Unsaturated Fatty Acids Promote the Phagocytosis of P. aeruginosa and R. equi by RAW264.7 Macrophages

Abstract

In the present study, using the murine monocyte/macrophage cell line RAW264.7 as a model system, we analyzed the phagocytosis rate and the bactericidal capacity of polyunsaturated fatty acids (PUFA)-enriched macrophages against Pseudomonas aeruginosa and Rhodococcus equi. The P. aeruginosa strain ATCC 10145, the virulent R. equi strain ATCC 33701, and the non-virulent R. equi strain ATCC 6939 were examined. Flow cytometric detection of intracellular microorganisms in combination with viability assays were used to determine the impact of PUFA on the number of engulfed, surviving as well as replicating bacteria. Macrophage enrichment with PUFA resulted in an increase of the internalization rate of the microorganisms by the immune cells. Moreover, an impeding action of the unsaturated fatty acids on the intracellular survival rates of the virulent strains P. aeruginosa ATCC 10145 and R. equi ATCC 33701 could be observed. The n-3 fatty acid docosahexaenoic acid (DHA) as well as the n-6 fatty acid arachidonic acid (AA) showed the most pronounced effects. Taken together, our data support the idea of supplementing PUFA to immunocompromised individuals as well as to people suffering from chronic infections with P. aeruginosa or R. equi to improve macrophage phagocytic and microbicidal activity.

Omega-3 Fatty Acids Enhance Phagocytosis of Alzheimer's Disease-Related Amyloid-β42 by Human Microglia and Decrease Inflammatory Markers

“…However, to our knowledge, the present study is the first to address the effects of ω3 FAs on microglial phagocytosis of A␤ 42 and on their M1/M2 phenotype. Several studies have shown stimulatory effects of ω3 FAs on other types of phagocytic cells of human or animal origin, such as caprine monocytes [69] and murine macrophages [70]. Also, Halvorsen and colleagues demonstrated that EPA increased adhesion of bacteria to human monocytes, indicating a positive effect on phagocytosis [71].…”

Dispersed cells represent a distinct stage in the transition from bacterial biofilm to planktonic lifestyles

“…Infected macrophages were then lysed with ddH 2 O containing 0.5% Triton X-100 (ref. 53). The cell lysates were then serially diluted, and 100 ml of each dilution was plated on triplicate LB agar plates and incubated at 37°C overnight.…”

It is all about fluidity: Fatty acids and macrophage phagocytosis

“…an increase in membrane unsaturated fatty acid content is correlated with an increase in phagocytosis rate (Fig. 2) (Adolph et al, 2012a;Calder et al, 1990;Davidson et al, 1998;Fuhrmann et al, 2007;Lecchi et al, 2011;Schroit and Gallily, 1979;Zheng et al, 1999). Available in vivo-data are less clear.…”

“…Fatty acids have been found to influence every type of immune cell in a variety of ways (Calder, 2008), regard to macrophage function the fatty acids are reported to modulate all of the known defense mechanisms of these cells including phagocytosis, respiratory burst, cytokine production and antigen presentation (Adolph et al, 2012a(Adolph et al, , 2012bSchoeniger et al, 2011). So far, tremendous effort has been put into enlightening the different effects of individual fatty acids and several fatty acid families as well as into elucidating the underlying mechanisms of action.…”

“…So far, tremendous effort has been put into enlightening the different effects of individual fatty acids and several fatty acid families as well as into elucidating the underlying mechanisms of action. It has become apparent that the immunological impact of a fatty acid is determined by its chain length, its number of double bonds and its belonging to a particular fatty acid family (Adolph et al, 2012a(Adolph et al, , 2012bSchoeniger et al, 2011). Moreover, it is known now that fatty acids bias immune response by several independent modes of action.…”