ghanaopendata/ghanaian-research-english huggingface dataset:
Immune Signature Against Plasmodium falciparum Antigens Predicts Clinical Immunity in Distinct Malaria Endemic Communities

The Department of Immunology conducts research in the field of immunology of infectious and non-infectious diseases. The Department has the overall goal of contributing knowledge to better diagnosis, management, control and prevention of infectious and non-infectious diseases in Ghana and worldwide. This is consistent with the overall strategy of the Noguchi Memorial Institute for Medical Research (NMIMR) and in line with the strategy of the College of Health Sciences of the University of Ghana.

Source: UG
Immunity against HIV/AIDS, Malaria, and Tuberculosis during Co-Infections with Neglected Infectious Diseases: Recommendations for the European Union Research Priorities

The Department of Immunology conducts research in the field of immunology of infectious and non-infectious diseases. The Department has the overall goal of contributing knowledge to better diagnosis, management, control and prevention of infectious and non-infectious diseases in Ghana and worldwide. This is consistent with the overall strategy of the Noguchi Memorial Institute for Medical Research (NMIMR) and in line with the strategy of the College of Health Sciences of the University of Ghana.

Source: UG
Immunity to plasmodium berghei yoelii in mice. II. specific and nonspecific cellular and humoral responses during the course of infection

The Department of Immunology conducts research in the field of immunology of infectious and non-infectious diseases. The Department has the overall goal of contributing knowledge to better diagnosis, management, control and prevention of infectious and non-infectious diseases in Ghana and worldwide. This is consistent with the overall strategy of the Noguchi Memorial Institute for Medical Research (NMIMR) and in line with the strategy of the College of Health Sciences of the University of Ghana.

Source: UG
Immunization with different PfAMA1 alleles in sequence induces clonal imprint humoral responses that are similar to responses induced by the same alleles as a vaccine cocktail in rabbits

Abstract Background Antibodies to key Plasmodium falciparum surface antigens have been shown to be important effectors that mediate clinical immunity to malaria. The cross-strain fraction of anti-malarial antibodies may however be required to achieve strain-transcending immunity. Such antibody responses against Plasmodium falciparum apical membrane antigen 1 (PfAMA1), a vaccine target molecule that is expressed in both liver and blood stages of the parasite, can be elicited through immunization with a mixture of allelic variants of the parasite molecule. Cross-strain antibodies are most likely elicited against epitopes that are shared by the allelic antigens in the vaccine cocktail. Methods A standard competition ELISA was used to address whether the antibody response can be further focused on shared epitopes by exclusively boosting these common determinants through immunization of rabbits with different PfAMA1 alleles in sequence. The in vitro parasite growth inhibition assay was used to further evaluate the functional effects of the broadened antibody response that is characteristic of multi-allele vaccine strategies. Results A mixed antigen immunization protocol elicited humoral responses that were functionally similar to those elicited by a sequential immunization protocol (p &gt; 0.05). Sequential exposure to the different PfAMA1 allelic variants induced immunological recall of responses to previous alleles and yielded functional cross-strain antibodies that would be capable of optimal growth inhibition of variant parasites at high enough concentrations. Conclusions These findings may have implications for the current understanding of the natural acquisition of clinical immunity to malaria as well as for rational vaccine design.

Source: UG
Immunodominant T cell peptides from four candidate malarial antigens as biomarkers of protective immunity against malaria

The Department of Immunology conducts research in the field of immunology of infectious and non-infectious diseases. The Department has the overall goal of contributing knowledge to better diagnosis, management, control and prevention of infectious and non-infectious diseases in Ghana and worldwide. This is consistent with the overall strategy of the Noguchi Memorial Institute for Medical Research (NMIMR) and in line with the strategy of the College of Health Sciences of the University of Ghana.

Source: UG
Immunofluorescence Confocal Laser Scanning Microscopy and immuno-electron microscopic identification of keratins in human maternofetal interaction zone.

