Poly(lactic acid-glycolic acid) nanoparticles markedly improve immunological protection provided by peptide P10 against murine paracoccidioidomycosis.
OBJECTIVE
The present study reports on the preparation and testing of a sustained delivery system for the immunomodulatory peptide P10 aimed at reducing the in vivo degradation of the peptide and the amount required to elicit a protective immune response against paracoccidioidomycosis.


METHODS
BALB/c mice were infected with the yeast Paracoccidioides brasiliensis to mimic the chronic form of paracoccidioidomycosis. The animals were treated daily with sulfamethoxazole/trimethoprim alone or combined with peptide P10, either emulsified in Freund's adjuvant or entrapped in poly(lactic acid-glycolic acid) (PLGA) nanoparticles at different concentrations (1 microg, 5 microg, 10 microg, 20 microg or 40 microg.50 microL(-1)). Therapeutic efficacy was assessed as fungal burden in tissues and the immune response by quantitative determination of cytokines.


RESULTS
Animals given combined chemotherapy and P10 nanotherapy presented a marked reduction of fungal load in the lungs, compared with the non-treated animals. After 30 days of treatment, P10 entrapped within PLGA (1 microg.50 microL(-1)) was more effective than 'free' P10 emulsified in Freund's adjuvant (20 microg.50 microL(-1)), as an adjuvant to chemotherapy. After treatment for 90 days, the higher doses of P10 entrapped within PLGA (5 or 10 microg.50 microL(-1)) were most effective. Treatment with P10 emulsified in Freund's adjuvant (20 microg.50 microL(-1)) or P10 entrapped within PLGA (1 microg.50 microL(-1)) were accompanied by high levels of interferon-gamma in lung.


CONCLUSIONS
Combination of sulfamethoxazole/trimethoprim with the P10 peptide entrapped within PLGA demonstrated increased therapeutic efficacy against paracoccidioidomycosis. P10 incorporation into PLGA nanoparticles dramatically reduced the peptide amount necessary to elicit a protective effect.
Amaral
André C
AC
Biological Sciences Institute, Universidade de Brasília, Brasília.
Marques
Alexandre F
AF
Muñoz
Julián E
JE
Bocca
Anamélia L
AL
Simioni
Andreza R
AR
Tedesco
Antonio C
AC
Morais
Paulo C
PC
Travassos
Luiz R
LR
Taborda
Carlos P
CP
Felipe
Maria Sueli S
MS
D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use; D003692:Delayed-Action Preparations; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers / Q000737:chemistry; D004359:Drug Therapy, Combination; D005620:Freund's Adjuvant / Q000737:chemistry; D006023:Glycoproteins / Q000008:administration & dosage / Q000494:pharmacology*; D007155:Immunologic Factors / Q000008:administration & dosage / Q000494:pharmacology; D019344:Lactic Acid / Q000737:chemistry*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles; D010228:Paracoccidioides / Q000276:immunology; D010229:Paracoccidioidomycosis / Q000188:drug therapy* / Q000276:immunology; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use
D000890:Anti-Infective Agents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D006023:Glycoproteins; D007155:Immunologic Factors; C550731:P10 peptide, Paracoccidioides brasiliensis; D010446:Peptide Fragments; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D005620:Freund's Adjuvant