Little to no attention has been paid to analyze the influence exerted by extracellular pH on the immune response. Tissue acidosis (pH 6.0 to 7.0) is usually associated with the course of infectious processes in peripheral tissues. Moreover, it represents a prominent feature of solid tumors. In fact, values of pH ranging from 5.7 to 7.0 are usually found in a number of solid tumors such as breast cancer, brain tumors, sarcomas, malignant melanoma, squamous cell carcinomas, and adenocarcinomas. Both the innate and adaptive arms of the immune response appear to be finely regulated by extracellular acidosis in the range of pH values found at inflammatory sites and tumors.
Microenvironmental acidity impacts tumor immune surveillance, contributing to immune escape and cancer progression. Anti-tumor effectors such as T and NK cells tend to lose their function when exposed to low pH environments. Local acidity also profoundly influences bio-activity and distribution of antibodies, thus potentially interfering with antibodies including immune checkpoint inhibitors. Hence tumor acidity is a central regulator of cancer immunity that orchestrates both local and systemic immunosuppression.
None of this is strange to scientists who know that many viruses are pH sensitive. Certain viruses (including the rhinoviruses and coronaviruses that are most often responsible for the common cold and influenza viruses that produce flu) infect host cells by fusion with cellular membranes at low pH. Thus they are classified as "pH-dependent viruses."
The immune system is pH and temperature sensitive and we will talk about using heat to stimulate the immune system separately. We can use pH and/or temperature to stimulate the immune system. The illusive etiology of autoimmune disease is in part due to pH and/or temperature changes.
Over acidity, which is highly common today, is a dangerous condition that contributes to a host of serious health conditions, yet doctors refuse to test pH levels (much better and less expensive to do at home) and resist prescribing sodium bicarbonate, which is simple baking soda, to address this common condition. An acidic internal environment is the perfect place for disease to thrive and that includes cancer. Normal pH environments resists disease and cancer formation. Sodium bicarbonate is the time-honored method to ‘speed up’ the return of the body’s bicarbonate levels to normal. Sodium bicarbonate is a strong medicinal, one of the strongest; it will drive pH levels up quickly, as well as oxygen, throughout most of the tissues, and that is why it is so effective.
A number of studies have shown that the extracellular pH in cancers is typically lower than that in normal tissue and that an acidic pH promotes invasive tumor growth in primary and metastatic cancers. The external pH of solid tumors is acidic as a consequence of increased metabolism of glucose and poor perfusion. Acid pH has been shown to stimulate tumor cell invasion and metastasis.