Single dose of a vaccine based on DNA encoding mycobacterial hsp65 protein plus TDM-loaded PLGA microspheres protects mice against a virulent strain of Mycobacterium tuberculosis.
The high incidence of tuberculosis around the world and the inability of BCG to protect certain populations clearly indicate that an improved vaccine against tuberculosis is needed. A single antigen, the mycobacterial heat shock protein hsp65, is sufficient to protect BALB/c mice against challenge infection when administered as DNA vaccine in a three-dose-based schedule. In order to simplify the vaccination schedule, we coencapsulated hsp65-DNA and trehalose dimicolate (TDM) into biodegradable poly(DL-lactide-co-glycolide) (PLGA) microspheres. BALB/c mice immunized with a single dose of DNA-hsp65/TDM-loaded microspheres produced high levels of IgG2a subtype antibody and high amounts of IFN-gamma in the supernatant of spleen cell cultures. DNA-hsp65/TDM-loaded microspheres were also able to induce high IFN-gamma production in bulk lung cells from challenged mice and confer protection as effective as that attained after three doses of naked DNA administration. This new formulation also allowed a ten-fold reduction in the DNA dose when compared to naked DNA. Thus, this combination of DNA vaccine and adjuvants with immunomodulatory and carrier properties holds the potential for an improved vaccine against tuberculosis.
Lima
K M
KM
Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
Santos
S A
SA
Lima
V M F
VM
Coelho-Castelo
A A M
AA
Rodrigues
J M
JM
Silva
C L
CL
D000276:Adjuvants, Immunologic / Q000235:genetics*; D000818:Animals; D001426:Bacterial Proteins; D018834:Chaperonin 60; D018833:Chaperonins / Q000235:genetics*; D003311:Cord Factors / Q000235:genetics*; D015316:Genetic Therapy / Q000379:methods*; D019344:Lactic Acid; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014376:Tuberculosis / Q000276:immunology*; D032581:Tuberculosis Vaccines / Q000008:administration & dosage* / Q000235:genetics
D000276:Adjuvants, Immunologic; D001426:Bacterial Proteins; D018834:Chaperonin 60; D003311:Cord Factors; D011108:Polymers; D032581:Tuberculosis Vaccines; C074119:heat-shock protein 65, Mycobacterium; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D018833:Chaperonins