Fire simulator exposure alters the innate epithelial response and inflammatory status in the airways of firefighters.

BACKGROUND: Firefighters are often exposed to high temperatures and by-products of combustion, which can compromise their health. We aimed to evaluate the effect of fire exposure in fire simulators on the airways of firefighters at different time-points. METHODOLOGY: Thirty-seven male firefighters exposed to fire simulators were evaluated in three phases: pre-exposure, at the end of the first week, and 4 weeks after. Pulmonary function by spirometry, nasal mucociliary clearance; peripheral oxygen saturation, inflammatory markers in the nasal lavage and CC16 in the sputum, nasal obstruction, and quality of life (using the questionnaires NOSE and SNOT-22) were assessed. RESULTS: Higher levels of IL-8, IL-10, and exhaled carbon monoxide were found more in phase 2 than in phase 1. Higher CC16 levels and lower peripheral oxygen saturation were observed in phase 3 as compared to phase 1. Lower levels of IL-2 and peripheral oxygen saturation were found in phase 3 than in phase 2. Higher nasal mucociliary clearance, as well as the worst quality of life and nasal obstruction, were observed in phases 2 and 3 as compared to phase 1. CONCLUSIONS: The firefighters’ exposures to high temperatures and by-products of combustion in the fire simulators elicit an inflammatory process in the airways with impairment in the innate epithelial response of the upper airway lining. Furthermore, changes in O2 transport affected the professionals’ quality of life negatively.

B-1 cells and concomitant immunity in Ehrlich tumour progression.

Concomitant immunity is a phenomenon in which a tumour-bearing host is resistant to the growth of an implanted secondary tumour. Metastases are considered to be secondary tumours that develop spontaneously during primary tumour growth, suggesting the involvement of concomitant immunity in controlling the rise of metastases. It has been demonstrated that B-1 cells, a subset of B-lymphocytes found predominantly in pleural and peritoneal cavities, not only increase the metastatic development of murine melanoma B16F10, but also are capable of differentiating into mononuclear phagocytes, modulating inflammatory responses in wound healing, in oral tolerance and in Paracoccidiose brasiliensis infections. Here, we studied B-1 cells' participation in concomitant immunity during Ehrlich tumour progression. Our results show that B-1 cells obtained from BALB/c mice previously injected with Ehrlich tumour in the footpad were able to protect BALB/c and BALB/Xid mice against Ehrlich tumour challenge. In addition, it was demonstrated that BALB/Xid show faster tumour growth and have lost concomitant immunity, and that this state can be partially restored by reconstituting these animals with B-1 cells. However, further researches are required to establish the mechanism involving B-1 cells in Ehrlich tumour growth.

Immune responses induced by Pelargonium sidoides extract in serum and nasal mucosa of athletes after exhaustive exercise: modulation of secretory IgA, IL-6 and IL-15.

The evidence that exhaustive exercise may compromise the immune response is mainly confirmed by upper respiratory tract infections which are probably related to the decrease in secretory immunoglobulin A in the upper airway mucosa and/or profile changes of systemic cytokines as well as local cytokines of the upper respiratory tract. An extract from Pelargonium sidoides roots is currently used to treat infections in the upper airways. The aim of the present study was to evaluate the action of this herbal medicine on the immune response of athletes submitted to an intense running session by analyzing the production of immunoglobulin A in their saliva and of cytokines both locally and systemically, using a placebo as control. The results show that Pelargonium sidoides extract modulates the production of secretory immunoglobulin A in saliva, both interleukin-15 and interleukin-6 in serum, and interleukin-15 in the nasal mucosa. Secretory immunoglobulin A levels were increased, while levels of IL-15 and IL-6 were decreased. Based on this evidence, we suggest that this herbal medicine can exert a strong modulating influence on the immune response associated with the upper airway mucosa in athletes submitted to intense physical activity.

B-1 cells modulate the kinetics of wound-healing process in mice.

Wound healing is a complex phenomenon whose mechanisms are not fully understood. Although inflammatory cells are recruited to the site of the lesion there are no reports concerning the participation of B lymphocytes in tissue repair. As demonstrated in our laboratory, B-1 cells migrate to a non-specific inflammatory focus and differentiate into a phagocyte. It has been reported that BALB/Xid mice are deficient in B-1 cells. Using this model, here we report that BALB/Xid mice have an increased inflammatory response, a delayed wound-healing process, a prominent neutrophilic infiltration of the lesion, and an increased neovascularization of the lesion as compared with BALB/c and BALB/Xid reconstituted with B-1 cells. The infiltration of B-1 cells into the wound was demonstrated. As B-1 cells secret and use interleukin 10 (IL-10) as an autocrine growth factor, the possible participation of this interleukin in the kinetics of wound healing was investigated. Results show that C57/BL6 IL-10 KO mice had an increased inflammatory response when compared with C57/BL6 and C57/BL6 IL-10 KO mice reconstituted with B-1 cells, thus suggesting that the observed effects of B-1 cells in the healing process is mediated by this interleukin. However, the mechanisms by which IL-10 influence these phenomena remain to be uncovered.