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Anandamide prior to sensitization increases cell-mediated immunity in mice

RIBEIRO, Alison; FERRAZ-DE-PAULA, Viviane; PINHEIRO, Milena L.; SAKAI, Monica; COSTA-PINTO, Frederico A.; PALERMO-NETO, Joao
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
95.92%
The endocannabinoid system has become a topic of great interest in pharmacology due to its remarkable distribution in mammal organisms and capacity to play a modulatory role on several physiological systems, including modulation of immunity. Many studies have shown that administration of cannabinoids causes inhibitory effects on immune cells, including decreased proliferation and antigen-presenting cell (APC) costimulatory activity. In contrast, other groups have shown that some cannabinoids might present stimulatory actions on macrophage activity and T cell activation. Therefore, we aimed to investigate whether a treatment in vivo with a low dose of anandamide (0.1 mg/kg) immediately prior to sensitization would have an immunosuppressive or immunostimulatory effect on cell-mediated immunity (Th1 response) in mice. We report here that anandamide, prior to sensitization, was able to increase the Th1 response to ovalbumin in vivo and ex vivo. Anandamide increased delayed type hypersensitivity (DTH), splenocyte proliferation, and IFN-gamma production in a co-culture of adherent and non-adherent splenocytes. Moreover, anandamide prior to sensitization increased both the expression of DC co-stimulatory molecules (CD80/CD86) and IL-12/IL23 (p40) production ex vivo. We have also assessed direct effects of anandamide in the IFN-gamma/IL-4 balance of ConA-stimulated splenocytes in vitro. Anandamide at nanomolar concentrations increased the production of IFN-gamma...

Humoral and cell-mediated immunity in large non-toxic multinodular goitre

Mota, N. G S; Kiy, Y.; Rezkallah-Iwasso, M. T.; Peracoli, M. T S
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 173-180
ENG
Relevância na Pesquisa
75.95%
Humoral and cell-mediated immunity was investigated in fourteen patients with non-toxic multinodular goitre and ten healthy controls by in vitro methods. These included determination of sheep erythrocyte and complement rosette-forming cells in the peripheral blood, immunoglobulin levels, titres of thyroglobulin and microsomal antibodies and migration inhibition test using thyroid extract and phytohemagglutinin. When compared with controls the patients showed high IgA levels and positive response to thyroid antigen in the leucocyte migration inhibition test. There was no correlation between the leucocyte migration results and the presence of auto-antibodies. These findings indicate a possible role of cell-mediated immunity in non-toxic multinodular goitre.

Infantile epileptic encephalopathy with hypsarrhythmia (infantile spasms/west syndrome) and immunity

Montelli, Terezinha de Cresci Braga; Peraçoli, M. T S
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Revisão Formato: 92-99
ENG
Relevância na Pesquisa
75.88%
West syndrome is a severe epilepsy, occurring in infancy, that comprises epileptic seizures known as spasms, in clusters, and a unique EEG pattern, hypsarrhythmia, with psychomotor regression. Maturation of the brain is a crucial component. The onset is within the first year of life, before 12 months of age. Patients are classified as cryptogenic (10 to 20%), when there are no known or diagnosed previous cerebral insults, and symptomatic (80 to 90%), when associated with pre-existing cerebral damages. The time interval from a brain insult to infantile spasms onset ranged from 6 weeks to 11 months. West syndrome has a time-limited natural evolutive course, usually disappearing by 3 or 4 years of age. In 62% of patients, there are transitions to another age-related epileptic encephalopathies, the Lennox-Gastaut Syndrome and severe epilepsy with multiple independent foci. Spontaneous remission and remission after viral infections may occur. Therapy with ACTH and corticosteroids are the most effective. Reports about intravenous immunoglobulins action deserve attention. There is also immune dysfunction, characterized mainly by anergy, impaired cell-mediated immunity, presence of immature thymocytes in peripheral blood, functional impairment of T lymphocytes induced by plasma inhibitory factors...

