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Int Immunopharmacol. 2017 Aug;49:77-84. doi: 10.1016/j.intimp.2017.05.024. Epub 2017 May 25.

Capsular specific IgM enhances complement-mediated phagocytosis and killing of Cryptococcus neoformans by methamphetamine-treated J774.16 macrophage-like cells.

Author information

1
Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY, United States.
2
Department of Biomedical Sciences, Long Island University-Post, Brookville, NY, United States.
3
Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, United States.
4
Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY, United States; Department of Biomedical Sciences, Long Island University-Post, Brookville, NY, United States; Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, United States. Electronic address: lmarti13@nyit.edu.

Abstract

Methamphetamine (METH) is a powerful and highly addictive stimulant that affects the central nervous system of users in the United States and worldwide, and its consumption is associated to the acquisition of HIV and AIDS-related infections. METH enhances cryptococcosis in mice, an opportunistic infection caused by the encapsulated fungus Cryptococcus neoformans. Due to its ability to survive within macrophages, C. neoformans is an ideal model to study pathogen-macrophage interactions. METH abrogates normal macrophage function, which might contribute to the higher rate and more rapid progression of infections in drug abusers. Hence, we investigated the role of complement and specific IgM to C. neoformans capsular polysaccharide on the function of J774.16 macrophage-like cells after exposure to METH. We found that complement and IgM significantly promotes complement-mediated phagocytosis of C. neoformans by J774.16 cells in comparison to co-incubation with complement alone. IgM enhances the expression of complement receptor 3 on the surface macrophages treated with the drug. Also, IgM-increased macrophage phagocytosis of C. neoformans may be associated with upregulation of GTPase-RhoA, a key regulator of the actin polymerization signaling cascade. Fungal cells incubated with complement and IgM in the presence of METH demonstrated higher number of cells per aggregate, a possible explanation for their enhanced ingestion by phagocytes. IgM increased killing of yeast cells by macrophages by inhibiting the alkalization of the phagosome and stimulating the intracellular production of nitric oxide. Together, our findings suggest that IgM stimulates the effector functions of macrophages against opportunistic pathogens in the setting of drug abuse.

KEYWORDS:

Complement; IgM; Infection; Methamphetamine; Nitric oxide; Phagocytosis

PMID:
28551495
PMCID:
PMC5599138
DOI:
10.1016/j.intimp.2017.05.024
[Indexed for MEDLINE]
Free PMC Article

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