COVID-19 is a type of virus that causes an infection in people. It starts with flu like symptoms and progresses to more serious conditions such as pneumonia, encephalitis, and even death. The severity of the COVID-19 infection can be exacerbated by CD47. The protein CD47 may contribute to the severity of COVID-19 infections in people because it binds to white blood cells which prevents them from fighting off viruses and bacteria effectively.
In previous studies, researchers were able to show that CD47 is required for the COVID-19 infection in mice. In order to determine whether or not CD47 was involved in people, a group of researchers from Tufts University School of Medicine performed a study. The study showed that people with genetic variants in CD47 do experience more severe COVID-19 infections. Also, people who have the variant are more likely to die if they contract COVID-19. The study was done on mice and human cells in a lab, so there is still much research left to do. However, this could be fantastic news for those who develop COVID-19 or similar viruses in the future. If researchers can find a way to inhibit the protein CD47, then people may be able to fight off virus infections more effectively.
A link between CD47 and inflammation in obese individuals has recently been revealed. Findings from the study show that obese people have high levels of CD47 which inhibits macrophage activity or ‘clean up’ cells. This then leads to inflammation which can contribute to the development of obesity related diseases like type 2 diabetes and cardiovascular disease.
CD47 protein is also responsible for cell death in colon cancer cells. Researchers found that CD47 is responsible for directing T cells to attack tumor cells. When CD47 was blocked, lymphocyte response against cancerous tissues increased and cancer cell proliferation was significantly reduced.
A monoclonal antibody against CD47, called IM638, has been used to treat patients with chronic lymphocytic leukemia (CLL). This treatment targeted and killed malignant cells while sparing non-malignant cells leading to a significant reduction in tumor bulk and improved patient response and survival. The treatment was well tolerated in CLL patients.
Besides leukemia, anti-CD47 has been used to induce apoptosis (programmed cell death) of human solid tumors and hematological malignancies such as multiple myeloma, non-Hodgkin lymphoma, chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML), T-cell acute lymphoblastic leukemia, and solid tumors such as renal cell carcinoma. Anti-CD47 antibody can be co-administered with other anticancer drugs to suppress tumor growth and induce apoptosis in a mouse xenograft model.
Study conducted by Mannick et al. showed that anti-CD47 antibody combined with the immune checkpoint Inhibitors such as anti PD1/PDL1 agents can enhance tumor infiltration of CD8+ T cells and have more antitumor activity.
In 2014, a study from Stanford showed that blocking CD47 with an antibody inhibits metastasis in human breast cancer models. The study showed that metastasis was inhibited not only in the DMBA-induced breast cancer model but also in a spontaneous triple-negative breast cancer model. Inhibiting CD47 opens up a new treatment paradigm for how to treat breast cancer both by itself and in association with existing treatments such as chemotherapies or other antibodies.
Another study showed that a CD47 antibody blocks metastasis in a preclinical model of pancreatic cancer. The study shows that blocking CD47 with an antibody inhibits tumor growth and induces apoptosis.