Introduction to Clinical Immunology: Overview of the Immune Response, Autoimmune Conditions, and Immunosuppressive Therapeutics for Rheumatic Diseases

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.

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Dragana Odobasic ◽  
A. Richard Kitching ◽  
Stephen R. Holdsworth

Neutrophils are no longer seen as leukocytes with a sole function of being the essential first responders in the removal of pathogens at sites of infection. Being armed with numerous pro- and anti-inflammatory mediators, these phagocytes can also contribute to the development of various autoimmune diseases and can positively or negatively regulate the generation of adaptive immune responses. In this review, we will discuss how myeloperoxidase, the most abundant neutrophil granule protein, plays a key role in the various functions of neutrophils in innate and adaptive immunity.


Author(s):  
I. A. Ivanovа ◽  
A. A. Trufanova ◽  
A. V. Filippenko ◽  
I. A. Bespalova ◽  
N. D. Omelchenko

Due to the emergence of antibiotic-resistant strains of bacteria in recent years, the treatment and prevention of various infections with bacteriophages have again become an important area of research. However, when using phages for this purpose, it is necessary to take into account the immune responses of a macroorganism to their introduction. The data about impact of bacterial viruses on the innate and adaptive immunity system of mammals in available literature are few and contradictory. This issue requires further detailed study, especially in the development of new therapeutic and prophylactic biological products based on bacteriophages.


2020 ◽  
pp. 325-336
Author(s):  
Paul Klenerman

The adaptive immune response is distinguished from the innate immune response by two main features: its capacity to respond flexibly to new, previously unencountered antigens (antigenic specificity), and its enhanced capacity to respond to previously encountered antigens (immunological memory). These two features have provided the focus for much research attention, from the time of Jenner, through Pasteur onwards. Historically, innate and adaptive immune responses have often been treated as separate, with the latter being considered more ‘advanced’ because of its flexibility. It is now clear this not the case, and in recent years the molecular basis for these phenomena has become much better understood.


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.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 64-64
Author(s):  
Tippi MacKenzie ◽  
Erin Jarvis ◽  
Amar Nijagal ◽  
Tom Le ◽  
Marta Wegorzewska ◽  
...  

Abstract Abstract 64 In utero hematopoietic stem cell transplantation (IUHSCTx) is a promising treatment strategy for many congenital hematopoietic disorders such as immunodeficiencies. However, clinical applications have been hampered by lack of engraftment, possibly secondary to a host immune response. This has been a conundrum in the field, since the fetus can also be tolerized to allogeneic cells in some circumstances. We hypothesized that it is the maternal immune response which limits engraftment of in utero transplanted cells. Methods: Fetal BALB/c mice at 14 days' gestation were transplanted with age-matched fetal liver (FL) cells (2.5 × 106 cells/fetus) from allogeneic C57B6 mice and levels of circulating donor cell chimerism were determined serially starting at 4 weeks after in utero transplantation. Rates of engraftment (number of chimeric pups/number of surviving pups) and levels of chimerism (donor CD45 cells/total CD45 cells) were compared to controls in which animals were transplanted with congenic cells (C57B6 (CD45.2) fetal hosts transplanted with C57B6 (CD45.1) FL). In order to determine the role of the maternal adaptive immune system, immunodeficient BALB/c.Rag−/− mothers (deficient in T and B cells) were bred to wild type BALB/c males, such that the fetuses (BALB/c.Rag+/−) would be immunocompetent. These fetuses were transplanted with C57B6 FL and rates of engraftment and levels of chimerism in these transplants were compared to those in wild type allogeneic transplants. In order to determine whether the maternal influence is caused by maternal lymphocytes trafficking into the fetus, C57B6 (CD45.2) females were bred to C57B6 (CD45.1) males, such that the fetal cells (CD45.1+/CD45.2+) could be distinguished from maternal cells (CD45.1−/CD45.2+). Fetal blood and tissues were examined for the presence of maternal cells by flow cytometry at various gestational ages. Results: The rate of engraftment after IUHSCTx in control animals transplanted with congenic cells was 14/16 (88%) and average levels of chimerism were 9.9±8.4%. In contrast, the rate of engraftment in wild-type BALB/c fetuses transplanted with allogeneic B6 cells was 11/25 (44%; p<0.05 compared to congenic), and levels of chimerism were 21±19 (p=NS), confirming there is an adaptive immune response to fetal stem cell transplantation. As expected, chimeric animals were tolerant to the donor strain by mixed lymphocyte reaction while injected, non-chimeric animals were sensitized. However, in the absence of a maternal adaptive immune system, rates of chimerism (in immunocompetent BALB/c.Rag+/− pups) increased to 100% (n=10, p<0.05 compared to wild type allogeneic) and levels of chimerism were significantly higher (44±18, p<0.05). Levels of chimerism in engrafted animals declined over time after allogeneic transplantation but not after congenic transplantation, indicating there is a second, late phase immune response to allogeneic cells. However, chimerism levels did not decline in the BALB/c.Rag+/− recipients, suggesting that the maternal immune system has long-lasting effects on the success of fetal transplantation, perhaps by priming the host immune system. In our analysis of maternal/fetal cellular trafficking, we detected maternal lymphocytes in the blood of midgestation fetuses (14±7% at E12.5–E14.5, n=9) which declined gradually and was undetectable after birth. Lineage analysis demonstrated that 45±15 % of maternal cells are Gr-1+ granulocytes and 21±15% are B cells. Trafficking of maternal cells into the fetus was increased following fetal manipulation (injection of PBS < injection of allogeneic HSC). Conclusions: There is an adaptive immune response which limits early engraftment after in utero transplantation of allogeneic cells and leads to a gradual decline in levels of chimerism in engrafted animals. However, in the selective absence of maternal T and B cells, all fetuses transplanted with allogeneic FL cells show long-term, multilineage engraftment and demonstrate donor-specific tolerance. These results indicate that the maternal immune system plays a significant role in the success of fetal HSC transplantation. Cellular trafficking between the mother and fetus may be a mechanism by which maternal lymphocytes encounter cells transplanted into the fetus. Our findings have clinical implications in that the success of IUHSCTx may be improved by harvesting cells from the mother or HLA-matching cells to the mother. Disclosures: No relevant conflicts of interest to declare.


