Research Lab Overview

The Kalkum lab is housed within the Department of Immunology & Theranostics at Beckman Research Institute of City of Hope and the Arthur Riggs Diabetes & Metabolism Research Institute. The lab conducts intradisciplinary research in the fields of mass spectrometry, biochemistry, microbiology and immunology. Active research highlights include:

Vaccines to protect against invasive fungal infections:
The Kalkum lab is developing vaccines against invasive pulmonary aspergillosis to protect immunosuppressed patients and animals from fatal infections with Aspergillus fumigatus and other pathogenic fungi. A protein vaccine, based on bacterially expressed, recombinant, A. fumigatus Asp f3 was shown by the lab to protect mice from invasive aspergillosis through a CD4+ T cell mediated mechanism. Antifungal vaccines are of interest to cancer patients, stem cell transplant recipients, and in veterinary care to protect exotic birds and other susceptible species.

Diagnostic assays for microbial toxins and diseases:

The Assay with a Large Immunosorbent Surface Area (ALISSA) invented by the lab detects botulinum neurotoxins and other proteolytically active agents with ultra-high sensitivity (femtomolar concentrations) in complex biological matrices, such as blood or foods. The lab is currently developing similar detection assays for a variety of diagnostic targets using targeted mass spectrometry and advanced nucleic acid amplification methods.

Immunomodulatory compounds of the human microbiome:
The lab has employed mass spectrometry to identify metabolites of commensal microbes that modulate the human immune system. Such immuno modulators include Lactobacillus reuteri-produced histamine, ethionine, and an unconventional form of vitamin B9 (folate), 5,10-ethenyl tetrahydrofolate. The latter is produced via metabolism of acetate the bacterium. In contrast to conventional folates, it can transfer not one but two carbon units at once via the folate cycle. Acetate and other short chain fatty acids are produced in the human gut through the microbial fermentation of dietary fibers. The laboratory’s research is aimed to explore the link between the immune system the microbiome and nutritional factors with relevance to cancer and metabolic diseases.

Proteomics of extremophiles and pathogens:
In collaboration with the Jet Propulsion Laboratory / NASA in Pasadena, California, the Kalkum lab discovered changes in specific protein abundances in fungi and bacteria that were exposed to microgravity and/or real space conditions on board of the international space station. Such changes appear to be integral to stress adaptation processes by the microorganism and were detected using quantitative proteomics using mass spectrometry. In another collaborative effort with our partners at the Fundación Instituto de Inmunología de Colombia (FIDIC) the Kalkum lab is investigating protein interactions by mass spectrometry that control host cell invasion by malaria parasites. These efforts are directed to further our understanding of microbial life adaptations as well as critical pathogen host interactions.