scholarly journals Human astrocytes inhibit Cryptococcus neoformans growth by a nitric oxide-mediated mechanism.

1994 ◽  
Vol 180 (1) ◽  
pp. 365-369 ◽  
Author(s):  
S C Lee ◽  
D W Dickson ◽  
C F Brosnan ◽  
A Casadevall
Keyword(s):  
Nitric Oxide ◽  
Cryptococcus Neoformans ◽  
Interleukin 1 ◽  
Primary Cultures ◽  
Immune Deficiency Syndrome ◽  
Deficiency Syndrome ◽  
Effector Cells ◽  
Human Astrocytes ◽  
Life Threatening

Cryptococcus neoformans is an opportunistic fungus that causes life-threatening meningoencephalitis in 5-10% of patients with acquired immune deficiency syndrome. Cryptococcal meningoencephalitis is characterized by a lymphohistiocytic infiltrate, accumulation of encapsulated forms of C. neoformans, and varying degrees of glial reaction. Little is known about the contribution of endogenous central nervous system cells to the pathogenesis of cryptococcal infections. In this study, we investigated the role of astrocytes as potential effector cells against C. neoformans. Primary cultures of human fetal astrocytes, activated with interleukin 1 beta plus interferon gamma inhibited the growth of C. neoformans. The inhibition of C. neoformans growth was paralleled by production of nitrite, and reversed by the inhibitors of nitric oxide (NO.) synthase, NG-methyl-mono-arginine and NG-nitro-arginine methyl ester. The results suggest a novel function for human astrocytes in host defence and provide a precedent for the use of NO. as an antimicrobial effector molecule by human cells.

scholarly journals Memory T cells are anergic to the superantigen staphylococcal enterotoxin B.

1992 ◽  
Vol 176 (2) ◽  
pp. 575-579 ◽  
Author(s):  
W T Lee ◽  
E S Vitetta
Keyword(s):  
T Cells ◽  
Memory T Cells ◽  
Immune Deficiency Syndrome ◽  
Deficiency Syndrome ◽  
Staphylococcal Enterotoxin ◽  
Peripheral Tolerance ◽  
Staphylococcal Enterotoxin B ◽  
Enterotoxin B

We have used staphylococcal enterotoxin B (SEB) to study the role of naive and memory T cells in the induction of peripheral tolerance. After administration of SEB to mice, the numbers of naive and memory T cells increase, as does the proportion of memory T cells, which are unresponsive to further stimulation with SEB in vitro. In addition, memory T cells generated in response to conventional antigen, which proliferate and provide help to B cells in the presence of the conventional antigen, fail to respond to superantigen. Hence, memory T cells, in general, are anergized by SEB. These results suggest that SEB-induced activation and anergy reflect the combined responses of naive and memory T cells. The differential activation vs. anergy of naive and memory T cells by superantigen may be related to cytokine production and may play an important role in the etiology of autoimmune diseases or immunodeficiency diseases such as acquired immune deficiency syndrome.

Role of Nitric Oxide in Down-Regulation of CYP2B1 Protein, but Not RNA, in Primary Cultures of Rat Hepatocytes

2001 ◽  
Vol 60 (1) ◽  
pp. 209-216 ◽  
Author(s):  
Luc Ferrari ◽  
Ning Peng ◽  
James R. Halpert ◽  
Edward T. Morgan
Keyword(s):  
Nitric Oxide ◽  
Primary Cultures ◽  
Rat Hepatocytes ◽  
Down Regulation

scholarly journals Contribution of HIV Infection, AIDS, and Antiretroviral Therapy to Exocrine Pathogenesis in Salivary and Lacrimal Glands

2018 ◽  
Vol 19 (9) ◽  
pp. 2747 ◽  
Author(s):  
Imran Nizamuddin ◽  
Peter Koulen ◽  
Carole McArthur
Keyword(s):  
Antiretroviral Therapy ◽  
Hiv Infection ◽  
Immune Deficiency Syndrome ◽  
Deficiency Syndrome ◽  
Exocrine Function ◽  
Lacrimal Glands ◽  
Immunodeficiency Virus ◽  
And Function ◽  
The Impact

The structure and function of exocrine glands are negatively affected by human immunodeficiency virus (HIV) infection and its co-morbidities, including innate and adaptive immune responses. At the same time, exocrine function may also be influenced by pharmacotherapies directed at the infectious agents. Here, we briefly review the role of the salivary glands and lacrimal glands in normal physiology and exocrine pathogenesis within the context of HIV infection and acquired immune deficiency syndrome (AIDS), including the contribution of antiretroviral therapies on both. Subsequently, we discuss the impact of HIV infection and the types of antiretroviral therapy on disease management and therapy development efforts.

scholarly journals Regulation of matrix turnover in meniscal explants: role of mechanical stress, interleukin-1, and nitric oxide

2003 ◽  
Vol 95 (1) ◽  
pp. 308-313 ◽  
Author(s):  
Sang-jin Shin ◽  
Beverley Fermor ◽  
J. Brice Weinberg ◽  
David S. Pisetsky ◽  
Farshid Guilak
Keyword(s):  
Nitric Oxide ◽  
Mechanical Stress ◽  
Dynamic Compression ◽  
Interleukin 1 ◽  
Joint Disease ◽  
Proteoglycan Synthesis ◽  
Compressive Stresses ◽  
Nitric Oxide Synthase 2 ◽  
Oxide Synthase

The meniscus is an intra-articular fibrocartilaginous structure that serves essential biomechanical roles in the knee. With injury or arthritis, the meniscus may be exposed to significant changes in its biochemical and biomechanical environments that likely contribute to the progression of joint disease. The goal of this study was to examine the influence of mechanical stress on matrix turnover in the meniscus in the presence of interleukin-1 (IL-1) and to determine the role of nitric oxide (NO) in these processes. Explants of porcine menisci were subjected to dynamic compressive stresses at 0.1 MPa for 24 h at 0.5 Hz with 1 ng/ml IL-1, and the synthesis of total protein, proteoglycan, and NO was measured. The effects of a nitric oxide synthase 2 (NOS2) inhibitor were determined. Dynamic compression significantly increased protein and proteoglycan synthesis by 68 and 58%, respectively, compared with uncompressed explants. This stimulatory effect of mechanical stress was prevented by the presence of IL-1 but was restored by specifically inhibiting NOS2. Release of proteoglycans into the medium was increased by IL-1 or mechanical compression and further enhanced by IL-1 and compression together. Stimulation of proteoglycan release in response to compression was dependent on NOS2 regardless of the presence of IL-1. These finding suggest that IL-1 may modulate the effects of mechanical stress on extracellular matrix turnover through a pathway that is dependent on NO.

scholarly journals Invasive Aspergillus Sinusitis in Human Immunodeficiency Virus Infection: Case Report and Review of the Literature

2016 ◽  
Vol 3 (3) ◽  
Author(s):  
John M. Humphrey ◽  
Thomas J. Walsh ◽  
Roy M. Gulick
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiretroviral Therapy ◽  
Immune Deficiency Syndrome ◽  
Deficiency Syndrome ◽  
Immunodeficiency Virus ◽  
Immunologic Factors ◽  
Life Threatening ◽  
Acquired Immune Deficiency ◽  
Orbital Invasion ◽  
Overall Mortality

Abstract Invasive Aspergillus (IA) sinusitis is a life-threatening opportunistic infection in immunocompromised individuals, but it is uncommon in human immunodeficiency virus (HIV) infection. To gain a better understanding of the characteristics of IA sinusitis in this population, we present a unique case of chronic IA sinusitis in an HIV-infected patient taking antiretroviral therapy and review the literature summarizing published cases of invasive aspergillosis of the paranasal (n = 41) and mastoid (n = 17) sinuses in HIV-infected individuals. Among these cases, only 4 were reported after 1999, and 98% of patients had acquired immune deficiency syndrome. Orbital invasion occurred in 54% of paranasal sinus cases, whereas intracranial invasion was reported in 53% of mastoid sinus cases. The overall mortality was 79%. We also discuss various clinical and immunologic factors that may play a role in the development of IA and consider the changing epidemiology of aspergillosis in the era of effective antiretroviral therapy.

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