Effect of vitamin E levels on the cell-mediated immunity of broilers vaccinated against coccidiosis

Silva,ICM da; Ribeiro,AML; Canal,CW; Vieira,MM; Pinheiro,CC; Gonçalves,T; de Moraes,ML; Ledur,VS
Fonte: Fundação APINCO de Ciência e Tecnologia Avícolas Publicador: Fundação APINCO de Ciência e Tecnologia Avícolas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2011 EN
Relevância na Pesquisa
75.93%
Studies on the relationships between animal nutrition and immunity have sought reliable methodologies to measure responses. Cell-mediated immune response is similarly studied in humans. The cutaneous basophil hypersensitivity test (CBH) is one of the methods to measure that response and consists in the infiltration of inflammatory cells, particularly of lymphocytes and basophils, as result of the application of substances capable of inducing cell proliferation in determined sites, such as wings, wattle, and interdigital space in birds. CBH is considered a simple and fast method and can be applied in birds of different ages. In immunocompetence studies with poultry, phytohemagglutinin-P (PHA-P) is a commonly used substance, despite the variability of the response related to the method of application (intradermal injection) and the antigens used. In the present experiment, PHA-P was used to observe the cell-mediated immune response of 216 chicks fed three dietary levels of vitamin E from 1 to 36 days of age. All birds were immunologically challenged by vaccination against coccidiosis at three days of age and against Newcastle Disease (NCD) at 14 and 30 days of age. At 36 days of age, birds were submitted to the CBH test according to the methodology of Corrier & DeLoach (1990). Birds fed 65mg/kg of vitamin E presented lasting cell reaction (p<0.08)...

Pertussis-specific cell-mediated immunity in infants after vaccination with a tricomponent acellular pertussis vaccine.

Zepp, F; Knuf, M; Habermehl, P; Schmitt, J H; Rebsch, C; Schmidtke, P; Clemens, R; Slaoui, M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1996 EN
Relevância na Pesquisa
65.98%
The aim of this study was to investigate pertussis-specific cell-mediated immunity in infants vaccinated with a tricomponent acellular vaccine. Infants were investigated during a primary vaccination schedule from the third month of life to the sixth month as well as before and after a booster at 15 to 24 months. This is the first report of specific cell-mediated immune responses to pertussis-related antigens in infants below the age of 12 months. Our data show that the vaccine induces T-cell responses specific for the vaccine components, detoxified pertussis toxin, filamentous hemagglutinin, and pertactin, that increase progressively over the course of the vaccination schedule. In contrast to declining antibody titers, cell-mediated immune responses are stable over the postprimary to prebooster period. Vaccination results in a progressive increase in the number of T cells that express activation marker CD45RO preferentially on CD4-positive T cells after stimulation with pertussis antigens. Measurements of cytokine secretion profiles demonstrated a preferential induction of interleukin 2- and gamma interferon-producing T-helper 1 cells and only low production of interleukin 10. The observed persistence of the specific cell-mediated immunity may have a bearing on the protective mechanisms induced by pertussis vaccination. Cell-mediated immunity requires further study...

Antigenic role of stress-induced catalase of Salmonella typhimurium in cell-mediated immunity.

Kagaya, K; Miyakawa, Y; Watanabe, K; Fukazawa, Y
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1992 EN
Relevância na Pesquisa
65.97%
The ability of the H2O2-induced catalase of Salmonella typhimurium to induce cell-mediated immunity against S. typhimurium infection in mice was examined. When exponentially growing cells of S. typhimurium were treated with 20 microM H2O2, the cells resisted killing by 1 mM H2O2 and showed the induction of a new species of catalase in addition to the constitutively produced one. Two molecules of catalases in S. typhimurium were isolated from mutant strains: H2O2-induced catalase (catalase II, 320 kDa), from a regulatory gene-deficient oxyR1 mutant, and constitutive catalase (catalase I, 350 kDa), from a katG gene-deleted mutant. When mice were inoculated with a sublethal dose of live cells, an intensive protective immunity (100% survival at 3 weeks) after challenge with a virulent strain associated with the delayed-type footpad hypersensitivity (DTH) reactions to both catalase I and catalase II was induced. Conversely, mice immunized with formalin-killed virulent S. typhimurium did not elicit protective immunity or DTH to either catalase. When mice were immunized with catalase I or catalase II, an enhanced protection (to a certain extent: 50% survival at 3 weeks) was induced in mice immunized with catalase II associated with DTH which did not cross-react with catalase I but not in those given catalase I. These results suggest that H2O2-induced stress proteins...

