The urinary tract response to entry of pathogens.

The urinary tract response to the entry of pathogens is complex and involves multiple aspects of the immune system. Herein we have divided them into cytokine, immunoglobulin, and cellular responses. Our current understanding suggests that interleukin 6 (IL-6) and IL-8 are the major contributors to the cytokine response. Both IL-6 and IL-8 are produced locally and systemically as part of the initiation of an inflammatory reaction. The cellular response becomes clinically apparent by the appearance of polymorphonuclear neutrophils (PMNs) in the urine. The contribution of gamma delta T-lymphocytes is beginning to be appreciated due to the use of gene-knockout mice in studies of urinary tract infection (UTI). B-lymphocytes are important because antibody response to UTI is important. In addition to the classic systemic antibody response, a local antibody response dominated by secretory immunoglobulin A (sIgA) has been shown to play a major role in the host response to UTI. Efforts to create a vaccine against UTI have focused on stimulation and intensification of this local sIgA production. Investigation continues to define the role of these responses, explain how they interact, and elucidate other aspects of the immune response to UTI that are yet unknown. Ultimately, this work aims to provide more effective treatment and prevention of UTI in those susceptible to invasions of the urinary tract by pathogens. Comprehension of how these responses interact may lead to a better understanding of UTI susceptibility and promote new and innovative types of treatment.