Impaired pathogen-specific CD4 +T cell functionality in patients with CLL

Abstract Chronic lymphocytic leukemia (CLL) is the most common type of in adults and remains an incurable disease. Many patients with CLL are affected by non-malignant complications, including infectious diseases, as witnessed during past years, very high COVID-19 mortality rates. Accumulating data indicate that T cells might become exhausted CLL, which be a contributing factor to poor control pathogenic infections. Here we developed flow cytometry protocols combine activation-induced molecule (AIM) assessment functional read-outs understand if bacteria- virus-specific CD4 +T cell responses impaired CLL. PBMCs were collected from indolent (n=23) age gender-matched blood donors (n=17) assess dysfunction against bacteria (S. Pneumonia, H. Influenzae, M. Catarrhalis, K. Pneumoniae) viruses (CMV, EBV, IAV). We show frequency assessed bacterial species was lower frequencies compared matched groups. Both experienced, general, signs exhaustion, diminished capacity produce IFN-γ, TNF, IL-2, IL-17, and/or IL-21, Functional exhaustion not coupled increased expression inhibitory receptors but instead reduced stem-like phenotypes cells. These untreated cells, lead pathogen control. Swedish Cancer Foundation(Cancerfonden)