Humoral and cell-mediated immune responses to BNT162b2 vaccine against SARS-CoV-2 in people with cystic fibrosis

Monoclonal antibodies derived from B cells in subjects with cystic fibrosis reduce Pseudomonas aeruginosa burden in mice

Pseudomonas aeruginosa (PA) is an opportunistic, frequently multidrug-resistant pathogen that can cause severe infections in hospitalized patients. Antibodies against the PA virulence factor, PcrV, protect from death and disease in a variety of animal models. However, clinical trials of PcrV-binding antibody-based products have thus far failed to demonstrate benefit. Prior candidates were derivations of antibodies identified using protein-immunized animal systems and required extensive engineering to optimize binding and/or reduce immunogenicity. Of note, PA infections are common in people with cystic fibrosis (pwCF), who are generally believed to mount normal adaptive immune responses. Here, we utilized a tetramer reagent to detect and isolate PcrV-specific B cells in pwCF and, via single-cell sorting and paired-chain sequencing, identified the B cell receptor (BCR) variable region sequences that confer PcrV-specificity. We derived multiple high affinity anti-PcrV monoclonal antibodies (mAbs) from PcrV-specific B cells across three donors, including mAbs that exhibit potent anti-PA activity in a murine pneumonia model. This robust strategy for mAb discovery expands what is known about PA-specific B cells in pwCF and yields novel mAbs with potential for future clinical use.

The efficacy of COVID-19 vaccination in cystic fibrosis patients: a systematic review

This systematic review evaluates the efficacy and safety of COVID-19 vaccines in individuals with cystic fibrosis (CF). A systematic search of major databases conducted between December 2019 and January 2024 identified eight cohort studies comprising 1,361 CF patients. Studies without subgroup analyses specific to CF patients were excluded, which may have limited the generalizability of findings, particularly for CF lung transplant recipients. COVID-19 vaccines generally induced robust serological responses following the second and third doses, although reduced antibody levels were observed in lung transplant recipients. Factors influencing humoral response included prior SARS-CoV-2 infection, age, inhaled corticosteroid use, and immunosuppressive therapy. Vaccination-related adverse events were predominantly mild. Although breakthrough infections were reported, severe COVID-19 outcomes were infrequent among vaccinated CF patients. The evidence supports the immunogenicity and safety of COVID-19 vaccines in the CF patients. However, individualized vaccination strategies may be necessary for CF lung transplant recipients and those on immunosuppressive therapies. Further research is essential to optimize vaccination strategies and to identify risk factors associated with breakthrough infections in this high-risk population.

Monoclonal antibodies derived from B cells in subjects with cystic fibrosis reduce Pseudomonas aeruginosa burden in mice

Pseudomonas aeruginosa (PA) is an opportunistic, frequently multidrug-resistant pathogen that can cause severe infections in hospitalized patients. Antibodies against the PA virulence factor, PcrV, protect from death and disease in a variety of animal models. However, clinical trials of PcrV-binding antibody-based products have thus far failed to demonstrate benefit. Prior candidates were derivations of antibodies identified using protein-immunized animal systems and required extensive engineering to optimize binding and/or reduce immunogenicity. Of note, PA infections are common in people with cystic fibrosis (pwCF), who are generally believed to mount normal adaptive immune responses. Here we utilized a tetramer reagent to detect and isolate PcrV-specific B cells in pwCF and, via single-cell sorting and paired-chain sequencing, identified the B cell receptor (BCR) variable region sequences that confer PcrV-specificity. We derived multiple high affinity anti-PcrV monoclonal antibodies (mAbs) from PcrV-specific B cells across 3 donors, including mAbs that exhibit potent anti-PA activity in a murine pneumonia model. This robust strategy for mAb discovery expands what is known about PA-specific B cells in pwCF and yields novel mAbs with potential for future clinical use.