Strategy to detect pre-existing immunity to AAV gene therapy.

Gene therapy may offer a new treatment option, particularly for patients with severe hemophilia, based on recent research. However, individuals with pre-existing immunity to adeno-associated viruses (AAVs) may be less likely to benefit from AAV vector-based therapies. To study pre-existing AAV5 immunity in humans, we validated two complementary, sensitive, and scalable in vitro assays to detect AAV5 total antibodies and transduction inhibition (TI). Using these two assays, we found that 53% of samples from 100 healthy male individuals were negative in both assays, 18% were positive in both assays, 5% were positive for total antibodies but negative for TI and, of interest, 24% were negative for total antibodies but positive for TI activity, suggesting the presence of non-antibody-based neutralizing factors in human plasma. Similar findings were obtained with 24 samples from individuals with hemophilia A. On the basis of these results, we describe the development of a dual-assay strategy to identify individuals without total AAV5 antibodies or neutralizing factors who may be more likely to respond to AAV5-directed gene therapy. These assays offer a universal, transferrable platform across laboratories to assess the global prevalence of AAV5 antibodies and neutralizing factors in large patient populations to help inform clinical development strategies.

Effects of Azadirachta indica on certain hematological parameters during benzo(a)pyrene induced murine forestomach tumorigenesis.

OBJECTIVES: Exposure to environmental toxicants/carcinogens, the process of carcinogenesis itself and cancer treatments lead to several secondary pathologies including hematological complications. Considering versatile pharmacological potentials of Azadirachta indica (A. indica), the present study was designed to evaluate its effects on certain hematological parameters in benzo(a)pyrene [B(a)P] induced murine forestomach tumorigenesis bioassay protocol. METHODS AND RESULTS: For tumor induction, starting from 3rd week of experimentation, female Balb/c mice received B(a)P intragastric instillations (40 mg/kg bwt) twice a week for 4 weeks. Aqueous A. indica leaf extract (AAILE) was orally administered (100 mg/kg bwt) using blunt-tipped canula on alternate days throughout experimentation. The study was continued for 24 weeks and certain hematological parameters were examined at 4 week intervals. In mice receiving only B(a)P, hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs), lymphocytes and monocytes decreased whereas neutrophils increased when compared to controls. However, A. indica reversed these alterations as seen in mice that received AAILE along with B(a)P when compared to only B(a)P receiving mice. In only AAILE receiving mice, increased Hb, RBCs, WBCs, lymphocytes and monocytes with decreased neutrophils were observed in comparison to control. Also, changes in eosinophils and basophils upon B(a)P exposure and their modulation by AAILE was observed. CONCLUSIONS: These findings strongly suggested the favorable effects of A. indica on hematological parameters studied and their significance with respect to overall well being, process of tumorigenesis and its chemoprevention have been discussed in the current research manuscript.