THE DYNAMICS OF ANTIGEN SPECIFIC PROLIFERATIVE RESPONSES OF LYMPHOCYTES AT EARLY STAGES OF BOVINE PARATUBERCULOSIS INFECTION

Abstract

The present study was aimed to quantify the dynamics of early antigen specific
proliferative responses of lymphocytes to (protein) antigens associated with experimental
Mycobacterium avium subsp. paratuberculosis (Mp) infection cattle. The data were collected from
20 experimentally infected calves, and 10 uninfected control animals, during the first 2 years of
their lives. Several purified protein derivative antigens (Ppdp, Ppda, and Ppdb), two
recombinant Mp heatshock proteins (Hsp65 and Hsp70) and whole bacteria (sonicated Mp
strain 316F) were used to measure lymphocyte proliferation in a lymphocyte proliferation
assay. Data were analyzed using a linear mixed effect (LME) model. The results showed
significant group and timed effects for all antigens tested. At several time points, the responses
in the infected group were found significantly higher as compared to control group. The Ppd
antigens induced similar lymphocyte proliferation patterns, as compared to whole bacteria
antigen and Hsp70. These results indicated that the antigen specific proliferative responses of
lymphocytes differs for different antigens, probably related to differences in their availability
during different stages of infection. The application of LME model is a useful tool for analyzing
the quantitative longitudinal datasets.

Keywords: dynamics, Mp, antigen, LME