scholarly journals Diversity of vaccination-induced immune responses can prevent the spread of vaccine escape mutants

2021 ◽  
Author(s):  
Judith Aveline Bouman ◽  
Céline Capelli ◽  
Roland Regoes

Pathogens that are resistant against drug treatment are widely observed. In contrast, pathogens that escape the immune response elicited upon vaccination are rare. Previous studies showed that the prophylactic character of vaccines, the multiplicity of epitopes to which the immune system responds within a host, and their diversity between hosts delay the evolution and emergence of escape mutants in a vaccinated population. By extending previous mathematical models, we find that, depending on the cost of the escape mutations, there even exist critical levels of immune response diversity that completely prevent vaccine escape. Furthermore, to quantify the potential for vaccine escape below these critical levels, we propose a concept of escape depth which measures the fraction of escape mutants that can spread in a vaccinated population. Determining this escape depth for a vaccine could help to predict its sustainability in the face of pathogen evolution.

2021 ◽  
Author(s):  
Faustina Pappoe ◽  
Samuel Victor Nuvor

Immune responses of the host to any infectious agents vary in controlling the pathogens. The process begins by the entry of microorganisms into the host to initiate host immune response to understand the type of microorganisms and react accordingly for possible elimination of the organisms. In some cases the host co-exists with the pathogens or unable to effectively deal with them leading to disease condition. Thus, the pathogens establish, multiply and cause disease. The review considered the mode of acquisition of infection, pathogenesis and immune responses to microbial infection. Other areas included the enhancement of immune responses to control infection, immune responses of the host under drug treatment and the control of microbial infection. The understanding of the relationship between infectious microbes and the host immune system leading to protective immunity or disease state will give much information about treatment and controlling of microbial infection in our environment.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Tian-Yu Lei ◽  
Ying-Ze Ye ◽  
Xi-Qun Zhu ◽  
Daniel Smerin ◽  
Li-Juan Gu ◽  
...  

AbstractThrough considerable effort in research and clinical studies, the immune system has been identified as a participant in the onset and progression of brain injury after ischaemic stroke. Due to the involvement of all types of immune cells, the roles of the immune system in stroke pathology and associated effects are complicated. Past research concentrated on the functions of monocytes and neutrophils in the pathogenesis of ischaemic stroke and tried to demonstrate the mechanisms of tissue injury and protection involving these immune cells. Within the past several years, an increasing number of studies have elucidated the vital functions of T cells in the innate and adaptive immune responses in both the acute and chronic phases of ischaemic stroke. Recently, the phenotypes of T cells with proinflammatory or anti-inflammatory function have been demonstrated in detail. T cells with distinctive phenotypes can also influence cerebral inflammation through various pathways, such as regulating the immune response, interacting with brain-resident immune cells and modulating neurogenesis and angiogenesis during different phases following stroke. In view of the limited treatment options available following stroke other than tissue plasminogen activator therapy, understanding the function of immune responses, especially T cell responses, in the post-stroke recovery period can provide a new therapeutic direction. Here, we discuss the different functions and temporal evolution of T cells with different phenotypes during the acute and chronic phases of ischaemic stroke. We suggest that modulating the balance between the proinflammatory and anti-inflammatory functions of T cells with distinct phenotypes may become a potential therapeutic approach that reduces the mortality and improves the functional outcomes and prognosis of patients suffering from ischaemic stroke.


2021 ◽  
pp. 160-197
Author(s):  
Elena Locci ◽  
Silvia Raymond

In recent years, immunotherapy has revolutionized the treatment of cancer; however, inflammatory reactions in healthy tissues often have side effects that can be serious and lead to permanent discontinuation of treatment. This toxicity is not yet well understood and is a major obstacle to the use of immunotherapy. When the immune system is so severely activated, the resulting inflammatory reaction can have detrimental effects and sometimes serious damage to healthy tissue. We wanted to know if there was a difference between an optimal immune response that aims to kill cancer and an unwanted response that could affect healthy tissue. Identifying the distinctive elements between these two immune responses allows the development of new, more effective and less toxic therapeutic approaches. Keywords: Cancer; Cells; Tissues, Tumors; Prevention, Prognosis; Diagnosis; Imaging; Screening; Treatment; Management


