Reinforce the antitumor activity of CD8+ T cells via glutamine restriction.

The antitumor activity of activated CD8+ T cells in the tumor microenvironment seems to be limited due to their being metabolically unfit. This metabolic unfitness is closely associated with T-cell exhaustion and impairment of memory formation, which are barriers to successful antitumor adoptive immunotherapy. We therefore assessed the role of glutamine metabolism in the antitumor activity of CD8+ T cells using a tumor-inoculated mouse model. The adoptive transfer of tumor-specific CD8+ T cells cultured under glutamine-restricted (dGln) conditions or CD8+ T cells treated with specific inhibitors of glutamine metabolism efficiently eliminated tumors and led to better survival of tumor-inoculated mice than with cells cultured under control (Ctrl) conditions. The decreased expression of PD-1 and increased Ki67 positivity among tumor-infiltrating CD8+ T cells cultured under dGln conditions suggested that the inhibition of glutamine metabolism prevents CD8+ T-cell exhaustion in vivo. Furthermore, the transferred CD8+ T cells cultured under dGln conditions expanded more efficiently against secondary OVA stimulation than did CD8+ T cells under Ctrl conditions. We found that the expression of a pro-survival factor and memory T cell-related transcription factors was significantly higher in CD8+ T cells cultured under dGln conditions than in those cultured under Ctrl conditions. Given these findings, our study uncovered an important role of glutamine metabolism in the antitumor activity of CD8+ T cells. The novel adoptive transfer of tumor-specific CD8+ T cells cultured in glutamine-restricted conditions may be a promising approach to improve the efficacy of cell-based adoptive immunotherapy.

Anterior Segment Optical Coherence Tomography of Patients With Late-Onset Tunnel Fungal Infections With Endophthalmitis After Cataract Surgery.

PURPOSE: To report the use of anterior segment optical coherence tomography for characterization of late-onset tunnel fungal infections with endophthalmitis after cataract surgery. METHODS: Case reports. RESULTS: A 77-year-old female (case 1) and a 76-year-old male (case 2) who received cataract surgery 15 and 1 year before their initial visits, respectively, were treated with topical steroids based on a diagnosis of uveitis, because they showed growing white lesions on the upper iris and beneath the cataract scleral wound. Irrigation of the anterior chambers and removal of the white lesions were performed in each case, and microbiological tests were positive for fungi (case 1, a positive culture of Fusarium sp.; case 2, a filamentous fungus present in a direct smear) in the white lesions. Both cases were diagnosed as late-onset fungal endophthalmitis after cataract surgery and were treated with topical and systemic antifungal agents. However, the white lesions reappeared, and the inflammation in the anterior chambers worsened. Anterior segment optical coherence tomography showed the spread of the white lesions into the scleral incisions from cataract surgery. Deroofing of the tunnel and sclerocorneal patch grafts were performed in both cases to treat the fungal tunnel infections. After these treatments, inflammation of both corneas and anterior chambers subsided. CONCLUSIONS: Anterior segment optical coherence tomography can be used to identify late-onset fungal tunnel infections with endophthalmitis after cataract surgery.

Development of an immunochromatographic assay kit using fluorescent silica nanoparticles for rapid diagnosis of Acanthamoeba keratitis.

We developed an immunochromatographic assay kit that uses fluorescent silica nanoparticles bound to anti-Acanthamoeba antibodies (fluorescent immunochromatographic assay [FICGA]) and evaluated its efficacy for the detection of Acanthamoeba and diagnosis of Acanthamoeba keratitis (AK). The sensitivity of the FICGA kit was evaluated using samples of Acanthamoeba trophozoites and cysts diluted to various concentrations. A conventional immunochromatographic assay kit with latex labels (LICGA) was also evaluated to determine its sensitivity in detecting Acanthamoeba trophozoites. To check for cross-reactivity, the FICGA was performed by using samples of other common causative pathogens of infectious keratitis, such as Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. Corneal scrapings from patients with suspected AK were tested with the FICGA kit to detect the presence of Acanthamoeba, and the results were compared with those of real-time PCR. The FICGA kit detected organisms at concentrations as low as 5 trophozoites or 40 cysts per sample. There were no cross-reactivities with other pathogens. The FICGA was approximately 20 times more sensitive than the LICGA for the detection of Acanthamoeba trophozoites. The FICGA kit yielded positive results for all 10 patients, which corresponded well with the real-time PCR results. The FICGA kit demonstrated high sensitivity for the detection of Acanthamoeba and may be useful for the diagnosis of AK.

Prospective clinical evaluation of 1.5% levofloxacin ophthalmic solution in ophthalmic perioperative disinfection.

PURPOSE: Gram-positive cocci and Propionibacterium acnes are widely reported agents of infectious postoperative endophthalmitis. This multicenter study was conducted to evaluate the eradication effectiveness and safety profile of levofloxacin 1.5% ophthalmic solution (LVFX 1.5%) for use in perioperative disinfection. METHODS: Patients who were scheduled for cataract surgery were enrolled. The perioperative regimen of LVFX 1.5% was administered 3 times daily as follows: preoperative 3 days; the day of surgery (in the morning, 1 h before surgery, and immediately after surgery); and postoperative 2 weeks. Conjunctival sac scrapings were collected 3 times in the observation period; before preoperative administration, before iodine eyewash on the day of surgery, and after completion of postoperative administration. Isolated and identified microbial strains were assessed for antibacterial susceptibility. RESULTS: One hundred patients were enrolled and data obtained from 96 patients (mean age, 72.7 ± 8.9 years). The preoperative eradication rate was 86.7% in total microbes. In the case of gram-positive cocci, the preoperative eradication rate was 100%, even though there were LVFX-registrant methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus, which had a high minimum inhibitory concentration against LVFX, such as 32 µg/mL. On the other hand, that of P. acnes was 78.3%. No acquired drug resistance was suspected in all strains. Adverse drug reactions occurred in 4.2% patients, and all were slight. CONCLUSIONS: For ophthalmic perioperative disinfection, the LVFX 1.5% ophthalmic solution showed a good safety profile, and critical eradication of gram-positive cocci, including the fluoroquinolone-resistant strains.