Congenital T cell activation impairs transitional to follicular B cell maturation in humans.

CTLA4-deficient patients exhibit profound humoral immune dysfunction, yet the basis for the B cell defect is not known. We observed a marked reduction in transitional to follicular B cell development in CTLA4-deficient patients, correlating with decreased CTLA4 function in regulatory T cells, increased CD40L levels in effector CD4+ T cells, and increased mTORC1 signaling in transitional B cells. Treatment of transitional B cells with CD40L was sufficient to induce mTORC1 signaling and inhibit follicular B cell maturation in vitro.

Impact of a tailored exercise regimen on physical capacity and plasma proteome profile in post-COVID-19 condition.

Background: Individuals affected by the post-covid condition (PCC) show an increased fatigue and the so-called post-exertion malaise (PEM) that led health professionals to advise against exercise although accumulating evidence indicates the contrary. The goal of this study is to determine the impact of a closely monitored 8-week mixed exercise program on physical capacity, symptoms, fatigue, systemic oxidative stress and plasma proteomic profiles of PCC cases.

Methods: Twenty-five women and men with PCC were assigned sequentially to exercise ( = 15) and non-exercise ( = 10) groups.

T peripheral helper (Tph) cells, a marker of immune activation in cancer and autoimmune disorders.

T peripheral helper (Tph) cells are a newly discovered subtype of CD4+ T cells that have emerged as the counterpart of T follicular helper (Tfh) cells in the peripheral tissues. These two cell types share some common characteristics, such as high levels of PD1 and CXCL13 expression, but differ in the expression of transcription factors and chemokine receptors. Tph cells have been studied in relation to B cells' effector functions, including cytokines production and antibody-mediated immune responses.

When Should I Get My Next COVID-19 Vaccine? Data From the Surveillance of Responses to COVID-19 Vaccines in Systemic Immune-Mediated Inflammatory Diseases (SUCCEED) Study.

Objective: To determine how serologic responses to coronavirus disease 2019 (COVID-19) vaccination and infection in immune-mediated inflammatory disease (IMID) are affected by time since last vaccination and other factors.

Methods: Post-COVID-19 vaccination, data, and dried blood spots or sera were collected from adults with rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, ankylosing spondylitis and spondylarthritis, and psoriasis and psoriatic arthritis. The first sample was collected at enrollment, then at 2 to 4 weeks and 3, 6, and 12 months after the latest vaccine dose.