Role of cell-mediated immunity in the resolution of secondary chlamydial genital infection in guinea pigs infected with the agent of guinea pig inclusion conjunctivitis.

Rank, R G; Soderberg, L S; Sanders, M M; Batteiger, B E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/1989 EN
Relevância na Pesquisa
65.96%
Guinea pigs which have recovered from a genital infection with the agent of guinea pig inclusion conjunctivitis demonstrate strong immunity to reinfection for a short period of time but then become susceptible to reinfection. The secondary infection is markedly shortened in duration and decreased in intensity. Previous studies have indicated an important role for humoral immunity in resistance to and in recovery from reinfection. However, the contribution of cell-mediated immunity to immunity toward or recovery from a secondary infection is not clear. Guinea pigs were infected in the genital tract with guinea pig inclusion conjunctivitis and were challenged at either 30 or 75 days after the primary infection. Prior to challenge, one group of animals were injected with rabbit anti-guinea pig thymocyte serum (ATS) while control groups received either normal rabbit serum or no treatment. Treatment was continued daily for the course of the experiment. On day 30, ATS-treated guinea pigs had a slightly higher rate of reinfection, and generally the infection persisted longer than in controls. On day 75, all animals became reinfected upon challenge, but control animals resolved their infections in 3 to 9 days. In contrast, most ATS-treated animals remained infected throughout the course of the experiment. Although the animals became reinfected...

CELLS INVOLVED IN CELL-MEDIATED AND TRANSPLANTATION IMMUNITY, II. A CONSIDERATION OF THE FUNCTIONAL IDENTITY OF THE CELLS INVOLVED IN BOTH HUMORAL AND CELL-MEDIATED IMMUNITY: A PHYLOGENETIC APPROACH

Richter, Maxwell
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1970 EN
Relevância na Pesquisa
65.96%
The literature concerned with the types of cells that participate in the humoral and cell-mediated immune response has been reviewed. It is postulated that the initial cells that are involved in mediating both types of immunity are functionally identical in that both are antigen-reactive cells. In the case of the humoral immune response, the interaction of the antigen-reactive cells with the antigen leads to the release or transfer of “information” to the antibody-forming cell, resulting in the synthesis and secretion of antibody molecules. In the case of cell-mediated immunity, it is considered that the primitive antigen-reactive cell itself transforms into the sensitized cell which infiltrates the site of antigen administration.

Suppression of cell-mediated immunity after infection with attenuated rubella virus.

Ganguly, R; Cusumano, C L; Waldman, R H
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1976 EN
Relevância na Pesquisa
65.96%
The effects of attenuated rubella virus infection upon cell-mediated immunity of human volunteers were studied. The volunteers received the vaccine either by nose drops or by the subcutaneous route. Changes in cell-mediated immunity in terms of delayed cutaneous sensitivity to recall antigens, phytohemagglutination stimulation, and spontaneous migration inhibitory factor-like activity were studied at various time periods after infection. Spontaneous migration inhibitory factor-like activity was studied on supernatants of the lymphocytes obtained from the volunteers and incubated for 72 h in the absence of any antigens. A significant proportion of the volunteers showed suppression of one or more parameters of cell-medicated immunity tested by week 2 of infection compared to the control; however, there was no correlation between suppression of the various parameters studied. No difference was noticed in the incidence of cell-mediated immunity suppression between nose drops and subcutaneous route groups.

