Abstract:
The lymphoid tissue of the upper respiratory tract includes paraocular and
paranasallymphoid structures as well as some lymphoid accumulations in the pharynx
and larynx. However, of all these paraocular lymphoid tissue, the Harderian gland
is highly immunopotent.
The role of the Harderian gland in the immunopathological response was
evaluated taking chicken and duck as models and RD, IBD and Duck plague
vaccines as antigens. The sequential cellular response following ocular antigenic
stimulation was clarified.
Significant increase in the plasma cell number, enlargement of the lymphoid
foci and Russell body formation following ocular antigenic stimulation were the hall
marks of the immune response of the Harderian gland of the chicken but this was
not so much significant in the case of ducks.
Harderian gland was highly reactive especially in the chicken but not so much
in the case of ducks. Intraocular vaccination was found to be comparatively more
effective in immunological protection in chicken. It would therefore, appear that
through local administration of the antigen at the Harderian gland the duck may
not respond in the same way as in the case of chicken.
It was pointed out that the local antibody produced by the Harderian gland
contributed in a major way to the immunological defence at the oculonasal and
oropharyngeal areas and it has an obvious relevance to the epidemiology and the
control of respiratory viral diseases in the avian species.
