Incorporation of a Dietary Omega 3 Fatty Acid Impairs Murine Macrophage Responses to Mycobacterium tuberculosis

by creating an immunosuppressive environment. We hypothesized that incorporation of n-3 PUFA suppresses activation of macrophage antimycobacterial responses and favors bacterial growth, in part, by modulating the IFNγ-mediated signaling pathway.. The fatty acid composition of macrophage membranes was modified significantly by DHA treatment. DHA-treated macrophages were less effective in controlling intracellular mycobacteria and showed impaired oxidative metabolism and reduced phagolysosome maturation. Incorporation of DHA resulted in defective macrophage activation, as characterized by reduced production of pro-inflammatory cytokines (TNFα, IL-6 and MCP-1), and lower expression of co-stimulatory molecules (CD40 and CD86). DHA treatment impaired STAT1 phosphorylation and colocalization of the IFNγ receptor with lipid rafts, without affecting surface expression of IFNγ receptor. in response to activation by IFNγ, by modulation of IFNγ receptor signaling and function, suggesting that n-3 PUFA-enriched diets may have a detrimental effect on host immunity to tuberculosis

Ecosystem services from smallholder forestry and agroforestry in the tropics

Smallholder forestry and agroforestry systems in the tropics provide essential products and services for millions of producers, their surrounding communities, national and international consumers, and global society. The diversity of products provided by these systems meet the needs of smallholder producers for fuelwood, food, animal fodder, and other household and farm needs; they provide additional income to supplement major commodity crops; and they offer flexibility in production and income to buffer against falling commodity prices, crop failure, or other sources of financial or economic difficulty. The sustainability of these systems is increasingly dependent upon sources of income beyond the sale of conventional products, such as price premiums from sustainability certification and agro- and ecotourism. Payments for ecosystem services (PES) programs have been developed at multiple levels to provide incentives for smallholders to conserve and enhance tree cover and management practices to provide ecosystem services such as watershed protection and carbon sequestration. Ecotourism provides an enterprise-based strategy to engage producers in conservation and enhancement of these services. This review evaluates the ability of smallholder systems to support the provision of ecosystem services (ES) and the capacity of smallholders to participate in support programs and take advantage of other emerging opportunities to support smallholder enterprises