Plaque Size Reduction as a Measure of Viral Cell-Mediated Immunity

Simmons, Richard L.; Centifanto, Ysolina; Kaufman, Herbert E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1974 EN
Relevância na Pesquisa
65.96%
This new assay of viral cell-mediated immunity is sensitive, reproducible, and in many ways resembles the in vivo state. The spread of herpes simplex virus between adjacent monolayer cells was inhibited in the presence of spleen cells from guinea pigs sensitized to that virus. This in vitro control of viral growth was quantified by determining plaque size in monolayers to which were added sensitized spleen cells as opposed to nonsensitized or no spleen cells. The simple measurement of plaque size reduction as an in vitro test of viral cell-mediated immunity is described. In addition to correlating highly with skin testing and macrophage migration inhibition as a test of viral cell-mediated immunity, the ability of sensitized spleen cells to reduce plaque size developed by day 7, paralleling the onset of delayed cutaneous hypersensitivity. The specificity of this lymphocyte-mediated interaction was demonstrated by the inability of herpes simplex virus-sensitized spleen cells to alter the growth of vaccinia virus in cell culture. A ratio of sensitized spleen cells to monolayer cells of 6:1 resulted in significant plaque size reduction on both HEp-2 and conjunctiva monolayers. The data presented demonstrate the potential usefulness of plaque size reduction as a technically simple...

Cell-mediated immunity in rheumatoid arthritis.

Andrianakos, A A; Sharp, J T; Person, D A; Lidsky, M D; Duffy, J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1977 EN
Relevância na Pesquisa
66.08%
Cell-mediated immunity in rheumatoid arthritis (RA) was assessed by skin testing with six antigens in 107 patients, 94 of whom were age, sex, and race-matched with healthy individuals or patients with diseases unrelated to immunological abnormalities. 20% of RA patients were anergic. Impaired cell-mediated immunity in the RA patients was manifested by a decrease in the magnitude of skin reactivity as well as a decrease in the incidence of positive reactions to multiple antigens. Depression in cell-mediated immunity was related to age but not to sex, duration of disease, or disease activity. A slight correlation was found between absolute peripheral lymphocyte counts and the number of positive skin tests, and was confirmed by finding an association between lymphocyte counts and the size of skin reactions. A correlation was also found between lymphocyte counts and disease activity. Four explanations of the observed depression in cell-mediated immunity in RA were considered: (1) a preoccupation of the immune mechanism of the host with cell-mediated immunity reactions related to the pathogenesis of the disease; (2) a depression of cell-mediated immune reactivity by a virus infection; (3) depression of cell-mediated immunity by therapy; and (4) immune complex suppression of cell-mediated immunity. No effect of gold therapy was found. The near universal use of salicylates or other anti-inflammatory drugs did not permit investigation of the effect of these drugs on cell-mediated immunity.

HLA-A2 Supertype-Restricted Cell-Mediated Immunity by Peripheral Blood Mononuclear Cells Derived from Malian Children with Severe or Uncomplicated Plasmodium falciparum Malaria and Healthy Controls

Lyke, Kirsten E.; Burges, Robin B.; Cissoko, Yacouba; Sangare, Lansana; Kone, Abdoulaye; Dao, Modibo; Diarra, Issa; Fernández-Viňa, Marcelo A.; Plowe, Christopher V.; Doumbo, Ogobara K.; Sztein, Marcelo B.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2005 EN
Relevância na Pesquisa
75.84%
Understanding HLA-restricted adaptive host immunity to defined epitopes of malarial antigens may be required for the development of successful malaria vaccines. Fourteen epitopes of preerythrocytic malarial antigens known to mediate cytotoxic T-lymphocyte responses against target cells expressing HLA-A2-restricted epitopes were synthesized and pooled based on antigen: thrombospondin-related anonymous protein (TRAP), circumsporozoite protein (CSP), and export protein 1 (Exp-1) peptides. HLA-A2 supertype (*0201, *0202, *0205, *6802) peripheral blood mononuclear cells collected from 774 Malian children, aged 3 months to 14 years, with severe Plasmodium falciparum malaria matched to uncomplicated malaria or healthy controls were stimulated with the HLA-A2-restricted peptide pools. Significant gamma interferon production, determined by enzyme-linked immunospot assay to at least one of the three peptide pools, was observed in 24/58 (41%) of the severe malaria cases, 24/57 (42%) of the uncomplicated malaria cases, and 34/51 (67%) of the healthy controls. Significant lymphoproliferation to these peptides was observed in 12/44 (27%) of the severe malaria cases, 13/55 (24%) of the uncomplicated malaria cases, and 18/50 (36%) of the healthy controls. Responses to individual peptide pools were limited. These studies confirm the presence of adaptive cell-mediated immunity to preerythrocytic malaria antigens in volunteers from Mali and demonstrate that suballeles of the HLA-A2 supertype can effectively present antigenic epitopes. However...

