Influence Of Single-& Co-infection With Different Immunosuppressive Viruses On Cellular Immunity Responses In Chickens

It was documented to clarify that some viruses including reticuloenendotheliosis virus (REV), Marek's disease virus(MDV), subgroup J of avian leucosis virus (ALV-J), infection bursal disease virus(IBDV), avian reovirus (ARV) et al are immunosuppressive viruses which can induce to inhibit the immunity in infected chickens and increase the suspectlity to some pathogens. Recently it was invested that some of them with co-infected and multi-infection can persist in chickens and result in more severe economical loss. So it is necessary to study the effect of co- or multi-infection with them on the immunity responsibility in chickens. The immunity in chickens includes humoral immunity and cellular immunity which can play an important role in resistantance to pathogens infection and clearance of tumor cells in vivo and can be accessed by detection of lymphocytes proliferation to mitogen agent such as ConA or PHA or LPS et al mostly with ~3H-thymidine (~3H-TdR) incorporation assay. This thesis mainly focuses on the changes of cellular immunity post infection with different immunosuppressive viruses in chickens.1 Evaluation of various factors in ~3H-thymidine (~3H-TdR) incorporation assay~3H-thymidine (~3H-TdR) incorporation assay has been used to measure chicken lymphocyte proliferation in peripheral blood, spleen, thymus and bursa. The effect of various parameters including concentration of lymphocyte, concanavalin A (ConA) or bacterial lipopolysaccharide (LPS) and percentage of heat inactivated fetal calf serum (FCS) incubation time was evaluated. The results showed that, the highest response of peripheral blood T-cells to ConA was 5μg/ml at 105~106 /ml in RPMI1640 including 10% FCS during incubation for 72h at 37℃, that of spleen T-cells to ConA was 5μg/ml at 5×106 /ml in RPMI1640 including 10% FCS, that of thymus T-cells to ConA was 40μg/ml at 106 /ml in RPMI1640 including 10% FCS and that of bursa B-cells to LPS was 40μg/ml at 5×106 /ml in RPMI1640 including 10% FCS. ~3H-TdR incorporation assays is useful to analyze lymphocyte proliferation of avian after infection with different immunosuppression viruses.2 The effect of different doses of REV infection on the specific and non-specific cellular immune in chickensMitogen responses of T lymphocytes to ConA, cytotoxic activity of natural killer cells and cytotoxic T lymphocytes(CTL)and humoral immunity response to vaccines were...