The role of Igs in natural protection against infection by Mycobacterium tuberculosis (Mtb), the causative agent of TB, is controversial. Although passive immunization with mAbs generated against mycobacterial antigens has shown protective efficacy in murine models of infection, studies in B cell-depleted animals only showed modest phenotypes. We do not know if humans make protective antibody responses. Here, we investigated whether healthcare workers in a Beijing TB hospital-who, although exposed to suprainfectious doses of pathogenic Mtb, remain healthy-make antibody responses that are effective in protecting against infection by Mtb. We tested antibodies isolated from 48 healthcare workers and compared these with 12 patients with active TB. We found that antibodies from 7 of 48 healthcare workers but none from active TB patients showed moderate protection against Mtb in an aerosol mouse challenge model. Intriguingly, three of seven healthcare workers who made protective antibody responses had no evidence of prior TB infection by IFN-γ release assay. There was also good correlation between protection observed in vivo and neutralization of Mtb in an in vitro human whole-blood assay. Antibodies mediating protection were directed against the surface of Mtb and depended on both immune complexes and CD4+ T cells for efficacy. Our results indicate that certain individuals make protective antibodies against Mtb and challenge paradigms about the nature of an effective immune response to TB.TB | antibodies | immune complex | humoral immunity | TB restrictors

Background:Autophagy is a programmed cell survival mechanism that has a key role in both physiologic and pathologic conditions. The relationship between autophagy and cancer is complex because autophagy can act as either a tumour suppressor or as a tumour promoter. The role of autophagy in oral squamous cell carcinoma (OSCC) is controversial. Several studies have claimed that either a high or low expression of autophagy-related proteins was associated with poor prognosis of OSCCs. The aims of the study were to compare autophagy in OSCCs, verrucous hyperplasias, and normal oral mucosas, and to inspect the prognostic role of autophagy in OSCCs.Methods:We used the autophagosome marker, LC3B, and autophagy flux marker, p62/SQSTM1 (p62), by using immunohistochemistry, and examined p62 mRNA by RNA in situ hybridization, to evaluate autophagy in 195 OSCCs, 47 verrucous hyperplasias, and 37 normal oral mucosas. The prognostic roles of LC3B and p62 protein expressions in OSCCs were investigated.Results:We discovered that the normal oral mucosa exhibited limited LC3B punctae and weak cytoplasmic p62 staining, whereas the OSCCs exhibited a marked increase in LC3B punctae and cytoplasmic p62 expression. The expression pattern of LC3B and cytoplasmic p62 of the verrucous hyperplasias were between normal oral mucosas and OSCCs. The normal oral mucosas, verrucous hyperplasias, and OSCCs presented no differences in nuclear p62 expression and the p62 mRNA level. p62 mRNA expression was elevated in a minority of cases. High p62 mRNA expression was associated with high p62 protein expression in the cytoplasm. Increased LC3B punctae, high cytoplasmic p62, and low nuclear p62 expressions in OSCCs were associated with aggressive clinicopathologic features and unfavourable prognosis. In addition, low nuclear p62 expression was an independent prognostic factor for overall and disease-specific survival rates. Furthermore, we disclosed that high cytoplasmic p62 expression accompanied with either a low or high LC3B expression, which indicated autophagy impairment under basal or activated autophagic activity, was associated with aggressive behaviour in advanced OSCCs.Conclusions:We suggested that autophagy was altered during cancer initiation and progression. Autophagy impairment contributed to cancer progression in advanced OSCCs.

Using rpoB and hsp65, M. abscessus subsp. bolletii could be distinguished from M. abscessus subsp. abscessus. Amikacin and azithromycin showed excellent activity against M. abscessus in vitro. Imipenem, linezolid, cefoxitin, and moxifloxacin also showed good activity. Levofloxacin was inactive against M. abscessus. Although clarithromycin showed excellent activity against M. abscessus on day 3, inducible resistance occurred, and after 14 days clarithromycin showed little activity against M. abscessus subsp. abscessus, but still had good activity against M. abscessus subsp. bolletii.