Comparison of different delivery systems of DNA vaccination for the induction of protection against tuberculosis in mice and guinea pigs

The great challenges for researchers working in the field of vaccinology are optimizing DNA vaccines for use in humans or large animals and creating effective single-dose vaccines using appropriated controlled delivery systems. Plasmid DNA encoding the heat-shock protein 65 (hsp65) (DNAhsp65) has been shown to induce protective and therapeutic immune responses in a murine model of tuberculosis (TB). Despite the success of naked DNAhsp65-based vaccine to protect mice against TB, it requires multiple doses of high amounts of DNA for effective immunization. In order to optimize this DNA vaccine and simplify the vaccination schedule, we coencapsulated DNAhsp65 and the adjuvant trehalose dimycolate (TDM) into biodegradable poly (DL-lactide-co-glycolide) (PLGA) microspheres for a single dose administration. Moreover, a single-shot prime-boost vaccine formulation based on a mixture of two different PLGA microspheres, presenting faster and slower release of, respectively, DNAhsp65 and the recombinant hsp65 protein was also developed. These formulations were tested in mice as well as in guinea pigs by comparison with the efficacy and toxicity induced by the naked DNA preparation or BCG. The single-shot prime-boost formulation clearly presented good efficacy and diminished lung pathology in both mice and guinea pigs.     

Intestinal enterobacteria of the hibernating Apis mellifera mellifera L. bees

Dynamics of enterobacteria of normal intestinal microflora was studied in Apis mellifera mellifera L. bees hibernating under snow in the Western Urals. The cell numbers (N) of the predominant species Klebsiella oxytoca increased from 10-10(6) CFU/bee in November 2004 to 10(4)-10(7) CFU/bee in March 2005; its frequency of occurrence (P) increased from 92 to 100%. Increase of Providencia rettgeri (11.2004: N up to 10(6), P 25%; 03.2005: N 10(2)-10(6), P 80%) was accompanied by the substitution of Morganella morganii (11.2004: N up to 10(6), P 25%) with Proteus vulgaris (03.2005: N up to 10(5), P 8%). By spring, Hafnia alvei and Citrobacter sp., which are pathogenic to bees, disappeared (11.2004: N up to 10(5), P 13 and 10%, respectively). Endophytic species Pantoea agglomerans, Leclecria sp., and other representatives of the "Enterobacter agglomerans" group were present in November and after the first emergence in spring (N up to 10(5); November: P 15%; April: P 23%). In April, the number of enterobacteria decreased to 10(5), and P. rettgeri became the predominant species (P 54%) instead of K. oxytoca (P 43%).     

The immunodiagnosis of tick-borne encephalitis by using the indirect immune rosette formation reaction

200 patients suspected for tick-borne encephalitis (TBE) were examined by the method of the indirect immune rosette-formation test. In 70.15% of patients with the serologically confirmed diagnosis of TBE immune lymphocytes were detected as early as on day 1 of examination. The level of rosette formation was higher in the meningeal form of the disease. Rosette-forming lymphocytes were also detected in 24.06% of patients with the serologically unconfirmed diagnosis of TBE. The test is proposed for the early diagnosis of TBE.