Infection and Immunity article about cigarette smoke

Cigarette Smoke Exposure Impairs Pulmonary Bacterial Clearance and Alveolar Macrophage Complement-Mediated Phagocytosis of Streptococcus pneumoniae

Cigarette smoke exposure increases the risk of pulmonary and invasive infections caused by Streptococcus pneumoniae, the most commonly isolated organism from patients with community-acquired pneumonia. Despite this association, the mechanisms by which cigarette smoke exposure diminishes host defense against S. pneumoniae infections are poorly understood. In this study, we compared the responses of BALB/c mice following an intratracheal challenge with S. pneumoniae after 5 weeks of exposure to room air or cigarette smoke in a whole-body exposure chamber in vivo and the effects of cigarette smoke on alveolar macrophage phagocytosis of S. pneumoniae in vitro. Bacterial burdens in cigarette smoke-exposed mice were increased at 24 and 48 h postinfection, and this was accompanied by a more pronounced clinical appearance of illness, hypothermia, and increased lung homogenate cytokines interleukin-1β (IL-1β), IL-6, IL-10, and tumor necrosis factor alpha (TNF-α). We also found greater numbers of neutrophils in bronchoalveolar lavage fluid recovered from cigarette smoke-exposed mice following a challenge with heat-killed S. pneumoniae. Interestingly, overnight culture of alveolar macrophages with 1% cigarette smoke extract, a level that did not affect alveolar macrophage viability, reduced complement-mediated phagocytosis of S. pneumoniae, while the ingestion of unopsonized bacteria or IgG-coated microspheres was not affected. This murine model provides robust additional support to the hypothesis that cigarette smoke exposure increases the risk of pneumococcal pneumonia and defines a novel cellular mechanism to help explain this immunosuppressive effect.

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  1. charlypriest said,

    September 3, 2014 at 10:26 am

    With all that I smoke….I´ll give myself a couple or four years more. I just can´t quit, as of right now I have run out of smokes, it has been one hour and a half and the person who went out of the house to buy the smokes hasn´t returned and I´m about to punch my dog, eat a cat, and paint a Picasso. I´m going nuts without smokes, plus my anger level tends to rise. So with my severe pancreatitis that already puts a little shorter my life expectancy now maybe I´ll die from pneumonia now, although I don´t know which is worst. I think is the pancreatitis one that really hurts don´t know about pneumonia.

    You scared the bejuses out of me! Good job, I probably need it.

    • LScott said,

      September 4, 2014 at 2:41 am

      dang man.. sucks to hear, i know it is a difficult struggle to fight against. idk.. working a little at a time to try to cut down would certainly be a good idea. some people i know begin by smoking half of what they usually do. that way they get their fix (to an extent) while resisting. hope you decide to cut back for your own sake, i don’t want you to far as the pancreatitis is concerned, are you doing anything to treat it?

      • charlypriest said,

        September 4, 2014 at 7:31 am

        pancreatitis the only way to treat it is to eat healthy in small amounts through out the day not to stuff yourself in one or two meals a day, no soft drinks too often, and certainly no alcohol, and I think I failed on the three of them.

      • LScott said,

        September 4, 2014 at 8:50 am

        well..for the sake of your well-being, i encourage you to eat healthy 🙂

      • charlypriest said,

        September 4, 2014 at 4:15 pm

        We try, but you know what they say that healthy is boring….most of the times but is my body and it´s like this so I better start taking better care of it.

        Hey, I´m still intrigued with that thing you said about doing it properly, you´re going to make me google it.

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