We show here that at least 5 keratin proteins are present in villous trophoblast and the same 5 in extravillous trophoblast. A further 14 tested were undetectable in these tissues. In contrast, 10 of the 19 keratins tested were present in amniotic epithelium. The marking of amniotic epithelium on the one hand, as distinct from villous and extravillous trophoblast on the other, can be achieved using 5 keratins (K4, 6, 13, 14 and 17) with a mixture of positive and negative discrimination that is expected, in combination, to be highly sensitive. All the specific keratins identified in trophoblast were apparently up-regulated on the pathway to extravillous trophoblast. Co-ordinated differentiation at the molecular expression level is indicated by this finding. The relevant keratins are K5, 7, 8, 18 and 19. Specific keratins have been identified that are down-regulated in villous trophoblast in pre-eclamptic pregnancy. This difference between healthy and pre-eclamptic chorionic villous trophoblast keratin expression was statistically significant in 4 out of the 5 keratins. This was not the case for the extravillous trophoblast at the immunofluorescence confocal level but significant differences were obtained using immunogold electron microscopy. We suggest that the villous trophoblast in pre-eclamptic placentae is cytoskeletally weaker with respect to the filaments made from these specific proteins and that this is one reason why, in pre-eclampsia, trophoblast is deported in greater quantity than in healthy placentae.

Source: UG
Immunogenicity and waning immunity from the oral cholera vaccine (Shanchol™) in adults residing in Lukanga Swamps of Zambia

Introduction In cholera endemic areas, the periodicity of cholera outbreaks remains unpredictable, making it difficult to organize preventive efforts. Lack of data on duration of protection conferred by oral cholera vaccines further makes it difficult to determine when to deploy preemptive vaccination. We report on the immunogenicity and waning of immunity to Shanchol™ in Lukanga Swamps. Methods We enrolled a cohort of 223 participants aged between 18 and 65 years old from whom serum samples were collected at baseline, day 28 before administration of the second dose, and consecutively at 6, 12, 24, 30, 36, and 48 months. Vibriocidal antibody titres were measured and expressed as geometric mean titres. Box plots and 95% CI were computed at each visit for both Inaba and Ogawa. Seroconversion was defined as a four fold or greater increase in antibody titres compared to baseline titres. Results Overall, seroconversion against V. cholerae Inaba and Ogawa after 1st dose was 35/134 (26%) and 34/134 (25%) respectively. We observed a statistical difference in seroconversion between the two subgroups of baseline titres (low <80 and high �80) for both Inaba (p = 0.02) and Ogawa (p<0.0001). From a baseline of 13.58, anti-Ogawa GMT increased to 21.95 after the first dose, but rapidly waned to 14.52, 13.13, and 12.78 at months 6, 12 and 24 respectively, and then increased to 13.21, 18.67 and 23.65 at months 30, 36 and 48 respectively. A similar trend was observed for anti-Inaba GMT across the same time points. Conclusion We found that Shanchol™ was immunogenic in our study population and that vibriocidal antibodies may not be a good marker for long-term immunity. The observed rise in titres after 36 months suggests natural exposure, and this may be a critical time window opening for natural transmission in an endemic areas. We recommend re-vaccination at this time point in high risk areas.

Source: UG
Immunogenicity of rotavirus vaccine (RotarixTM) in infants with environmental enteric dysfunction

