Protective and Pathogenic Immune Responses to Cutaneous Leishmaniasis

Leishmania (Kinetoplastida: Trypanosomatidae) parasites are known to cause a broad spectrum of clinical diseases in humans, collectively known as the leishmaniases. Cutaneous leishmaniasis is the most common clinical presentation with varying degrees of severity largely driven by host immune responses, specifically the interplay between innate and adaptive immune response. The establishment of a T lymphocyte driven cell-mediated immune response, leading to activated phagocytic cells, leading to Leishmania parasite killing and control of infection. Alternatively, the Leishmania parasite manipulates the host immune system, enabling parasite proliferation and clinical disease. Here we review how the cumulative interactions of different aspects of the host immune response determines disease outcome, severity, and immunity to re-infection.

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Assessment of the pulmonary adaptive immune response to Cladosporium cladosporioides infection using an experimental mouse model

Scientific Reports ◽

10.1038/s41598-020-79642-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xiaoping Ma ◽

Jing Hu ◽

Yan Yu ◽

Chengdong Wang ◽

Yu Gu ◽

...

Keyword(s):

Immune Response ◽

Immune Responses ◽

Adaptive Immune Response ◽

Pulmonary Hemorrhage ◽

Cladosporium Cladosporioides ◽

Th2 Cells ◽

Intercellular Adhesion Molecule ◽

Post Inoculation ◽

Adaptive Immune ◽

Systemic Infections

AbstractCladosporium cladosporioides causes asthma and superficial and deep infections, mostly in immunodeficient individuals and animals. This study aimed to investigate whether C. cladosporioides spores can enter the lungs through pulmonary circulation and influence pulmonary immune response. We intravenously injected mice with C. cladosporioides spore suspension and conducted several assays on the lungs. Pulmonary hemorrhage symptoms and congestion were most severe on days 1, 2, and 3 post-inoculation (PI). Extensive inflammatory cell infiltration occurred throughout the period of infection. More spores and hyphae colonizing the lungs were detected on days 1, 2, and 3 PI, and fewer spores and hyphae were observed within 21 d of infection. Numerous macrophages, dendritic cells, and neutrophils were observed on day 5 PI, along with upregulation of CD54, an intercellular adhesion molecule. Th1 and Th2 cells increased after infection; specifically, Th2 cells increased considerably on day 5 PI. These results suggest that days 2 and 5 PI represent the inflammatory peak in the lungs and that the Th2 and Th1 signaling pathways are potentially involved in pulmonary immune responses. In conclusion, the further adaptive immune responses played important roles in establishing effective pulmonary immunity against C. cladosporioides systemic infections based on innate immune responses.

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Impact of Influenza A Virus Shutoff Proteins on Host Immune Responses

Vaccines ◽

10.3390/vaccines9060629 ◽

2021 ◽

Vol 9 (6) ◽

pp. 629

Author(s):

Megan M. Dunagan ◽

Kala Hardy ◽

Toru Takimoto

Keyword(s):

Immune Response ◽

Immune Responses ◽

Influenza A Virus ◽

Influenza A ◽

Human Populations ◽

Lymphocyte Migration ◽

Host Immune Responses ◽

Mhc Molecules ◽

The Impact

Influenza A virus (IAV) is a significant human pathogen that causes seasonal epidemics. Although various types of vaccines are available, IAVs still circulate among human populations, possibly due to their ability to circumvent host immune responses. IAV expresses two host shutoff proteins, PA-X and NS1, which antagonize the host innate immune response. By transcriptomic analysis, we previously showed that PA-X is a major contributor for general shutoff, while shutoff active NS1 specifically inhibits the expression of host cytokines, MHC molecules, and genes involved in innate immunity in cultured human cells. So far, the impact of these shutoff proteins in the acquired immune response in vivo has not been determined in detail. In this study, we analyzed the effects of PA-X and NS1 shutoff activities on immune response using recombinant influenza A/California/04/2009 viruses containing mutations affecting the expression of shutoff active PA-X and NS1 in a mouse model. Our data indicate that the virus without shutoff activities induced the strongest T and B cell responses. Both PA-X and NS1 reduced host immune responses, but shutoff active NS1 most effectively suppressed lymphocyte migration to the lungs, antibody production, and the generation of IAV specific CD4+ and CD8+ T cells. NS1 also prevented the generation of protective immunity against a heterologous virus challenge. These data indicate that shutoff active NS1 plays a major role in suppressing host immune responses against IAV infection.

