Fig. 1.

Illustration of role of chronic CP intracellular infection in asthma pathogenesis. The figure illustrates multiple pathways whereby chronic intracellular CP infection (1) is directly responsible for Immunopathologic damage and/or (2) indirectly influences allergic response as demonstrated in multiple animal models. Effects on the clinical manifestations of viral infections and the microbiome as they relate to asthma are speculative at this time. CP infection has also been shown to enhance histidine decarboxylase (HDC) to produce histamine as shown in cell culture, and the production of Cp-specific IgE antibodies is demonstrated in human asthma patients. Finally, CP infection of the airways (i) may induce hyperresponsiveness through infection of bronchial smooth muscle cells, (ii) produces inflammatory cytokines and (iii) induces ciliostasis of bronchial epithelial cells similar to the effects of cigarette smoking