RESUMO
Se caracterizó la estructura y composición florística del remanente boscoso ubicado en la Reserva Forestal de la Institución Educativa Cajete, Popayán (Cauca). El inventario florístico se hizo mediante colecta libre realizada en el interior y la periferia del bosque. Se registraron en total 164 especies, 130 géneros y 58 familias. En Magnoliophyta se registraron 142 especies, 112 géneros y 44 familias; las familias más diversas fueron Asteraceae (31 especies y 26 géneros) y Araceae (10 especies y 3 géneros). En Lycophyta y Monylophyta se reconocieron 22 especies, 18 géneros y 14 familias; siendo Polypodiaceae con 4 especies la familia con mayor riqueza. Para determinar la estructura se muestrearon todos los individuos con DAP ≥ 1 cm en 10 bandas de 50 x 2 m, hallándose 560 individuos de plantas vasculares pertenecientes a 39 especies, 33 géneros y 25 familias. El bosque presentó 3 estratos: herbáceo, arbustivo y arbóreo. El estrato arbustivo fue el dominante con un elevado número de especies; el estrato arbóreo estuvo constituido por unas pocas especies. Quercus humboldtii y Banara guianensis fueron las especies con mayor dominancia e índice de valor de importancia en el bosque.
The floristic structure and composition of the remaining wooded area located in the Cajete Educational institution forest reserve in Popayan (Cauca) was studied. The floristic inventory was performed through free collection carried out inside and in the periphery of the forest. In total 164 species, 130 genera and 58 families were recorded. In Magnoliophyta 142 species belonging to 112 genera and 44 families were recorded, being Asteraceae (31 species and 26 genera) and Araceae (10 species and 3 genera) the most diverse families. In Monylophyta and Lycophyta 22 species belonging to 18 genera and 14 families were recognized, being Polypodiaceae with 4 species, the family with more richness. To determine the structure all individuals were sampled with ≥ 1 cm DAP in 10 bands of 50 x 2 m, and in total 560 individuals of vascular plants belonging to 39 species, 33 genera and 25 families were found. The forest presented three different strata: herbaceous, shrubby and arboreal. The shrubby stratum was dominant with a high number of species whereas the arboreal stratum consisted only of a few species. Quercus humboldtii and Banara guianensis were the species with greater dominance and with high importance value index in the forest.
Assuntos
Humanos , Recuperação e Remediação Ambiental , Florestas , Agricultura Florestal , MicrobiotaRESUMO
Malaria is transmitted by Plasmodium-infected anopheles mosquitoes. Widespread resistance of mosquitoes to insecticides and resistance of parasites to drugs highlight the urgent need for malaria vaccines. The most advanced malaria vaccines target sporozoites, the infective form of the parasite. A major target of the antibody response to sporozoites are the repeat epitopes of the circumsporozoite (CS) protein, which span almost one half of the protein. Antibodies to these repeats can neutralize sporozoite infectivity. Generation of protective antibody responses to the CS protein (anti-CS Ab) requires help by CD4 T cells. A CD4 T cell epitope from the CS protein designated T* was previously identified by screening T cells from volunteers immunized with irradiated P. falciparum sporozoites. The T* sequence spans twenty amino acids that contains multiple T cell epitopes restricted by various HLA alleles. Subunit malaria vaccines including T* are highly immunogenic in rodents, non-human primates and humans. In this study we characterized a highly conserved HLA-DRß1*04:01 (DR4) restricted T cell epitope (QNT-5) located at the C-terminus of T*. We found that a peptide containing QNT-5 was able to elicit long-term anti-CS Ab responses and prime CD4 T cells in HLA-DR4 transgenic mice despite forming relatively unstable MHC-peptide complexes highly susceptible to HLA-DM editing. We attempted to improve the immunogenicity of QNT-5 by replacing the P1 anchor position with an optimal tyrosine residue. The modified peptide QNT-Y formed stable MHC-peptide complexes highly resistant to HLA-DM editing. Contrary to expectations, a linear peptide containing QNT-Y elicited almost 10-fold lower long-term antibody and IFN-γ responses compared to the linear peptide containing the wild type QNT-5 sequence. Some possibilities regarding why QNT-5 is more effective than QNT-Y in inducing long-term T cell and anti-CS Ab when used as vaccine are discussed.
