Ecomorphology and Morphological Disparity of Caquetaia Kraussii (Perciformes: Cichlidae) in Colombia.

Understanding the interspecific morphological variability of Caquetaia kraussii (Perciformes: Cichlidae) between different localities in its distribution range is becoming essential, as this species constitutes a valuable resource for the economy and subsistence of the local human communities where it is endemic in Colombia and Venezuela. In order to develop efficient farming and handling plans for this species, a deep understanding of the factors and mechanisms generating morphological variability is crucial. This study analyzes the morphological variability of C. kraussii by using geometric morphometrics in four localities distributed between the Dique and North channels, which are part of the Bolívar department in Colombia. Likewise, the effect of environmental variables such as temperature (T°), dissolved oxygen (OD) and pH on morphological variability was analyzed using a partial least squares approach. The results show that environmental stress has an influence on ~10% of the body shape of C. kraussii, whereas ~90% of the body shape is not directly influenced by environmental parameters, suggesting an effect from stress related to sexual dimorphism. Similarly, the analyses show shape variation among localities, mainly between populations of lotic environments and those of lentic environments. This morphological disparity seems to be subject to environmental and sexual stresses in the different localities.

Stereo electronic principles for selecting fully-protective, chemically-synthesised malaria vaccines.

Major histocompatibility class II molecule-peptide-T-cell receptor (MHCII-p-TCR) complex-mediated antigen presentation for a minimal subunit-based, multi-epitope, multistage, chemically-synthesised antimalarial vaccine is essential for inducing an appropriate immune response. Deep understanding of this MHCII-p-TCR complex's stereo-electronic characteristics is fundamental for vaccine development. This review encapsulates the main principles for achieving such epitopes' perfect fit into MHC-II human (HLADRß̞1*) or Aotus (Aona DR) molecules. The enormous relevance of several amino acids' physico-chemical characteristics is analysed in-depth, as is data regarding a 26.5 ± 2.5Å distance between the farthest atoms fitting into HLA-DRß1* structures' Pockets 1 to 9, the role of polyproline II-like (PPIIL) structures having their O and N backbone atoms orientated for establishing H-bonds with specific HLA-DRß1*-peptide binding region (PBR) residues. The importance of residues having specific charge and orientation towards the TCR for inducing appropriate immune activation, amino acids' role and that of structures interfering with PPIIL formation and other principles are demonstrated which have to be taken into account when designing immune, protection-inducing peptide structures (IMPIPS) against diseases scourging humankind, malaria being one of them.

SM-COLSARSPROT: Highly Immunogenic Supramutational Synthetic Peptides Covering the World's Population.

Fifty ~20-amino acid (aa)-long peptides were selected from functionally relevant SARS-CoV-2 S, M, and E proteins for trial B-21 and another 53 common ones, plus some new ones derived from the virus' main genetic variants for complementary trial C-21. Peptide selection was based on tremendous SARS-CoV-2 genetic variability for analysing them concerning vast human immunogenetic polymorphism for developing the first supramutational, Colombian SARS-protection (SM-COLSARSPROT), peptide mixture. Specific physicochemical rules were followed, i.e., aa predilection for polyproline type II left-handed (PPIIL) formation, replacing ß-branched, aromatic aa, short-chain backbone H-bond-forming residues, π-π interactions (n→π* and π-CH), aa interaction with π systems, and molecular fragments able to interact with them, disrupting PPIIL propensity formation. All these modified structures had PPIIL formation propensity to enable target peptide interaction with human leukocyte antigen-DRß1* (HLA-DRß1*) molecules to mediate antigen presentation and induce an appropriate immune response. Such modified peptides were designed for human use; however, they induced high antibody titres against S, M, and E parental mutant peptides and neutralising antibodies when suitably modified and chemically synthesised for immunising 61 major histocompatibility complex class II (MHCII) DNA genotyped Aotus monkeys (matched with their corresponding HLA-DRß1* molecules), predicted to cover 77.5% to 83.1% of the world's population. Such chemically synthesised peptide mixture represents an extremely pure, stable, reliable, and cheap vaccine for COVID-19 pandemic control, providing a new approach for a logical, rational, and soundly established methodology for other vaccine development.

In vivo evaluation of the toxic activity and genotoxicity of the Hymenaea courbaril L.'s resin in Drosophila melanogaster.

