Identification of antigen-specific neutrophils in the tonsils with recurrent acute inflammation.

The pathogenesis of recurrent acute tonsillitis (Rtn) is to be further investigated. Polymorphonuclear neutrophils (PMN) often associate with the pathogenesis of acute and chronic inflammation. This study aims to identify the antigen-specific PMNs (sPMNs) isolated from the tonsillar tissues with recurrent acute inflammation. In this study, CD66b+ PMNs were isolated from surgically removed tonsils (40 tonsils were from 20 Rtn patients; 24 tonsils were from 12 tonsil tumour patients) by flow cytometry cell sorting. sPMNs were identified through immunological approaches. We found that compared with the control tonsil samples (from marginal non-tumour tissues of tonsil cancer), Rtn samples showed higher PMN frequency, higher levels of myeloperoxidase (MPO) and neutrophil elastase (NE), in which positive correlation was detected between the inflammatory scores in the Rtn tissues and PMN counts (r = .7352; p = .0002), or MPO (r = .6565, p = .0017), or NE (r = .6687, p = .0013). Upon exposure to tonsillar tissue protein extracts in the culture, a portion of Rtn PMNs was activated and released inflammatory mediators. A complex of tonsillar tissue-specific IgG and FcγRI was observed on the surface of Rtn PMNs; these PMNs could specifically recognize the Rtn tissue extracts and were designated the tonsillar antigen-specific PMNs (sPMNs). A signal transduction pathway of mitogen-activated protein kinase (MAPK)-nuclear factor of T cell activation (NFAT) was activated in sPMNs after exposure to Rtn tissue extracts. In summary, a fraction of sPMN in the Rtn tonsillar tissues was identified and characterized. The sPMNs can be activated upon exposure to tonsil-specific antigens. These sPMNs may contribute to the Rtn pathogenesis.

Oral application of bacterial lysate in infancy diminishes the prevalence of atopic dermatitis in children at risk for atopy.

Numerous interventions such as avoidance of food allergens, prolonged breast feeding and supplementation of pro-and/or prebiotics have been tried as primary prevention of atopic dermatitis. Recent data suggest that prevention of infantile eczema is possible in a subgroup of children by feeding bacterial lysates early in life. Bacterial lysates of Escherichia coli and Enterococcus faecalis were found to impair allergic immune responses in rats. An interventional trial in 606 infants at risk for atopy showed a reduction of atopic dermatitis at the end of the treatment phase (month 2 until month 7) of 50% in a subgroup of children with single heredity for atopy. This was even more pronounced in the group of children with paternal heredity for atopy. This effect was still seen at age 1 year. There was no effect on food sensitisation. In conclusion, an immune modulation in terms of prevention of atopic dermatitis in infancy if single atopic family history is present seems to be possible by feeding bacterial lysates early in life.

Ganoderma lucidum extracts inhibited leukemia WEHI-3 cells in BALB/c mice and promoted an immune response in vivo.

Ganoderma lucidum (G. lucidum) is a medicinal mushroom having biological effects such as immunomodulation and anti-tumor actions. In China and many other Asian countries, G. lucidum is used as a folk remedy to promote health and longevity. Although many studies have shown that G. lucidum modulates the immune system, including, for example, antigen-presenting cells, natural killer (NK) cells, and the T and B lymphocytes, the effects of G. lucidum on the WEHI-3 leukemic BALB/c mice are unclear. We attempted to determine whether G. lucidum would promote immune responses in BALB/c mice injected with WEHI-3 leukemia cells. The effects of G. lucidum on the survival rate of WEHI-3 leukemia cells injected into BALB/c mice were examined. It increased the percentages of CD3 and CD19, but decreased the percentages of Mac-3 and CD11b markers, suggesting that differentiation of the precursor of T and B cells was promoted but macrophages were inhibited. It decreased the weight of spleens as compared with control mice. It also promoted phagocytosis by macrophage from peripheral blood mononuclear cell (PBMC) and it also promoted natural killer cell activity. It decreased the percentage of leukemia cells in the spleens of mice before they were injected with WEHI-3 cells. Apparently, G. lucidum affects murine leukemia WEHI-3 cells in vivo.

Standardization of allergen extracts.

Allergens are molecules with the capacity to elicit IgE responses in humans. When stimulated with allergens, most allergic patients respond with production of IgE specific for several proteins/allergens in the source material. The standardization of allergen extracts is essential in order to control variability and to achieve consistency and reproducibility in a clinical setting. Because the IgE binding capacity of an allergen extract is related to the content of one or a few major allergens, it is important that the standardization procedure ensures consistency, not only in the overall IgE binding potency, but also in the content and ratio of individual major allergens. Owing to the complexity of allergen extracts, a key element in standardization of allergen extracts is the use of standards. This chapter describes the principles for standardization of allergen extracts to be used by research laboratories. Other chapters in this volume describe methods in detail.

Heat shock treatment of tumor lysate-pulsed dendritic cells enhances their capacity to elicit antitumor T cell responses against medullary thyroid carcinoma.

