scholarly journals Protective Efficacy of H Antigen fromHistoplasma capsulatum in a Murine Model of Pulmonary Histoplasmosis

2001 ◽  
Vol 69 (5) ◽  
pp. 3128-3134 ◽  
Author(s):  
George S. Deepe ◽  
Reta Gibbons

ABSTRACT We previously reported that immunization with H antigen fromHistoplasma capsulatum did not protect mice against an intravenous challenge with yeasts. Here, we investigated the utility of H antigen to protect mice in a model of pulmonary histoplasmosis. Mice immunized with H antigen and challenged intranasally 4 weeks postvaccination were protected against sublethal and lethal challenges with H. capsulatum yeasts. If the challenge was performed 3 months after vaccination, there was a reduction in fungal burden following sublethal challenge and a modest delay in mortality in mice given a lethal inoculum. Vaccination was associated with production of gamma interferon, granulocyte-macrophage colony-stimulating factor, interleukin-4, and interleukin-10 by splenocytes. Vaccination with H antigen was not accompanied by a major expansion of CD4+ or CD8+ cells in spleens of mice. These results demonstrate that H antigen may be useful as a protective immunogen against pulmonary exposure to H. capsulatum.

2003 ◽  
Vol 60 (5) ◽  
pp. 531-538 ◽  
Author(s):  
Miodrag Colic ◽  
Dusan Jandric ◽  
Zorica Stojic-Vukanic ◽  
Jelena Antic-Stankovic ◽  
Petar Popovic ◽  
...  

Several laboratories have developed culture systems that allow the generation of large numbers of human dendritic cells (DC) from monocytes using granulocyte-macrophage colony stimulating factor (GM-CSF), and interleukin-4 (IL-4). In this work we provided evidence that GM-CSF (100 ng/ml) in combination with a low concentration of IL-4 (5 ng/ml) was efficient in the generation of immature, non-adherent, monocyte-derived DC as the same concentration of GM-CSF, and ten times higher concentration of IL-4 (50 ng/ml). This conclusion was based on the similar phenotype profile of DC such as the expression of CD1a, CD80, CD86, and HLA-DR, down-regulation of CD14, and the absence of CD83, as well as on their similar allostimulatory activity for T cells. A higher number of cells remained adherent in cultures with lower concentrations of IL-4 than in cultures with higher concentrations of the cytokine. However, most of these adherent cells down-regulated CD14 and stimulated the proliferation of alloreactive T cells. In contrast adherent cells cultivated with GM-CSF alone were predominantly macrophages as judged by the expression of CD14 and the inefficiency to stimulate alloreactive T cells. DC generated in the presence of lower concentrations of IL-4 had higher proapoptotic potential for the Jurkat cell line than DC differentiated with higher concentrations of IL-4, suggesting their stronger cytotoxic, anti-tumor effect.


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