scholarly journals DEVELOPMENT AND CHARACTERISTICS OF VIRAL INDUCED CELL-MEDIATED IMMUNE RESPONSES IN UPPER RESPIRATORY TRACT

1974 ◽  
Vol 8 (4) ◽  
pp. 415-415
Author(s):  
A M Moras ◽  
J M Bernstein ◽  
K Beutner ◽  
B Moras ◽  
P L Ogra
Keyword(s):  
Immune Responses ◽  
Respiratory Tract ◽  
Upper Respiratory Tract ◽  
Upper Respiratory

scholarly journals Mucosal Immunization Against Pertussis: Lessons From the Past and Perspectives

2021 ◽  
Vol 12 ◽  
Author(s):  
Violaine Dubois ◽  
Camille Locht
Keyword(s):  
Immune Responses ◽  
Respiratory Tract ◽  
Mucosal Immunity ◽  
Outer Membrane Vesicles ◽  
Upper Respiratory Tract ◽  
Mucosal Immunization ◽  
Eligibility Criteria ◽  
Vaccine Candidates ◽  
Vaccination Strategies ◽  
Upper Respiratory

BackgroundCurrent vaccination strategies against pertussis are sub-optimal. Optimal protection against Bordetella pertussis, the causative agent of pertussis, likely requires mucosal immunity. Current pertussis vaccines consist of inactivated whole B. pertussis cells or purified antigens thereof, combined with diphtheria and tetanus toxoids. Although they are highly protective against severe pertussis disease, they fail to elicit mucosal immunity. Compared to natural infection, immune responses following immunization are short-lived and fail to prevent bacterial colonization of the upper respiratory tract. To overcome these shortcomings, efforts have been made for decades, and continue to be made, toward the development of mucosal vaccines against pertussis.ObjectivesIn this review we systematically analyzed published literature on protection conferred by mucosal immunization against pertussis. Immune responses mounted by these vaccines are summarized.MethodThe PubMed Library database was searched for published studies on mucosal pertussis vaccines. Eligibility criteria included mucosal administration and the evaluation of at least one outcome related to efficacy, immunogenicity and safety.ResultsWhile over 349 publications were identified by the search, only 63 studies met the eligibility criteria. All eligible studies are included here. Initial attempts of mucosal whole-cell vaccine administration in humans provided promising results, but were not followed up. More recently, diverse vaccination strategies have been tested, including non-replicating and replicating vaccine candidates given by three different mucosal routes: orally, nasally or rectally. Several adjuvants and particulate formulations were tested to enhance the efficacy of non-replicating vaccines administered mucosally. Most novel vaccine candidates were only tested in animal models, mainly mice. Only one novel mucosal vaccine candidate was tested in baboons and in human trials.ConclusionThree vaccination strategies drew our attention, as they provided protective and durable immunity in the respiratory tract, including the upper respiratory tract: acellular vaccines adjuvanted with lipopeptide LP1569 and c-di-GMP, outer membrane vesicles and the live attenuated BPZE1 vaccine. Among all experimental vaccines, BPZE1 is the only one that has advanced into clinical development.

scholarly journals Innate Immune Responses to Influenza Virus Infections in the Upper Respiratory Tract

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2090
Author(s):  
Edin J. Mifsud ◽  
Miku Kuba ◽  
Ian G. Barr
Keyword(s):  
Influenza Virus ◽  
Immune System ◽  
Epithelial Cells ◽  
Immune Responses ◽  
Respiratory Tract ◽  
Innate Immune System ◽  
Innate Immune ◽  
Upper Respiratory Tract ◽  
Adaptive Immune ◽  
Upper Respiratory

The innate immune system is the host’s first line of immune defence against any invading pathogen. To establish an infection in a human host the influenza virus must replicate in epithelial cells of the upper respiratory tract. However, there are several innate immune mechanisms in place to stop the virus from reaching epithelial cells. In addition to limiting viral replication and dissemination, the innate immune system also activates the adaptive immune system leading to viral clearance, enabling the respiratory system to return to normal homeostasis. However, an overzealous innate immune system or adaptive immune response can be associated with immunopathology and aid secondary bacterial infections of the lower respiratory tract leading to pneumonia. In this review, we discuss the mechanisms utilised by the innate immune system to limit influenza virus replication and the damage caused by influenza viruses on the respiratory tissues and how these very same protective immune responses can cause immunopathology.

The microbiota in pneumonia: From protection to predisposition

2021 ◽  
Vol 13 (576) ◽  
pp. eaba0501
Author(s):  
Charlotte Thibeault ◽  
Norbert Suttorp ◽  
Bastian Opitz
Keyword(s):  
Immune Responses ◽  
Respiratory Tract ◽  
Pathogenic Bacteria ◽  
Upper Respiratory Tract ◽  
Medical Interventions ◽  
Interindividual Variations ◽  
Age Related ◽  
Mucosal Surfaces ◽  
Upper Respiratory ◽  
Lung Infections

Mucosal surfaces of the upper respiratory tract and gut are physiologically colonized with their own collection of microbes, the microbiota. The normal upper respiratory tract and gut microbiota protects against pneumonia by impeding colonization by potentially pathogenic bacteria and by regulating immune responses. However, antimicrobial therapy and critical care procedures perturb the microbiota, thus compromising its function and predisposing to lung infections (pneumonia). Interindividual variations and age-related alterations in the microbiota also affect vulnerability to pneumonia. We discuss how the healthy microbiota protects against pneumonia and how host factors and medical interventions alter the microbiota, thus influencing susceptibility to pneumonia.

scholarly journals Experimental re-infected cats do not transmit SARS-CoV-2

2021 ◽  
Author(s):  
Natasha N. Gaudreault ◽  
Mariano Carossino ◽  
Igor Morozov ◽  
Jessie D. Trujillo ◽  
David A. Meekins ◽  
...  
Keyword(s):  
Immune Responses ◽  
Respiratory Tract ◽  
Clinical Signs ◽  
Viral Rna ◽  
Lymphoid Tissues ◽  
Upper Respiratory Tract ◽  
Post Secondary ◽  
Secondary Challenge ◽  
Global Pandemic ◽  
Upper Respiratory

AbstractSARS-CoV-2 is the causative agent of COVID-19 and responsible for the current global pandemic. We and others have previously demonstrated that cats are susceptible to SARS-CoV-2 infection and can efficiently transmit the virus to naïve cats. Here, we address whether cats previously exposed to SARS-CoV-2 can be re-infected with SARS-CoV-2. In two independent studies, SARS-CoV-2-infected cats were re-challenged with SARS-CoV-2 at 21 days post primary challenge (DPC) and necropsies performed at 4, 7 and 14 days post-secondary challenge (DP2C). Sentinels were co-mingled with the re-challenged cats at 1 DP2C. Clinical signs were recorded, and nasal, oropharyngeal, and rectal swabs, blood, and serum were collected and tissues examined for histologic lesions. Viral RNA was transiently shed via the nasal, oropharyngeal and rectal cavities of the re-challenged cats. Viral RNA was detected in various tissues of re-challenged cats euthanized at 4 DP2C, mainly in the upper respiratory tract and lymphoid tissues, but less frequently and at lower levels in the lower respiratory tract when compared to primary SARS-CoV-2 challenged cats at 4 DPC. Histologic lesions that characterized primary SARS-CoV-2 infected cats at 4 DPC were absent in the re-challenged cats. Naïve sentinels co-housed with the re-challenged cats did not shed virus or seroconvert. Together, our results indicate that cats previously infected with SARS-CoV-2 can be experimentally re-infected with SARS-CoV-2; however, the levels of virus shed was insufficient for transmission to co-housed naïve sentinels. We conclude that SARS-CoV-2 infection in cats induces immune responses that provide partial, non-sterilizing immune protection against reinfection.

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