Sib-pair analysis of 170 individuals from 11 Amish families revealed evidence for linkage of five markers in chromosome 5q31.1 with a gene controlling total serum immunoglobulin E (IgE) concentration. No linkage was found between these markers and specific IgE antibody concentrations. Analysis of total IgE within a subset of 128 IgE antibody-negative sib pairs confirmed evidence for linkage to 5q31.1, especially to the interleukin-4 gene (IL4). A combination of segregation and maximum likelihood analyses provided further evidence for this linkage. These analyses suggest that IL4 or a nearby gene in 5q31.1 regulates IgE production in a nonantigen-specific (noncognate) fashion.

A novel gene, designated ML-1, was identified from a human genomic DNA clone and human T cell cDNA sequences. The second exon of ML-1 gene shares significant sequence identity with the gene encoding IL-17 (IL-17). ML-1 gene expression was up-regulated in activated PBMCs, CD4+ T cells, allergen-specific Th0, Th1, and Th2 clones, activated basophils, and mast cells. Increased expression of the ML-1 gene, but not IL-17, was seen following allergen challenge in four asthmatic subjects, suggesting its role in allergic inflammatory responses. ML-1 from transiently transfected COS-7 cells was able to induce gene expression and protein production for IL-6 and IL-8 (at 10 ng/ml of ML-1: for IL-6, 599.6 ± 19.1 pg/ml; for IL-8, 1724.2 ± 132.9 pg/ml; and at 100 ng/ml of ML-1: for IL-6, 1005.3 ± 55.6 pg/ml; for IL-8, 4371.4 ± 280.5 pg/ml; p < 0.05 for both doses vs baseline) in primary bronchial epithelial (PBE) cells. Furthermore, increased expression of ICAM-1 was found in ML-1-stimulated PBE cells (mean fluorescence intensity (MFI) = 31.42 ± 4.39 vs baseline, MFI = 12.26 ± 1.77, p < 0.05), a functional feature distinct from IL-17 (MFI = 11.07 ± 1.22). This effect was not inhibited by a saturating amount of IL-17. These findings demonstrate that ML-1 is a novel cytokine with a distinct function, and suggest a different receptor for ML-1 on PBE cells.

Endothelial cells, by virtue of their capacity to express adhesion molecules and cytokines, are intricately involved in inflammatory processes. Endothelial cells have been shown to express interleukin-1 (IL-1), IL-5, IL-6, IL-8, IL-11, IL-15, several colony-stimulating factors (CSF), granulocyte-CSF (G-CSF), macrophage CSF (M-CSF) and granulocyte-macrophage CSF (GM-CSF), and the chemokines, monocyte chemotactic protein-1 (MCP-1), RANTES, and growth-related oncogene protein-alpha (GRO-alpha). IL-1 and tumor necrosis factor-alpha (TNF-alpha) produced by infiltrating inflammatory cells can induce endothelial cells to express several of these cytokines as well as adhesion molecules. Induction of these cytokines in endothelial cells has been demonstrated by such diverse processes as hypoxia and bacterial infection. Recent studies have demonstrated that adhesive interactions between endothelial cells and recruited inflammatory cells can also signal the secretion of inflammatory cytokines. This cross-talk between inflammatory cells and the endothelium may be critical to the development of chronic inflammatory states. Endothelial-derived cytokines may be involved in hematopoiesis, cellular chemotaxis and recruitment, bone resorption, coagulation, and the acute-phase protein synthesis. As many of these processes are critical to the maturation of an inflammatory and reparative state, it appears likely that endothelial-derived cytokines play a crucial role in several diseases, including atherosclerosis, graft rejection, asthma, vasculitis, and sepsis. Genetic and pharmacologic manipulation of endothelial-derived cytokines provides an additional approach to the management of chronic inflammatory diseases.