2016 ◽  
Author(s):  
Steven K. Lundy ◽  
Alison Gizinski ◽  
David A. Fox

The immune system is a complex network of cells and mediators that must balance the task of protecting the host from invasive threats. From a clinical perspective, many diseases and conditions have an obvious link to improper functioning of the immune system, and insufficient immune responses can lead to uncontrolled acute and chronic infections. The immune system may also be important in tumor surveillance and control, cardiovascular disease, health complications related to obesity, neuromuscular diseases, depression, and dementia. Thus, a working knowledge of the role of immunity in disease processes is becoming increasingly important in almost all aspects of clinical practice. This review provides an overview of the immune response and discusses immune cell populations and major branches of immunity, compartmentalization and specialized immune niches, antigen recognition in innate and adaptive immunity, immune tolerance toward self antigens, inflammation and innate immune responses, adaptive immune responses and helper T (Th) cell subsets, components of the immune response that are important targets of treatment in autoimmune diseases, mechanisms of action of biologics used to treat autoimmune diseases and their approved uses, and mechanisms of other drugs commonly used in the treatment of autoimmune diseases. Figures show the development of erythrocytes, platelets, lymphocytes, and other immune system cells originating from hematopoietic stem cells that first reside in the fetal liver and later migrate to the bone marrow, antigen–major histocompatibility complex recognition by T cell receptor control of T cell survival and activation, and Th cells as central determinants of the adaptive immune response toward different stimuli. Tables list cell populations involved in innate and adaptive immunity, pattern recognition receptors with known ligands, autoantibody-mediated human diseases: examples of pathogenic mechanisms, selected Food and Drug Administration–approved autoimmune disease indications for biologics, and mechanism of action of biologics used to treat autoimmune diseases.   This review contains 3 highly rendered figures, 5 tables, and 64 references.


2019 ◽  
Vol 49 (2) ◽  
Author(s):  
Francesca Millanta ◽  
Simona Sagona ◽  
Maurizio Mazzei ◽  
Mario Forzan ◽  
Alessandro Poli ◽  
...  

ABSTRACT: The innate immune system of honeybees mainly consists in antimicrobial peptides, cellular immunity and melanisation. In order to investigate the immune response of honeybees to immune stressors, three stress degrees were tested. Newly emerged bees naturally DWV-infected were collected from a Varroa mite-free apiary and divided into three experimental groups: naturally DWV infected bees, PBS injected bees, and artificially DWV super infected bees. Phenoloxidase activity and haemolymph cellular subtype count were investigated. Phenoloxidase activity was highest (P<0.05) in DWV-superinfected bees, and the haemocyte population differed within the three observed groups. Although, immune responses following DWV infection have still not been completely clarified, this investigation sheds light on the relation between cell immunity and the phenoloxidase activity of DWV-naturally infected honeybees exposed to additional stress such as injury and viral superinfection.


2005 ◽  
Vol 65 (2) ◽  
pp. 203-209 ◽  
Author(s):  
J. M. Barreto-Medeiros ◽  
E. G. Feitoza ◽  
K. Magalhães ◽  
R. R. da Silva ◽  
F. M. Manhães-de-Castro ◽  
...  

The repercussion on the immune response of the expression of intraspecific aggressiveness in the face of a stressor agent was investigated in rats. Ninety-day-old animals were divided into three groups: the control group (only immunological measurements were performed), the foot-shock (FS) (animals individually receiving FS), and the intraspecific aggressive response (IAR) group (animals receiving FS and presenting IAR). For immunological measurements, blood samples were collected promptly at 7 and 15 days after FS or IAR. The FS reduced the total leukocyte amount presented. However, aggressiveness triggered not only reduction of the leukocytes, but also lymphocyte decrease and neutrophil increase. Moreover, an elevation in total leukocytes associated with an increase in the humoral immune response was also observed one week after IAR. In this study, the expression of intraspecific aggressiveness in the face of a stressor seemed to activate the immune system and to potentiate the antigen specific humoral response.


2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Víctor H. Salazar-Castañon ◽  
Martha Legorreta-Herrera ◽  
Miriam Rodriguez-Sosa

More than one-third of the world’s population is infected with one or more helminthic parasites. Helminth infections are prevalent throughout tropical and subtropical regions where malaria pathogens are transmitted. Malaria is the most widespread and deadliest parasitic disease. The severity of the disease is strongly related to parasite density and the host’s immune responses. Furthermore, coinfections between both parasites occur frequently. However, little is known regarding how concomitant infection with helminths andPlasmodiumaffects the host’s immune response. Helminthic infections are frequently massive, chronic, and strong inductors of a Th2-type response. This implies that infection by such parasites could alter the host’s susceptibility to subsequent infections byPlasmodium. There are a number of reports on the interactions between helminths andPlasmodium; in some, the burden ofPlasmodiumparasites increased, but others reported a reduction in the parasite. This review focuses on explaining many of these discrepancies regarding helminth-Plasmodiumcoinfections in terms of the effects that helminths have on the immune system. In particular, it focuses on helminth-induced immunosuppression and the effects of cytokines controlling polarization toward the Th1 or Th2 arms of the immune response.


2008 ◽  
Vol 26 (20) ◽  
pp. 3445-3455 ◽  
Author(s):  
John M. Kirkwood ◽  
Ahmad A. Tarhini ◽  
Monica C. Panelli ◽  
Stergios J. Moschos ◽  
Hassane M. Zarour ◽  
...  

PurposeImmunotherapy has a long history with striking but limited success in patients with melanoma. To date, interleukin-2 and interferon-alfa2b are the only approved immunotherapeutic agents for melanoma in the United States.DesignTumor evasion of host immune responses, and strategies for overcoming tumor-induced immunosuppression are reviewed. Several novel immunotherapies currently in worldwide phase III clinical testing for melanoma are discussed.ResultsThe limitations of immunotherapy for melanoma stem from tumor-induced mechanisms of immune evasion that render the host tolerant of tumor antigens. For example, melanoma inhibits the maturation of antigen-presenting cells, preventing full T-cell activation and downregulating the effector antitumor immune response. New immunotherapies targeting critical regulatory elements of the immune system may overcome tolerance and promote a more effective antitumor immune response. These include monoclonal antibodies that block the cytotoxic T lymphocyte-associated antigen 4 (CTLA4) and toll-like receptor 9 (TLR9) agonists. Blockade of CTLA4 prevents inhibitory signals that downregulate T-cell activation. TLR9 agonists stimulate dendritic cell maturation and ultimately induce a more effective immune response. These approaches have been shown to stimulate acute immune activation with concomitant appearance of transient adverse events mediated by the immune system. The pattern and duration of immune responses associated with these new modalities differ from those associated with cytokines and cytotoxic agents. In addition, vaccines are being developed that may ultimately target melanoma either alone or in combination with these immunomodulatory therapies.ConclusionThe successes of cytokine and interferon therapy of melanoma, coupled with an array of new approaches, are generating new enthusiasm for the immunotherapy of melanoma.


2000 ◽  
Vol 2 (9) ◽  
pp. 1-20 ◽  
Author(s):  
Mark Harber ◽  
Anette Sundstedt ◽  
David Wraith

Current immunosuppression protocols, although often effective, are nonspecific and therefore hazardous. Consequently, immunological tolerance that is antigen specific and does not globally depress the patient's immune system has become one of the Holy Grails of immunology. Since the discovery that cytokines have immunomodulatory effects, extensive research has investigated the potential of these molecules to induce and maintain specific immunological tolerance in the context of transplantation, allergy and autoimmunity. In this article, we review the possible mechanisms by which cytokines can modulate the immune response and the animal models that frequently confound the theory that a single cytokine, or group of cytokines, can induce tolerance in a predictable manner. Finally, we discuss the role of cytokines at a paracrine level, particularly in the context of inducing and maintaining antigen-specific, regulatory T cells with the clinical potential to suppress specific immune responses.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hossein Ansariniya ◽  
Seyed Mohammad Seifati ◽  
Erfan Zaker ◽  
Fateme Zare

Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and Coronavirus Disease 2019 (COVID-19) infections are the three epidemiological diseases caused by the Coronaviridae family. Perceiving the immune responses in these infections and the escape of viruses could help us design drugs and vaccines for confronting these infections. This review investigates the innate and adaptive immune responses reported in the infections of the three coronaviruses SARS, MERS, and COVID-19. Moreover, the present study can trigger researchers to design and develop new vaccines and drugs based on immune system responses. In conclusion, due to the need for an effective and efficient immune stimulation against coronavirus, a combination of several strategies seems necessary for developing the vaccine.


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