A peptide of Chlamydia trachomatis shown to be a primary T-cell epitope in vitro induces cell-mediated immunity in vivo.

Knight, S C; Iqball, S; Woods, C; Stagg, A; Ward, M E; Tuffrey, M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1995 EN
Relevância na Pesquisa
65.96%
Chlamydiae are a major cause of infertility and preventable blindness and there is currently no effective vaccine in humans or rodents against these organisms. We have previously shown that a peptide of 12 amino acids (termed TINKP) from a conserved region of the major outer membrane protein (MOMP) of Chlamydia trachomatis (C. trachomatis) is a primary T-cell epitope in humans. Here we showed that when dendritic cells (DC) from C3H or BALB/c mice were pulsed in vitro with the peptide they stimulated proliferation of syngeneic T cells in vitro indicating that the peptide is also a primary T-cell epitope in mice. Since the skin is a rich source of DC, we immunized mice from each strain with an intradermal injection of the peptide. Humoral and cell-mediated immunity to peptide, MOMP or whole elementary bodies (EB) of C. trachomatis (F/NI1/GU) were assessed. No antibody response to TINKP was observed. However, immunized mice showed recall responses to all three chlamydial antigens. T-cell-mediated immunity in the absence of antibody was induced by a single injection of the peptide intradermally. C. trachomatis isolated from the human genital tract causes salpingitis in mice. Preliminary studies in susceptible C3H mice indicated that intradermal injection of peptide conferred some protection against the development of salpingitis. Thus...

Potentiation of T-cell mediated immunity by levamisole.

Renoux, G; Renoux, M; Teller, M N; McMahon, S; Guillaumin, J M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1976 EN
Relevância na Pesquisa
65.96%
Cell-mediated immunity is a requirement for recognition and elimination of cells and for prevention or treatment of a variety of diseases. Therefore, the development of a product potentially active in increasing immunity involves its testing in assays specific for cell-mediated immunity. The effectiveness of a single administration of levamisole was demonstrated in the rejection of isografts in a male to female C57BL/6 system, and on the enhancement of levels of the delayed type hypersensitivity (DTH) to sheep red cells (SRBC). Indeed, in five on nine tests, an injection of 25 mg/kg of levamisole to female recipients either on the day of grafting or 7 days after grafting resulted in a RT50% rejection time of 25 days, compared with 46 days in untreated controls. Levamisole administered at the time of immunization with various doses of SRBC elicited earlier, higher and more sustained DTH levels than in untreated controls. Such induction of T-cell activation was accompanied by a switch on anti-SRBC antibodies from IgM to IgG. These findings confirm and extend data evidencing the ability of levamisole to recruit and activate T cells for an increased or restored cell-mediated immunity.

Cell-mediated immunity in patients with chronic fatigue syndrome, healthy control subjects and patients with major depression.

Lloyd, A; Hickie, I; Hickie, C; Dwyer, J; Wakefield, D
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1992 EN
Relevância na Pesquisa
65.96%
The chronic fatigue syndrome (CFS) is characterized by severe persistent fatigue and neuropsychiatric symptoms. It has been proposed that the abnormalities in cell-mediated immunity which have been documented in patients with CFS may be attributable to a clinical depression, prevalent in patients with this disorder. Cell-mediated immune status was evaluated in patients with carefully defined CFS and compared with that of matched subjects with major depression (non-melancholic, non-psychotic) as well as healthy control subjects. Patients with CFS demonstrated impaired lymphocyte responses to phytohaemagglutinin (PHA) stimulation, and reduced or absent delayed-type hypersensitivity (DTH) skin responses when compared either with subjects with major depression or with healthy control subjects (P less than 0.05 for each analysis). Although depression is common in patients with CFS, the disturbances of cell-mediated immunity in this disorder differ in prevalence and magnitude from those associated with major depression. These observations strengthen the likelihood of a direct relationship between abnormal cell-mediated immunity and the etiology of CFS.

