ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04748.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04749.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04750.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04751.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe immunoprophylactic capacity of colostrum‐derivedRhodococcus equiantibodies was evaluated in pony foals experimentally infected withR. equi.Six pony mares (Group 1) were injected serially with liveR. equiduring pregnancy; a further six pony mares were not vaccinated and used as controls All (Group 2) foals were permitted to suck from their dams and the adequacy of IgG, passively transferred via colostrum, was determined by single radial immunodiffusion. The presence and relative value of R. equi specific antibodies were determined by ELISA. Mares vaccinated withR. equideveloped significantly (P<0.05) increasedR. equiantibody levels, and the principal foals from these mares had specific antibody values that were significantly (P<0.01) higher than control foals.Rhodococcus equiwere aerosolised into a caudal lung lobe of all foals at seven days of age. Clinical signs, haematological alterations, immune responses and thoracic radiographs were monitored. Foals were subjected to euthanasia and complete post mortem examinations were performed. All foals developed pneumonia as evidenced by clinical and radiographic signs. The survival rate for Group 1 foals did not differ significantly from that of control foals. Two of the six foals in each group survived the bacterial challenge. Also, there were no significant differences between groups for duration of survival, peak febrile responses, duration of fever, time from infection to onset of fever, or peak concentrations of leucocytes and neutrophils. Post mortem examinations of four foals from each group, destroyed approximately three weeks post infection because of terminal disease, revealed severe pyogranulomatous pneumonia involving primarily the caudal portion of one lung. One control foal had miliary pyogranulomatous lesions in both lungs.Rhodococcus equiwas cultured from the pulmonary lesions in these foals. Two principal and two control foals that recovered from the infections had mild pulmonary fibrosis at three months post infection.Rhodococcus equiwas not cultured from any of these foals at necropsy. The results of this investigation suggest that passive immunisation of newborn foals, by ingestion of colostrum derivedR. equispecific antibodies, does not provide adequate protection against experimental infection withR. equ

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04752.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe immunotherapeutic efficacy of specific immune plasma was evaluated in pony foals infected experimentally withRhodococcus equi. ViableR. equiwere aerosolised into the right caudodorsal lung of 10 foals at seven days of age. Immune plasma, produced by repeated parenteral administration of viableR. equito an adult donor gelding, was harvested and frozen. Group 1 (4 foals) and Group 2 (6 foals) foals received lactated Ringer's solution and immune plasma, respectively, at seven and nine days post infection. Clinical signs, haematological alterations, immune responses and thoracic radiographs were monitored throughout the study. All foals were destroyed and complete post mortem examinations were performed. All foals developed pneumonia as evidenced by clinical and radiographic alterations. Immune plasma had no significant effect on survival rate, length of survival, temperature response or peripheral blood concentrations of leucocytes, neutrophils or fibrinogen. Enzyme‐linked immunosorbent assay values forR. equi‐specific antibody and serum concentrations of IgG were significantly greater in Group 2 foals following treatment with immune plasma. Post mortem examination of three Group 1 and four Group 2 foals, destroyed because of terminal disease, revealed severe pyogranulomatous pneumonia. The two surviving Group 2 foals were free of gross pulmonary lesions and had minimal microscopic scar formation three months post infection; whereas the one surviving Group 1 foal had a large, encapsulated, caseonecrotic pulmonary mass three months post infection. This study demonstrates that the parenteral administration ofR. equiimmune plasma to foals seven days after experimental infection withR. equidoes not alleviate the clinical signs nor alter the course of dise

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04753.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe one‐way primary equine mixed lymphocyte reaction (MLR) was used to generate allospecific major histocompatibilty complex (MHC) class‐I‐restricted cytotoxicityin vitro. Allospecific cytotoxicity, demonstrated against Con A stimulated peripheral blood mononuclear cells (PBMC) in a 6 h chromium‐release assay, was present from approximately 72 to 168 h of primary culture and peaked between 120 and 168 h. Optimal cytotoxicity was generated at a responder to stimulator ratio of 4:1 and at an effector to target ratio of 50:1. The cytotoxicity was blocked by an anti‐equine leucocyte antigen (ELA) class‐I and an anti‐equine CD8‐homologue monoclonal antibody. An anti‐ELA class‐11 and an anti‐equine CD4‐homologue monoclonal antibody ha

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04754.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryFour specific pathogen‐ (Equid Herpesvirus type 1 [EHV‐1]) free foals aged 2 to 3 months were intranasally inoculated with 7 times 107p.f.u. of EHV‐1. Virus isolation was attempted from peripheral blood and nasal mucus, and clinical signs of disease and haematological changes were monitored. Also, lymphocyte subpopulations were enumerated using flow cytometric analysis of lymphocytes identified using a polyclonal anti‐equine immunoglobulin reagent and monoclonal antibodies recognising the equine homologues of CD4, CD5 and CD8. The primary intranasal inoculation of virus resulted in an EHV‐1 infection demonstrated by viraemia, persistent nasal shedding of virus, seroconversion and clinical signs of disease. Associated with this infection there was a fall in lymphocyte and neutrophil counts, which subsequently rose to normal levels with alleviation of the clinical signs of disease. The decline in lymphocyte count resulted from a fall in T‐lymphocyte numbers only, and the subsequent increase was initially also a T‐lymphocyte‐restricted event with a later increase in the number of B lymphocytes. The fall in T lymphocyte count affected the CD4+ and CD8+ subpopulations equally; however, during the subsequent rise there was a proportionately greater increase in the CD8+ subpopulation. Following recovery from the primary infection, the foals were re‐challenged with a repeat inoculation two months after the primary infection. This second inoculation did not result in clinical disease, detectable viraemia, increased antibody titres or persistent nasal shedding of virus, suggesting an effective immune response or subclinical infection. The marked patterns of leucocyte and lymphocyte subsets of the primary infection were not evident; however, there was a definite decline in the numbers of CD8+ lymphocytes that lasted for several days. The implications of these findi

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04755.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummarySix ponies were experimentally infected with an isolate of Equid Herpesvirus type 1 (EHV‐I) recovered from an aborted foetus. Clinical, virological and serological observations confirmed that infection was established in all ponies. EHV‐I specific cellular immune responses as measured by T cell proliferation developed in parallel with specific antibody. In contrast to this, non‐specific lymphocyte function was shown to be compromised after infection in that polyclonal T cell activation was depressed for at least 40 days. The dissociation of specific and non‐specific cellular immune responses suggests that an immunological defect may develop in horses after EHV‐I infection. The mechanism for this immunosuppression is not understood but it is unlikely to reflect a reduction in responding lymphocyte numbersin vivobecause the observed immunosuppression continued well beyond the period of transient leucopaenia commonly seen w

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04756.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1991.tb04757.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY