Differential regulation of lung homeostasis and silicosis by the TAM receptors MerTk and Axl.

Introduction: TAM receptor-mediated efferocytosis plays an important function in immune regulation and may contribute to antigen tolerance in the lungs, a site with continuous cellular turnover and generation of apoptotic cells. Some studies have identified failures in efferocytosis as a common driver of inflammation and tissue destruction in lung diseases. Our study is the first to characterize the function of the TAM receptors, Axl and MerTk, in the innate immune cell compartment, cytokine and chemokine production, as well as the alveolar macrophage (AM) phenotype in different settings in the airways and lung parenchyma.

Immune Responses in Leishmaniasis: An Overview.

Leishmaniasis is a parasitic, widespread, and neglected disease that affects more than 90 countries in the world. More than 20 species cause different forms of leishmaniasis that range in severity from cutaneous lesions to systemic infection. The diversity of leishmaniasis forms is due to the species of parasite, vector, environmental and social factors, genetic background, nutritional status, as well as immunocompetence of the host.

Salivary ZG16B expression loss follows exocrine gland dysfunction related to oral chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) targets include the oral mucosa and salivary glands after allogeneic hematopoietic stem cell transplant (HSCT). Without incisional biopsy, no diagnostic test exists to confirm oral cGVHD. Consequently, therapy is often withheld until severe manifestations develop.

Inflammatory Cytokines Are Involved in Focal Demyelination in Leprosy Neuritis.

Mycobacterium leprae (ML) infection causes nerve damage that often leads to permanent loss of cutaneous sensitivity and limb deformities, but understanding of the pathogenesis of leprous neuropathy that would lead to more effective treatments is incomplete. We studied reactional leprosy patients with (n = 9) and without (n = 8) acute neuritis. Nerve conduction studies over the course of the reactional episode showed the findings of demyelination in all patients with neuritis.

The PGE2/IL-10 Axis Determines Susceptibility of B-1 Cell-Derived Phagocytes (B-1CDP) to Leishmania major Infection.

B-1 cells can be differentiated from B-2 cells because they are predominantly located in the peritoneal and pleural cavities and have distinct phenotypic patterns and activation properties. A mononuclear phagocyte derived from B-1 cells (B-1CDP) has been described. As the B-1CDP cells migrate to inflammatory/infectious sites and exhibit phagocytic capacity, the microbicidal ability of these cells was investigated using the Leishmania major infection model in vitro.

Innate immunity to Leishmania infection: within phagocytes.

Infection by Leishmania takes place in the context of inflammation and tissue repair. Besides tissue resident macrophages, inflammatory macrophages and neutrophils are recruited to the infection site and serve both as host cells and as effectors against infection. Recent studies suggest additional important roles for monocytes and dendritic cells.

Infection with Leishmania major induces a cellular stress response in macrophages.

We investigated early cellular responses induced by infection with Leishmania major in macrophages from resistant C57/BL6 mice. Infection increased production of reactive oxygen species by resident, but not inflammatory peritoneal macrophages. In addition, infection increased activation of stress-activated protein kinases/c-Jun N-terminal kinases (SAPK/JNK) in resident, but not in inflammatory peritoneal macrophages.

Schwann cells producing matrix metalloproteinases under Mycobacterium leprae stimulation may play a role in the outcome of leprous neuropathy.

Matrix metalloproteinases (MMPs) mediate demyelination and breakdown of the blood-nerve barrier in peripheral neuropathies. Matrix metalloproteinases and tissue inhibitor of metalloproteinase 1 gene expression and secretion were studied in cells of the human Schwann cell line ST88-14 stimulated with Mycobacterium leprae and tumor necrosis factor (TNF) and in nerve biopsies from patients with neural leprosy (n = 21) and nonleprous controls (n = 3). Mycobacterium leprae and TNF induced upregulation of MMP-2 and MMP-9 and increased secretion of these enzymes in cultured ST88-14 cells.

Morphological and functional characterizations of Schwann cells stimulated with Mycobacterium leprae.

Nerve damage, a characteristic of leprosy, is the cause of patient deformities and a consequence of Schwann cells (SC) infection by Mycobacterium leprae. Although function/dysfunction of SC in human diseases like leprosy is difficult to study, many in vitro models, including SC lines derived from rat and/or human Schwannomas, have been employed. ST88-14 is one of the cell lineages used by many researchers as a model for M.