July 2020

Unlike humans, llamas produce heavy-chain only antibodies (HCAbs) that have a single variable domain. These HCAbs are much smaller, have higher thermal and chemical stability than Abs produced by humans, making it easier to construct into multimers that could potentially be used as therapeutics that could be adminstered in various ways including using inhalers.

Safety and immunological results from the phase 1 COVID-19 trial testing, the candidate vaccine mRNA-127, were published in NEJM on 14th July. Overall vaccination with mRNA-1273 did not result in severe side-effects, however, the frequency of side effects correlated with vaccination dose. Researchers reported rapid seroconversion, within 15 days of the first vaccination ...

Professor Adrian Hayday shares an overview of a completed deep immunophenotyping of 100 COVID-19 patients and controls (figure below), in the 13th IUIS webinar. Highlights of the webinar include the discovery of an immune cell signature based on cell phenotypes that distinguished COVID-19 treated patients from SARS-CoV-2 seronegative and seropositive controls.

This week we highlight talks by Dr Fabienne Tacchini-Cottier and Dr David Sacks which focused on anti-leishmania immunity. Dr Tacchini-Cottier gave an interesting lecture on the innate immunity to Leishmania parasites. She explained how the body recognizes the parasite by the PRRs and talked about the role of selected innate cells in immunity against the parasite. She also showed how the parasite has developed sophisticated ways to bypass the first barrier of immunity...

In addition to pulmonary pathology, gastrointestinal tract (GIT) symptoms have also been observed in COVID-19 patients and are more associated with severe compared to mild pathology. How does SARS-CoV-2 infection cause GIT complications? A recent review in Cell Reports by Trottein & Sokol aimed to “suggest hypothetical mechanisms leading to gut symptoms, and discuss the potential consequences of gastrointestinal disorders on the outcome of the disease.”

In this week's IUIS-Frontiers webinar series, Hans-Martin Jäck gave a talk on Prevention and Therapy of COVID-19 with Monoclonal Antibodies. Highlights of his talk include, on-going collaborative research on SARS-CoV-2 (humanised) murine models that produce human antibodies. He presented data the describes the development of spike protein-specific monoclonal Abs that have neutralisation capacity, as well as challenges with vaccines

Chen and colleagues reviewed findings on how aging alters immunity to respiratory viral infections with the aim of suggesting potential mechanisms of age-enhanced COVID-19 mortality. They present evidence that indicated that influenza infection is associated with increased monocyte infiltration in the lung, which leads to increased levels of IL-6 and IL-β, as well as reduced T cell and B cell responses. Reduced adaptive immune responses in older individuals (> 65 years) have been...

Dr Iva Kolarova from Charles University (Czech Republic), gave insights on the “Role of sand flies in Leishmania transmission and immune interactions”. In her talk she highlighted leishmaniasis epidemiology, causative agents, distribution, prevalence and populations at risk (350 million  people in 98 countries). She also mentioned that the risk factors of this disease include but are not limited to poverty, migration, climate changes and immunodeficiency. She also highlighted how the disease is transmitted...

Recent Pre-print by Jouan and colleagues analysed the biology of innate T cells: mucosal associated invariant T (MAIT) cells, γδ T and invariant natural killer (iNK) T cells in critically ill COVID-19 patients with varying co-morbidities (46.7% with Hypertension; 30% with Type 2 diabetes; 10% with cardiovascular disease). Researchers observed that innate T cells from COVID-19 patients were highly pro-inflammatory characterised by high expression of IL-17 but not IFN-g, compared to healthy controls.

Dysregulated immune responses along with metabolic dysfunction can lead to multiple organ failure, which seems to be a hallmark of COVID-19 severity. In a recent pre-peer reviewed paper, authors used a transcriptomic, proteomic and metabolomic approach in peripheral blood to distinguish the range COVID-19 severity in 66 individuals with confirmed symptoms. There was “continuous activation of IFN-I signalling and neutrophils ...