Due to the negative consequences carried by the usage of synthetic insecticides, a global interest into finding substitutes for these chemical compounds through natural products has arisen. When yielded to external attacks, plants generally produce metabolites to defend themselves. The physicochemical characteristics of this kind of compounds have allowed their usage as potential bioinsecticides. The Hymenaea courbaril L. (algarrobo) has proven to be a plant rich in metabolites with outstanding biological activity, in such a way that some of its extracts have been tested as insecticides. The goal of this study was to know the phytochemical composition of Hymenaea courbaril L.'s resin and perform evaluations in vivo of its toxic and genotoxic effects in the biological model Drosophila melanogaster. For this, two resin extracts were prepared and both a phytochemical analysis were carried out on them, having found in the ethanolic total extract the presence of terpenes, flavonoids and coumarins, while in the partial ethanolic extract only presence of terpenes and flavonoids was found. Drosophila larvae were submitted to different concentrations of the extracts and both the survival and the sexual ratio were evaluated, finding that larvae are more sensitive to the partial ethanolic extract. Subsequently, the induction of somatic mutation and mitotic recombination (SMART) was evaluated in the flies' eyes. The most significant affectations at a genotoxic level were found when larvae were tested with the partial extract, indicating that possibly the coumarins absence makes this insect more susceptible to damages at a genetic material level.

The First Chemically-Synthesised, Highly Immunogenic Anti-SARS-CoV-2 Peptides in DNA Genotyped Aotus Monkeys for Human Use.

Thirty-five peptides selected from functionally-relevant SARS-CoV-2 spike (S), membrane (M), and envelope (E) proteins were suitably modified for immunising MHC class II (MHCII) DNA-genotyped Aotus monkeys and matched with HLA-DRß1* molecules for use in humans. This was aimed at producing the first minimal subunit-based, chemically-synthesised, immunogenic molecules (COLSARSPROT) covering several HLA alleles. They were predicted to cover 48.25% of the world's population for 6 weeks (short-term) and 33.65% for 15 weeks (long-lasting) as they induced very high immunofluorescent antibody (IFA) and ELISA titres against S, M and E parental native peptides, SARS-CoV-2 neutralising antibodies and host cell infection. The same immunological methods that led to identifying new peptides for inclusion in the COLSARSPROT mixture were used for antigenicity studies. Peptides were analysed with serum samples from patients suffering mild or severe SARS-CoV-2 infection, thereby increasing chemically-synthesised peptides' potential coverage for the world populations up to 62.9%. These peptides' 3D structural analysis (by 1H-NMR acquired at 600 to 900 MHz) suggested structural-functional immunological association. This first multi-protein, multi-epitope, minimal subunit-based, chemically-synthesised, highly immunogenic peptide mixture highlights such chemical synthesis methodology's potential for rapidly obtaining very pure, highly reproducible, stable, cheap, easily-modifiable peptides for inducing immune protection against COVID-19, covering a substantial percentage of the human population.

Specific ß-Turns Precede PPIIL Structures Binding to Allele-Specific HLA-DRß1* PBRs in Fully-Protective Malaria Vaccine Components.

The 3D structural analysis of 62 peptides derived from highly pathogenic Plasmodium falciparum malaria parasite proteins involved in host cell invasion led to finding a striking association between particular ß-turn types located in the N-terminal peripheral flanking residue region (preceding the polyproline II left-handed structures fitting into the HLA-DRß* allele family) and modified immune protection-inducing protein structure induced long-lasting protective immunity. This is the first time association between two different secondary structures associated with a specific immunological function has been described: full, long-lasting protective immunity.

Conserved Binding Regions Provide the Clue for Peptide-Based Vaccine Development: A Chemical Perspective.

Synthetic peptides have become invaluable biomedical research and medicinal chemistry tools for studying functional roles, i.e., binding or proteolytic activity, naturally-occurring regions' immunogenicity in proteins and developing therapeutic agents and vaccines. Synthetic peptides can mimic protein sites; their structure and function can be easily modulated by specific amino acid replacement. They have major advantages, i.e., they are cheap, easily-produced and chemically stable, lack infectious and secondary adverse reactions and can induce immune responses via T- and B-cell epitopes. Our group has previously shown that using synthetic peptides and adopting a functional approach has led to identifying Plasmodium falciparumconserved regions binding to host cells. Conserved high activity binding peptides' (cHABPs) physicochemical, structural and immunological characteristics have been taken into account for properly modifying and converting them into highly immunogenic, protection-inducing peptides (mHABPs) in the experimental Aotus monkey model. This article describes stereo-electron and topochemical characteristics regarding major histocompatibility complex (MHC)-mHABP-T-cell receptor (TCR) complex formation. Some mHABPs in this complex inducing long-lasting, protective immunity have been named immune protection-inducing protein structures (IMPIPS), forming the subunit components in chemically synthesized vaccines. This manuscript summarizes this particular field and adds our recent findings concerning intramolecular interactions (H-bonds or π-interactions) enabling proper IMPIPS structure as well as the peripheral flanking residues (PFR) to stabilize the MHCII-IMPIPS-TCR interaction, aimed at inducing long-lasting, protective immunological memory.

