scholarly journals Analysis of spleen histopathology, splenocyte composition and haematological parameters in four strains of mice infected with Plasmodium berghei K173

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Huajing Wang ◽  
Shuo Li ◽  
Zhao Cui ◽  
Tingting Qin ◽  
Hang Shi ◽  
...  
Keyword(s):  
Plasmodium Berghei ◽  
Parasite Burden ◽  
Splenic Macrophages ◽  
Immune Mediated ◽  
Infected Rbcs ◽  
Host Mortality ◽  
Km Mice ◽  
Different Strains ◽  
Host Parasite

Abstract Background Malaria is a fatal disease that presents clinically as a continuum of symptoms and severity, which are determined by complex host-parasite interactions. Clearance of infection is believed to be accomplished by the spleen and mononuclear phagocytic system (MPS), independent of artemisinin treatment. The spleen filters infected red blood cells (RBCs) from circulation through immune-mediated recognition of the infected RBCs followed by phagocytosis. This study evaluated the tolerance of four different strains of mice to Plasmodium berghei strain K173 (P. berghei K173), and the differences in the role of the spleen in controlling P. berghei K173 infection. Methods Using different strains of mice (C57BL/6, BALB/C, ICR, and KM mice) infected with P. berghei K173, the mechanisms leading to splenomegaly, histopathology, splenocyte activation and proliferation, and their relationship to the control of parasitaemia and host mortality were examined and evaluated. Results Survival time of mice infected with P. berghei K173 varied, although the infection was uniformly lethal. Mice of the C57BL/6 strain were the most resistant, while mice of the strain ICR were the most susceptible. BALB/c and KM mice were intermediate. In the course of P. berghei K173 infection, all infected mice experienced significant splenomegaly. Parasites were observed in the red pulp at 3 days post infection (dpi) in all animals. All spleens retained late trophozoite stages as well as a fraction of earlier ring-stage parasites. The percentages of macrophages in infected C57BL/6 and KM mice were higher than uninfected mice on 8 dpi. Spleens of infected ICR and KM mice exhibited structural disorganization and remodelling. Furthermore, parasitaemia was significantly higher in KM versus C57BL/6 mice at 8 dpi. The percentages of macrophages in ICR infected mice were lower than uninfected mice, and the parasitaemia was higher than other strains. Conclusions The results presented here demonstrate the rate of splenic mechanical filtration and that splenic macrophages are the predominant roles in controlling an individual’s total parasite burden. This can influence the pathogenesis of malaria. Finally, different genetic backgrounds of mice have different splenic mechanisms for controlling malaria infection.

scholarly journals Analysis of Spleen Histopathology, Splenocyte composition and Hematological Parameters in Mice Infected with Plasmodium berghei K173

2021 ◽  
Author(s):  
Huajing Wang ◽  
Shuo Li ◽  
Zhao Cui ◽  
Tingting Qin ◽  
Hang Shi ◽  
...  
Keyword(s):  
Hematological Parameters ◽  
Parasite Burden ◽  
Splenic Macrophages ◽  
Immune Mediated ◽  
Infected Rbcs ◽  
Host Mortality ◽  
Km Mice ◽  
Different Strains ◽  
Host Parasite ◽  
Late Trophozoite

ABSTRACTMalaria is a fatal disease that presents clinically as a continuum of symptoms and severity, which are determined by complex host-parasite interactions. Clearance of infection is believed to be accomplished by the spleen and mononuclear phagocytic system (MPS), both in the presence and absence of artemisinin treatment. The spleen filters infected RBCs from circulation through immune-mediated recognition of the infected RBCs followed by phagocytosis. Using different strains of mice infected with P. berghei K173 (PbK173), the mechanisms leading to splenomegaly, histopathology, splenocyte activation and proliferation, and their relationship to control of parasitemia and host mortality were examined. Survival time of mice infected with PbK173 varied, although the infection was uniformly lethal. Mice of the C57BL/6 strain were the most resistant, while mice of the strain ICR were the most susceptible. BALB/c and KM mice were intermediate. In the course of PbK173 infection, both strains of mice experienced significant splenomegaly. Parasites were observed in the red pulp at 3 days post infection in all animals. All spleens retained late trophozoite stages as well as a fraction of earlier ring-stage parasites. The percentages of macrophages in infected C57BL/6 and KM mice were higher than uninfected mice on 8 dpi. Spleens of infected ICR and KM mice exhibited structural disorganization and remodeling. Furthermore, parasitemia was significantly higher in KM versus C57BL/6 mice at 8 dpi. The percentages of macrophages in ICR infected mice were lower than uninfected mice, and the parasitemia was higher than other strains. The results presented here demonstrate the rate of splenic mechanical filtration and the splenic macrophages likely contribute to an individual’s total parasite burden. This in turn can influence the pathogenesis of malaria. Finally, different genetic backgrounds of mice have different splenic mechanisms for controlling malaria infection.

The regulation of host population growth by parasitic species

Parasitology ◽  
1978 ◽  
Vol 76 (2) ◽  
pp. 119-157 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Population Growth ◽  
Reproductive Potential ◽  
Parasite Burden ◽  
Host Population ◽  
Parasitic Species ◽  
Regulatory Influence ◽  
Host Mortality ◽  
Parasite Reproduction ◽  
Over Dispersion ◽  
Host Parasite

SummaryThe nature of parasitism at the population level is defined in terms of the parasite's influence on the natural intrinsic growth rate of its host population. It is suggested that the influence on this rate is related to the average parasite burden/host and hence to the statistical distribution of parasites within the host population.Theoretical models of host–parasite associations are used to assess the regulatory influence of parasitic species on host population growth. Model predictions suggest that three specific groups of population processes are of particular importance: over-dispersion of parasite numbers/host, density dependence in parasite mortality or reproduction and parasite-induced host mortality that increases faster than linearly with the parasite burden. Other population mechanisms are shown to have a destabilizing influence, namely: parasite-induced reduction in host reproductive potential, direct parasite reproduction within the host and time delays in the development of transmission stages of the parasite.These regulatory and destabilizing processes are shown to be commonly observed features of natural host-parasite associations. It is argued that interactions in the real world are characterized by a degree of tension between these regulatory and destabilizing forces and that population rate parameter values in parasite life-cycles are very far from being a haphazard selection of all numerically possible values. It is suggested that evolutionary pressures in observed associations will tend to counteract a strong destabilizing force by an equally strong regulatory influence. Empirical evidence is shown to support this suggestion in, for example, associations between larval digeneans and molluscan hosts (parasite-induced reduction in host reproductive potential counteracted by tight density-dependent constraints on parasite population growth), and interactions between protozoan parasites and mammalian hosts (direct parasite reproduction counteracted by a well-developed immunological response by the host).The type of laboratory and field data required to improve our understanding of the dynamical properties of host–parasite population associations is discussed and it is suggested that quantitative measurement of rates of parasite-induced host mortality, degrees of over-dispersion, transmission rates and reproductive and mortality rates of both host and parasite would provide an important first step. The value of laboratory work in this area is demonstrated by reference to studies which highlight the regulatory influence of parasitic species on host population growth.

Mouse background and IVIG dosage are critical in establishing the role of inhibitory Fcγ receptor for the amelioration of experimental ITP

Blood ◽  
2012 ◽  
Vol 119 (22) ◽  
pp. 5261-5264 ◽  
Author(s):  
Danila Leontyev ◽  
Yulia Katsman ◽  
Donald R. Branch
Keyword(s):  
Intravenous Immunoglobulin ◽  
Immune Thrombocytopenia ◽  
Published Data ◽  
Therapeutic Action ◽  
Wild Type ◽  
Fcγ Receptor ◽  
Splenic Macrophages ◽  
Different Strains ◽  
Deficient Mice

A recognized paradigm for the therapeutic action of intravenous immunoglobulin (IVIG) in immune thrombocytopenia (ITP) involves up-regulation of the inhibitory Fcγ receptor (FcγRIIB) in splenic macrophages. However, published data have indicated that opposing results are obtained when using FcγRIIB-deficient mice on different strain backgrounds. Herein we show BALB/c FcγRIIB−/− and wild-type, with or without spleens, all recover ITP with similar dynamics after IVIG (1 g/kg) treatment; however, this was not the case for C57BL/6 (B6) FcγRIIB−/−. In investigating this conundrum, we found that wild-type B6 mice are much less sensitive than BALB/c to IVIG-mediated amelioration of ITP, requiring approximately 2- to 2.5-fold more IVIG than BALB/c. When using 2.5 g/kg IVIG in FcγRIIB−/− B6 mice, amelioration of ITP was as in wild-type in all animals. Our findings led us to the conclusion that different strains of mice respond differently to IVIG and that FcγRIIB plays no role in the mechanism of effect of IVIG in experimental ITP.

