Comparative susceptibility of Marek's disease cell lines to chicken infectious anemia virus

Chicken infectious anemia virus (CIAV) is known to infect and replicate in various Marek's disease chicken cell lines (MDCCs) derived from Marek's dis ease (MD) tumors. One line, MDCC-MSB1, has been the substrate used in most studies. We compared a total of 26 MDCCs, including two sublines of MDCC-MS B1, MSB1 (L) and MSB1 (S), four other MD tumor-derived lines, and 20 lines derived from MD virus-induced local lesions, for susceptibility to the Cux- 1 and CIA-1 strains of CIAV. The cell lines represented six phenotypic grou ps of T cells based on the expression of CD4, CD8, and TCR-2 and -3 surface markers. Susceptibility was measured by the number of cells positive for v iral antigen in immunofluorescence (IF) tests at 3-10 days postinfection. N o clear-cue differences were found in susceptibility related to phenotype, although CD4-/8+ lines and CD4-/8- lines might be more susceptible than CD4 +/8- lines. However, several individual lines were more susceptible to Cux- 1 than the two MSB1 sublines tested. Contrary to an earlier report, cells o f MDCC-CU147, a CD8+, TCR3+, local-lesion derived line, were found to be su sceptible to CIA-1. In fact, CU147 was distinguished by very high susceptib ility to both CIAV strains. In direct comparisons with MSB1, CU147 detected approximately 10-fold lower doses of virus. Also, virus spread was faster (P < 0.05) in CU147 than in MSB1 and other lines. Results from polymerase c hain reaction (PCR) tests to detect infection in titrations were in general agreement with IF test results although PCR detected infection in a few te rminal dilution cultures that were negative by IF.