A Large Size Chimeric Highly Immunogenic Peptide Presents Multistage Plasmodium Antigens as a Vaccine Candidate System against Malaria.

Rational strategies for obtaining malaria vaccine candidates should include not only a proper selection of target antigens for antibody stimulation, but also a versatile molecular design based on ordering the right pieces from the complex pathogen molecular puzzle towards more active and functional immunogens. Classical Plasmodium falciparum antigens regarded as vaccine candidates have been selected as model targets in this study. Among all possibilities we have chosen epitopes of PfCSP, STARP; MSA1 and Pf155/RESA from pre- and erythrocyte stages respectively for designing a large 82-residue chimeric immunogen. A number of options aimed at diminishing steric hindrance for synthetic procedures were assessed based on standard Fmoc chemistry such as building block orthogonal ligation; pseudo-proline and microwave-assisted procedures, therefore the large-chimeric target was produced, characterized and immunologically tested. Antigenicity and functional in vivo efficacy tests of the large-chimera formulations administered alone or as antigen mixtures have proven the stimulation of high antibody titers, showing strong correlation with protection and parasite clearance of vaccinated BALB/c mice after being lethally challenged with both P. berghei-ANKA and P. yoelii 17XL malaria strains. Besides, 3D structure features shown by the large-chimera encouraged as to propose using these rational designed large synthetic molecules as reliable vaccine candidate-presenting systems.

Functionally relevant proteins in Plasmodium falciparum host cell invasion.

A totally effective, antimalarial vaccine must involve sporozoite and merozoite proteins (or their fragments) to ensure complete parasite blocking during critical invasion stages. This Special Report examines proteins involved in critical biological functions for parasite survival and highlights the conserved amino acid sequences of the most important proteins involved in sporozoite invasion of hepatocytes and merozoite invasion of red blood cells. Conserved high activity binding peptides are located in such proteins' functionally strategic sites, whose functions are related to receptor binding, nutrient and protein transport, enzyme activity and molecule-molecule interactions. They are thus excellent targets for vaccine development as they block proteins binding function involved in invasion and also their biological function.

TCR-contacting residues orientation and HLA-DRß* binding preference determine long-lasting protective immunity against malaria.

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged 60 days later with a lethal Aotus monkey-adapted P. falciparum strain was found to be associated with preferential high binding capacity to HLA-DRß1* allelic molecules of the major histocompatibility class II (MHC-II), rather than HLA-DRß3*, ß4*, ß5* alleles. Complete PPIIL 3D structure, a longer distance (26.5 Å ± 1.5 Å) between residues perfectly fitting into HLA-DRß1*PBR pockets 1 and 9, a gauche(-) rotamer orientation in p8 TCR-contacting polar residue and a larger volume of polar p2 residues was also found. This data, in association with previously-described p3 and p7 apolar residues having gauche(+) orientation to form a perfect MHC-II-peptide-TCR complex, determines the stereo-electronic and topochemical characteristics associated with FPLLI immunological memory.

IMPIPS: the immune protection-inducing protein structure concept in the search for steric-electron and topochemical principles for complete fully-protective chemically synthesised vaccine development.

Determining immune protection-inducing protein structures (IMPIPS) involves defining the stereo-electron and topochemical characteristics which are essential in MHC-p-TCR complex formation. Modified high activity binding peptides (mHABP) were thus synthesised to produce a large panel of IMPIPS measuring 26.5 ±3.5Å between the farthest atoms fitting into Pockets 1 to 9 of HLA-DRß1* structures. They displayed a polyproline II-like (PPIIL) structure with their backbone O and N atoms orientated to establish H-bonds with specific residues from HLA-DRß1*-peptide binding regions (PBR). Residues having specific charge and gauche+ orientation regarding p3χ1, p5χ2, and p7χ1 angles determined appropriate rotamer orientation for perfectly fitting into the TCR to induce an appropriate immune response. Immunological assays in Aotus monkeys involving IMPIPS mixtures led to promising results; taken together with the aforementioned physicochemical principles, non-interfering, long-lasting, protection-inducing, multi-epitope, multistage, minimal subunit-based chemically-synthesised peptides can be designed against diseases scourging humankind.