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.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Danielle Minns ◽  
Katie Jane Smith ◽  
Emily Gwyer Findlay

Neutrophils are the most abundant leukocytes in peripheral blood and respond rapidly to danger, infiltrating tissues within minutes of infectious or sterile injury. Neutrophils were long thought of as simple killers, but now we recognise them as responsive cells able to adapt to inflammation and orchestrate subsequent events with some sophistication. Here, we discuss how these rapid responders release mediators which influence later adaptive T cell immunity through influences on DC priming and directly on the T cells themselves. We consider how the release of granule contents by neutrophils—through NETosis or degranulation—is one way in which the innate immune system directs the phenotype of the adaptive immune response.


2016 ◽  
Vol 8 ◽  
pp. III.S38707 ◽  
Author(s):  
Shuai Jiang

Fungal diseases are major causes of morbidity and mortality among the immunocompromised, including HIV-infected individuals and patients with cancer. Individuals without a weakened immune system can also suffer from these infections. Not surprisingly, fungi are a major target for the immune system, rendered visible to it by expression of pathogen-associated molecular patterns/signatures. We now appreciate the roles of both innate and adaptive immunity in eliminating fungal infections, and how a disproportionate or inadequate immune response can diminish the host's capacity to eliminate fungi. This review focuses on our current understanding of the roles of innate and adaptive immunity in clearing common and emergent fungal pathogens. A clearer understanding of how the host's immune response tackles fungal infection may provide useful clues as to how we might develop new agents to treat those diseases in the future.


2005 ◽  
Vol 110 (1) ◽  
pp. 21-35 ◽  
Author(s):  
Steven E. Williams ◽  
Thomas I. Brown ◽  
Ali Roghanian ◽  
Jean-Michel Sallenave

Elafin and SLPI (secretory leucocyte protease inhibitor) have multiple important roles both in normal homoeostasis and at sites of inflammation. These include antiprotease and antimicrobial activity as well as modulation of the response to LPS (lipopolysaccharide) stimulation. Elafin and SLPI are members of larger families of proteins secreted predominantly at mucosal sites, and have been shown to be modulated in multiple pathological conditions. We believe that elafin and SLPI are important molecules in the controlled functioning of the innate immune system, and may have further importance in the integration of this system with the adaptive immune response. Recent interest has focused on the influence of inflamed tissues on the recruitment and phenotypic modulation of cells of the adaptive immune system and, indeed, the local production of elafin and SLPI indicate that they are ideally placed in this regard. Functionally related proteins, such as the defensins and cathelicidins, have been shown to have direct effects upon dendritic cells with potential alteration of their phenotype towards type I or II immune responses. This review addresses the multiple functions of elafin and SLPI in the inflammatory response and discusses further their roles in the development of the adaptive immune response.


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