Introduction Deployment of rotavirus vaccines has contributed to significant declines in diarrheal morbidity and mortality globally. Unfortunately, vaccine performance in low-middle income countries (LMICs) is generally lower than in developed countries. The cause for this has been associated with several host and maternal factors including poor water sanitation and hygiene (WASH) status, which are predominant in LMICs. More recently, environmental enteric dysfunction (EED) has specifically been hypothesized to contribute to poor vaccine uptake and response. The aim of this study was to examine the association between serological biomarkers of EED and seroconversion to rotavirus vaccine in Zambian infants. Methods This was a retrospective cohort study of 142 infants who had been fully immunized with Rotarix™, and had known seroconversion status. Seroconversion was defined as 4-fold or more increase in rotavirus-specific IgA titres between pre-vaccination and one month post-dose two vaccination. We performed ELISA assays to assess soluble CD14 (sCD14), Endotoxin Core IgG Antibodies (EndoCAb), intestinal fatty acid binding protein (i-FABP) and Zonulin according to the manufacturers protocols. Generalised linear model with family-poisson, link-log and robust standard error was used to estimate the independent effects of biomarkers on seroconversion adjusting for important cofounders. Results The median concentration of Zonulin, Soluble CD14, EndoCaB, and IFABP were 209.3 (IQR = 39.7, 395.1), 21.5 (IQR = 21.5, 21.5), 0.3 (IQR = 0.3, 0.3), and 107.7 (IQR = 6.4, 1141.4) respectively. In multivariable analyses adjusting for the independent effect of other biomarkers and confounders (i.e. age of child at vaccination, breast-milk anti-rotavirus IgA, infant serum anti-rotavirus IgG, and IgA seropositivity at baseline), there was strong evidence of about 24% increase in seroconversion due to doubling Zonulin concentration (Adjusted risk ratio (aRR) = 1.24; 95% CI = 1.12 to1.37; p<0.0001). Similarly, we found about 7% increase in seroconversion due to doubling IFABP concentration (aRR = 1.07; 95% CI = 1.02 to 1.13; p = 0.006). Conclusion We found that high levels of zonulin and IFABP played a role in seroconversion. It is plausible that increased gut permeability in EED allows greater uptake of the live virus within the vaccine, but later consequences result in deleterious local structural distortions and malabsorption syndromes. © 2017 Mwape et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Source: UG
Immunogenicity of the pentavalent rotavirus vaccine in African infants

The main research focus of the Electron Microscopy and Histopathology Department in the past 20 years has been in the areas of enteric diarrhoeas with special emphasis on rotavirus. Through its diarrhoea surveillance studies, the Department has helped to firmly establish rotaviruses as a major cause of diarrhoea in children, and document the circulation of unusual rotavirus genotypes in Ghana. The Department has also recently expanded its diagnostic repertoire to include the identification and characterization of noroviruses, astroviruses, and other enteric viruses.

Source: UG
Immunolocalization of pectic polysaccharides during abscission in pea seeds (Pisum sativum L.) and in abscission less def pea mutant seeds

Background: In pea seeds (Pisum sativum L.), the presence of the Def locus determines abscission event between its funicle and the seed coat. Cell wall remodeling is a necessary condition for abscission of pea seed. The changes in cell wall components in wild type (WT) pea seed with Def loci showing seed abscission and in abscission less def mutant peas were studied to identify the factors determining abscission and non-abscission event. Methods: Changes in pectic polysaccharides components were investigated in WT and def mutant pea seeds using immunolabeling techniques. Pectic monoclonal antibodies (1 → 4)-β-d-galactan (LM5), (1 → 5)-α-l-arabinan(LM6), partially de-methyl esterified homogalacturonan (HG) (JIM5) and methyl esterified HG (JIM7) were used for this study. Results: Prior to abscission zone (AZ) development, galactan and arabinan reduced in the predestined AZ of the pea seed and disappeared during the abscission process. The AZ cells had partially de-methyl esterified HG while other areas had highly methyl esterified HG. A strong JIM5 labeling in the def mutant may be related to cell wall rigidity in the mature def mutants. In addition, the appearance of pectic epitopes in two F3 populations resulting from cross between WT and def mutant parents was studied. As a result, we identified that homozygous dominant lines (Def/Def) showing abscission and homozygous recessive lines (def/def) showing non-abscission had similar immunolabeling pattern to their parents. However, the heterogeneous lines (Def/def) showed various immunolabeling pattern and the segregation pattern of the Def locus. Conclusions: Through the study of the complexity and variability of pectins in plant cell walls as well as understanding the segregation patterns of the Def locus using immunolabeling techniques, we conclude that cell wall remodeling occurs in the abscission process and de-methyl esterification may play a role in the non-abscission event in def mutant. Overall, this study contributes new insights into understanding the structural and architectural organization of the cell walls during abscission.

