ABSTRACT
Cancer stem cells (CSCs) with their self-renewal ability are accepted as cells which initiate tumors. CSCs are regarded as interesting targets for novel anticancer therapeutic agents because of their association with tumor recurrence and resistance to conventional therapies, including radiotherapy and chemotherapy. Chimeric antigen receptor (CAR)-T cells are engineered T cells which express an artificial receptor specific for tumor associated antigens (TAAs) by which they accurately target and kill cancer cells. In recent years, CAR-T cell therapy has shown more efficiency in cancer treatment, particularly regarding blood cancers. The expression of specific markers such as TAAs on CSCs in varied cancer types makes them as potent tools for CAR-T cell therapy. Here we review the CSC markers that have been previously targeted with CAR-T cells, as well as the CSC markers that may be used as possible targets for CAR-T cell therapy in the future. Furthermore, we will detail the most important obstacles against CAR-T cell therapy and suggest solutions.
ABSTRACT
Streptococcus pneumoniae is an important problem worldwide and nasopharyngeal colonization plays significant role in pneumococcal infections. The aims of this study were to determine the nasopharyngeal colonization rate, serotyping, antibiotics susceptibility and study the risk factors for nasopharyngeal colonization with S. pneumoniae in students in Kashan, Iran. A cross-sectional study was conducted on children aged 7 to 19 years from December 2011 to November 2012. Nasopharyngeal swabs were plated onto brain heart infusion agar plates with 5% sheep blood and 4 micro g/ml of gentamycin. Antimicrobial susceptibility profiles were determined on Mueller-Hinton agar in accordance with CLSI. S. pneumoniae strains were investigated for the presence of the most common pneumococcal serotypes using a multiplex polymerase chain reaction. 13.9% were found to be carriers. The most prevalent serogroups were 19F [30%], 6A/B [18.9%], 15A [16.5%], 11 [11.3%], 23F [8.2%], 1 [6.2%], 19A [3.4%], and 35B [2.4%]. Nine strains [3.1%] were non-typeable. The carrier rate was significantly higher in 12 to15 year old age group. Upper respiratory tract infections within the last month [OR=1.5, P<0.011], previous hospitalization [OR=1.6, P<0.001], previous antibiotic usage last two weeks [OR=1.89, P<0.001], rhinorea [OR=1.9P<0.001], male sex [OR=3.5 P< 0.001] and passive smoking [OR=1.56, P< 0.001] have been determined to be risk factors for S. pneumoniae carriage. The highest pneumococcal resistance was to tetracycline [25.4%]. All strains were susceptible to linezolid and levofloxacin. Our information leads to an important source to screen the future impact of pneumococcal vaccination on bacterial colonization