scholarly journals Hemocyte-hemocyte adhesion by granulocytes is associated with cellular immunity in the cricket, Gryllus bimaculatus

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Youngwoo Cho ◽  
Saeyoull Cho
Keyword(s):  
Immune Responses ◽  
Cellular Immunity ◽  
Post Infection ◽  
Plasma Membranes ◽  
Immune Cell ◽  
Gryllus Bimaculatus ◽  
Cellular Immune Responses ◽  
Size And Morphology ◽  
Cellular Immune ◽  
Unique Mechanism

AbstractIn this study, more than 1,000 cricket (Gryllus bimaculatus) hemocytes were classified based on their size and morphology. These hemocytes were classified into six types: granulocytes, plasmatocytes, prohemocytes, spherulocytes, coagulocytes, and oenocytoids. Hemocyte cultures was observed in real time to determine which hemocytes were associated with cellular immune responses against potential pathogens. Granulocytes were identified as the professional immune cell that mediates nodulation, encapsulation, and phagocytosis of pathogens. Granulocytes have been shown to actively produce various sticky nets (amoeba-like hairs and extracellular traps) from their plasma membranes that they use to gather other hemocytes and to implement cellular immune responses. The activation of lysosomes in granulocytes started at 4 h, peaked at 12 h, and returned to baseline by 24 h post-infection. At 48 h post-infection, cells could be found within the cytoplasm of granulocytes and reactivated lysosomes surrounding these cells were visible. This result seems to reflect a phenomenon in which necrotic granulocytes are removed by other healthy granulocytes. This unique mechanism of cellular immunity is therefore a way to efficiently and effectively remove pathogens and simultaneously maintain healthy hemocytes.

scholarly journals Implementation of Adenovirus-Mediated Pulmonary Expression of Human ACE2 in HLA Transgenic Mice Enables Establishment of a COVID-19 Murine Model for Assessment of Immune Responses to SARS-CoV-2 Infection

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 940
Author(s):  
Theodor Chitlaru ◽  
Erez Bar-Haim ◽  
Liat Bar-On ◽  
Shahar Rotem ◽  
Hila Cohen ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Immune Responses ◽  
Post Infection ◽  
High Reproducibility ◽  
Cellular Immune Responses ◽  
Loss Of Weight ◽  
Transient Loss ◽  
Different Strains ◽  
Cellular Immune ◽  
Human Specific

HLA transgenic mice are instrumental for evaluation of human-specific immune responses to viral infection. Mice do not develop COVID-19 upon infection with SARS-CoV-2 due to the strict tropism of the virus to the human ACE2 receptor. The aim of the current study was the implementation of an adenovirus-mediated infection protocol for human ACE2 expression in HLA transgenic mice. Transient pulmonary expression of the human ACE2 receptor in these mice results in their sensitisation to SARS-CoV-2 infection, consequently providing a valuable animal model for COVID-19. Infection results in a transient loss in body weight starting 3 days post-infection, reaching 20–30% loss of weight at day 7 and full recovery at days 11–13 post-infection. The evolution of the disease revealed high reproducibility and very low variability among individual mice. The method was implemented in two different strains of HLA immunized mice. Infected animals developed strong protective humoral and cellular immune responses specific to the viral spike-protein, strictly depending on the adenovirus-mediated human ACE2 expression. Convalescent animals were protected against a subsequent re-infection with SARS-CoV-2, demonstrating that the model may be applied for assessment of efficacy of anti-viral immune responses.

scholarly journals Changes in cellular immune responses of Chilo suppressalis Walker (Lepidoptera: Crambidae) due to pyriproxyfen treatment

2015 ◽  
Vol 55 (3) ◽  
pp. 287-293 ◽  
Author(s):  
Seyyedeh Kimia Mirhaghparast ◽  
Arash Zibaee ◽  
Hassan Hoda ◽  
Jalal Jalali Sendi
Keyword(s):  
Immune Responses ◽  
Cellular Immunity ◽  
Entomopathogenic Fungus ◽  
The Other ◽  
Chilo Suppressalis ◽  
Combined Effects ◽  
Phenoloxidase Activity ◽  
Cellular Immune Responses ◽  
Cellular Immune

Abstract The effects of pyriproxyfen were determined on the cellular immunity and phenoloxidase activity in the 4th instar larvae of Chilo suppressalis Walker. The bioassay results revealed the effective concentrations of: 10L : 18C, 30L : 72C and 50L : 190C μg · ml−1. The sole effect of 18 and 72 μg · ml−1 concentrations at intervals of 1–3 h caused a higher number of total hemocytes in the treated larvae than the control, but the reverse results were observed after 6–24 h. The number of plasmatocytes was lower than that of the control for intervals of 3–24 h but the number of granulocytes was higher than the control after 1–3 h although no significant differences were observed at the other times. In the treated larvae, the activities of phenoloxidase were higher and lower than those of the control after 1–3 h and 6–24 h, respectively. The combined effects of pyriproxyfen and the entomopathogenic fungus, Beauveria bassiana isolate B3 caused higher numbers of total hemocytes, plasmatocytes, and granulocytes in the treated larvae by use of the three concentrations of pyriproxyfen, at intervals of 6 and 12 h. Although the numbers of nodules in the larvae treated with concentrations of 18 μg · ml−1 were higher than those of other treatments, the overall numbers were lower than those of the control. Finally, the activity of phenoloxidase in the treated larvae was higher than that of the control, at intervals of 6 and 12 h post-treatment. Findings of the current study indicate an intervening role of pyriproxyfen in the cellular immunity of C. suppressalis to entomopathogenic objects.