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Extracellular Vesicles from Different Pneumococcal Serotypes Are Internalized by Macrophages and Induce Host Immune Responses

Pathogens ◽

10.3390/pathogens10121530 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1530

Author(s):

Alfonso Olaya-Abril ◽

Rafael Prados-Rosales ◽

José A. González-Reyes ◽

Arturo Casadevall ◽

Liise-anne Pirofski ◽

...

Keyword(s):

Immune Response ◽

Biological Activity ◽

Immune Responses ◽

Extracellular Vesicles ◽

Host Cells ◽

Pneumococcal Serotypes ◽

Human Pathogen ◽

Host Immune Responses ◽

Serotype 1 ◽

Transient Loss

Bacterial extracellular vesicles are membranous ultrastructures released from the cell surface. They play important roles in the interaction between the host and the bacteria. In this work, we show how extracellular vesicles produced by four different serotypes of the important human pathogen, Streptococcus pneumoniae, are internalized by murine J774A.1 macrophages via fusion with the membrane of the host cells. We also evaluated the capacity of pneumococcal extracellular vesicles to elicit an immune response by macrophages. Macrophages treated with the vesicles underwent a serotype-dependent transient loss of viability, which was further reverted. The vesicles induced the production of proinflammatory cytokines, which was higher for serotype 1 and serotype 8-derived vesicles. These results demonstrate the biological activity of extracellular vesicles of clinically important pneumococcal serotypes.

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SARS-CoV-2 Serology Status Detected by Commercialized Platforms Distinguishes Previous Infection and Vaccination Adaptive Immune Responses

10.1101/2021.03.10.21253299 ◽

2021 ◽

Author(s):

Raymond T. Suhandynata ◽

Nicholas J. Bevins ◽

Jenny T. Tran ◽

Deli Huang ◽

Melissa A. Hoffman ◽

...

Keyword(s):

Immune Response ◽

Immune Responses ◽

Neutralizing Antibodies ◽

Natural Infection ◽

Adaptive Immune Response ◽

Antibody Assay ◽

Adaptive Immune Responses ◽

Adaptive Immune ◽

Previous Infection ◽

A Cell

AbstractBackgroundThe severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected over 110 million individuals and led to 2.5 million deaths worldwide. As more individuals are vaccinated, the clinical performance and utility of SARS-CoV-2 serology platforms needs to be evaluated.MethodsThe ability of four commercial SARS-CoV-2 serology platforms to detect previous infection or vaccination were evaluated using a cohort of 53 SARS-CoV-2 PCR-positive patients, 89 SARS-CoV-2-vaccinated healthcare workers (Pfizer or Moderna), and 127 SARS-CoV-2 negative patients. Serology results were compared to a cell based SARS-CoV-2 pseudovirus (PSV) neutralizing antibodies assay.ResultsThe Roche S-(spike) antibody and Diazyme neutralizing antibodies (NAbs) assays detected adaptive immune response in 100.0% and 90.1% of vaccinated individuals who received two-doses of vaccine (initial and booster), respectively. The Roche N-(nucleocapsid) antibody assay and Diazyme IgG assay did not detect adaptive immune response in vaccinated individuals. The Diazyme Nabs assay correlated with the PSV SARS-CoV-2 ID50 neutralization titers (R2= 0.70), while correlation of the Roche S-antibody assay was weaker (R2= 0.39). Median PSV SARS-CoV-2 ID50 titers more than doubled in vaccinated individuals who received two-doses of the Moderna vaccine (ID50: 597) compared to individuals that received a single dose (ID50: 284).ConclusionsThe Roche S-antibody and Diazyme NAbs assays robustly detected adaptive immune responses in SARS-CoV-2 vaccinated individuals and SARS-CoV-2 infected individuals. The Diazyme NAbs assay strongly correlates with the PSV SARS-CoV-2 NAbs in vaccinated individuals. Understanding the reactivity of commercially available serology platforms is important when distinguishing vaccination response versus natural infection.SummaryThe Roche S (spike protein)-antibody and Diazyme neutralizing-antibodies (NAbs) assays were evaluated for their clinical utility in the detection of SARS-CoV-2 related adaptive immune responses by testing SARS-CoV-2 PCR-confirmed patients, SARS-CoV-2-vaccinated individuals, and SARS-CoV-2-negative individuals. Commercial serology results were compared to results generated using a cell-based SARS-CoV-2 pseudovirus (PSV) NAbs assay and previously validated SARS-CoV-2 commercial serology assays (Roche N (nucleocapsid protein) antibody and Diazyme IgG). We demonstrate that the Roche S-antibody and Diazyme NAbs assays detected adaptive immune response in SARS-CoV-2 vaccinated individuals and the presence of SARS-CoV-2 PSV NAbs. The Roche S-antibody assay had an observed positive percent agreement (PPA) of 100% for individuals who received two doses of the Pfizer or Moderna vaccine. By contrast, the Roche N assay and Diazyme IgG assay did not detect vaccine adaptive immune responses. Our findings also indicate that the Diazyme NAbs assay correlates strongly with the levels of SARS-CoV-2 ID50 neutralization titers using the PSV Nab assay in vaccinated individuals.