In spite of recent advances with experiments on animal models, strongyloidiasis, an infection caused by the nematode parasite Strongyloides stercoralis, has still been an elusive disease. Though endemic in some developing countries, strongyloidiasis still poses a threat to the developed world. Due to the peculiar but characteristic features of autoinfection, hyperinfection syndrome involving only pulmonary and gastrointestinal systems, and disseminated infection with involvement of other organs, strongyloidiasis needs special attention by the physician, especially one serving patients in areas endemic for strongyloidiasis. Strongyloidiasis can occur without any symptoms, or as a potentially fatal hyperinfection or disseminated infection. Th2 cell-mediated immunity, humoral immunity and mucosal immunity have been shown to have protective effects against this parasitic infection especially in animal models. Any factors that suppress these mechanisms (such as intercurrent immune suppression or glucocorticoid therapy) could potentially trigger hyperinfection or disseminated infection which could be fatal. Even with the recent advances in laboratory tests, strongyloidiasis is still difficult to diagnose. But once diagnosed, the disease can be treated effectively with antihelminthic drugs like Ivermectin. This review article summarizes a case of strongyloidiasis and various aspects of strongyloidiasis, with emphasis on epidemiology, life cycle of Strongyloides stercoralis, clinical manifestations of the disease, corticosteroids and strongyloidiasis, diagnostic aspects of the disease, various host defense pathways against strongyloidiasis, and available treatment options.

Chronic Granulomatous Disease is the most commonly encountered immunodeficiency involving the phagocyte, and is characterized by repeated infections with bacterial and fungal pathogens, as well as the formation of granulomas in tissue. The disease is the result of a disorder of the NADPH oxidase system, culminating in an inability of the phagocyte to generate superoxide, leading to the defective killing of pathogenic organisms. This can lead to infections with Staphylococcus aureus, Psedomonas species, Nocardia species, and fungi (such as Aspergillus species and Candida albicans). Involvement of vital or large organs can contribute to morbidity and/or mortality in the affected patients. Major advances have occurred in the diagnosis and treatment of this disease, with the potential for gene therapy or stem cell transplantation looming on the horizon.

Eosinophil-mediated diseases, such as allergic asthma, eosinophilic fasciitis, and certain hypersensitivity pulmonary disorders, are characterized by eosinophil infiltration and tissue injury. Mast cells and T cells often colocalize to these areas. Recent data suggest that mast cells can contribute to eosinophil-mediated inflammatory responses. Activation of mast cells can occur by antigen and immunoglobulin E (IgE) via the high-affinity receptor (FcepsilonRI) for IgE. The liberation of proteases, leukotrienes, lipid mediators, and histamine can contribute to tissue inflammation and allow recruitment of eosinophils to tissue. In addition, the synthesis and expression of a plethora of cytokines and chemokines (such as granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin-1 [IL-1], IL-3, IL-5, tumor necrosis factor-alpha [TNF-alpha], and the chemokines IL-8, regulated upon activation normal T cell expressed and secreted [RANTES], monocyte chemotactic protein-1 [MCP-1], and eotaxin) by mast cells can influence eosinophil biology. Stem cell factor (SCF)-c-kit, cytokine-cytokine receptor, and chemokine-chemokine receptor (CCR3) interactions leading to nuclear factor kappaB (NF-kappaB), mitogen-activated protein kinase (MAPK) expression, and other signaling pathways can modulate eosinophil function. Eosinophil hematopoiesis, activation, survival, and elaboration of mediators can all be regulated thus by mast cells in tissue. Moreover, because eosinophils can secrete SCF, eosinophils can regulate mast cell function in a paracrine manner. This two-way interaction between eosinophils and mast cells can pave the way for chronic inflammatory responses in a variety of human diseases. This review summarizes this pivotal interaction between human mast cells and eosinophils.

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Mast cells are multifunctional, tissue-dwelling cells capable of secreting a wide variety of mediators. They develop from bone marrow-derived progenitor cells, primed with stem cell factor (SCF), which mediates its actions by interacting with the SCF receptor or c-kit on the cell surface. Mast cells continue their maturation and differentiation in peripheral tissue, developing into two well described subsets of cells, MCT and MCTC cells, varying in content of tryptase and chymase as well as in immunobiology. Mast cells are activated by numerous stimuli, including antigen (acting via the high affinity IgE receptor, Fc?RI), superoxides, complement proteins, neuropeptides and lipoproteins resulting in activation and degranulation. Following activation, these cells express mediators such as histamine, leukotrienes and prostanoids, as well as proteases, and many cytokines and chemokines, pivotal to the genesis of an inflammatory response. Recent data suggests that mast cells may play an active role in such diverse diseases as atherosclerosis, malignancy, asthma, pulmonary fibrosis and arthritis. Mast cells directly interact with bacteria and appear to play a vital role in host defense against pathogens. Drugs, such as glucocorticoids, cyclosporine and cromolyn have been demonstrated to have inhibitory effects on mast cell degranulation or mediator release.