Banca de DEFESA: JOSE LUCAS ANDRADE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JOSE LUCAS ANDRADE
DATE: 31/08/2023
TIME: 09:00
LOCAL: Virtual
TITLE:

EVALUATION OF THE IMMUNOGENIC RESPONSE OF PROTEIN EXTRACTS FROM Plasmodium berghei ANKA AND ITS POTENTIAL PROTECTIVE EFFECT IN EXPERIMENTAL INFECTION

KEY WORDS:

malaria; protein extracts; immunogenicity; murine model.

PAGES: 99
BIG AREA: Ciências Biológicas
AREA: Parasitologia
SUMMARY:

Malaria is a parasitic disease with a wide distribution across continents and is an important public health issue worldwide, in view of the high annual rates of morbidity and mortality. Immune responses against Plasmodium are complex and slow, as a protozoan mechanism to attenuate the host's immune processes to infection. Numerous efforts have been employed to understand the ability of plasmodium proteins to modulate a protective immune response in the host in order to reduce the replication of the protozoan in the blood phase and minimize the complications of severe malaria. In this context, this study aimed to analyze the ability of protein extracts obtained from the erythrocytic phase of Plasmodium berghei ANKA to stimulate an effector immune response in the murine model and suppress parasitemia after challenge with 105 infected red blood cells, using the intraperitoneal route. Three cycles of immunizations were performed using the crude extract of P. berghei ANKA, associated with two different adjuvants: aluminum hydroxide and Freund's adjuvant. Furthermore, this immunization scheme was also evaluated in infected mice, subsequently treated and cured, as well as in animals without prior immunity against malaria. Each immunization was performed at an interval of 15 days, in female mice, Mus musculus species, lineage BALB/C, aged between 6 and 8 weeks. 30 days after the last immunization, the animals were challenged with the infecting inoculum and evaluated for parasitemia suppression and humoral immune response. A significant humoral immune response was observed compared to the control group already in the first immunization. With an increase in the production of cytophilic antibodies, IgG2a and IgG2b, for animals previously exposed to malaria. In addition, in these same groups, there was a suppression of parasitemia when compared to the group of non-infected/untreated animals. The experimental group composed of animals previously exposed to the infection and immunized with protein extract/aluminium hydroxide showed total suppression of parasitemia on the 13th day. A similar result was observed in the group immunized with protein extract/Freund's adjuvant, showing a significant reduction in the parasitic load, both in comparison with the control group and in comparison with the non-immunized group, but subjected to successive infections. The results obtained in this study show that the animals immunized with the adjuvants used and, in the condition of previous exposure to the parasite, present high levels of specific antibodies, and, possibly, are less prone to the development of complications of severe malaria, when compared to the non-immunized group and with animals submitted to reinfection, without immunizations.

COMMITTEE MEMBERS:
Presidente - 2213126 - VALTER FERREIRA DE ANDRADE NETO
Externa à Instituição - ISABELA PENNA CERÁVOLO - FIOCRUZ
Externo à Instituição - ANDRE TALVANI PEDROSA DA SILVA - UFOP