Interaction between Pneumocystis jirovecii and host immune defense

Abstract

Abstract: Pneumocystis pneumonia (PCP) is a form of pneumonia, caused by the yeast-like fungus Pneumocystis jirovecii (Pj). It is an important lethal factor in immunodeficient patients.Pj generally does not cause systemic infection, only multiply in the lungs. Interstitial pneumonia caused by Pj seriously damages the oxygen exchange function of the lung.Pj uses major surface glycoprotein (MSG) antigen switch to escape host immune elimination. The host initiates innate immune response through the interactions of macrophage mannose receptors with the MSG as well as through interaction of macrophage dectin-1 receptors interacting with the beta-1,3-D-glucan (BG) moiety of the organisms. Pattern recognition induces chemokines and inflammatory cytokine production, which promoting neutrophils and T-lymphocytes recruitment and activation. Cytotoxic 1 CD8⁺T cells which producing interferon-γ are critical in helping control of Pj infections. IgG may facilitate the uptake process by opsonization of the organisms. Neutrophil and non Tc1 CD8⁺T cell recruitment seems to closely correlate with lung injury in humans. The level of BG can help diagnosing PCP. The level of interleukin-8 in the bronchoalveolar lavage fluid could be a predictor of lung impairment and death from PCP.

Key words: Pneumocystis pneumonia, Pneumocystis jirovecii, major surface glycoprotein

CLC Number:

R379.9

REN Yi, SONG Ying-gai, LI Ruo-yu. Interaction between Pneumocystis jirovecii and host immune defense[J]. Chinese Journal of Mycology, 2013, 8(1): 51-54.

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