Ultrasensitive ELISA for measurement of human cytokine responses in primary culture.

ELISAs offer excellent specificity and, once fully optimized, sensitivity that rivals that of bioassays. The major variables that need to be experimentally determined when developing an ELISA are the optimal number of fresh cells required per well, the optimal antigen concentrations for stimulation, period of culture, and the anticipated intensity of the response. In this chapter, we review the major factors to be considered in the development and application of ultrasensitive ELISAs to the analysis of human immune responses. We specify the conditions we have found to be optimal for quantifying a number of cytokines of demonstrated relevance to human immune regulation and discuss the major pitfalls inherent in this approach.

Allergic humans are hyporesponsive to a CXCR3 ligand-mediated Th1 immunity-promoting loop.

CXCR3 binding chemokine CXCL10 (IP-10) markedly enhances antigen-specific Th1 recall responses in healthy humans, suggesting a role for this pathway in maintenance of clinical tolerance to environmental allergens as well as a potential therapeutic role for CXCR3 ligands in re-balancing the Th2-dominated responses that underlie generation and maintenance of allergic disorders. Here, we investigated the capacity of CXCR3 ligands to modulate allergen-driven IFNgamma production by healthy and allergic individuals characterized by Th1 and Th2 immunity-dominated allergen specific responses, respectively. Exogenous CXCR3 ligands up-regulated antigen-dependent IFNgamma production from healthy individuals' peripheral blood mononuclear cells up to 120-fold, a response neutralized by anti-CXCR3 treatment and not emulated by CCR5 ligands. In contrast, allergic individuals were strikingly hypo-responsive to CXCR3 ligands (P=0.0004). Chemokine-enhanced IFNgamma production correlated with T cell CXCR3 expression (r=0.736, P=0.0001) in vivo and was independent of Th2 cytokine levels. These findings demonstrate that CXCR3-ligation preferentially augments ongoing Th1 over Th2 responses and suggest that reduced capacity of allergic individuals to respond to CXCR3 ligands promotes the maintenance of human allergic disorders.

RanBPM interacts with psoriasin in vitro and their expression correlates with specific clinical features in vivo in breast cancer.

BACKGROUND: Psoriasin has been identified as a gene that is highly expressed in pre-invasive breast cancer, but is often downregulated with breast cancer progression. It is currently unknown whether psoriasin influences epithelial cell malignancy directly or by affecting the surrounding environment. However the protein is found in the nucleus, cytoplasm as well as extracellularly. In the present study we have sought to identify potential psoriasin-binding proteins and to describe their expression profile in breast tumors. METHODS: The yeast two-hybrid method was used to identify potential binding partners for psoriasin. The interaction of psoriasin with RanBPM was confirmed in-vitro by co-immunoprecipitation. The expression of RanBPM and psoriasin was measured by RT-PCR in a series of breast cell lines, breast tumors and primary lymphocytes. RESULTS: We have identified RanBPM as an interacting protein by the yeast two-hybrid assay and confirmed this interaction in-vitro by co-immunoprecipitation. RT-PCR analysis of RanBPM mRNA expression in cell lines (n = 13) shows that RanBPM is widely expressed in different cell types and that expression is higher in tumor than in normal breast epithelial cell lines. RanBPM expression can also be induced in peripheral blood mononuclear cells by treatment with PHA. RanBPM mRNA is also frequently expressed in invasive breast carcinomas (n = 64) and a higher psoriasin/RanBPM ratio is associated with both ER negative (p < 0.0001) and PR negative status (p < 0.001), and inflammatory cell infiltrates (p < 0.0001) within the tumor. CONCLUSIONS: These findings support the hypothesis that psoriasin may interact with RanBPM and this may influence both epithelial and stromal cells and thus contribute to breast tumor progression.

Systemic chemokine and chemokine receptor responses are divergent in allergic versus non-allergic humans.

T(h)1- and T(h)2-polarized human T cell clones display distinct patterns of chemokine receptor expression and selective chemokine responsiveness in vitro. We hypothesized that natural exposure to environmental grass pollen would induce differential systemic chemokine and chemokine receptor expression patterns in individuals with allergic rhinitis compared to healthy controls with type 2- and type 1-dominated responses to allergen respectively. To this end, we compared chemokine receptor expression on peripheral blood T cells directly ex vivo and plasma chemokine levels between these two groups of study participants prior to and during the grass pollen season. T(h)1-associated CXC chemokine receptor (CXCR) 3 was strongly expressed on >50% CD4(+)/CD45RO(+) cells of all subjects. When examined longitudinally, CXCR3 expression increased over the grass pollen season (P < 0.0001), solely in non-allergic subjects. In contrast, for both allergic and non-allergic subjects, CC chemokine receptor (CCR) 5 (T(h)1-associated) and CCR3 (T(h)2-associated) were weakly expressed on <10% of CD4(+)/CD45RO(+) cells both prior to and during the grass pollen season. Type 1 chemokines CXC chemokine ligand (CXCL) 9 and CXCL10 (monokine induced by IFN-gamma and IFN-gamma-inducible protein of 10 kDa: CXCR3 ligands), and type 2 chemokines CC chemokine ligand (CCL) 11 (eotaxin: CCR3 ligand), CCL17 (thymus and activation-regulated chemokine: CCR4 ligand) and CCL22 (monocyte-derived chemokine: CCR4 ligand) were readily detectable in the plasma of most participants. Systemic CXCL9 levels decreased from pre- to grass pollen season in allergics (P < 0.05), whereas CCL17 decreased in non-allergics (P < 0.05) over the same period. Taken together, these longitudinal data suggest a systemic shift to more intensely type 1-dominated responses in non-allergic individuals and, conversely, to more type 2-dominated responses in allergic individuals upon natural re-exposure to grass pollen.

Matrix metalloproteinase-9 deficiency results in enhanced allergen-induced airway inflammation.

Matrix metalloproteinases (MMPs) are a large family of endopeptidases that proteolytically degrade extracellular matrix. Many different cells produce MMP-9, and levels have been shown to be up-regulated in patients with allergic asthma. The aim of this study was to investigate the in vivo role of MMP-9 during allergen-induced airway inflammation. Acute allergic pulmonary eosinophilia was established in MMP-9 knockout (KO) and wild-type (WT) control mice by sensitization and challenge with OVA. Cell recruitment was significantly increased in both bronchoalveolar lavage (BAL) and lung tissue compartments in MMP-9 KO mice compared with WT mice. This heightened cell recruitment was primarily due to increased eosinophils and Th2 cells in the BAL and lung tissue of MMP-9 KO mice in comparison with WT controls. Moreover, levels of the Th2 cytokines, IL-4 and IL-13, and the chemokines eotaxin/CCL11 and macrophage-derived chemokine/CCL22 were substantially increased in MMP-9 KO mice compared with WT after OVA challenge. Resolution of eosinophilia was similar between MMP-9 KO and WT mice, but Th2 cells persisted in BAL and lungs of MMP-9 KO mice for longer than in WT mice. Our results indicate that MMP-9 is critically involved in the recruitment of eosinophils and Th2 cells to the lung following allergen challenge, and suggest that MMP-9 plays a role in the development of Th2 responses to allergen.