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Multiomic Immunophenotyping of COVID-19 Patients Reveals Early Infection Trajectories

10.1101/2020.07.27.224063 ◽

2020 ◽

Cited By ~ 3

Author(s):

Yapeng Su ◽

Daniel Chen ◽

Christopher Lausted ◽

Dan Yuan ◽

Jongchan Choi ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

Immune Responses ◽

Cell Receptor ◽

B Cell Receptor ◽

Surface Proteins ◽

Host Immune Responses ◽

Therapeutic Development ◽

Clinical Measures ◽

Whole Transcriptome

SUMMARYHost immune responses play central roles in controlling SARS-CoV2 infection, yet remain incompletely characterized and understood. Here, we present a comprehensive immune response map spanning 454 proteins and 847 metabolites in plasma integrated with single-cell multi-omic assays of PBMCs in which whole transcriptome, 192 surface proteins, and T and B cell receptor sequence were co-analyzed within the context of clinical measures from 50 COVID19 patient samples. Our study reveals novel cellular subpopulations, such as proliferative exhausted CD8+ and CD4+ T cells, and cytotoxic CD4+ T cells, that may be features of severe COVID-19 infection. We condensed over 1 million immune features into a single immune response axis that independently aligns with many clinical features and is also strongly associated with disease severity. Our study represents an important resource towards understanding the heterogeneous immune responses of COVID-19 patients and may provide key information for informing therapeutic development.

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An appraisal of survival strategies

Parasitology ◽

10.1017/s0031182000085486 ◽

1984 ◽

Vol 88 (4) ◽

pp. 575-577 ◽

Cited By ~ 1

Author(s):

N. A. Mitchison

Keyword(s):

Immune System ◽

Immune Responses ◽

Survival Strategies ◽

Host Immune System ◽

Cellular Immunology ◽

Host Immune Responses ◽

Host Defence System ◽

Bio Engineering

Only a few years ago parasite immunology looked an unattractive subject better left to the dogged specialists. Parasites and hosts had been playing chess together for a million years, and there seemed little prospect of perturbing matters in favour of the host immune system. All that has changed, for three reasons. Firstly, we have learned how to grow at least some parasites in vitro, and prospects of doing so with others are encouraging. Secondly, progress in cellular immunology has revealed the sort of loopholes in the host defence system which parasites are likely to exploit: we are learning the questions which matter about parasites as antigens. Thirdly, and most importantly, molecular genetics is being brought to bear on parasites: we can now see a real, though long-term, prospect of manufacturing practicable vaccines through bio-engineering, and more immediately it gives us the tools needed to probe the host immune responses in the form of cloned antigens.

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Adaptive immunity

Oxford Textbook of Medicine ◽

10.1093/med/9780198746690.003.0040 ◽

2020 ◽

pp. 325-336

Author(s):

Paul Klenerman

Keyword(s):

Immune Response ◽

Immune Responses ◽

Adaptive Immunity ◽

Innate Immune Response ◽

Molecular Basis ◽

Adaptive Immune Response ◽

Antigenic Specificity ◽

Adaptive Immune Responses ◽

Research Attention ◽

Adaptive Immune

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.

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Host Immune Response and Novel Diagnostic Approach to NTM Infections

International Journal of Molecular Sciences ◽

10.3390/ijms21124351 ◽

2020 ◽

Vol 21 (12) ◽

pp. 4351

Author(s):

Yuko Abe ◽

Kiyoharu Fukushima ◽

Yuki Hosono ◽

Yuki Matsumoto ◽

Daisuke Motooka ◽

...

Keyword(s):

Immune Response ◽

Immune Responses ◽

Humoral Immunity ◽

Diagnostic Approach ◽

Post Transplantation ◽

Diagnosis And Management ◽

Immunological Responses ◽

Host Immune Responses ◽

Diagnostic Approaches ◽

Proper Diagnosis

The incidence and prevalence of non-tuberculous mycobacteria (NTM) infections are steadily increasing worldwide, partially due to the increased incidence of immunocompromised conditions, such as the post-transplantation state. The importance of proper diagnosis and management of NTM infection has been recently recognized. Host immunological responses play integral roles in vulnerability to NTM infections, and may contribute to the onset of specific types of NTM infection. Furthermore, distinct NTM species are known to affect and attenuate these host immune responses in unique manners. Therefore, host immune responses must be understood with respect to each causative NTM species. Here, we review innate, cellular-mediated, and humoral immunity to NTM and provide perspectives on novel diagnostic approaches regarding each NTM species.

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HNSCC: Tumour Antigens and Their Targeting by Immunotherapy

Cells ◽

10.3390/cells9092103 ◽

2020 ◽

Vol 9 (9) ◽

pp. 2103 ◽

Cited By ~ 1

Author(s):

Adrian von Witzleben ◽

Chuan Wang ◽

Simon Laban ◽

Natalia Savelyeva ◽

Christian H. Ottensmeier

Keyword(s):

Immune Response ◽

Immune Cell ◽

Adaptive Immune Response ◽

Tobacco Consumption ◽

Host Immune System ◽

Malignant Tumours ◽

Current Thinking ◽

Tumour Antigens ◽

Early Phase Clinical Trials ◽

Line Setting

Head and neck squamous cell carcinomas (HNSCC) are a heterogeneous group of malignant tumours typically caused by alcohol and tobacco consumption, although an increasing number of HNSCC arise due to persistent infection with high-risk human papilloma virus (HPV). The treatment of HNSCC remains challenging, and the first-line setting is focused on surgery and chemoradiotherapy. A substantial proportion of HNSCC patients die from their disease, especially those with recurrent and metastatic disease. Among factors linked with good outcome, immune cell infiltration appears to have a major role. HPV-driven HNSCC are often T-cell rich, reflecting the presence of HPV antigens that are immunogenic. Tumour-associated antigens that are shared between patients or that are unique to an individual person may also induce varying degrees of immune response; studying these is important for the understanding of the interaction between the host immune system and the cancer. The resulting knowledge is critical for the design of better immunotherapies. Key questions are: Which antigens lead to an adaptive immune response in the tumour? Which of these are exploitable for immunotherapy? Here, we review the current thinking regarding tumour antigens in HNSCC and what has been learned from early phase clinical trials.

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Macrophages in Organ Transplantation

Frontiers in Immunology ◽

10.3389/fimmu.2020.582939 ◽

2020 ◽

Vol 11 ◽

Author(s):

Farideh Ordikhani ◽

Venu Pothula ◽

Rodrigo Sanchez-Tarjuelo ◽

Stefan Jordan ◽

Jordi Ochando

Keyword(s):

Immune Response ◽

Organ Transplantation ◽

Survival Rates ◽

Adaptive Immune Response ◽

Phagocytic Cells ◽

Term Survival ◽

Vast Number ◽

Monocytes And Macrophages

Current immunosuppressive therapy has led to excellent short-term survival rates in organ transplantation. However, long-term graft survival rates are suboptimal, and a vast number of allografts are gradually lost in the clinic. An increasing number of animal and clinical studies have demonstrated that monocytes and macrophages play a pivotal role in graft rejection, as these mononuclear phagocytic cells recognize alloantigens and trigger an inflammatory cascade that activate the adaptive immune response. Moreover, recent studies suggest that monocytes acquire a feature of memory recall response that is associated with a potent immune response. This form of memory is called “trained immunity,” and it is retained by mechanisms of epigenetic and metabolic changes in innate immune cells after exposure to particular ligands, which have a direct impact in allograft rejection. In this review article, we highlight the role of monocytes and macrophages in organ transplantation and summarize therapeutic approaches to promote tolerance through manipulation of monocytes and macrophages. These strategies may open new therapeutic opportunities to increase long-term transplant survival rates in the clinic.

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