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Effective Immune Response (effective + immune_response)
Selected AbstractsDendritic cell vaccination and immune monitoringISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue 1 2009E. H. J. G. Aarntzen Dendritic cells (DCs) are the professional antigen-presenting cells of the immune system. Following infection or inflammation, they undergo a complex process of maturation and migrate to lymph nodes where they present antigens to T cells. Their decisive role in inducing immunity formed the rationale for DC immunotherapy: DCs loaded with tumour antigens are injected into cancer patients to stimulate T cells to eradicate tumours. Effective immune responses and favourable clinical outcomes have indeed been observed, but only in a minority of patients. Therefore, it is obvious that current DC-based protocols need to be improved. For this reason, we study in small proof-of-principle trials the fate, interactions and effectiveness of the injected DC. The success of DC-based immunotherapy to induce cellular immunity against tumours is highly dependent on accurate delivery and trafficking of the DC to T cell-rich areas of secondary lymphoid tissues. [source] In vivo immunization following virus suppression: a novel approach for inducing immune control in chronic hepatitis B,JOURNAL OF VIRAL HEPATITIS, Issue 1 2003D. Sprengers summary. Antiviral treatment of patients with active chronic hepatitis B may lead to significant reduction in morbidity and mortality. However, after stopping nucleoside therapy, relapse rates are high in those without acquired specific immunity. We have treated two chronic hepatitis B patients with in vivo immunization. In vivo immunization aims to optimize conditions for an effective immune response: following rapid and profound virus suppression by interferon-lamivudine combination therapy, lamivudine is withdrawn intermittently for 4 weeks during continued interferon therapy. In both patients with profound virus suppression a rapid rebound in viral replication was observed after lamivudine withdrawal; despite continued interferon. These periods of renewed viral replication were followed by rises in hepatitis activity. After re-introduction of lamivudine HBV DNA became undetectable by PCR followed by normalization of serum ALT. These observations are a stimulus to further explore the concept of in vivo immunization as a novel therapeutic approach for chronic hepatitis B. [source] DNA barcodes show cryptic diversity and a potential physiological basis for host specificity among Diplostomoidea (Platyhelminthes: Digenea) parasitizing freshwater fishes in the St. Lawrence River, CanadaMOLECULAR ECOLOGY, Issue 13 2010SEAN A. LOCKE Abstract Diplostomoid metacercariae parasitize freshwater fishes worldwide and cannot be identified to species based on morphology. In this study, sequences of the barcode region of cytochrome c oxidase subunit 1 (CO1) were used to discriminate species in 1088 diplostomoids, most of which were metacercariae from fish collected in the St. Lawrence River, Canada. Forty-seven diplostomoid species were detected, representing a large increase in known diversity. Most species suggested by CO1 sequences were supported by sequences of internal transcribed spacer (ITS) of rDNA and host and tissue specificity. Three lines of evidence indicate that physiological incompatibility between host and parasite is a more important determinant of host specificity than ecological separation of hosts and parasites in this important group of freshwater fish pathogens. First, nearly all diplostomoid species residing outside the lens of the eyes of fish are highly host specific, while all species that occur inside the lens are generalists. This can be plausibly explained by a physiological mechanism, namely the lack of an effective immune response in the lens. Second, the distribution of diplostomoid species among fish taxa reflected the phylogenetic relationships of host species rather than their ecological similarities. Third, the same patterns of host specificity were observed in separate, ecologically distinctive fish communities. [source] Candida albicans THI13 disruption affects production of monocytic cytokinesMOLECULAR ORAL MICROBIOLOGY, Issue 5 2007Z. Y. Zhu Introduction:, The Candida albicansTHI13 gene was identified by its homology to the Candida tropicalis CtNMT1 gene, which is involved in pyrimidine precursor biosynthesis. Methods:, Disruption of THI13 revealed that this gene played a minor role in thiamin biosynthesis in C. albicans. Purified human monocytes were incubated with C. albicans at the optimal Candida: monocyte ratio of 0.5 and cytokines in the supernatants were measured by enzyme-linked immunosorbent assay. Results and discussion:, This experiment showed that the wild-type strain significantly induced interleukin-10 (IL-10) production but had little effect on IL-12 production, and that THI13 mutants had no significant effect on IL-10 production, though the IL-12 level