scholarly journals Immune Modulation in PrimaryVaccinia virusZoonotic Human Infections

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Juliana Assis Silva Gomes ◽  
Fernanda Fortes de Araújo ◽  
Giliane de Souza Trindade ◽  
Bárbara Resende Quinan ◽  
Betânia Paiva Drumond ◽  
...  
Keyword(s):  
Immune Responses ◽  
Immune Modulation ◽  
Immune Cell ◽  
Acute Infection ◽  
Immunological Responses ◽  
Cellular Immune Responses ◽  
Cell Compartments ◽  
Acute Infections ◽  
Human Infections ◽  
Cellular Immune

In 2010, the WHO celebrated the 30th anniversary of the smallpox eradication. Ironically, infections caused by viruses related to smallpox are being increasingly reported worldwide, includingMonkeypox,Cowpox,andVaccinia virus(VACV). Little is known about the human immunological responses elicited during acute infections caused by orthopoxviruses. We have followed VACV zoonotic outbreaks taking place in Brazil and analyzed cellular immune responses in patients acutely infected by VACV. Results indicated that these patients show a biased immune modulation when compared to noninfected controls. Amounts of B cells are low and less activated in infected patients. Although present, T CD4+cells are also less activated when compared to noninfected individuals, and so are monocytes/macrophages. Similar results were obtained when Balb/C mice were experimentally infected with a VACV sample isolated during the zoonotic outbreaks. Taking together, the data suggest that zoonotic VACVs modulate specific immune cell compartments during an acute infection in humans.

scholarly journals Erythropoietin Protects against Murine Cerebral Malaria through Actions on Host Cellular Immunity

2013 ◽  
Vol 82 (1) ◽  
pp. 165-173 ◽  
Author(s):  
Xu Wei ◽  
Ying Li ◽  
Xiaodan Sun ◽  
Xiaotong Zhu ◽  
Yonghui Feng ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cerebral Malaria ◽  
Cellular Immunity ◽  
Inflammatory Responses ◽  
Cytotoxic T Lymphocyte ◽  
Endothelial Activation ◽  
Content Type ◽  
Cellular Immune Responses ◽  
Proinflammatory Responses ◽  
Cellular Immune

ABSTRACTCerebral malaria (CM) is associated with excessive host proinflammatory responses and endothelial activation. The hematopoietic hormone erythropoietin (EPO) possesses neuroprotective functions in animal models of ischemic-hypoxic, traumatic, and inflammatory injuries. In thePlasmodium bergheiANKA model of experimental CM (ECM), recombinant human EPO (rhEPO) has shown evident protection against ECM. To elucidate the mechanism of EPO in this ECM model, we investigated the effect of rhEPO on host cellular immune responses. We demonstrated that improved survival of mice with ECM after rhEPO treatment was associated with reduced endothelial activation and improved integrity of the blood-brain barrier. Our results revealed that rhEPO downregulated the inflammatory responses by directly inhibiting the levels and functions of splenic dendritic cells. Conversely, rhEPO treatment led to significant expansion of regulatory T cells and increased expression of the receptor cytotoxic T lymphocyte antigen 4 (CTLA-4). The data presented here provide evidence of the direct effect of rhEPO on host cellular immunity during ECM.

scholarly journals Differential immunogenicity of homologous versus heterologous boost in Ad26.COV2.S vaccine recipients.

2021 ◽  
Author(s):  
Nicholas Kim Huat Khoo ◽  
Joey Ming Er Lim ◽  
Upkar Singh Gill ◽  
Ruklanthi de Alwis ◽  
Nicole Tan ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cellular Immunity ◽  
Immunological Parameters ◽  
Humoral And Cellular Immunity ◽  
Cellular Immune Responses ◽  
Cellular Immune ◽  
The Impact ◽  
Heterologous Boost

Protection offered by COVID-19 vaccines wanes over time, requiring an evaluation of different boosting strategies to revert such a trend and enhance the quantity and quality of Spike-specific humoral and cellular immune responses. These immunological parameters in homologous or heterologous vaccination boosts have thus far been studied for mRNA and ChAdOx1 nCoV-19 vaccines, but knowledge on individuals who received a single dose of Ad26.COV2.S is lacking. We studied Spike-specific humoral and cellular immunity in Ad26.COV2.S vaccinated individuals (n=55) who were either primed with Ad26.COV2.S only (n=13), or boosted with a homologous (Ad26.COV2.S, n=28) or heterologous (BNT162b2, n=14) second dose. We compared our findings with the results found in individuals vaccinated with a single (n=16) or double (n=44) dose of BNT162b2. We observed that a strategy of heterologous vaccination enhanced the quantity and breadth of both, Spike-specific humoral and cellular immunity in Ad26.COV2.S vaccinated. In contrast, the impact of homologous boost was quantitatively minimal in Ad26.COV2.S vaccinated and Spike-specific antibodies and T cells were narrowly focused to the S1 region. Although a direct association between quantity and quality of immunological parameters and in vivo protection has not been demonstrated, the immunological features of Spike-specific humoral and cellular immune responses support the utilization of a heterologous strategy of vaccine boost in individuals who received Ad26.COV2.S vaccination.

Sign in / Sign up

Export Citation Format

Share Document