Biology subjects

Ochola, L.

Publications and source records attributed to Ochola, L..

3 recordsLinked to original sources

bioRxiv2021

Distinct gene regulatory signatures of dominance rank and social bond strength in wild baboons

The social environment is a major determinant of morbidity, mortality, and Darwinian fitness in social animals. Recent studies have begun to uncover the molecular processes associated with these relationships, but the degree to which they vary across different dimensions of the social environment remains unclear. Here, we draw on a long-term field study of wild baboons to compare the signatures of affiliative and competitive aspects of the social environment in white blood cell gene regulation, under both immune stimulated and non-stimulated conditions. We find that the effects of dominance rank on gene expression are directionally opposite in males versus females, such that high-ranking males resemble low-ranking females, and vice-versa. Among females, rank and social bond strength are both reflected in the activity of cellular metabolism and proliferation genes. However, pronounced rank-related differences in baseline immune gene activity are near-absent for social bond strength, while only bond strength predicts the fold-change response to immune (lipopolysaccharide) stimulation. Together, our results indicate that the directionality and magnitude of social effects on gene regulation depend on the aspect of the social environment under study. This heterogeneity may help explain why social environmental effects on health and longevity can also vary between measures.

genomics↗

bioRxiv2021

Concomitant infection with Leishmania donovani and Plasmodium berghei alters clinical and immune responses in BALB/c mice

Malaria and visceral leishmaniasis coexist in the same geographical regions. However, dual co-infection with parasites causing these diseases and their impact on public health is poorly documented. Interactions between these parasites may play a role in disease outcome. The present study set out to evaluate the clinical and immunological parameters following Leishmania donovani and Plasmodium berghei co-infection in BALB/c mice. Mice were divided into four groups; L. donovani- only, L. donovani- P. berghei, P. berghei- only and naive. Body weight, parasite burden, total IgG, IFN-{gamma} and IL-4 responses were determined. To determine the survival rate, four mice were used from each group. Tissues for histological analysis were taken from spleen, liver and brain. Results indicated significant differences in body weight (P<0.0001), L. donovani parasite load (P< 0.0001), L. donovani IgG (P< 0.0001), P. berghei parasitemia (P= 0.0222), P. berghei IgG (P= 0.002), IFN-{gamma} (P<0.0001) and IL-4 (P<0.0001) in dual-infected mice. There was no correlation between L. donovani parasite load and IgG responses in single or dual infections, while there was a positive relationship of P. berghei parasitemia and IgG responses in the dual infection group only. Plasmodium berghei had the highest mortality rate compared to L. donovani- only and L. donovani- P. berghei infected mice groups. Histological analyses showed enlarged red and white pulps and pathological changes in the spleen, liver and brain tissues which were less pronounced in co- infected group. We conclude that L. donovani and P. berghei co-infection reduces disease severity and these changes seem to correlate with variation in serum IgG and cytokines (IFN-{gamma} and IL-4). Therefore, the study recommends the importance of inclusion of early screening of malaria in Visceral Leishmaniasis patients in regions where malaria is co- endemic. Author SummaryVisceral leishmaniasis and malaria are the principal causes of morbidity and mortality affiliated with parasitic diseases universally warranting the necessity to investigate the control and immunology of the infections. Notwithstanding the probable incidences of leishmaniasis- malaria infections in endemic regions are not readily eminent to the clinicians if an individual is co-infected and almost frequently, such patients develop a fever and are customarily treated against malaria and hence the need to study disease progression and outcome during a co- infection. Furthermore, it is unclear if this co-infection could impede the clinical symptoms of the separate diseases and thus the necessity to demonstrate disease outcome in experimentally co-infected murine models. This present study was crucial to find out whether this mode of co- infection alters disease progression and enhanced severity leading to high morbidity and mortality. This current research was an imperative step in using murine as a model in the study of disease outcome and immunopathogenesis of visceral leishmaniasis and malaria co-infection thus establishing the feasibility of co-infecting the BALB/c mice with Leishmania donovani and Plasmodium berghei.

immunology↗

bioRxiv2018

A survey of influenza subtypes in olive baboons in selected areas in Kenya

3.BackgroundWorldwide infections with influenza A viruses are associated with substantial illness and death among mammals and birds, in humans it accounts for 250,000-500,000 deaths per year its continuous mutation in different hosts poses a threat that can result in the emergence of a novel virus with an ability to cause a widespread pandemic. Surveillance of Influenza A viral genome from diverse hosts and subtyping is critical in understanding of the antigenic shift and drift of the influenza virus especially in hosts that are closely related to human beings like the Non-Human Primates (NHPs),pigs and birds. This study therefore identified the influenza subtypes circulating in Papio anubis (Olive baboons) at the interface of human and NHPs in Kenya.\n\nMethodsFifty nasal swabs samples were collected from baboons from the colony at the Institute of Primate Research (IPR), these animals were originally collected from Olorbototo, Yatta, Aberdares, Movoloni and Laikipia. The nasal swabs were collected in viral transport media using sterile dacron swabs and stored at -80{degrees}C. In this study, samples were screened initially using real time RT-PCR-CDC protocol for influenza A virus detection that targets the matrix gene and twenty five were found to be positive.\n\nResultsThe proportion positive were as follows, Olorbototo (75%), Ngurumani (44%) Aberdares (43%), Mavoloni (37.5%), Yatta (14%), and Laikipia (9%). These samples were taken through conventional PCR to amplify the haemagglutinin, neuraminidase and the matrix genes and eight samples were successfully amplified and later sequenced through 24-capillaries ABI 3500 XL Genetic Analyzer.Upon BLAST of these sequences, influenza subtypes H1N1 and H3N2 were detected. It was observed that the subtypes in baboons were as follows Olorbototo H1N1,Yatta H3N2, Aberdares H3N2, Mavoloni H1N1, Ngurumani H1N1 and Laikipia H1N1.Upon further analysis, the influenza positive Olive baboons were found to have been reared in the colony at at IPR colony for between 1-2 years and were in close contact with personnel.\n\nCoclusionGiven the presence of H1N1 and H3N2 subtypes in baboons suggests that baboons can be naturally infected with seasonal endemic human influenza viruses, avian emerging pandemic or pandemic swine flu origin.

molecular biology↗