A dominant Jurkat T cell mutation that inhibits LFA-1-mediated cell adhesion is associated with increased cell growth.

LFA-1 exists in a low avidity state on resting leukocytes and is believed to adopt a high avidity state when the cells are exposed to a stimulus. Current evidence supports both aggregation of LFA-1 on the cell surface and conformational changes in the reversible acquisition of a high avidity state. We studied this regulation by selecting a Jurkat T cell clone, J-lo1.3, that expresses LFA-1 yet fails to bind to purified ICAM-1 despite treatment of the cells with PMA or Mn2+. Several lines of evidence demonstrated the absence of any changes within LFA-1 itself. LFA-1 protein purified from the J-lo1.3 clone and the wild-type Jurkat clone, Jn.9, were found to be functionally equivalent. The cDNA sequences encoding the LFA-1 alpha- and beta-chains from J-lo1.3 were identical with the published sequences except for nine base pairs. However, these differences were also found in a Jurkat mutant with a constitutively avid phenotype, J+hi1.19 or the wild-type Jn.9 genomic or cDNA. Fusion of J-lo1.3 with Jn.9 yielded hybrids that exhibited the J-lo1.3 adhesion phenotype, which indicated a dominant mutation in J-lo1.3. This phenotype was relatively specific for LFA-1 among all integrins expressed by Jurkat. Interestingly, the J-lo1.3 cells had a 1.2-fold faster doubling time than did the Jn.9 cells. Reversion of J-lo1.3 to the wild-type adhesion phenotype by mutagenesis and selection also decreased the growth rate. These data support a connection between cellular growth and cellular adhesion in lymphocytes.

Safety and efficacy of 0.5% podofilox gel in the treatment of anogenital warts.

OBJECTIVE: To determine the safety and efficacy of a new gel formulation of podofilox in the treatment of anogenital warts. DESIGN: Double-blind, randomized, multicenter, vehicle-controlled investigation. SETTING: Private dermatology practices, university clinics (dermatology, gynecology, and infectious diseases), and contract research organizations. PATIENTS: Three hundred twenty-six patients with anogenital warts. MAIN OUTCOME MEASURE: Number of patients with clearing of all treated warts (treatment success). RESULTS: The 0.5% podofilox gel was significantly better than vehicle gel for successfully eliminating and reducing the number and size of anogenital warts. In the intent-to-treat population, 62 (37.1%) of 167 patients treated with 0.5% podofilox gel had complete clearing of the treated areas (treatment successes) compared with 2 (2.3%) of 86 patients who had clearing of warts with the vehicle gel (P < .001) after 4 weeks. Nineteen additional patients treated with 0.5% podofilox gel and 2 patients treated with vehicle gel had clearing of warts with continued treatment up to 8 weeks. After 8 weeks, 35.9% of the baseline anogenital warts treated with 0.5% podofilox gel remained; this was significantly fewer than in the vehicle-treated group (88.4% of the baseline number) (P = .001). The 0.5% podofilox gel was generally well tolerated, with predominantly mild or moderate local adverse reactions occurring in the majority of patients. Only 7 patients (3.2%), all receiving 0.5% podofilox gel, discontinued study treatment because of drug-related local reactions. CONCLUSIONS: The results demonstrated that 0.5% podofilox gel is safe and significantly more effective than vehicle gel in the treatment of anogenital warts.