In vivoshort-term exposure to residual oil fly ash impairs pulmonary innate immune response against environmental mycobacterium infection

Abstract

Epidemiological studies have shown that pollution derived from industrial and vehicular transportation induces adverse health effects causing broad ambient respiratory diseases. Therefore, air pollution should be taken into account when microbial diseases are evaluated. Environmental mycobacteria (EM) are opportunist pathogens that can affect a variety of immune compromised patients, which impacts significantly on human morbidity and mortality. The aim of this study was to evaluate the effect of residual oil fly ash (ROFA) pre-exposure on the pulmonary response after challenge with opportunistic mycobacteria by means of an acute short-term in vivo experimental animal model. We exposed BALB/c mice to ROFA and observed a significant reduction on bacterial clearance at 24 h post infection. To study the basis of this impaired response four groups of animals were instilled with (a) saline solution (Control), (b) ROFA (1 mg kg(-1) BW), (c) ROFA and EM-infected (Mycobacterium phlei, 8 × 10(6) CFU), and (d) EM-infected. Animals were sacrificed 24 h postinfection and biomarkers of lung injury and proinflammatory madiators were examined in the bronchoalveolar lavage. Our results indicate that ROFA was able to produce an acute pulmonary injury characterized by an increase in bronchoalveolar polymorphonuclear (PMN) cells influx and a rise in O2 (-) generation. Exposure to ROFA before M. phlei infection reduced total cell number and caused a significant decline in PMN cells recruitment (p < 0.05), O2 (-) generation, TNFα (p < 0.001), and IL-6 (p < 0.001) levels. Hence, our results suggest that, in this animal model, the acute short-term pre-exposure to ROFA reduces early lung response to EM infection.

Environmental Factors Related to Pulmonary Tuberculosis in HIV-Infected Patients in the Combined Antiretroviral Therapy (cART) Era

“…On the other hand, it also reduces early lung immune responses to mycobacteria infection (i.e. it reduces the total immune cell number and causes a significant decline in the recruitment of polymorphonuclear leukocytes as measured in bronchoalveolar lavage fluid, O2 (-) generation, and secretion of TNFα, and IL-6) in an animal model [58]. …”

Towards effective COVID‑19 vaccines: Updates, perspectives and challenges (Review)

“…Strategic treatments eliminate tangible factors that contribute to weaken the immune system. Some examples of such factors, based on existing studies, include titanium dioxide, air pollution, chlorpyrifos, aluminum sulfate, prenatal alcohol exposure, ZnO, oil fly ash, and many others (3)(4)(5)(6)(7)(8)(9). Also the real life exposure scenario in which we are exposed continuously to combination of stressors influences in the long term the immune system and the response of the organism to the viral stressors (10)(11)(12)(13)(14).…”

Subacute exposure to residual oil fly ash (ROFA) increases eHSP70 content and extracellular-to-intracellular HSP70 ratio: a relation with oxidative stress markers

“…ROFA is rich in metals and significantly contributes to urban PM 2.5 (Ghio et al 2002;Heck et al 2015). ROFA exposure promotes oxidative stress (OS) in experimental models (Zanchi et al 2008) and triggers a cell stress response, thereby contributing to changes in immune response (Delfosse et al 2012(Delfosse et al , 2015.…”