Allen studies helminthiasis, a disease caused by helminth (parasitic worm) infection. The infection is associated with the induction of a type 2 immune response in mammals. Allen has identified macrophages with a specific type 2 expression profile, which are found both at the site of the infection and in injured tissue. The macrophage phenotype is influenced by the genotype of the host and the infected site. Allen discovered a relationship between the chitinase-like protein 3 YM1 and Interleukin 17, an inflammatory cytokine associated with autoimmune disease.[8][9]
Judi Allen has also completed some research explaining the relationship between a type 2 cytokine Interleukin 13, IL-13, and SARS-Cov-2 infection, better known as COVID-19. SARS-Cov-2 is a virus that affects the respiratory system and patients exhibit higher levels of inflammatory cytokines in response to infection. Allen helped discover that IL-13 encourages SARS-Cov-2 to progress in severity through the increased accumulation of hyaluronan polysaccharide (HA) in the lungs. In her study, Allen discovered Interleukin 13 neutralization resulted in a decrease in the amount of HA in the lungs and a decrease in the severity of the disease.[10]
Allen also published a paper in 2023 concerning T helper 2 cells and nematode infection. Allen used mice with different immune genotypes to measure the different immune responses to Litomosoides sigmodontis, a nematode that infects the pleural cavity. Th2 cells, T helper 2, controlled the cell’s pathway of the tissue-resident macrophages from monocytes which affected the infection response. C57BL/6 mice had a strong conversion to large cavity macrophage from the monocyte while BALB/c mice had a weak conversion. Therefore, Allen has made an impact in the adaptive immune response component of cells in immunobiology.[12]
Judi Allen has helped to establish a relationship between the extracellular matrix in organisms and the immune system. The matrix and the immune system must work together to fight any infection or disease in organisms. There are many molecules and relationships that contribute to this working partnership. For example, the immune system will regulate the extracellular matrix through chemokines or cytokines, inflammatory signals, which will call for leukocyte extravasation to an injury site. Interleukin 13, a type 2 cytokine Allen has worked with previously, not only regulates hyaluronan polysaccharide but also mucus which is an important structure in the extracellular matrix as well. Allen has also emphasized the importance this relationship has for potential new immunotherapies.[13]