scholarly journals The Diverse Functions of the Ubiquitous Fcγ Receptors and Their Unique Constituent, FcRγ Subunit

Pathogens ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 140 ◽  
Author(s):  
Thamer A. Hamdan ◽  
Philipp A. Lang ◽  
Karl S. Lang
Keyword(s):  
Immune Response ◽  
Specific Binding ◽  
Structural Diversity ◽  
Structural Heterogeneity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Biological Functions ◽  
Natural Cytotoxicity ◽  
Fcγ Receptors ◽  
Γ Subunit ◽  
Acute Viral Infection

Fc gamma receptors (FcγRs) are widely expressed on a variety of immune cells and play a myriad of regulatory roles in the immune system because of their structural diversity. Apart from their indispensable role in specific binding to the Fc portion of antibody subsets, FcγRs manifest diverse biological functions upon binding to their putative ligands. Examples of such manifestation include phagocytosis, presentation of antigens, mediation of antibody-dependent cellular cytotoxicity, anaphylactic reactions, and the promotion of apoptosis of T cells and natural killer cells. Functionally, the equilibrium between activating and inhibiting FcγR maintains the balance between afferent and efferent immunity. The γ subunit of the immunoglobulin Fc receptor (FcRγ) is a key component of discrete immune receptors and Fc receptors including the FcγR family. Furthermore, FcγRs exert a key role in terms of crosslinking the innate and adaptive workhorses of immunity. Ablation of one of these receptors might positively or negatively influence the immune response. Very recently, we discovered that FcRγ derived from natural cytotoxicity triggering receptor 1 (NCR1) curtails CD8+ T cell expansion and thereby turns an acute viral infection into a chronic one. Such a finding opens a new avenue for targeting the FcγRs as one of the therapeutic regimens to boost the immune response. This review highlights the structural heterogeneity and functional diversity of the ubiquitous FcγRs along with their featured subunit, FcRγ.

scholarly journals Comparable Long-Term Rabies Immunity in Foxes after IntraMuscular and Oral Application Using a Third-Generation Oral Rabies Virus Vaccine

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 49
Author(s):  
Verena te Kamp ◽  
Virginia Friedrichs ◽  
Conrad M. Freuling ◽  
Ad Vos ◽  
Madlin Potratz ◽  
...  
Keyword(s):  
Immune Response ◽  
Rabies Virus ◽  
Specific Binding ◽  
Lethal Dose ◽  
Genetically Engineered ◽  
Routes Of Administration ◽  
Safety Studies ◽  
Oral Rabies Vaccine ◽  
Cellular Immune

The live genetically-engineered oral rabies virus (RABV) variant SPBN GASGAS induces long-lasting immunity in foxes and protection against challenge with an otherwise lethal dose of RABV field strains both after experimental oral and parenteral routes of administration. Induction of RABV-specific binding antibodies and immunoglobulin isotypes (IgM, total IgG, IgG1, IgG2) were comparable in orally and parenterally vaccinated foxes. Differences were only observed in the induction of virus-neutralizing (VNA) titers, which were significantly higher in the parenterally vaccinated group. The dynamics of rabies-specific antibodies pre- and post-challenge (365 days post vaccination) suggest the predominance of type-1 immunity protection of SPBN GASGAS. Independent of the route of administration, in the absence of IgG1 the immune response to SPBN GAGAS was mainly IgG2 driven. Interestingly, vaccination with SPBN GASGAS does not cause significant differences in inducible IFN-γ production in vaccinated animals, indicating a relatively weak cellular immune response during challenge. Notably, the parenteral application of SPBN GASGAS did not induce any adverse side effects in foxes, thus supporting safety studies of this oral rabies vaccine in various species.

GAMYB TF modulates bHLH142 and is homeostatically regulated by TDR TF during rice anther tapetal and pollen development

2021 ◽  
Author(s):  
Swee-Suak Ko ◽  
Min-Jeng Li ◽  
Yi-Cheng Ho ◽  
Chun-Ping Yu ◽  
Ting-Ting Yang ◽  
...  
Keyword(s):  
Pollen Development ◽  
Molecular Mechanisms ◽  
Early Stage ◽  
Specific Binding ◽  
Biological Functions ◽  
Altered Expression ◽  
Regulatory Pathways ◽  
E Box ◽  
And Function ◽  
Different Tissues

Abstract GAMYB, UDT1, TIP2/bHLH142, TDR, and EAT1/DTD are important transcription factors (TFs) that play a crucial role during rice pollen development. This study demonstrates that bHLH142 acts downstream of UDT1 and GAMYB and works as a “hub” in these two pollen pathways. We show that GAMYB modulates bHLH142 expression through specific binding to the MYB motif of bHLH142 promoter during early stage of pollen development; while TDR acts as a transcriptional repressor of the GAMYB modulation of bHLH142 by binding to the E-box close to the MYB motif on the promoter. The altered expression of TFs highlights the importance that a tight, precise, and coordinated regulation among these TFs is essential for normal pollen development. Most notably, this study illustrates the regulatory pathways of GAMYB and UDT1 that rely on bHLH142 in a direct and an indirect manner, respectively, and function in different tissues with distinct biological functions during pollen development. This study advances our understanding of the molecular mechanisms of rice pollen development.