Protecting capacity against malaria of chemically defined tetramer forms based on the Plasmodium falciparum apical sushi protein as potential vaccine components.

Developing novel generations of subunit-based antimalarial vaccines in the form of chemically-defined macromolecule systems for multiple antigen presentation represents a classical problem in the field of vaccine development. Many efforts involving synthesis strategies leading to macromolecule constructs have been based on dendrimer-like systems, the condensation of large building blocks and conventional asymmetric double dimer constructs, all based on lysine cores. This work describes novel symmetric double dimer and condensed linear constructs for presenting selected peptide multi-copies from the apical sushi protein expressed in Plasmodium falciparum. These molecules have been proved to be safe and innocuous, highly antigenic and have shown strong protective efficacy in rodents challenged with two Plasmodium species. Insights into systematic design, synthesis and characterisation have led to such novel antigen systems being used as potential platforms for developing new anti-malarial vaccine candidates.

Presencia de Munidopsis robusta en el Caribe colombiano (A. Milne Edwards, 1880) (Crustacea: Anomura: Munidopsidae / Presence of Munidopsis robusta in the Colombian Caribbean (A. Milne-Edwards, 1880) (Crustacea: Anomura: Munidopsidae) / Presença de Munidopsis robusta no Caribe Colombiano (A. Milne Edwards, 1880) (Crustacea: Anomura: Munidopsidae)

Se presenta el primer registro para Colombia de Munidopsis robusta. Los ejemplares fueron recolectados frente a los departamentos de La Guajira y Bolívar a 500 m de profundidad mediante arrastre con una red tipo semi-balón. En cubierta fueron enjuagados con agua de mar y preservados en etanol al 95 %. Las características de la columna de agua fueron evaluadas con una sonda multiparámetros CTDO. Los sedimentos fueron recolectados por medio de un nucleador de caja y se realizó el análisis granulométrico de los mismos. Se incluye la diagnosis de la especie y comentarios sobre distribución y ámbito batimétrico y geográfico. Con este nuevo registro se aumenta a 23 el número de especies de Munidopsis para Colombia. Además, se amplía la distribución de esta especie en el Caribe.

The first record of M. robusta in Colombia is presented. The specimens were collected by demersal trawling at 500 m depth in front of the departments of La Guajira and Bolívar using a semi-ballon net. Collected specimens were washed onboard with seawater and preserved in 95 % ethanol. The characteristics of the water column were measured with a multi-parameter CTDO instrument. Sediments were collected using a Box-corer and a granulometric analysis was performed. A species diagnosis is presented together with comments regarding its distribution and bathymetric and geographic ranges. With this new record, the number of Colombian species of Munidopsis increases to 23. Moreover, the distribution of this species for the Caribbean is extended.

É apresentado o primeiro registro de Munidopsis robusta na Colômbia. Os espécimes foram coletados em frente dos departamentos de La Guajira e Bolívar por arrasto a 500 m de profundidade com uma rede semi-balão. Foram lavados com água do mar a bordo e preservados em álcool a 95 %. As características da coluna de água foram medidas com um instrumento multi-parâmetro CTDO. Os sedimentos foram coletados por meio de um Box-corer e foi realizada uma análise granulométrica. Um diagnóstico da espécie é apresentado juntamente com comentários sobre sua distribuição, batimétrica e áreas geográficas. Com este novo registro, o número de espécies colombianas de Munidopsis aumenta para 23. Além disso, a distribuição desta espécie para o Caribe é aumentada.

Gauche(+) side-chain orientation as a key factor in the search for an immunogenic peptide mixture leading to a complete fully protective vaccine.

Topological and stereo-electron characteristics are essential in major histocompability class II-peptide-T-cell receptor (MHC-p-TCR) complex formation for inducing an appropriate immune response. Modified high activity binding peptides (mHABPs) were synthesised for complete full protection antimalarial vaccine development producing a large panel of individually fully protection-inducing protein structures (FPIPS) and very high long-lasting antibody-inducing (VHLLAI) mHABPs. Most of those which did not interfere, compete, inhibit or suppress their individual VHLLAI or FPIPS activity contained or displayed a polyproline II-like (PPIIL) structure when mixed. Here we show that amino acid side-chains located in peptide binding region (PBR) positions p3 and p7 displayed specific electron charges and side-chain gauche(+) orientation for interacting with the TCR. Based on the above, and previously described physicochemical principles, non-interfering, long-lasting, full protection-inducing, multi-epitope, multistage, minimal subunit-based chemically synthesised mHABP mixtures can be designed for developing vaccines against diseases scourging humankind, malaria being one of them.

