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M Parant

Publications and source records attributed to M Parant.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Stimulation of non-specific resistance to infections by synthetic immunoregulatory agents.

Muramyl dipeptide or MDP (AcMur-L-Ala-D-iGln) is a synthetic immunoadjuvant which can also enhance non-specific resistance to bacterial infections in mice, even by the oral route. By the use of several derivatives, it has been shown that neither adjuvanticity nor pyrogenicity was a perequisite for eliciting an increased resistance, and that unwanted pharmacological effects can be eliminated by minor chemical modifications. Moreover, some lipophilic analogs or derivatives obtained by linking the glycopeptide to a carrier were found to be more active than MDP. Their effectiveness also depended on the dose and the timing of administration, and varied according to the bacterial challenge. The most appropriately timed administration of MDP and derivatives was established between one and four days before the challenge. In some cases, MDP was protective even when injected one hour after the challenge, whereas with other immunostimulants such as lipopolysaccharides or BCG, a negative phase of higher susceptibility may occur under these conditions. MDP still enhanced resistance to bacterial infections in animals with a poor immune status, like newborns or adult mice under immunosuppressive treatment. Moreover, the protective activity was not impaired after repeated injections of large doses of MDP or other adjuvant analogs, a treatment which is known to inhibit specific immune responses.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMedDate not supplied

Influence of synthetic adjuvants on nonspecific resistance to infections.

Among the numerous synthetic compounds of the MDP series capable of acting as adjuvants of vaccines, some can also stimulate the resistance of mice to experimental bacterial infections when given alone as a single dose before the challenge. This increase in nonspecific resistance appears to be mainly related to a priming effect on phagocytic cells leading to an enhancement in responses to the bacterial challenge, such as bactericidal activity and release of cytokines. The mediators produced by monocytes and macrophages (TNF, IL-1) are known to exert a protective effect when given early at the beginning of infection. Moreover, TNF and muramyl peptides could exert a synergistic activity against a bacterial or fungal challenge.

Acetylmuramyl-Alanyl-Isoglutamine↗