BACKGROUND: In vitro and in vivo studies have shown that dendritic cells (DCs) can stimulate antitumor T cell responses against medullary thyroid carcinoma (MTC). However, despite promising results in selected cases, the clinical efficacy of DC immunotherapy in patients with MTC has been limited. Recently, it has been demonstrated in mice that heat shock enhances the capacity of bone-marrow-derived DCs to stimulate antigen-specific T cells. The aim of our investigations was to evaluate whether heat shock also increases the capacity of human monocyte-derived DCs to stimulate antitumor T cell responses against MTC tumor cells. METHODS: DCs from six patients with metastatic MTC were pulsed with tumor lysate derived from allogeneic MTC tumor cells and were heat shocked for 12 h at 40 C or kept at 37 C. Thereafter, the DCs were matured and cocultured with T cells. Finally, the cytotoxic activity of T cells against MTC tumor cells was measured in vitro. RESULTS: In all patient samples, cytotoxic T cell responses against MTC tumor cells could be induced. Notably, heat-shocked DCs were more potent stimulators of cytotoxic T cell responses than control DCs, with T cells stimulated with heat-shocked DCs displaying a significantly increased cytotoxic activity against MTC tumor cells as compared with T cells stimulated with control DCs. In none of the experiments was a cytotoxic T cell response against unrelated pancreatic tumor cells (PANC-1) observed, using both control and heat-shocked DCs. CONCLUSIONS: Our study shows that heat-shocking DCs may be a valuable strategy to increase the immunostimulatory capacity of DCs used for immunotherapy of MTC.

Deletion of the GPI pre-anchor sequence in human p97--a general approach for generating the soluble form of GPI-linked proteins.

Melanotransferrin, also named p97, belongs to the transferrin-like group of iron-binding proteins. Unlike the other members of this family, p97 exists in two forms-one soluble form and one attached to the cell membrane by a glycosylphosphatidylinositol (GPI) anchor. The GPI-linked form plays a role in the uptake of iron, while the soluble form of p97 has the unique ability of traversing the blood-brain barrier and may be utilized to deliver drug conjugates into the brain. To investigate these possibilities, a recombinant soluble form of p97 from the GPI-linked p97 protein is required. The approach involved sequential deletions of the p97 GPI pre-anchor sequence (PAS) up to the putative site of cleavage/attachment, releasing p97 from attachment to the GPI-anchor and rendering it soluble. Transfection of the p97 deletion constructs into both the CHO and BHK TK(-) cells was performed with the aim of optimizing the production of p97 by utilizing the cell characteristics unique to each cell line. Altering the GPI PAS resulted in the generation of a recombinant soluble form that was secreted at significantly higher rates than from the full-length expressing cell lines. Increases were from 22 x 10(-9) to 241 x 10(-9)microg/cell/h for expression in the CHO cell system and from 220 x 10(-9) to 4970 x 10(-9)microg/cell/h for the BHK system. Furthermore, there appeared to be differences in the secretion rates between the various deletions suggesting the need for closer examination of the C-terminus in achieving maximum production of the altered proteins. The results of this study are likely applicable for expressing soluble forms of other GPI-linked proteins.

A species-specific monoclonal antibody to Cynodon dactylon.

BACKGROUND: It is usually difficult to differentiate between the pollens of different grass species on the basis of their appearance under a microscope, as they often appear similar. Such distinctions are important when interpreting the clinical relevance of pollens in air samples as individuals can differ in their allergic responses to different grass species. As this allergenic distinction occurs at the level of presence and differences of epitopes on the allergens associated with different species, it could be anticipated that species-specific monoclonal antibodies could provide such distinctions between pollens. METHOD: Monoclonal antibodies raised against Cynodon dactylon were screened and characterised in ELISA assays and blotting, using a range of grass pollen extracts, to identify clones which were species specific. RESULTS: The most specific monoclonal raised to C. dactylon did not react at a level of greater than 1.2% to extracts of 10 other grass pollens in a direct ELISA assay and showed no detectable cross-reactivity in a particle blotting assay. CONCLUSION: It has been possible to produce a monoclonal antibody that is functionally species specific to C. dactylon.

[In vitro transfer of immunity against PPD with dialyzable extract of leukocytes from human colostrum]. / Transferencia in vitro de inmunidad a PPD con extracto dializable de leucocitos de calostro humano.

The aim of this study is to demonstrate the transference of PPD hypersensibility in an in vitro model, with dialysable colostral leukocyte extract (DCLE) of PPD+ and PPD-mothers, through measurements of leukocyte migration inhibition factor activity (LIF) from blood obtained of the umbilical cord of newborns from PPD+ mothers. The results show that DCLE PPD+ incubated with leukocytes of newborns from PPD- mothers had inhibition of leukocyte migration compared with migration of leukocytes incubated with DCLE PPD-. These results suggest that in this in vitro model, DCLE transfers hypersensibility to PPD.