scholarly journals Macrophages and Iron: A Special Relationship

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1585
Author(s):  
Stefania Recalcati ◽  
Gaetano Cairo
Keyword(s):  
Immune Response ◽  
Iron Metabolism ◽  
Blood Cells ◽  
Essential Role ◽  
Cell Types ◽  
Special Relationship ◽  
Biological Functions ◽  
Principal Function ◽  
Iron Trafficking ◽  
Hemoglobin Degradation

Macrophages perform a variety of different biological functions and are known for their essential role in the immune response. In this context, a principal function is phagocytic clearance of pathogens, apoptotic and senescent cells. However, the major targets of homeostatic phagocytosis by macrophages are old/damaged red blood cells. As such, macrophages play a crucial role in iron trafficking, as they recycle the large quantity of iron obtained by hemoglobin degradation. They also seem particularly adapted to handle and store amounts of iron that would be toxic to other cell types. Here, we examine the specific and peculiar iron metabolism of macrophages.

scholarly journals Immunobiology of mild micronutrient deficiencies

2001 ◽  
Vol 85 (S2) ◽  
pp. S75-S80 ◽  
Author(s):  
P. Bhaskaram
Keyword(s):  
Immune Response ◽  
Developing Countries ◽  
Vitamin A ◽  
Immune Homeostasis ◽  
Micronutrient Deficiencies ◽  
Biological Functions ◽  
Critical Determinant ◽  
Iron And Zinc ◽  
Microbe Interactions ◽  
Host Microbe Interactions

Nutrition is a critical determinant of the outcome of host microbe interactions through a modulation of the immune response. Besides macronutrient malnutrition, deficiencies of several macronutrients also influence immune homeostasis and thus affect infection-related morbidity and mortality. Deficiencies of micronutrients like vitamin A, iron and zinc are widely prevalent among populations living in developing countries. Besides their severe deficiencies, subclinical deficiencies are known to impair biological functions in the host, immune function being one of them. The effects of these micronutrients on various immune mechanisms are briefly reviewed in this article.

scholarly journals Antioxidant Treatment Regulates the Humoral Immune Response during Acute Viral Infection

2012 ◽  
Vol 87 (5) ◽  
pp. 2577-2586 ◽  
Author(s):  
K. E. Crump ◽  
P. K. Langston ◽  
S. Rajkarnikar ◽  
J. M. Grayson
Keyword(s):  
Immune Response ◽  
Viral Infection ◽  
Humoral Immune Response ◽  
Antioxidant Treatment ◽  
Humoral Immune ◽  
Acute Viral Infection

Effects of thinning-induced changes in structural heterogeneity on growth, ingrowth, and mortality in secondary coastal Douglas-fir forests

2015 ◽  
Vol 45 (11) ◽  
pp. 1448-1461 ◽  
Author(s):  
Christian Kuehne ◽  
Aaron R. Weiskittel ◽  
Shawn Fraver ◽  
Klaus J. Puettmann
Keyword(s):  
Species Diversity ◽  
Prediction Models ◽  
Structural Diversity ◽  
Structural Heterogeneity ◽  
Variable Density ◽  
Douglas Fir ◽  
Tree Level ◽  
Spatially Explicit ◽  
Individual Tree ◽  
Diversity Measures

Thinning is believed to accelerate the development of late-successional attributes, thereby enhancing stand structural heterogeneity in young, secondary forests. By making use of a large-scale experiment implemented in 40- to 60-year-old coastal Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) forests, we addressed the following objectives: (i) determine the effect of three thinning treatments on the temporal dynamics (first 11 years after thinning) of key forest structure measures, (ii) evaluate the relationships between spatially explicit structural diversity measures and spatially nonexplicit stand metrics, and (iii) test the relationships between stand structure and observed periodic stand volume growth, ingrowth, and mortality. Treatments consisted of high-density, moderate-density, and variable-density thinnings-from-below, as well as a control. Differences in stand structural heterogeneity between treatments were mostly nonsignificant. However, our results suggest that variable-density stands displayed structural enrichment as tree size and tree species diversity increased throughout the study period as a result of continuous ingrowth of species other than Douglas-fir. Simple spatially nonexplicit metrics could not be used to reliably model spatially explicit structural diversity measures. The inclusion of structural and species diversity measures only rarely improved accuracy of sample plot level growth, ingrowth, and mortality prediction models. Despite the short-term nature of this study, we conclude that variable-density thinning shows promise in increasing structural heterogeneity in young even-aged stands. The inclusion of structural diversity measures in growth and mortality models may be beneficial, but further work is needed to clarify the underlying relationships, particularly at the individual-tree level.

Sign in / Sign up

Export Citation Format

Share Document