interleukin-8 and Actinomycetales-Infections

Rhodococcus equi is an intracellular pathogen of macrophages that causes rhodococcal pneumonia in foals and immunocompromised people. Evidence exists that neutrophils play a vital role in resistance to infection with R. equi; however, the means by which neutrophils exert their effects have not been clearly defined. In addition to directly killing bacteria, neutrophils also may exert a protective effect by linking innate and adaptive immune responses. In the present study we evaluated the cytokine expression profiles of adult equine neutrophils in response to stimulation with isogenic strains of virulent and avirulent R. equi in vitro. After 2 and 4h incubation with virulent or avirulent R. equi, adult equine neutrophils expressed significantly (P<0.05) greater tumor necrosis factor alpha (TNFalpha), interleukin (IL)-12p40, IL-6, IL-8 and IL-23p19 mRNA, but not interferon gamma (IFNgamma) or IL-12p35 mRNA than unstimulated neutrophils. Furthermore, virulent R. equi induced significantly greater IL-23p19 mRNA than avirulent R. equi. These results demonstrate that R. equi-stimulated neutrophils are a source of many proinflammatory cytokines. Furthermore, these results suggest that IL-23 may be preferentially expressed over IL-12 in response to exposure with R. equi, and that this response may be more strongly induced by virulent R. equi than avirulent R. equi. Collectively, the data presented herein suggest a non-phagocytic role for neutrophils that may influence the type of adaptive immune response to R. equi.

Topics: Actinomycetales Infections; Animals; Base Sequence; Cytokines; DNA Primers; Gene Expression; Gene Expression Profiling; Horse Diseases; Horses; In Vitro Techniques; Interleukin-12 Subunit p40; Interleukin-23 Subunit p19; Interleukin-6; Interleukin-8; Neutrophils; Rhodococcus equi; RNA, Messenger; Tumor Necrosis Factor-alpha; Virulence

This study was undertaken to assess if levels of interleukin-1beta (IL-1beta), IL-8, sialidase, prolidase and immunoglobulin A against Gardenerella vaginalis hemolysin (anti-Gvh IgA) in vaginal secretions differ between BV+ women with (M+) and without (M-) Mobiluncus spp.. Vaginal secretions were obtained from 265 women at their first prenatal care visit and assessed for all study parameters. Gram stain evaluation using Nugent criteria was performed and coinfection with sexually transmitted infections determined. Differences between BV+/M+ and BV+/M- women were evaluated using the chi2 statistic or Mann-Whitney test.. Of the 265 BV+ women, 43% (n = 113) were M+ of which 97% (n = 110) had Nugent scores of 9 or 10 . BV+/M+ women had elevated levels of sialidase (median value: 4.11 nmol vs 1.91 nmol of converted substrate; P = .003) but no difference in prolidase, anti-Gvh IgA, IL-1beta, IL-8, levels were found between the two groups. BV+/M- women had significantly higher rates of coinfection with Trichomonas vaginalis.. BV+/M+ women have higher vaginal concentrations of sialidase and lower rates of T. vaginalis compared with BV+/M- women. Further research is needed to assess the association of this, and other, microbiologic profiles to risk of adverse pregnancy outcome.

Topics: Actinomycetales Infections; Adult; Dipeptidases; Female; Gardnerella vaginalis; Humans; Immunoglobulin A; Interleukin-1; Interleukin-8; Mobiluncus; Neuraminidase; Pregnancy; Pregnancy Complications, Infectious; Trichomonas Vaginitis; Vagina; Vaginal Smears; Vaginosis, Bacterial