-Ig were protective in mice, and of other species were inactive. The protecting activity of HA-Ig was confined to IgG2a and IgG3, and to a lesser degree to IgG1 isotypes, and resided in the Fc domain. Removal of phagocytic cells from the CS-immune target cells, or blocking with anti-FcgammaR mAb, abolished HA-Ig protection of CS-effector T cells from suppression. We suggest that HA-Ig multimers acted via Fc domains, in one of two ways: by binding to FcgammaR of macrophages to produce positive-acting cytokines, or by blocking FcgammaR on macrophages, to compete with suppressive factors that can also bind to FcgammaR. If HA-Ig protection of T cells is generalized, it is likely that IC in vivo may non-specifically overcome suppression of responses to antigen that normally are under the control of T suppressive cells, and thus may contribute to the development of autoimmunity.
Asunto(s)
Fragmentos Fc de Inmunoglobulinas/inmunología , Isotipos de Inmunoglobulinas/inmunología , Macrófagos Peritoneales/inmunología , Receptores Fc/inmunología , Linfocitos T Reguladores/inmunología , Linfocitos T/inmunología , Animales , Calefacción , Inmunoglobulina G/inmunología , Masculino , Ratones , Ratones Endogámicos CBA , Fagocitos/inmunología , Conejos , Ratas , Bazo/citología , Bazo/inmunología , Células Tumorales CultivadasRESUMEN
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.
Asunto(s)
Envejecimiento/inmunología , Adaptación Fisiológica , Anciano , Anciano de 80 o más Años , Humanos , Inmunidad Celular/fisiología , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Recuento de Linfocitos , Linfocitos T/inmunologíaRESUMEN
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.
Asunto(s)
Formación de Anticuerpos/inmunología , Linfocitos B/inmunología , Interleucina-10/biosíntesis , Receptor Cross-Talk , Receptores de Antígenos de Linfocitos T gamma-delta , Linfocitos T/inmunología , Animales , Anticuerpos Monoclonales/farmacología , Comunicación Celular , Células Cultivadas , Interleucina-2/biosíntesis , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBA , Ovinos , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
Recombinant soluble T cell receptors (sTCR) protected contact sensitivity (CS) effector T cells from down-regulation or immunosuppression. CS-protecting sTCR were released enzymatically from the surface of thymoma cells transfected with cDNAs encoding TCR-alpha and -beta extracellular domains that were expressed with a phosphatidylinositol linkage. sTCR affinity purified on anti-TCR-alpha and anti-TCR-beta mAb columns had identical CS-protective activity, as did sTCR from a CD4+ Th2 clone or from a CD8+ cytotoxic clone. Reduced sTCR alpha- and beta-chains had no CS-protective activity, but this was restored when the TCR chains were rejoined into disulfide-linked alphabeta heterodimers. sTCR CS protection was Ag nonspecific, MHC unrestricted, and not influenced by the relevant synthetic peptide specific for the TCR complexed with appropriate MHC. CS protection may have resided in the sTCR constant region. When heated at 62 degrees C for 30 min, sTCR formed a CS-protecting aggregate, with a molecular mass of 481 +/- 37 kDa, corresponding to an alphabeta TCR pentamer. HPLC gel filtration essentially confirmed the molecular mass at 516 kDa for the multimer, while the monomer, which was an alphabeta TCR heterodimer, had an expected molecular mass of approximately 104 kDa and no bioactivity. In summary, the pentameric sTCR may bind to and activate lymphoid cells, perhaps via constant domains, resulting in protection of CS effector T cells from down-regulation. The ability of sTCR to protect CS effector T cells from down-regulation/suppression, if generalized, could overcome immunosuppression accompanying infectious diseases, particularly AIDS, or in tumors.
Asunto(s)
Tolerancia Inmunológica , Receptores de Antígenos de Linfocitos T alfa-beta/química , Receptores de Antígenos de Linfocitos T alfa-beta/fisiología , Linfocitos T/inmunología , Animales , Western Blotting , Dermatitis por Contacto/prevención & control , Disulfuros/química , Electroforesis en Gel de Poliacrilamida , Ratones , Ratones Endogámicos CBA , Pliegue de Proteína , Proteínas Recombinantes/farmacologíaRESUMEN
Contact sensitivity (CS) responses to reactive hapten antigens (Ag), such as picryl chloride, are classical examples of T-cell-mediated immune responses in vivo. There is also abundant evidence that T cells exposed in vivo to high intravenous doses of Ag can downregulate CS (high-dose Ag tolerance). To clarify cell types that effect CS and mediate its downregulation, we have studied CS in mice congenitally deficient in alpha/beta T cells (alpha-/- mice). We show that alpha-/- mice cannot mount CS, implicating alpha/beta T cells as critical CS effector cells. However, after high-dose Ag tolerization, these alpha-/- mice can downregulate alpha/beta CS effector cells adoptively transferred to them. The active cells in tolerized alpha-/- mice are gamma/delta TCR+ cells which downregulate CS effector alpha/beta T cells Ag-specifically upon adoptive cell transfer. Moreover, gamma/delta cells can Ag-specifically downregulate IFN-gamma production by CS effector cells in vitro. These findings establish that gamma/delta T cells are not CS effector cells but downregulate CS, in agreement with recent reports that gamma/delta T cells downregulate IgE responses.