was increased in the supernatants. These results suggest that THI13 is involved in the host effective immune response by regulating IL-10 and IL-12 production. [source] Complement and fungal pathogens: an updateMYCOSES, Issue 6 2008Cornelia Speth Summary Fungal infections are a serious complication in immunocompromised patients such as human immunodeficiency virus-infected individuals, patients with organ transplantations or with haematological neoplasia. The lethality of opportunistic fungal infection is high despite a growing arsenal of antimycotic drugs, implying the urgent need for supportive immunological therapies to strengthen the current inefficient antimicrobial defences of the immunocompromised host. Therefore, increasing effort has been directed to investigating the interplay between fungi and the host immunity and thus to find starting points for additional therapeutic approaches. In this article, we review the actual state of the art concerning the role of complement in the pathogenesis of fungal infections. Important aspects include the activation of the complement system by the fungal pathogen, the efficiency of the complement-associated antimicrobial functions and the arsenal of immune evasion strategies applied by the fungi. The twin functions of complement as an interactive player of the innate immunity and at the same time as a modulator of the adaptive immunity make this defence weapon a particularly interesting therapeutic candidate to mobilise a more effective immune response and to strengthen in one fell swoop a broad spectrum of different immune reactions. However, we also mention the ,Yin-Yang' nature of the complement system in fungal infections, as growing evidence assigns to complement a contributory part in the pathogenesis of fungus-induced allergic manifestations. [source] HLA phenotypes and outcomes of hepatitis B virus infection in Taiwan,JOURNAL OF MEDICAL VIROLOGY, Issue 1 2004Ya-Fang Wu Abstract The relationship of HLA phenotype and outcome of hepatitis B virus (HBV) infection was studied in two ethnic groups of Taiwan: Han Chinese and Taiwanese Aborigines. In Han Chinese, the study groups consisted of 98 persons who tested both hepatitis B surface antigen (HBsAg) and anti-HBs negative (Uninfected Group), 324 persons who tested HBsAg negative and both anti-HBs and anti-HBc positive (Recovered Group), and 98 patients who tested HBsAg positive for at least 6 months (Chronically Infected Group). In Taiwanese Aborigines, the study groups consisted of 34 persons in Uninfected Group, 229 persons in the Recovered Group, and 138 patients in the Chronically Infected Group. All subjects were tested for HLA (A, B, DRB1) phenotypes by sequence-specific oligonucleotide probe hybridization (SSOPH). HLA-DR*0406 was significantly more frequent in the Recovered Group, compared with the Chronically Infected Group (P,<,0.001) in Han Chinese. There was a significant excess of HLA-B*4001 (P,=,0.045) in the Recovered Group, compared with the Chronically Infected Group in Taiwanese Aborigines. The observation that different HLA phenotypes associated with recovery from HBV infection in different racial groups implies that various HLA molecules could present different HBV epitopes to induce effective immune responses. J. Med. Virol. 72:17,25, 2004. © 2004 Wiley-Liss, Inc. [source] Immunization for Protection of the Reproductive Tract: A ReviewAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2002MICHAEL W. RUSSELL PROBLEM: Local application of non-replicating antigens to the female reproductive tract is ineffective in stimulating the common mucosal immune system, and induces only weak genital antibody responses. Studies of immune responses to genital infections such as gonorrhea also support the concept that, lacking mucosal immune inductive sites, the reproductive tract is ill-equipped to mount effective immune responses. METHOD OF STUDY: Intranasal (i.n.) and intravaginal (i.vag.) routes of immunization of mice with a protein antigen coupled to cholera toxin (CT) B subunit, or genetically engineered as chimeric proteins with the A2/B sunbunits of CT or type II heat-labile enterotoxin, were compared for their ability to induce specific antibody responses in vaginal fluids, saliva, and serum. RESULTS: Mice immunized i.n. developed substantially stronger vaginal immunoglobulin A (IgA) and immunoglobulin G (IgG) and serum IgG and IgA antibodies, than those immunized i.vag. which also failed to develop salivary antibodies. Vaginal antibody responses induced i.n. persisted for at least 1 year, and were recallable by booster immunization after a prolonged period. CONCLUSIONS: Such alternative strategies for inducing potent genital antibody responses offer the prospect of prophylactic immunization against genital infections. Further studies are required to evaluate their applicability to humans, and to comprehend the cellular and molecular mechanisms involved in delivering effective immune responses to the reproductive tracts. [source] | |||||||||||||