Source: UG
Immunolocalization of the 29 kDa Schistosoma haematobium species-specific antigen: a potential diagnostic marker for urinary schistosomiasis

BACKGROUND: The 29 kDa Schistosoma haematobium species-specific antigen (ShSSA) is of remarkable interest in the diagnosis of urinary schistosomiasis although it had not been fully characterized.METHOD: To determine the biological importance of ShSSA in S. haematobium and pathogenesis of the disease, we immunolocalized ShSSA in schistosome eggshells, miracidia and adult worm sections using indirect fluorescent antibody test (IFAT).RESULTS: ShSSA was strongly immunolocalized in the schistosome eggshells, selective regions of the miracidia body and walls of internal organs such as oviduct, ovary, vitelline duct and gut of the adult worm.CONCLUSION: The strong immunolocalization of ShSSA in schistosome eggshells and adult worm internal organs suggests that the antigens involved in the pathogenesis of urinary schistosomiasis could have originated from the eggs and adult worms of the parasite. The findings also indicate that ShSSA may play a mechanical protective role in the survival of the parasite.

Source: UG
Immunolocalization of the 29 kDa Schistosoma haematobium species-specific antigen: A potential diagnostic marker for urinary schistosomiasis

Background: The 29 kDa Schistosoma haematobium species-specific antigen (ShSSA) is of remarkable interest in the diagnosis of urinary schistosomiasis although it had not been fully characterized. Method: To determine the biological importance of ShSSA in S. haematobium and pathogenesis of the disease, we immunolocalized ShSSA in schistosome eggshells, miracidia and adult worm sections using indirect fluorescent antibody test (IFAT). Results: ShSSA was strongly immunolocalized in the schistosome eggshells, selective regions of the miracidia body and walls of internal organs such as oviduct, ovary, vitelline duct and gut of the adult worm. Conclusion: The strong immunolocalization of ShSSA in schistosome eggshells and adult worm internal organs suggests that the antigens involved in the pathogenesis of urinary schistosomiasis could have originated from the eggs and adult worms of the parasite.

Source: UG
Immunological background in children with persistent diarrhea in Ghana

The Department of Immunology conducts research in the field of immunology of infectious and non-infectious diseases. The Department has the overall goal of contributing knowledge to better diagnosis, management, control and prevention of infectious and non-infectious diseases in Ghana and worldwide. This is consistent with the overall strategy of the Noguchi Memorial Institute for Medical Research (NMIMR) and in line with the strategy of the College of Health Sciences of the University of Ghana.

Source: UG
Immunological unresponsiveness and apoptotic cell death of T cells in measles virus infection

The phenotypic alterations associated with T cells during measles virus infection have been demonstrated and an attempt has been made to show programmed cell death (PCD) of T cells activated in vivo. During the acute phase of illness, activated T cells increased rapidly. Memory T cells (CD45RO+), especially CD8+ memory T cells also tend to increase. During the recovery phase, CD8+ T cells declined rapidly, and naive (CD45RA+) T cells increased in numbers. The anti-CD3 monoclonal antibody-induced expression of interleukin-2 receptor (CD25) was suppressed. However, the addition of phorbol 12-myristate 13-acetate (PMA) caused the significant recovery of CD25 expression. In addition, PCD of activated T cells from measles patients was induced in culture. After triggering of the T cell receptor-CD3 complex, cells became more susceptible to PCD. Interestingly, the addition of PMA could inhibit PCD of activated T cells. Taken together, these data suggest unresponsiveness and activation-induced cell death of T cells during the primary response to measles virus antigens, depending on the activation status of protein kinase C.