Asunto(s)
Antígenos/inmunología , Dermatitis por Contacto/prevención & control , Interferón gamma/biosíntesis , Receptores de Antígenos de Linfocitos T alfa-beta/deficiencia , Receptores de Antígenos de Linfocitos T gamma-delta/fisiología , Linfocitos T/fisiología , Animales , Autoinmunidad , Tolerancia Inmunológica , Ratones , Receptores de Antígenos de Linfocitos T alfa-beta/fisiologíaRESUMEN
Antigen (trinitrochlorobenzene)-specific T cell lines were obtained by repeated stimulation of lymph node cells from immune mice with antigen in vitro. These T cell lines, consisting of more than 90% CD4+ Vbeta8.2+ and 6 to 9% gammadelta+ T lymphocytes, transfer contact sensitivity (CS) locally when injected at the same site as the challenge antigen, but fail to mediate a systemic passive transfer when injected i.v. Injection of T cell lines together with spleen cells from mice immunized 1 day beforehand (1-day cells) allowed a successful, specific systemic transfer of CS. Phenotypic analysis showed that the 1-day immune cell was alphabeta+, gammadelta-, sIg-, CD3+, CD4-, CD8-, CD5+, B220 (CD45R)+, Thy 1.2+. The effect of 1-day immune cells occurred through a mechanism involving IL-4, as 1-day immune cells failed to allow systemic transfer of CS by T cell lines in recipient mice treated with mAb to IL-4. These observations strongly indicate that three cell subsets are required for the systemic passive transfer of CS by T cell lines: alphabeta+ CD4+, gammadelta+, and a third cell subset, which is CD45R+, alphabeta+, CD3+, but double (CD4, CD8) negative.
Asunto(s)
Dermatitis por Contacto/inmunología , Hipersensibilidad Tardía/inmunología , Subgrupos de Linfocitos T/inmunología , Animales , Línea Celular , Inmunofenotipificación , Interleucina-4/inmunología , Ganglios Linfáticos/inmunología , Masculino , Ratones , Ratones Endogámicos CBA , Cloruro de Picrilo/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Bazo/inmunología , Subgrupos de Linfocitos T/trasplanteRESUMEN
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.
Asunto(s)
Gastrectomía/efectos adversos , Subgrupos de Linfocitos T/citología , Subgrupos de Linfocitos T/inmunología , Animales , Antígenos CD/metabolismo , Movimiento Celular , Integrina alfa4 , Molécula 1 de Adhesión Intercelular/metabolismo , Selectina L/metabolismo , Ganglios Linfáticos/citología , Ganglios Linfáticos/inmunología , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Masculino , Mesenterio , Ratones , Ratones Endogámicos CBA , Ganglios Linfáticos Agregados/citología , Ganglios Linfáticos Agregados/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Estrés Fisiológico/inmunología , Estrés Fisiológico/patología , Factores de TiempoRESUMEN
Contact sensitivity (CS) responses to reactive hapten Ag, such as picryl chloride (PCl) or oxazolone (OX), are classical examples of T cell-mediated immune responses in vivo that are clearly subject to multifaceted regulation. There is abundant evidence that downregulation of CS may be mediated by T cells exposed to high doses of Ag. This is termed high dose Ag tolerance. To clarify the T cell types that effect CS responses and mediate their downregulation, we have undertaken studies of CS in mice congenitally deficient in specific subsets of lymphocytes. The first such studies, using alpha beta T cell-deficient (TCR alpha -/-) mice, are presented here. The results clearly show that TCR alpha -/- mice cannot mount CS, implicating alpha beta T cells as the critical CS-effector cells. However, TCR alpha -/- mice can, after high dose tolerance, downregulate alpha +/+ CS-effector T cells adoptively transferred into them. By mixing ex vivo and then adoptive cell transfers in vivo, the active downregulatory cells in tolerized alpha -/- mice are shown to include gamma delta TCR+ cells that also can downregulate interferon-gamma production by the targeted CS-effector cells in vitro. Downregulation by gamma delta cells showed specificity for hapten, but was not restricted by the MHC. Together, these findings establish that gamma delta T cells cannot fulfill CS-effector functions performed by alpha beta T cells, but may fulfill an Ag-specific downregulatory role that may be directly comparable to reports of Ag-specific downregulation of IgE antibody responses by gamma delta T cells. Comparisons are likewise considered with downregulation by gamma delta T cells occurring in immune responses to pathogens, tumors, and allografts, and in systemic autoimmunity.