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F Bosque

Publications and source records attributed to F Bosque.

6 recordsLinked to original sources
PubMed2000

Distinct innate and acquired immune responses to Leishmania in putative susceptible and resistant human populations endemically exposed to L. (Viannia) panamensis infection.

Mechanisms of constitutive and acquired susceptibility/resistance to Leishmania Viannia panamensis (L. (V ) p.) were investigated in endemically exposed human populations presenting either recurrent disease (putative susceptible) or subclinical infection (clinically resistant). Cutaneous delayed type hypersensitivity response to leishmanin was significantly lower among individuals experiencing recurrent leishmaniasis than among those whose skin test converted without developing the disease. Monocyte derived macrophages from individuals with recurrent disease were more permissive in vitro to the entry of parasites than macrophages from subclinically infected individuals. In vitro proliferation of CD4 and CD8 T lymphocytes in response to intracellular amastigotes was significantly lower among individuals with a history of recurrent disease compared with subclinically infected individuals. Linear regression analyses revealed a strong direct relationship between the production of interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha and interleukin (IL)-10 by peripheral blood mononuclear cells (PBMC) from resistant (subclinically infected) individuals and no correlation in the production of these cytokines by PBMC from individuals who experienced recurrent disease. The results provide evidence of differences in the innate and acquired responses to Leishmania according to the outcome of the natural infection. These findings support the feasibility of identifying the immunological bases of innate and acquired resistance through studies in naturally exposed human populations.

Adolescent↗
PubMed1998

Permissiveness of human monocytes and monocyte-derived macrophages to infection by promastigotes of Leishmania (Viannia) panamensis.

During natural infections, Leishmania is in contact with a variety of mononuclear phagocytic cells in different tissues, including resident macrophages and monocytes mobilized to the site of infection from the bone marrow and blood circulation. Because the functional capabilities of fully differentiated macrophages and blood monocytes differ, the outcome of infection by Leishmania may depend upon the stage of differentiation of the host cells. To address this question, we evaluated Leishmania panamensis infection of (1) the human promonocytic/histiocytic cell line U-937 before and after induction of differentiation by phorbol myristate acetate; (2) fresh human peripheral blood monocytes; and (3) macrophages derived from monocytes by differentiation in vitro. Based on the percentage of cells infected and the number of parasites per cell, macrophages derived from monocytes or by induction of differentiation of U-937 cells were significantly more permissive to infection by stationary-phase L. (Viannia) panamensis promastigotes than monocytes. Increasing time and maturation in culture prior to exposure to infective promastigotes was associated with the increased permissiveness of differentiated macrophages to infection (P<0.05). The percentage of cells infected and number of amastigotes per cell increased with time postinfection for both monocytes and macrophages but remained significantly greater for macrophages. The increased expression of CD68, CD16, and lysozyme, and decreased expression of peroxidase by macrophages cultured for 5 days in vitro compared with fresh monocytes, whether adherent or in suspension, supported the distinct maturation status of these cells.

Animals↗
PubMed1997

The biology of macrophages.

The main properties of the mononuclear phagocytic system (MPS) are summarized, focusing on their relevance within the framework of the steady-state and the inducible functions of the mammalian immune system, more specifically the immune system of the laboratory mouse, a reference vertebrate which remains the best studied. A peculiar attention is given to the rationale underlying the generation of so-called specific tools and reagents whose use is promoted to characterize this lineage, whatever the level under study, i.e. tissular, cellular, or subcellular levels. As one lineage among other lineages of the hemopoietic system, the MPS is characterizable by constitutive and inducible phenotypic and functional markers whose combination is unique for a given tissular micro-environment. Considering our present understanding of the innate and adaptive immune system functions, some of the properties of the MPS are discussed in relation with properties of another recently recognized hemopoietic lineage, namely the dendritic leukocyte system.

Animals↗
PubMed1995

Parasite-host relationships: in-situ study of Leishmania spp. in resistant and susceptible mice.

The host's skin is a critical tissue in the natural life cycle of the Leishmania spp. known to cause an 'asymptomatic' infectious process or cutaneous or visceral leishmaniasis in mammals. The dermis, once disturbed by the inoculation of infective parasites, becomes a site of dynamic events, the progression of which depends upon both host and parasite characteristics. Whatever the final site of the morbidity caused by the parasites, whether it be cutaneous, visceral or muco-cutanous, this site reflects the parasite and host's ability to create a pro- or anti-parasite micro-environment. The characteristics of this environment are now amenable to analysis in situ, as illustrated by the study of the cutaneous processes initiated by inoculation of Leishmania major in laboratory mice.

Animals↗