IMMUNE RESPONSE TO CHEMICALLY MODIFIED FLAGELLIN : II. EVIDENCE FOR A FUNDAMENTAL RELATIONSHIP BETWEEN HUMORAL AND CELL-MEDIATED IMMUNITY

Parish, C. R.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/07/1971 EN
Relevância na Pesquisa
66.04%
Flagellin (mol.wt. 40,000) from S. adelaide organisms and a series of acetoacetyl derivatives of flagellin were tested for their ability to induce humoral and cell-mediated immunity in adult rats. It was found that unmodified flagellin was an excellent inducer of antibody formation but a poor inducer of delayed-type hypersensitivity. In contrast, increasing acetoacetylation steadily destroyed the ability of flagellin to initiate antibody formation but enhanced the capacity of the molecule to induce flagellin-specific cell-mediated immunity and antibody tolerance. In fact, it appeared that in adult rats antibody formation and cell-mediated immunity may well be opposing immunological processes. Furthermore, the affinity of the acetoacetyl flagellins for anti-flagellin antibodies appeared to determine the type of immune response which predominated. High affinity antigen produced antibody formation whereas low affinity antigen induced cell-mediated immunity and antibody tolerance. The importance of affinity was further evidenced by the fact that a CNBr digest of flagellin induced humoral and cellular immune responses identical to an acetoacetylated flagellin of comparable antigenic activity. From these studies it was proposed that both humoral and cell-mediated immunity can be directed against the same antigenic determinants but that the specificity requirements for delayed hypersensitivity (and antibody tolerance) are less than those required for antibody formation. Some remarkable immunological features of the flagellin system were revealed. Flagellin induced comparable delayed-type hypersensitivity when injected in either saline or FCA. Furthermore...

STUDIES ON CELL-MEDIATED IMMUNITY TO LYMPHOCYTIC CHORIOMENINGITIS VIRUS IN MICE

Marker, Ole; Volkert, Mogens
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/06/1973 EN
Relevância na Pesquisa
65.98%
A large amount of experimental evidence has already been presented indicating the great importance of the cell-mediated immunity in the pathogenesis of the LCM virus infection in mice. In this laboratory a method which makes it possible to measure this cellular immunity quantitatively in vitro has been developed. The method is based on the determination of the radioisotope released after the interaction between specifically sensitized lymphocytes and syngeneic 1Cr-labeled LCM virus-infected target cells. By using this technique the time-course of the cell-mediated immunity has been established in acutely infected mice and in virus carriers adoptively immunized with syngeneic sensitized lymphocytes. Lymphocytes from acutely infected mice showed a strong lysing effect on the target cells, with a sharp maximum at about the 9th day after infection. The cell-mediated immunity in adoptively immunized virus carrier mice showed the same time-course, but in these animals the lytic effect of the lymphoid cells was considerably less pronounced. Lymphocytes from untreated virus carriers did not, however, have any effect on the target cells, and in these animals it was not possible to demonstrate any evidence of enhancing antibodies, In experiments employing serial dilutions of sensitized lymphocytes in normal cells a direct linear relationship between the number of sensitized lymphocytes and target cell destruction was found. These experiments seem to indicate that the underlying mechanism in the cytotoxic reaction is a direct cell-to-cell interaction.

