[Frontiers in Bioscience 3, a38-46, June 9, 1998]

	[Frontiers in Bioscience 3, a38-46, June 9, 1998] Reprints PubMed CAVEAT LECTOR
	*CHARACTERIZATION OF KINETICS OF ANTI-TRICHINELLA SPIRALIS* NEWBORN LARVAE IMMUNITY IN RATS Ching-Hua Wang** Biology Department, California State University, 5500 University Parkway, San Bernardino, CA 92407, USA Received 5/11/98 Accepted 5/24/98 2. INTRODUCTION Thichinella spiralis is a highly immunogenic nematode parasite that can elicit strong and protective immune responses directed at various stages of the parasite in its mammalian host (1-8). Although most of the studies have been focused on host immunity against the adult and muscle larvae stages, it has been established that anti-newborn larvae immunity also plays an important role in the overall immune protection generated by the host and can be extremely effective in preventing newborn larvae from establishing in striated muscles (9-18). The kinetics of anti-newborn larvae immunity has been mainly studied by examining the time-course of cuticular cell adherence after in vitro incubation of newborn larvae with host leukocytes and immune serum obtained from rats (19,20) or mice (21) after a primary T. spiralis infection. Positive immune serum-mediated cell-attachment to newborn larvae was first detectable on day 15 or 30 in rats or mice, respectively. However, Bell et al. (22) demonstrated that in DBA/1 and AKR mice, sufficient immunity was generated after an i.v .injection of newborn larvae to provide 96-98% protection against a newborn larvae challenge given on day 10. These results indicate that in mice, anti-newborn larvae immunity can occur quite quickly after exposure to newborn larvae antigen. Whether rats have similar immune response patterns in vivo needs to be studied. There has been considerable evidence of larval killing via the antibody-dependent cell mediated cytotoxicity(23-26). Most except a few (17,18) were carried out in vitro. Once more, the kinetics of such response was not studied. As yet, no information is available on the dose-response characteristics of anti-newborn larvae immunity. However, the effects of different numbers of T. spiralis intestinal worms on anti-adult and anti-fecundity immune responses have been studied (6,27-33). The results of these studies show that worm dose is an important factor that influences the expression of host immunity. Both newborn larvae (34) and muscle larvae (35) have been shown to be immunosuppressive and it is possible that suppression could also be affected by larvae dose. In this study, the following aspects of anti-newborn larvae immunity were examined: 1). The kinetics of rat anti-newborn larvae immunity in vivo; 2). The effect of different doses of newborn larvae or muscle larvae on anti-newborn larvae immunity; 3). The effect of various doses of newborn larvae in a challenge infection on expression of immunity.

[Frontiers in Bioscience 3, a38-46, June 9, 1998]
Reprints
PubMed
CAVEAT LECTOR

CHARACTERIZATION OF KINETICS OF ANTI-TRICHINELLA SPIRALIS NEWBORN LARVAE IMMUNITY IN RATS

Ching-Hua Wang

Biology Department, California State University, 5500 University Parkway, San Bernardino, CA 92407, USA

Received 5/11/98 Accepted 5/24/98

2. INTRODUCTION

Thichinella spiralis is a highly immunogenic nematode parasite that can elicit strong and protective immune responses directed at various stages of the parasite in its mammalian host (1-8). Although most of the studies have been focused on host immunity against the adult and muscle larvae stages, it has been established that anti-newborn larvae immunity also plays an important role in the overall immune protection generated by the host and can be extremely effective in preventing newborn larvae from establishing in striated muscles (9-18). The kinetics of anti-newborn larvae immunity has been mainly studied by examining the time-course of cuticular cell adherence after in vitro incubation of newborn larvae with host leukocytes and immune serum obtained from rats (19,20) or mice (21) after a primary T. spiralis infection. Positive immune serum-mediated cell-attachment to newborn larvae was first detectable on day 15 or 30 in rats or mice, respectively. However, Bell et al. (22) demonstrated that in DBA/1 and AKR mice, sufficient immunity was generated after an i.v .injection of newborn larvae to provide 96-98% protection against a newborn larvae challenge given on day 10. These results indicate that in mice, anti-newborn larvae immunity can occur quite quickly after exposure to newborn larvae antigen. Whether rats have similar immune response patterns in vivo needs to be studied. There has been considerable evidence of larval killing via the antibody-dependent cell mediated cytotoxicity(23-26). Most except a few (17,18) were carried out in vitro. Once more, the kinetics of such response was not studied.

As yet, no information is available on the dose-response characteristics of anti-newborn larvae immunity. However, the effects of different numbers of T. spiralis intestinal worms on anti-adult and anti-fecundity immune responses have been studied (6,27-33). The results of these studies show that worm dose is an important factor that influences the expression of host immunity. Both newborn larvae (34) and muscle larvae (35) have been shown to be immunosuppressive and it is possible that suppression could also be affected by larvae dose.

In this study, the following aspects of anti-newborn larvae immunity were examined: 1). The kinetics of rat anti-newborn larvae immunity in vivo; 2). The effect of different doses of newborn larvae or muscle larvae on anti-newborn larvae immunity; 3). The effect of various doses of newborn larvae in a challenge infection on expression of immunity.