Towards the development of a fully protective Plasmodium falciparum antimalarial vaccine.

If ever there were a truism then it would be that a completely protective Plasmodium falciparum malaria vaccine is desperately needed. Our institute has devoted all its efforts during the last 30 years to developing a fully protective, minimal subunit-based, multiepitope, multistage (targeting sporozoite and merozoite proteins), chemically synthesized antimalarial vaccine, given that peptides with high binding activity to their corresponding host cells (liver cells or red blood cells) form the springboard for vaccine design. However, such conserved high activity binding peptides have to be specifically modified to render them into highly immunogenic and protection-inducing peptides since they are immunologically silent. These modifications, analyzed at the 3D structural level by (1)H-NMR, allow them a better fit into the MHC II-peptide-T-cell receptor complex to induce an appropriate immune response, providing a rational and logical approach (analyzed at the single atom level) for vaccine development, particularly in the field of malaria.

The high immunogenicity induced by modified sporozoites' malarial peptides depends on their phi (ϕ) and psi (ψ) angles.

The importance of CSP- and STARP-derived ϕ and ψ dihedral angles in mHABP structure was analysed by (1)H NMR in the search for molecules which can be included as components of a first-line-of-defence Plasmodium falciparum sporozoite multi-epitope vaccine against the most lethal form of human malaria. Most of the aforementioned dihedral angles were left-hand-like polyproline type II (PPII(L)) structures whilst others had right-hand-like α-helix (α(R)), thus allowing mHABPS to fit better into MHCII molecules and thereby form an appropriate pMHCII complex and also establish the H-bonds which stabilise such complex and by this means induce an appropriate immune response. This information has great implications for vaccine development, malaria being one of them.

Phi (Φ) and psi (Ψ) angles involved in malarial peptide bonds determine sterile protective immunity.

Modified HABP (mHABP) regions interacting with HLA-DRß1(∗) molecules have a more restricted conformation and/or sequence than other mHABPs which do not fit perfectly into their peptide binding regions (PBR) and do not induce an acceptable immune response due to the critical role of their Φ and Ψ torsion angles. These angle's critical role was determined in such highly immunogenic, protection-inducing response against experimental malaria using the conformers (mHABPs) obtained by (1)H-NMR and superimposed into HLA-DRß1(∗)-like Aotus monkey molecules; their phi (Φ) and psi (Ψ) angles were measured and the H-bond formation between these molecules was evaluated. The aforementioned mHABP propensity to assume a regular conformation similar to a left-handed polyproline type II helix (PPII(L)) led to suggesting that favouring these conformations according to their amino acid sequence would lead to high antibody titre production and sterile protective immunity induction against malaria, thereby adding new principles or rules for vaccine development, malaria being one of them.

Binding activity, structure, and immunogenicity of synthetic peptides derived from Plasmodium falciparum CelTOS and TRSP proteins.

Several sporozoite proteins have been associated with Plasmodium falciparum cell traversal and hepatocyte invasion, including the cell-traversal protein for ookinetes and sporozoites (CelTOS), and thrombospondin-related sporozoite protein (TRSP). CelTOS and TRSP amino acid sequences have been finely mapped to identify regions specifically binding to HeLa and HepG2 cells, respectively. Three high-activity binding peptides (HABPs) were found in CelTOS and one HABP was found in TRSP, all of them having high α-helical structure content. These HABPs' specific binding was sensitive to HeLa and HepG2 cells' pre-treatment with heparinase I and chondroitinase ABC. Despite their similarity at three-dimensional (3D) structural level, TRSP and TRAP HABPs located in the TSR domain did not compete for the same binding sites. CelTOS and TRSP HABPs were used as a template for designing modified sequences to then be assessed in the Aotus monkey experimental model. Antibodies directed against these modified HABPs were able to recognize both the native parasite protein by immunofluorescence assay and the recombinant protein (expressed in Escherichia coli) by Western blot and ELISA assays. The results suggested that these modified HABPs could be promising targets in designing a fully effective, antimalarial vaccine.