HTLV-1 bZIP factor impairs cell-mediated immunity by suppressing production of Th1 cytokines

Sugata, Kenji; Satou, Yorifumi; Yasunaga, Jun-ichirou; Hara, Hideki; Ohshima, Kouichi; Utsunomiya, Atae; Mitsuyama, Masao; Matsuoka, Masao
Fonte: American Society of Hematology Publicador: American Society of Hematology
Tipo: Artigo de Revista Científica
Publicado em 12/01/2012 EN
Relevância na Pesquisa
65.96%
Adult T-cell leukemia (ATL) patients and human T-cell leukemia virus-1 (HTLV-1) infected individuals succumb to opportunistic infections. Cell mediated immunity is impaired, yet the mechanism of this impairment has remained elusive. The HTLV-1 basic leucine zipper factor (HBZ) gene is encoded in the minus strand of the viral DNA and is constitutively expressed in infected cells and ATL cells. To test the hypothesis that HBZ contributes to HTLV-1–associated immunodeficiency, we challenged transgenic mice that express the HBZ gene in CD4 T cells (HBZ-Tg mice) with herpes simplex virus type 2 or Listeria monocytogenes, and evaluated cellular immunity to these pathogens. HBZ-Tg mice were more vulnerable to both infections than non-Tg mice. The acquired immune response phase was specifically suppressed, indicating that cellular immunity was impaired in HBZ-Tg mice. In particular, production of IFN-γ by CD4 T cells was suppressed in HBZ-Tg mice. HBZ suppressed transcription from the IFN-γ gene promoter in a CD4 T cell–intrinsic manner by inhibiting nuclear factor of activated T cells and the activator protein 1 signaling pathway. This study shows that HBZ inhibits CD4 T-cell responses by directly interfering with the host cell-signaling pathway...

Innate Immunity and the Evolution of Resistance to an Emerging Infectious Disease in a Wild Bird

Bonneaud, Camille; Balenger, Susan L.; Zhang, Jiangwen; Edwards, Scott V.; Hill, Geoffrey E.
Fonte: Wiley Blackwell (Blackwell Publishing) Publicador: Wiley Blackwell (Blackwell Publishing)
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
75.87%
Innate immunity is expected to play a primary role in conferring resistance to novel infectious diseases, but few studies have attempted to examine its role in the evolution of resistance to emerging pathogens in wild vertebrate populations. Here, we used experimental infections and cDNA microarrays to examine whether changes in the innate and/or acquired immune responses likely accompanied the emergence of resistance in house finches (Carpodacus mexicanus) in the eastern United States subject to a recent outbreak of conjunctivitis-causing bacterium (Mycoplasma gallisepticum—MG). Three days following experimental infection with MG, we observed differences in the splenic transcriptional responses between house finches from eastern U.S. populations, with a 12-year history of MG exposure, versus western U.S. populations, with no history of exposure to MG. In particular, western birds down-regulated gene expression, while eastern finches showed no expression change relative to controls. Studies involving poultry have shown that MG can manipulate host immunity, and our observations suggest that pathogen manipulation occurred only in finches from the western populations, outside the range of MG. Fourteen days after infection, eastern finches...

Cell mediated immunity in Chagas' disease: Trypanosoma cruzi antigens induce suppression of the in vitro proliferative response of mononuclear cells

Mosca,Walter; Briceño,Luis; Hernandez,Maria Ignacia
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/1991 EN
Relevância na Pesquisa
85.82%
The partial suppression of the cell-mediated immune response by Trypanosoma cruzi antigens in patients with Chagas' disease is demonstrated in a costimulation assay with T. cruzi antigens and Mycobacterium tuberculosis purified protein derivative (PPD) or Tetanus toxoid (TT). ononuclear cells from 13 patients with chagasic infection without evidence of heart disease, 10 patients with chagasic cardiomyopathy and 7 healthy blood donors were stimulated with antigen A (autoclaved epimastigotes), PPD, TT, PPD + A, PPD + TT and TT + A. The average percentage of suppression induced by costimulation of mononuclear cells with PPD and antigen A was 47.1% in patients with chagasic infection without heart disease (INF), 38.8% in patients with chagasic cardiomyopathy (CDM) and 23.3% in healthy controls. Similar values were observed when living trypomastigotes were used. A costimulatory study with PPD and TT, PPD and A and TT and A was carried out in 8 patients with chagasic infection, in order to evaluate the possibility that this difference could be due to a nonspecific inhibitory effect. The mean suppression induced by TT + PPD was -8.9, with TT + A was 52.7 and with PPD + A was 50.1. The data reported show that T. cruzi antigens induce a specific suppression of the proliferative responseof mononuclear cells...