Development of anti-IgA monoclonal and polyclonal reagents for detecting mucosal and systemic IgA in nonhuman...

Nonhuman primates (NHPs), such as rhesus macaques, are widely used as models for studying human health and disease due to their physiological and immunological similarities. Measuring immunoglobulin A (IgA) levels in NHPs can offer valuable insights into immune responses and vaccine efficacy; however, accurate quantitation of IgA in tissues, fluids, and serum of NHPs has been challenging. This difficulty stems from the high cross-reactivity of anti-monkey IgA antibodies with other immunoglobulin classes (IgG and IgM), as well as IgA polymorphisms within rhesus macaques. To address these limitations, we aimed to develop novel anti-rhesus IgA reagents; this included a polyclonal antibody capable of binding diverse IgA allotypes of rhesus macaques, along with two monoclonal antibodies that specifically target rhesus IgA with minimal cross-reactivity with rhesus IgG and human IgM. These antibodies were validated across multiple conjugation formats (HRP, biotin, and unconjugated), enabling compatibility with various immunoassay platforms. Here, we describe the generation and characterization of anti-IgA reagents that overcome previous specificity issues and improve the detection and quantification of rhesus IgA. These reagents are now available to the scientific community through the Nonhuman Primate Reagent Resource (NHPRR) and offer valuable tools for investigating mucosal immunity, monitoring vaccine-induced responses, and evaluating antibody function in translational NHP models. By enabling more precise IgA detection in rhesus macaques, these tools will facilitate translational research aimed at understanding the role of IgA in immune defense and informing the development of targeted interventions against mucosal infections in humans.