Host Defense Against Cryptococcal Disease: Is There a Role for B Cells and Antibody-Mediated Immunity?

The role of B cells and antibody-mediated immunity (AMI) is poorly understood regarding infections with the encapsulated yeast species, Cryptococcus. Human cryptococcal disease, or cryptococcosis, generally occurs in the setting of immune suppression, including deficits of T cells and other components of cell-mediated immunity (CMI), as observed in HIV/AIDS, cancer, solid-organ transplant, and similar conditions. The protective role of CMI is, therefore, well-described in the literature. However, CMI deficiencies alone cannot adequately explain the quantum of cryptococcal disease noted in human and animal populations, and a wealth of clinical and experimental data, mostly spanning the past several decades, has shed light upon a significant role of AMI in anticryptococcal immunity. Recent evidence suggests that rather than functioning discretely, these two host immune compartments work synergistically, with the AMI modulating CMI functions in order to provide a critical balance for host benefit. We describe what is currently known.