More work is needed to understand the relationship of TIGIT+ and TIGIT- cTfh to their counterparts in the germinal centre but this study shows that there is scope in further studying cTfh subsets not just in the context of infection but also vaccination and autoimmunity.

We also found that TIGIT+ and TIGIT- cTfh are Tfh1 and Tfh17 skewed, respectively, and that TIGIT- cTfh express more CD40L following activation. Given the importance of CD40L in germinal centre reactions this may explain the superior ability of TIGIT- cTfh to provide B cell help.

Following this observation, we went on to further characterise TIGIT expressing cTfh and found that TIGIT+ cTfh are worse than TIGIT- cTfh at providing help to B cells in an in vitro coculture system.

As previously described, we observed a positive correlation between S1 IgG titre (and strength of nAbs) and circulating follicular helper T cells (cTfh) expressing activation markers such as ICOS and CD38. Interestingly, this correlation was inverse when we looked at TIGIT+ cTfh.

Using spectral flow cytometry, we saw increased frequencies of activated CD4 and CD8 T cells in patients with severe COVID-19. Similarly, we saw higher titres of serum IgG targeting the SARS-CoV-2 S1 spike as well as an increased strength of neutralising Abs in severe disease.

Excited for our new study exploring humoral immune responses in COVID-19 to be out @FrontImmunol today. Thanks to everyone @LucyWalkerlab, collaborators, the clinical team and all patients that participated in the study. 🧵.

RT @LucyWalkerlab: Still time to apply for the Research Technician post in our lab! .

RT @LucyWalkerlab: Postdoc position available in our lab! Are you interested in self-reactive T cells & how costimulatory pathways shape th….

RT @LucyWalkerlab: Our new review on the Immunology of #Type1Diabetes now out in @NatRevImmunol – really important area for understanding a….

RT @LucyWalkerlab: New review from Lina Petersone & I highlights recent findings on IL-21 and germinal center biology. Such an interesting….

RT @LIG_Seminar: We are v proud to finally share this!. Following @NatalieEdner's seminar (@LucyWalkerlab) in series 1, we were invited by….

RT @LucyWalkerlab: Really looking forward to Black in Immuno Week 2023! The past events have been superb. Excited for the Autoimmunity/Alle….

RT @LIG_Seminar: If you want to see fantastic images like THIS, be sure to catch our next seminar with Lina Petersone to discuss the role o….

RT @LucyWalkerlab: BSI Triggers of Autoimmunity online meeting 26th Oct! Speakers include David Wraith @cameron_wraith Dana Orange @danaora….

RT @LucyWalkerlab: Just a few days left to apply for the Research Technician post in our lab! @iit_ucl .

RT @LucyWalkerlab: New study led by Lina Petersone now in @JExpMed . Cytokine IL-21 from Tfh promotes germinal center (GC) responses & is o….

RT @JExpMed: Petersone et al. @LucyWalkerlab @iit_ucl investigate IL-21–dependent germinal center (GC) regulation and reveal key roles for….

RT @iit_ucl: Thrilled to have Her Majesty The Queen visit @iit_ucl to hear about the type 1 diabetes research in Professor Lucy Walker’s la….

RT @LucyWalkerlab: It was an honour to welcome Her Majesty The Queen to the UCL Institute of Immunity & Transplantation. Such a fantastic J….

Looking forward to presenting at the LIG seminar series tomorrow!. If you are interested in hearing about biomarkers of response to checkpoint blockade in melanoma join here: