ISOLATION AND PHENOTYPIC CHARACTERIZATION OF ABOMASAL MUCOSAL LYMPHOCYTES IN THE COURSE OF A PRIMARY OSTERTAGIA-OSTERTAGI INFECTION AN CALVES

Isolation and characterization of surface marker phenotypes of abomasa l intraepithelial (IEL), lamina propria (LPL) and abomasal lymph node lymphocytes (ABLN) from uninfected calves were conducted, and the dyna mics of change in these populations during the course of a primary Ost ertagia ostertagi infection were defined. To obtain viable IEL and LPL from the abomasal mucosa of cattle, a modified isolation method was d eveloped. The phenotypic characterization of abomasal lymphocytes was accomplished by indirect immunofluorescence staining. In uninfected an imals, numbers of T cells exceeded the number of immunoglobulin-bearin g cells in IEL, LPL and ABLN. The predominant T cell type in IEL and L PL was CD8(+) cells, while the CD4(+) T cell predominated in ABLN. Lev els of activated cells and T cell receptor-1 gamma delta T cells were higher in IEL and LPL compared to ABLN. Within 3 weeks of infection, t he number of lymphocytes recovered from the abomasal lamina propria an d the mass of the ABLN was dramatically increased when compared to uni nfected animals. Laser flow cytometric analysis demonstrated increased levels of immunoglobulin-bearing cells, gamma delta T cells, and acti vated T cells in IEL, LPL and ABLN in the infected animals. The greate st changes in LPL and ABLN took place during the first days of infecti on, and these changes were apparent throughout the 28 days covered by the experiment. (C) 1997 Elsevier Science B.V.