Immunization with a tetramer derivative of an anti-inflammatory pentapeptide produced by Entamoeba histolytica protects gerbils (Meriones unguiculatus) against experimental amoebic abscess of the liver.
Axenically grown Entamoeba histolytica produces a pentapeptide (Met-Gln-Cys-Asn-Ser) with several anti-inflammatory properties, including the inhibition of human monocyte locomotion (Monocyte Locomotion Inhibitory Factor (MLIF)). A construct displays the same effects as the native material. It remains to be seen if MLIF is used, or even produced in vivo by the tissue-invading parasite. If MLIF were to be relevant in invasive amoebiasis, immunizing against it could diminish this parasite advantage and prevent lesions. KLH-linked MLIF mixed with Freund's adjuvant was too aggressive an immunizing material to answer this question. However, immunization with a tetramer of MLIF (but not a scrambled version of MLIF) around a lysine core (MLIF-MAPS), that displays increased antigenicity, yet lacks excessive innate immunity activation, completely protects gerbils against amoebic abscess of the liver caused by the intraportal injection of virulent E. histolytica. Liver abscesses caused by Listeria monocytogenes were not prevented. Invasive E. histolytica may produce the parent protein of MLIF in vivo, and if appropriately cleaved, it may play a role in invasive amoebiasis. MLIF may join new vaccination strategies against amoebiasis.
Giménez-Scherer
Juan Antonio
JA
Unidad de Investigación Médica en Inmunología, Hospital de Pediatría, Coordinacion de Investigacion en Salud, Centro Medico Nacional, Siglo XXI, IMSS. Mexico, D.F., Mexico.
Cárdenas
Guadalupe
G
López-Osuna
Martha
M
Velázquez
Juan Raymundo
JR
Rico
Guadalupe
G
Isibasi
Armando
A
Maldonado
María del Carmen
Mdel C
Morales
María Esther
ME
Fernández-Diez
Jorge
J
Kretschmer
Roberto R
RR
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000276:immunology* / Q000494:pharmacology; D004748:Entamoeba histolytica / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005849:Gerbillinae; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007114:Immunization / Q000379:methods*; D007074:Immunoglobulin G / Q000097:blood; D008101:Liver Abscess, Amebic / Q000276:immunology* / Q000517:prevention & control*; D008213:Lymphocyte Activation / Q000276:immunology; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology; D008297:Male; D009842:Oligopeptides / Q000276:immunology* / Q000494:pharmacology; D010455:Peptides / Q000276:immunology; D011897:Random Allocation
D000893:Anti-Inflammatory Agents; D007074:Immunoglobulin G; D009842:Oligopeptides; D010455:Peptides; C430647:monocyte locomotion inhibitory factor