Cellular and humoral responses in the respiratory tract of goats following intranasal stimulation using formalin-killed Pasteurella haemolytica A2.
A study to determine the immunoglobulin and cellular responses in the respiratory tract of goats following intranasal exposures to formalin-killed Pasteurella haemolytica A2 was carried out. Forty-two goats were divided into two groups. Goats in Group 1 were subjected to double intranasal exposures to formalin-killed P. haemolytica A2 while goats in Group 2 were the unexposed control. Prior to and at weekly intervals post-exposure, three goats from each group were killed, serum samples were collected while the lungs were flushed with 50 ml normal saline before the right apical lobes were fixed in 10% buffered formalin. Both serum and lung lavage fluid were subjected to enzyme-linked immunosorbent assay (ELISA) to determine the levels of IgA, IgM and IgG while the formalin-fixed tissues were examined histologically. IgA levels in the lung lavage fluid increased rapidly to reach a significantly (p < 0.05) high level as early as Week 2 post-exposure and remained significantly (p < 0.05) high throughout the study period. The IgM levels increased at an intermediate rate to reach a significantly (p < 0.05) high level at Week 3 post-exposure before they decreased to an insignificant (p > 0.05) level the following week and the weeks thereafter. IgG levels increased gradually and only reached a significantly (p < 0.01) high level at Weeks 5 and 6 of the study. The size of the bronchus-associated lymphoid tissue (BALT) and the number of lymphocytes in BALT increased significantly from Week 2 and remained high thereafter. However, differences in the numbers of BALT were insignificant (p > 0.05) initially before becoming significantly (p < 0.05) high at Weeks 5 and 6. The BALT responses were parallel to those of imunoglobulins in the lung lavage fluid.
Zamri-Saad
M
M
Faculty of Veterinary Medicine and Animal Science, Universiti Putra Malaysia, Selangor. zamri@vet.upm.edu.my
Effendy
A W
AW
Israf
D A
DA
Azmi
M L
ML
D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D018893:Bronchoalveolar Lavage / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005557:Formaldehyde / Q000737:chemistry; D015511:Goat Diseases / Q000276:immunology* / Q000382:microbiology; D006041:Goats; D007111:Immunity, Cellular / Q000276:immunology; D007136:Immunoglobulins / Q000032:analysis / Q000097:blood; D008221:Lymphoid Tissue / Q000276:immunology / Q000382:microbiology; D016978:Mannheimia haemolytica / Q000276:immunology*; D010326:Pasteurella Infections / Q000276:immunology / Q000662:veterinary*; D012137:Respiratory System / Q000276:immunology* / Q000382:microbiology; D012140:Respiratory Tract Diseases / Q000276:immunology / Q000662:veterinary*
D000907:Antibodies, Bacterial; D007136:Immunoglobulins; D005557:Formaldehyde