189 research outputs found

    Standardization and performance evaluation of mononuclear cell cytokine secretion assays in a multicenter study

    Get PDF
    BACKGROUND: Cryopreservation of peripheral blood mononuclear cells has been used to preserve and standardize immunologic measurements for multicenter studies, however, effects of cryopreservation on cytokine responses are incompletely understood. In designing immunologic studies for a new multicenter birth cohort study of childhood asthma, we performed a series of experiments to determine the effects of two different methods of cryopreservation on the cytokine responses of cord and peripheral blood mononuclear cells. RESULTS: Paired samples of PBMC were processed freshly, or after cryopreservation in a Nalgene container (NC) or a controlled-rate freezer (CRF). Although there were some differences between the methods, cryopreservation inhibited PHA-induced IL-10 secretion and Der f 1-induced IL-2 secretion, and augmented PHA-induced IL-2 secretion and spontaneous secretion of TNF-α. In separate experiments, NC cryopreservation inhibited secretion of several cytokines (IL-13, IL-10, IFN-γ, TNF-α) by PHA-stimulated cord blood mononuclear cells. With the exception of PHA-induced IL-13, results from fresh and cryopreserved cord blood samples were not significantly correlated. Finally, in reproducibility studies involving processing of identical cell samples in up to 4 separate laboratories, variances in cytokine responses of fresh cells stimulated at separate sites did not exceed those in cryopreserved cells stimulated at a central site. CONCLUSION: Collectively, these studies indicate that cryopreservation can affect mononuclear cell cytokine response profiles, and that IL-10 secretion and antigen-induced responses may be especially vulnerable. These studies also demonstrate that mononuclear cell responses can be standardized for performance in a small number of laboratories for multicenter studies, and underscore the importance of measuring reproducibility and of testing whether cryopreservation techniques alter specific immunologic outcomes

    The Urban Environment and Childhood Asthma (URECA) birth cohort study: design, methods, and study population

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The incidence and morbidity of wheezing illnesses and childhood asthma is especially high in poor urban areas. This paper describes the study design, methods, and population of the Urban Environment and Childhood Asthma (URECA) study, which was established to investigate the immunologic causes of asthma among inner-city children.</p> <p>Methods and Results</p> <p>URECA is an observational prospective study that enrolled pregnant women in central urban areas of Baltimore, Boston, New York City, and St. Louis and is following their offspring from birth through age 7 years. The birth cohort consists of 560 inner-city children who have at least one parent with an allergic disease or asthma, and all families live in areas in which at least 20% of the population has incomes below the poverty line. In addition, 49 inner-city children with no parental history of allergies or asthma were enrolled. The primary hypothesis is that specific urban exposures in early life promote a unique pattern of immune development (impaired antiviral and increased Th2 responses) that increases the risk of recurrent wheezing and allergic sensitization in early childhood, and of asthma by age 7 years. To track immune development, cytokine responses of blood mononuclear cells stimulated <it>ex vivo </it>are measured at birth and then annually. Environmental assessments include allergen and endotoxin levels in house dust, pre- and postnatal maternal stress, and indoor air nicotine and nitrogen dioxide. Nasal mucous samples are collected from the children during respiratory illnesses and analyzed for respiratory viruses. The complex interactions between environmental exposures and immune development will be assessed with respect to recurrent wheeze at age 3 years and asthma at age 7 years.</p> <p>Conclusion</p> <p>The overall goal of the URECA study is to develop a better understanding of how specific urban exposures affect immune development to promote wheezing illnesses and asthma.</p

    Genetic control of the immune response in mice: V. Minor genes involved in the response to H-Y and Ea-1 antigens

    Full text link
    Murine responses to both the male specific histocompatibility antigen H-Y and the erythrocyte alloantigen Ea-1 are regulated by genetic factors. In each case a single major gene that controls the immune response has been identified, but additional modifying factors can be demonstrated if appropriate strain combinations are studied. A single gene controlling the response to Ea-1 antigens, which segregates when strains YBR and B10.D2 are crossed, has been shown not to be an allele of the Ir-2 locus. A new phenomenon has also been observed in the control of anti-Ea-1 antibody production in that the mating of two responding strains, YBR and HTG, produces an F 1 generation of complete nonresponders. By linkage tests it was shown that the responding strain HTG possesses the nonresponder allele at the Ir- 2 locus, so there appear to be recessive genes in the background which are able to overcome the suppressive influence of this allele.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46729/1/251_2005_Article_BF01564054.pd

    Oral Immunotherapy for Treatment of Egg Allergy in Children

    Get PDF
    For egg allergy, dietary avoidance is the only currently approved treatment. We evaluated oral immunotherapy using egg-white powder for the treatment of children with egg allergy

    Evidence for a third, Ir -associated histocompatibility region in the H-2 complex of the mouse

    Full text link
    Skin grafts transplanted from B10.HTT donors onto (A.TL × B10)F 1 recipients are rapidly rejected despite the fact that the B10.HTT and A.TL strains should be carrying the same H-2 chromosomes and that both the donor and the recipient contain the B10 genome. The rejection is accompanied by a production of cytotoxic antibodies against antigens controlled by the Ir region of the H-2 complex. These unexpected findings are interpreted as evidence for a third histocompatibility locus in the H-2 complex, H-2I , located in the Ir region close to H-2K . The B10.HTT and A.TL strains are postulated to differ at this hypothetical locus, and the difference between the two strains is explained as resulting from a crossing over between the H-2 t1 and H-2 s chromosomes in the early history of the B10.HTT strain. The H-2 genotypes of the B10.HTT and A.TL strains are assumed to be H-2K s Ir s / k Ss k H-2D d and H-2K s Ir k Ss k H-2D d , respectively. Thus, the H-2 chromosomes of the two strains differ only in a portion of the Ir region, including the H-2I locus. The B10.HTT( H-2 tt ) and B10.S(7R)( H-2 th ) strains differ in a relatively minor histocompatibility locus, possibly residing in the Tla region outside of the H-2 complex.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46727/1/251_2005_Article_BF01564045.pd

    Graph based study of allergen cross-reactivity of plant lipid transfer proteins (LTPs) using microarray in a multicenter study.

    Get PDF
    The study of cross-reactivity in allergy is key to both understanding. the allergic response of many patients and providing them with a rational treatment In the present study, protein microarrays and a co-sensitization graph approach were used in conjunction with an allergen microarray immunoassay. This enabled us to include a wide number of proteins and a large number of patients, and to study sensitization profiles among members of the LTP family. Fourteen LTPs from the most frequent plant food-induced allergies in the geographical area studied were printed into a microarray specifically designed for this research. 212 patients with fruit allergy and 117 food-tolerant pollen allergic subjects were recruited from seven regions of Spain with different pollen profiles, and their sera were tested with allergen microarray. This approach has proven itself to be a good tool to study cross-reactivity between members of LTP family, and could become a useful strategy to analyze other families of allergens
    corecore