The influence of Hymenolepis diminuta on the survival and fecundity of the intermediate host, Tribolium confusum

Parasitology ◽  
1980 ◽  
Vol 81 (2) ◽  
pp. 405-421 ◽  
Author(s):  
Anne E. Keymer
Keyword(s):  
Experimental Study ◽  
Intermediate Host ◽  
Parasite Burden ◽  
Tribolium Confusum ◽  
Hymenolepis Diminuta ◽  
Density Dependent ◽  
Host Mortality ◽  
Host Parasite ◽  
The Relationship ◽  
High Parasite

SUMMARYAn experimental study of the effects of parasitism by H. diminuta on the intermediate host, Tribolium confusum, is described. No density- dependent constraints on parasite establishment within individual hosts are evident, although a reduction in cysticercoid size at high parasite burdens is demonstrated. The relationship between parasite burden, host mortality and host fecundity is investigated. Host mortality is linearly related to parasite burden, whereas the relationship between parasite burden and host fecundity is non-linear. There is no difference in viability between eggs from infected and uninfected females. The generative causes of these effects are not investigated experimentally, although it is postulated that survival is related to the degree of damage to the midgut wall caused by parasite penetration, and fecundity to the biomass of parasites harboured by the host. The significance of these effects is discussed in relation to the overall dynamics of the host-parasite association.

A pro-inflammatory role of type 2 innate lymphoid cells in murine immune-mediated hepatitis

2015 ◽  
Vol 53 (12) ◽  
Author(s):  
K Karimi ◽  
K Neumann ◽  
J Meiners ◽  
R Voetlause ◽  
W Dammermann ◽  
...  
Keyword(s):  
Innate Lymphoid Cells ◽  
Lymphoid Cells ◽  
Immune Mediated

Monitoring the marine environment for small round structured viruses (SRSVS): a new approach to combating the transmission of these viruses by molluscan shellfish

1998 ◽  
Vol 38 (12) ◽  
pp. 51-56 ◽  
Author(s):  
K. Henshilwood ◽  
J. Green ◽  
D. N. Lees
Keyword(s):  
Enteric Virus ◽  
Winter Period ◽  
Rt Pcr ◽  
Cloning And Sequencing ◽  
New Approach ◽  
Human Enteric Virus ◽  
Different Strains ◽  
The Uk ◽  
Public Health Protection

This study investigates human enteric virus contamination of a shellfish harvesting area. Samples were analysed over a 14-month period for Small Round Structured Viruses (SRSVs) using a previously developed nested RT-PCR. A clear seasonal difference was observed with the largest numbers of positive samples obtained during the winter period (October to March). This data concurs with the known winter association of gastroenteric illness due to oyster consumption in the UK and also with the majority of the outbreaks associated with shellfish harvested from this area during the study period. RT-PCR positive amplicons were further characterised by cloning and sequencing. Sequence analysis of the positive samples identified eleven SRSV strains, of both Genogroup I and Genogroup II, occurring throughout the study period. Many shellfish samples contained a mixture of strains with a few samples containing up to three different strains with both Genogroups represented. The observed common occurrence of strain mixtures may have implications for the role of shellfish as a vector for dissemination of SRSV strains. These results show that nested RT-PCR can identify SRSV contamination in shellfish harvesting areas. Virus monitoring of shellfish harvesting areas by specialist laboratories using RT-PCR is a possible approach to combating the transmission of SRSVs by molluscan shellfish and could potentially offer significantly enhanced levels of public health protection.

scholarly journals Kidney organoid systems for studies of immune-mediated kidney diseases: challenges and opportunities

2021 ◽  
Author(s):  
Melissa C. Stein ◽  
Fabian Braun ◽  
Christian F. Krebs ◽  
Madeleine J. Bunders
Keyword(s):  
Kidney Diseases ◽  
Three Dimensional ◽  
Renal Tissue ◽  
Chronic Kidney Diseases ◽  
Immune Mediated ◽  
Primary Epithelial Cell ◽  
Challenges And Opportunities ◽  
Underlying Mechanisms ◽  
Global Population

AbstractAcute and chronic kidney diseases are major contributors to morbidity and mortality in the global population. Many nephropathies are considered to be immune-mediated with dysregulated immune responses playing an important role in the pathogenesis. At present, targeted approaches for many kidney diseases are still lacking, as the underlying mechanisms remain insufficiently understood. With the recent development of organoids—a three-dimensional, multicellular culture system, which recapitulates important aspects of human tissues—new opportunities to investigate interactions between renal cells and immune cells in the pathogenesis of kidney diseases arise. To date, kidney organoid systems, which reflect the structure and closer resemble critical aspects of the organ, have been established. Here, we highlight the recent advances in the development of kidney organoid models, including pluripotent stem cell-derived kidney organoids and primary epithelial cell-based tubuloids. The employment and further required advances of current organoid models are discussed to investigate the role of the immune system in renal tissue development, regeneration, and inflammation to identify targets for the development of novel therapeutic approaches of immune-mediated kidney diseases.

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