Natural killer (NK) and NK-like cells at mucosal epithelia: Mediators of anti-microbial defense and maintenance of tissue integrity

Natural killer (NK) cells are innate lymphocytes that play important roles in the defense against microbial pathogens through secretion of IFN-γ and recognition and lysis of virally or bacterially infected host cells. A recently identified population of NK-like cells that shares characteristics of both NK cells and lymphoid tissue inducer (LTi) cells promotes innate immune responses in epithelial tissue through the secretion of IL-22. In contrast to classical NK cells, NK-like cells are localized preferentially at mucosal sites, such as the intestinal mucosa. In this review, we consider the function of NK and NK-like cells in anti-microbial defense as well as the maintenance of tissue integrity in the mucosal epithelium of the intestine, lung, and female reproductive tract. Current experimental evidence supports an important protective role for IL-22-producing NK-like cells during intestinal infections, whereas classical NK cells are crucial in the early defense against many pathogens in the respiratory tract. NK cells isolated from the pregnant uterus differ significantly in phenotype and function from those at other tissue locations. Uterine NK cells clearly contribute to the tissue remodeling that takes place during placentation, but their role in anti-microbial defense remains largely undefined.

Primary lung adenocarcinoma: characteristics by smoking habit and sex

The incidence of adenocarcinoma is increasing, particularly among females. We sought to assess the role of tobacco consumption in clinical presentation according to sex. In this retrospective study, 848 patients diagnosed between 1997 and 2006 at Grenoble University Hospital (Grenoble, France) were stratified into four groups according to smoking habits. Differences between sexes and two contrasting female profiles emerged. Female current smokers were younger than female never-smokers (median 51 versus 69 yrs; p < 0.001), more often had surgery (62.7% versus 39%; p = 0.01) and had a median (95% CI) estimated survival of 26.2 (18.1-49.2) versus 15.1 (12.8-22.2) months (p = 0.002). Both groups had similar survival when taking treatment into account. Among males, smoking did not influence presentation. Male current smokers were older than female current smokers (median 59 yrs; p < 0.001) and fewer had surgery (48.8%; p = 0.015), although the percentage of stage IIIb-IV disease was similar (53% and 46%; nonsignificant) and they had a poorer estimated survival of 14.3 (13.0-18.5) months (p = 0.0024). Males smoked more than females (median 41 versus 30 pack-yrs; p < 0.001). Quitting smoking delayed age at diagnosis by 11 yrs for females (p = 0.0035) and 8 yrs for males (p < 0.001). Our results support the hypothesis that carcinogenesis differs between males and females, and between female smokers and never-smokers.

Biomolecular, biochemical, and radiologic evaluation of patients on anti-VEGF treatment for mCRC

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Background: K-ras mutation is a negative predictor of clinical benefit (CB) from anti-EGFR treatment in mCRC. Bevacizumab combined with chemotherapy prolongs both PFS and OS in first-line treatment of mCRC. Previously data suggested that this results are independent of K-ras status. We conducted a study to investigate the CB of Bevacizumab in treatment of mCRC according to K-ras status and to evaluate timing of response to treatment trough the correlation between tumor markers values and clinical responses. Finally we evaluated CB in patients affected by mCRC with only hepatic metastases vs patients with multiple metastasis sites.

Methods: 82 patients were enrolled and underwent first-line chemotherapy with Folfiri or FolFoX and bevacizumab. Tissue samples were analyzed for DNA sequencing in order to identify K-ras mutations in codons 12 and 13. Before therapy all patients were investigated with CT scan and with a blood sample to define tumor markers values; a new evaluation of tumor markers after 2 months of chemotherapy was performed and a CT scan after 3 months.

Results: An overall objective response rate (RR) of 40% and a CB of 79% were obtained, with a correlation between tumor markers values and clinical response of 89%. 49% of population presented only hepatic metastases while other 51% showed multiple metastatic sites. RR in exclusive hepatic metastatic group was 45% vs 33% multiple metastatic sites group, CB was 90% vs 66% respectively. No grade 3 or 4 bevacizumab associated toxicity was showed in patients. K-ras mutations were investigated in 75 of 82 patients. 49 patients were wild-type (wt 65%) while 26 patients were mutated (mut 35%). RR in wt group was 45% vs 35% in mut group, while CB was 82% vs 81% respectively. Correlation between tumor markers values and clinical response was 90% in wt group vs 93% in mut group.

Conclusions: RR in two K-ras groups was different with an advantage in K-ras wt group, but this difference does not observe in CB. Bevacizumab provides significant RR and CB after a short time of treatment and tumor markers values could be an optimal correlative parameters of early clinical response. Bevacizumab provides significant CB in patients with only hepatic metastases vs patients with multiple metastatic sites.

No significant financial relationships to disclose.