Attached
Introduction: Gram positive food grade bacteria Lactococci have significant advantages over
attenuated pathogens a s vaccine delivery vehicles due to inherent safety.
Methods: Plasmodium falciparum merozoite surface antigen2(PfMSA2) w as expressed in
recombinant Lactococcus lactis. Recombinant L.lactis strain, delivered oro-nasally for mucosal
immunisation to Balb/c mice. Non-recombinant L.lactis used as control. Serum antibody response
investigated by E L IS A and immunofluorescence assay. Histopathological changes in gut associated
lymphoid tissue investigated. The cholinergic nerve ending and the distribution of alpha subunits of
n A C h R s in the spleen, Peyeris patches and mesenteric lymph nodes were studied by indirect
immunohistochemistry
Results: Serum IgG anti-MSA2 responses w as significantly higher in Balb/c mice, after oronasal
delivery. Antibodies elicited reacted with native M SA 2 in the surface of P. falciparum merozoites in an
immunofluorescence assay. Enlargement of mesenteric lymph nodes and increased lymphatic
infiltration of the lamina propria were noted. Spleen showed periarteriolar lymphoid aggregation iri
immunized mice. The a1 n A C h R s were distributed in the capsule and red pulp of spleen. Germinal
centres of Peyeris patches showed diffuse( +1) distribution of a ln A C h R and expressed a low
immunoreactivity(IR) of anti-nAChRs.
Conclusions: Recombinant L. lactis is a suitably safe vector for subunit vaccines. Neuronal control of
immune response by parasympathetic cholinergic innervation through n A C h R s is suggestive.
