Nanobodies as immunotherapy for invasive fungal infections

The National Institute of Allergy and Infectious Diseases awarded The Trustees of Columbia University in the City of New York $214,906 on June 1, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855) to develop nanobodies as immunotherapy against invasive aspergillosis.

The project addresses therapeutic limitations in treating invasive aspergillosis, a devastating infection with mortality rates exceeding 50% in immunocompromised populations despite three classes of available antifungals, compounded by rising drug resistance in Aspergillus species. Columbia's research leverages nanobodies—small, monomeric variable antigen-binding domains from camelid heavy-chain-only antibodies—to circumvent constraints of conventional monoclonal antibodies. The team previously identified nanobodies with substantial binding to Aspergillus fumigatus surfaces and demonstrated reduced fungal viability in a subset upon binding. The funded work includes five specific aims: performing iterative selection rounds to define nanobody clones that bind A. fumigatus, identifying subordinate positive clones, characterizing binding and functional properties, and developing the lead candidates as candidate therapeutics against invasive aspergillosis.

Performance occurs in New York, New York (10032) through May 30, 2028. The award is classified as a Project Grant, a standard assistance type for the Allergy and Infectious Diseases Research program, which supports biomedical research in infectious diseases and related areas at public and private nonprofit institutions.

Abstract

Invasive aspergillosis is a devastating infection for those with a vulnerable immune system, chronic lung disease, or preceding respiratory viral infection. Despite the current three classes of antifungal drugs (polyenes, azoles, echinocandins), mortality rates surpass 50% for these high-risk populations and have not improved over time with the introduction of newer antifungals. Furthering the issue is drug resistance in aspergillus SPP., which continues to rise, highlighting the critical need for the development of new therapeutic strategies. The use of antibodies as immunotherapy has emerged as a powerful strategy to combat human diseases, including cancer and infectious diseases. Nanobodies are small, monomeric, and comprise the variable antigen-binding portion of camelid heavy-chain-only antibodies. Their size enables advantages to circumvent the major limitations of conventional monoclonal antibodies, highlighting their value as potential therapeutics. The development of nanobodies has led to clinical trials for diseases, including infections. Limited information is known about the therapeutic potential of nanobodies against aspergillus fumigatus. We leveraged a saccharomyces cerevisiae library expressing every mathematically possible nanobody and identified a collection of nanobodies with substantial binding to the surface of a. Fumigatus. Furthermore, we revealed reduced fungal viability in a subset of nanobodies using a flare strain upon binding, suggesting that some nanobodies effectively killed the AF conidia. Our major goal is to examine if nanobodies that bind to cell surface antigens on the a. Fumigatus surface can be developed as immunotherapy against invasive aspergillosis. To address our primary objective, we propose the following five specific aims: [1] perform four iterative rounds of selection to define positive nanobody clones that bind to a. Fumigatus, [2] identify subsets of clones that either kill a. Fumigatus or bind and inhibit growth, [3] define antigen specificity of selected nanobodies, [4] characterize nanobody binding using purified a. Fumigatus proteins and in vivo pharmacokinetics and toxicity, and [5] test 10 nanobodies in a mouse model of invasive aspergillosis to determine whether they inhibit pathogenesis. The first two aims will be the focus of the R21 phase of the grant, while the last three aims will be covered during the R33 phase. Our work will identify nanobodies for development into novel therapeutics for invasive aspergillosis.