Assuntos
Anticorpos Antiprotozoários/imunologia , Linfócitos T CD4-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Antígeno HLA-DR4/imunologia , Memória Imunológica , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Animais , Epitopos de Linfócito T/genética , Feminino , Antígeno HLA-DR4/genética , Humanos , Vacinas Antimaláricas/genética , Vacinas Antimaláricas/imunologia , Masculino , Camundongos , Camundongos Transgênicos , Estabilidade Proteica , Proteínas de Protozoários/genéticaRESUMO
Conserved Plasmodium falciparum merozoite high activity binding peptides (HABPs) involved in red blood cell (RBC) invasion which are present in merozoite surface proteins (MSPs) involved in attachment, rolling over RBC, those derived from soluble proteins loosely bound to the membrane, and those present in microneme and rhoptry organelles have an alpha-helical structure and bind with high affinity to HLA-DR52 molecules. On the contrary, conserved HABPs belonging to molecules anchored to the membrane by a GPI tail, or a transmembranal region, or those molecules presenting PEXEL motifs have a strand, turn or unordered configuration and bind with high affinity to HLA-DR53 molecules. Such functional, cellular, structural, and immunological compartmentalisation has tremendous implications in subunit-based, multi-epitope, synthetic, anti-malarial vaccine development.
Assuntos
Antígenos de Protozoários/química , Antígenos de Protozoários/fisiologia , Malária/metabolismo , Plasmodium falciparum/patogenicidade , Proteínas de Protozoários/química , Proteínas de Protozoários/fisiologia , Sequência de Aminoácidos , Animais , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Antígenos HLA-DR/metabolismo , Humanos , Malária/imunologia , Malária/parasitologia , Dados de Sequência Molecular , Plasmodium falciparum/química , Plasmodium falciparum/imunologia , Plasmodium falciparum/metabolismo , Ligação Proteica/imunologia , Proteínas de Protozoários/metabolismoRESUMO
The C-terminal portion of the Plasmodium falciparum blood stage MSP-1 antigen plays a key role in invasion of human erythrocytes. The MSP-1(1282-1301) non-polymorphic 1585 peptide, from the processed MSP-1(42) fragment, is poorly immunogenic and highly alpha-helical [Angew. Chem. Int. Ed. 40 (2001) 4654]. Assessing the alpha-carbon asymmetry and its implication in the host immune response is proposed in this work to overcome the 1585 peptide's immunological properties. Accordingly, the effect of incorporating single D-amino acids and psi-[CH(2)-NH] isoster bonds into the 1585 peptide was examined both at the immunogenic and 3D-structure levels. Therefore, specific binding to RBCs is promoted by site-directed chiral modifications on the native peptide as well as by simultaneously combining specific D-substitutions with psi-[CH(2)-NH] isoster bonds transforming this molecule into a high specific HLAbeta1*1101 allele binder. D-analog pseudopeptide immunized animals induced antibodies selectively recognizing a recombinant as well as native MSP-1(42) and MSP-1(33) fragments. Protection and low parasitemia levels were induced in Aotus monkeys immunized with the EVLYL(dK)PLAGVYRSLKKQLE analog. Peptide alpha-carbon chiral transformation is therefore an important target for structural modulation and, consequently, represents a novel approach towards designing multi-component subunit-based malarial vaccines.