Source: UG
Immunomic analysis of the repertoire of T-cell specificities for influenza A virus in humans

Continuing antigenic drift allows influenza viruses to escape antibody-mediated recognition, and as a consequence, the vaccine currently in use needs to be altered annually. Highly conserved epitopes recognized by effector T cells may represent an alternative approach for the generation of a more universal influenza virus vaccine. Relatively few highly conserved epitopes are currently known in humans, and relatively few epitopes have been identified from proteins other than hemagglutinin and nucleoprotein. This prompted us to perform a study aimed at identifying a set of human T-cell epitopes that would provide broad coverage against different virus strains and subtypes. To provide coverage across different ethnicities, seven different HLA supertypes were considered. More than 4,000 peptides were selected from a panel of 23 influenza A virus strains based on predicted high-affinity binding to HLA class I or class II and high conservancy levels. Peripheral blood mononuclear cells from 44 healthy human blood donors were tested for reactivity against HLA-matched peptides by using gamma interferon enzyme-linked immunospot assays. Interestingly, we found that PB1 was the major target for both CD4(+) and CD8(+) T-cell responses. The 54 nonredundant epitopes (38 class I and 16 class II) identified herein provided high coverage among different ethnicities, were conserved in the majority of the strains analyzed, and were consistently recognized in multiple individuals. These results enable further functional studies of T-cell responses during influenza virus infection and provide a potential base for the development of a universal influenza vaccine.

Source: UG
Immunomodulatory and erythropoietic effects of aqueous extract of the fruits of solanum torvum swartz (solanaceae)

Aim The effect of Solanum torvum (Fam: Solanaceae) on delayed type hypersensitivity (DTH) response, hemagglutinating antibody (HA) titer, white blood cells (WBC), red blood cells (RBC) and hemoglobin concentration was investigated in Sprague-Dawley rats to establish immunomodulatory and erythropoietic activity. Materials and Methods Sheep red blood cells (SRBC)-immunized and challenged rats were treated with Solanum torvum extract, levamisole and dexamethasone. Phenylhydrazine (PHZ)-induced anemia in rats was treated with the extract. Results The aqueous Solanum torvum extract and levamisole significantly enhanced DTH response, increased HA titer and WBC count, while dexamethasone significantly decreased DTH response, did not increase HA titer, and did not enhance WBC profile. The extract and Feroglobin, the reference heamatinic, were able to reverse PHZ-induced anemia, and increase the RBCs and Hb concentration above baseline values within 24 days. Conclusion: Solanum torvum extract showed a concentration-dependent immunostimulant and erythropoietic activity.

Source: UG
Immunoproteomics identification of major IgE and IgG4 reactive schistosoma japonicum adult worm antigens using chronically infected human plasma

The Department of Immunology conducts research in the field of immunology of infectious and non-infectious diseases. The Department has the overall goal of contributing knowledge to better diagnosis, management, control and prevention of infectious and non-infectious diseases in Ghana and worldwide. This is consistent with the overall strategy of the Noguchi Memorial Institute for Medical Research (NMIMR) and in line with the strategy of the College of Health Sciences of the University of Ghana.

Source: UG
Immunostaining in hirschsprung's disease: Al-khobar experience

The role of immunoperoxidase stains in the diagnosis of Hirschsprung's disease was evaluated in a total of 60 sections from 40 cases originally diagnosed based on the findings from hematoxylin-eosin staining done in our laboratory. Neuron-specific enolase was very effective in highlighting rare scanty ganglion cells in two cases that had been classified as aganglionic. S-100 protein was effective in illustrating nerve fiber proliferation in submucosa and lamina propria, which may be difficult to demonstrate using hematoxylin-eosin alone. We recommend the use of immunoperoxidase stains as an important adjunct to hematoxylineosin for the diagnosis of Hirschsprung's disease when using paraffin sections.

Source: UG