National Jewish Health

About: National Jewish Health is a healthcare organization based out in Denver, Colorado, United States. It is known for research contribution in the topics: T cell & Asthma. The organization has 883 authors who have published 833 publications receiving 79201 citations. The organization is also known as: National Jewish Medical and Research Center.

In vivo response of murine gamma delta T cells to a heat shock protein-derived peptide

Abstract: Recent results suggested that a large subset of heat shock protein HSP-60 reactive peripheral lymphoid gamma delta T cells preexists in normal adult mice, all members of which respond to a single segment of this common HSP. However, the experimental evidence supporting this idea involved in vitro peptide responses of gamma delta T-cell hybridomas generated from unprimed spleen cells. Here, we report an attempt to elicit a gamma delta T-cell response in vivo by stimulation of adult C57BL/10 mice with HSP-60 or an HSP-60-derived peptide fragment comprising amino acids 180-196 of mycobacterial HSP-60. Whereas no gamma delta T-cell response was detectable in mice injected with the intact protein, stimulation with the peptide altered the reactive gamma delta T-cell population in vivo. These changes were detected among hybridomas generated with cells restimulated in vitro and included a large increase in hybridizable gamma delta T cells, a nearly maximal increase in the relative frequency of HSP-60-reactive cells, and structural changes in expressed T-cell receptors of HSP-60-reactive cells. Interestingly, we failed to elicit a detectable alpha beta T-cell response to the particular peptide stimulatory for gamma delta T cells, although at least three other HSP-60 epitopes were recognized. Our data show that normal gamma delta T cells can respond in vivo to small peptide antigens. The gamma delta T-cell response to the HSP-60-derived peptide studied here is apparently independent of antigen-specific alpha beta T-cell reactivity.

The role of virus-specific immunoglobulin E in airway hyperresponsiveness.

Abstract: Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis during infancy and is associated with subsequent wheezing and asthma, but the nature of this association is not fully understood. We investigated the role of RSV-specific IgE antibodies in the pathophysiology of virus-induced airway dysfunction in a mouse model. Lung infection with RSV resulted in significant increases in mRNA expression for IgE and both of its high- and low-affinity receptors. In serum, virus-specific IgE antibodies reached peak levels by Day 21 after infection. Data from in vitro experiments show that RSV can induce mast cell degranulation, but only if these cells are sensitized with specific IgE. When passively sensitized in vivo with virus-specific IgE, mice developed exaggerated airway responsiveness to methacholine on airway infection, an effect that required the high-affinity receptor of IgE. These data suggest that RSV-specific IgE may contribute to the pathophysiology of airway dysfunction in children who develop this class of specific antibody.

Drug-resistant tuberculosis: what do we do now?

Abstract: Drug-resistant tuberculosis (TB) represents a threat to TB control programmes. Erratic and inappropriate use of currently available medications, HIV-TB coinfection, and concern about transmission of drug-resistant strains in the general population all contribute to a worrying picture. What do we do now? In the last few years, there has been considerable progress in the understanding of mechanisms of action and resistance to antituberculosis agents, and in establishing the value of directly observed therapy in preventing treatment failure. However, a limited effort has been devoted to the development of new active compounds or of rapid diagnostic tests, and their relevance to global tuberculosis control has been questioned.

ATOPIC DERMATITIS: New insights and opportunities for therapeutic intervention

Abstract: Atopic dermatitis (AD) is a chronic inflammatory skin disease that frequently predates the development of allergic rhinitis or asthma. It is an important skin condition with significant costs and morbidity to patients and their families; the disease affects more than 10% of children. Recent studies have demonstrated the complex interrelationship of genetic, environmental, skin barrier, pharmacologic, psychologic, and immunologic factors that contribute to the development and severity of AD. The current review will examine the cellular and molecular mechanisms that contribute to AD as well as the immunologic triggers involved in its pathogenesis. These insights provide new opportunities for therapeutic intervention in this common skin condition. (J Allergy Clin Immunol 2000;105:860-76.)

Mammalian mitogen-activated protein kinase kinase kinase (MEKK) can function in a yeast mitogen-activated protein kinase pathway downstream of protein kinase C.

Abstract: Mitogen-activated protein kinase cascades are conserved in fungal, plant, and metazoan species. We expressed murine MAP kinase kinase kinase (MEKK) in the yeast Saccharomyces cerevisiae to determine whether this kinase functions as a general or specific activator of genetically and physiologically distinct MAP-kinase-dependent signaling pathways and to investigate how MEKK is regulated. Expression of MEKK failed to correct the mating deficiency of a ste11 delta mutant that lacks an MEKK homolog required for mating. MEKK expression also failed to induce expression of a reporter gene controlled by the HOG1 gene product (Hog1p), a yeast MAP kinase homolog involved in response to osmotic stress. Expression of MEKK did correct the cell lysis defect of a bck1 delta mutant that lacks an MEKK homolog required for cell-wall assembly. MEKK required the downstream MAP kinase homolog in the BCK1-dependent pathway, demonstrating that it functionally replaces the BCK1 gene product (Bck1p) rather than bypassing the pathway. MEKK therefore selectively activates one of three distinct MAP-kinase-dependent pathways. Possible explanations for this selectivity are discussed. Expression of the MEKK catalytic domain, but not the full-length molecule, corrected the cell-lysis defect of a pkc1 delta mutant that lacks a protein kinase C homolog that functions upstream of Bck1p. MEKK therefore functions downstream of the PKC1 gene product (Pkc1p). The N-terminal noncatalytic domain of MEKK, which contains several consensus protein kinase C phosphorylation sites, may, therefore, function as a negative regulatory domain. Protein kinase C phosphorylation may provide one mechanism for activating MEKK.