ANTIBODY-RESPONSE IN DOGS EXPERIMENTALLY INFECTED WITH LEISHMANIA-INFANTUM - INFECTION COURSE ANTIGEN MARKERS

Five-month-old beagle dogs were experimentally infected with amastigot es of Leishmania infantum and kept for 14 months. infection course was monitored by clinical examination, serum protein variations, and leve ls of specific antibodies against Leishmania estimated by indirect imm unofluorescence test and Western blotting (WE). infected animals devel oped notable changes in serum protein levels reaching maximum protein concentrations 2-3 months postinfection (p.i.) related to the gamma-gl obulin fraction. Specific antibody titers were in good agreement with the serum protein rise, reaching immunofluorescence values of over 1:8 00 3 months p.i. Serial Western blotting analysis with L. infantum pro mastigotes protein showed a strong response against immunodominant ant igens of 50-57, 42, and 29 kDa during most of the studied period with immunofluorescence titers of over 1:100 and in addition the response w as remarkably homogeneous among the infected dogs. Immunoreactivity pa tterns displayed time-related variations; the response against 29 and 50-57 kDa was seen very early, followed by the reaction around 42, 76, and 86 kDa. In addition the recognition of peptides around 34-35.4 an d 26 kDa was restricted to the acute phase of the experimental infecti on. Preliminary results obtained in naturally infected dogs seem to su pport the predictive value of the WB. (C) 1996 Academic Press, Inc.