The role of M cells of human nasopharyngeal lymphoid tissue in influenza virus sampling

• Published in: Virchows Archiv : an international journal of pathology Vol. 444; no. 1; pp. 36 - 42
• Main Authors: FUJIMURA, Yoshinori, TAKEDA, Masaharu, IKAI, Hidenori, HARUMA, Ken, AKISADA, Takeshi, HARADA, Tamotsu, SAKAI, Tatsuya, OHUCHI, Masanobu
• Format: Journal Article
• Language: English
• Published: Berlin Springer 2004; Springer Nature B.V
• Subjects: Adolescent; Biological and medical sciences; Child; Child, Preschool; Cytoplasm - ultrastructure; Female; Humans; Immune system; Influenza; Influenza A virus - isolation & purification; Influenza A virus - ultrastructure; Investigative techniques, diagnostic techniques (general aspects); Lymphocytes - virology; Lymphoid Tissue - ultrastructure; Lymphoid Tissue - virology; Macrophages - virology; Male; Medical sciences; Microscopy, Electron; Microscopy, Immunoelectron; Nasopharynx - ultrastructure; Nasopharynx - virology; Palatine Tonsil - chemistry; Palatine Tonsil - ultrastructure; Palatine Tonsil - virology; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Respiratory tract; Respiratory Tract Infections - virology; Sialoglycoproteins - analysis; Virion - ultrastructure; Viruses; Human; Lectin; Lymphoid cell; M cell; Samplings; Orthomyxoviridae; Nasopharynx; Lymphoid tissue; Electron microscopy; Influenzavirus; Virus; Anatomic pathology; Influenza A virus; Nasopharyngeal; Sampling; NALT
• ISSN: 0945-6317; 1432-2307
• DOI: 10.1007/s00428-003-0898-8

Little is known about the role of the M cells of human nasopharyngeal lymphoid tissue in the sampling of viruses that cause respiratory infections. To clarify whether M cells could function as a gateway for influenza virus into human nasopharyngeal lymphoid tissue, excised adenoid tissue was incubated in media containing influenza A virus for 30, 60, and 90 min, respectively. Transmission electron microscopic observation revealed that many influenza viruses adhered to M cell surfaces and were taken up into the cytoplasmic vesicles of M cells after 30 min incubation; the viruses had been transported into enfolded lymphoid cells after 60 min incubation. By staining M cells with Sambucus nigra lectin, which specifically recognizes the NeuAcalpha2,6 Gal linkage of sialoprotein, it was also found that abundant receptors for the human influenza virus are present on the M cell surface. Our findings indicated that M cells of human nasopharyngeal tonsils function as a major port for influenza A virus entry and that the virus could be efficiently transferred to enfolded macrophages and lymphoid cells by M cells. The transport of influenza viruses to lymphoid cells by M cells may promote antigen delivery to the immune system, and these findings may be important for systemic delivery of those influenza viruses that have the capacity to productively infect cells outside of the respiratory tract.