Assuntos
Malária Falciparum/imunologia , Malária Falciparum/prevenção & controle , Modelos Moleculares , Plasmodium falciparum/imunologia , Plasmodium falciparum/metabolismo , Subtilisinas/imunologia , Subtilisinas/uso terapêutico , Substituição de Aminoácidos , Animais , Antimaláricos , Aotidae , Sítios de Ligação , Células Cultivadas , Simulação por Computador , Humanos , Isomerismo , Vacinas Antimaláricas , Camundongos , Camundongos Endogâmicos BALB C , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade , Subtilisinas/química , MulheresRESUMO
EBA-175 protein is used as ligand in Plasmodium falciparum binding to erythrocytes. Evidence shows that conserved peptide 1815 from this protein having high red blood cell binding ability plays an important role in the invasion process. This peptide is neither immunogenic nor protective. Residues were substituted by amino acids having similar volume or mass but different polarity in 1815 analogues had to make them fit into HLA-DRbeta1*03 molecules; these were synthesised and inoculated into Aotus monkeys, generating different immunogenic and/or protective immune responses. A shortening in alpha-helix structure was found in the immunogenic and protective ones when their secondary structure was analyzed by NMR to correlate their structure with their immunological properties. This data, together with results from previous studies, suggests that this shortening in high-activity binding peptide (HABP) helical configuration may lead to better fitting into immune system molecules as shown by binding to purified HLA-DRbeta1* molecules rendering them immunogenic and protective and therefore, excellent candidates for consideration as components of a subunit based multi-component synthetic vaccine against malaria.
Assuntos
Anticorpos Antiprotozoários/biossíntese , Aotus trivirgatus , Antígenos HLA-DR/imunologia , Malária/imunologia , Malária/prevenção & controle , Fragmentos de Peptídeos/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antiprotozoários/genética , Anticorpos Antiprotozoários/metabolismo , Sítios de Ligação de Anticorpos , Antígenos HLA-DR/genética , Antígenos HLA-DR/metabolismo , Cadeias HLA-DRB1 , Malária/genética , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Plasmodium falciparum/imunologiaRESUMO
Conserved, high-activity, red blood cell binding malaria peptide 6786, from the HRP-I protein, having a random 3D structure as determined by 1H-NMR, was non-immunogenic and non-protection inducing when used as an immunogen in Aotus monkeys. Modifications made in its amino acid sequence were thus performed to render it immunogenic and protection inducing. Non-immunogenic, non-protection inducing modified peptide 13852 presented A2-H8 and K14-L18 helix fragments. Immunogenic, non-protection inducing modified peptide 23428 presented a short, displaced helix in a different region, whilst immunogenic, protection inducing peptide 24224 had 2 displaced helical regions towards the central region giving more flexibility to its N- and C-terminals. Immunogenic and protection inducing peptides bound with high affinity to HLA-DRB1* 0301 whilst others did not bind to any HLA-DRB1* purified molecule. Structural modifications may thus lead to inducing immunogenicity and protection associated with their capacity to bind specifically to purified HLA-DRB1* molecules, suggesting a new way of developing multi-component, subunit-based malarial vaccines.
Assuntos
Antígenos de Protozoários/imunologia , Antígenos HLA-DR/imunologia , Vacinas Antimaláricas/imunologia , Malária Falciparum/imunologia , Oligopeptídeos/imunologia , Peptídeos/imunologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Protozoários/química , Aotidae/imunologia , Antígenos HLA-DR/metabolismo , Humanos , Malária Falciparum/prevenção & controle , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Plasmodium falciparum/química , Ligação Proteica/imunologia , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas de Protozoários/químicaAssuntos
Complexo Principal de Histocompatibilidade/imunologia , Malária/imunologia , Malária/prevenção & controle , Peptídeos/química , Sequência de Aminoácidos , Sequência Conservada/imunologia , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/imunologia , Conformação Proteica , Relação Estrutura-AtividadeRESUMO
6671 is a non-immunogenic, conserved high activity red blood cell binding peptide located between residues 141 and 160 of the Plasmodium falciparum RESA protein. This peptide's critical red blood cell (RBC) binding residues have been replaced by amino acids having similar mass but different charge to change their immunologic properties. Three analogues (two of them immunogenic and protective and one immunogenic) were studied by purified HLA-DRbeta1* binding and NMR to correlate their structure with their immunological properties. Native peptide 6671 had a very flexible beta-sheet structure, whilst its immunogenic, protective, and non-protective peptide analogues presented an alpha-helical structure having different locations and lengths. These changes in peptide structure facilitated their fitting into HLA-DRbeta1* molecules. This paper shows for the first time how modifications performed on RESA protein non-immunogenic, non-protectogenic peptides impose a configuration allowing them to fit perfectly into the MHC II-TCR complex, in turn leading to appropriate activation of the immune system.
Assuntos
Antígenos HLA-DR/imunologia , Antígenos HLA-DR/metabolismo , Malária Falciparum/imunologia , Peptídeos/imunologia , Peptídeos/metabolismo , Proteínas de Protozoários/imunologia , Proteínas de Protozoários/metabolismo , Alelos , Sequência de Aminoácidos , Animais , Formação de Anticorpos/imunologia , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Sítios de Ligação , Dicroísmo Circular , Imunofluorescência , Cadeias HLA-DRB1 , Haplorrinos , Modelos Moleculares , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Peptídeos/química , Peptídeos/genética , Ligação Proteica , Conformação Proteica , Proteínas de Protozoários/genéticaRESUMO
In vitro peptide binding assays and DCs pulsed with recombinant KMP-11 (rKMP-11) plus six 20-mer overlapping peptides covering the entire protein of Leishmania (Viannia) panamensis (L(V)p) promastigotes were used to identify T-cell epitopes in this protein. Such in vitro binding assays, using HLA DRB1* 0101, -0401, -0701 and -1101 alleles, demonstrated that two peptide sequences (DEEFNKKMQEQNAKFFADKP and FKHKFAELLEQQKAAQYPSK) exhibited high HLA DRB1* 0401 allele binding capacity. rKMP-11 specific T-cell proliferation and cytokine production, derived from 13 volunteers exposed to the parasite, suggested that using autologous DCs as APCs becomes advantageous in uncovering T-cell epitopes promoting proliferation and differences in IFN-gamma and IL-4 production in T-cells from volunteers with ACTIVE and CURED undetectable disease when other APCs were used. The two peptides which bound in vitro to the HLA DRB1* 0401 allele were immunogenic in HLA DRB1* 04 volunteers, thus validating the use of in vitro binding assays for predicting epitopes in this protein. The experimental approach used here may prove useful for characterizing T-cell epitopes in a protein useful in designing peptide-based vaccine candidates for Leishmania and other intracellular pathogens.
Assuntos
Imunidade Celular , Leishmania guyanensis/imunologia , Leishmaniose Mucocutânea/imunologia , Proteínas de Membrana/imunologia , Proteínas de Protozoários/imunologia , Sequência de Aminoácidos , Animais , Apresentação de Antígeno , Antígenos de Protozoários/genética , Ligação Competitiva , Estudos de Casos e Controles , Linhagem Celular , Citocinas/biossíntese , Células Dendríticas/imunologia , Mapeamento de Epitopos , Epitopos/genética , Feminino , Antígenos HLA-DR/metabolismo , Cadeias HLA-DRB1 , Humanos , Técnicas In Vitro , Leishmania guyanensis/genética , Ativação Linfocitária , Masculino , Proteínas de Membrana/genética , Dados de Sequência Molecular , Proteínas de Protozoários/genética , Linfócitos T/imunologiaRESUMO
Peptide 1585 (EVLYLKPLAGVYRSLKKQLE) has a highly conserved amino-acid sequence located in the Plasmodium falciparum main merozoite surface protein (MSP-1) C-terminal region, required for merozoite entry into human erythrocytes and therefore represents a vaccine candidate for P. falciparum malaria. Original sequence-specific binding to five HLA DRB1* alleles (0101, 0102, 0401, 0701, and 1101) revealed this peptide's specific HLA DRB1*0102 allele binding. This peptide's allele-specific binding to HLA DRB1*0102 took on broader specificity for the DRB1*0101, -0401, and -1101 alleles when lysine was replaced by glycine in position 17 (peptide 5198: EVLYLKPLAGVYRSLKG(17)QLE). Binding of the identified G(10)VYRSLKGQLE(20) C-terminal register to these alleles suggests that peptide promiscuous binding relied on fitting Y(12), L(15), and G(17) into P-1, P-4, and P-6, respectively. The implications of the findings and the future of this synthetic vaccine candidate are discussed.