Immune responses of chemically modified homologous LDH-C4 and their effect on fertility regulation in mice.
OBJECTIVE
Lactate dehydrogenase-C4 (LDH-C4) is an iso-, allo- and auto-antigen of mammalian sperm. In spite of being cell specific, LDH-C4 does not induce infertility in females of homologous species after immunization. The present study examines the application of homologous LDH-C4 after chemical modifications in the immunological infertility of female mice.


METHODS
LDH-C4 from testes of LACA mice was chemically modified by interacting it with gossypol (gossy-LDH-C4) and glucosylation with lactose (Glu-LDH-C4) in vitro and evaluated for immune responses and induced immunological infertility in allogeneic Balb/c mice after inoculation through intrarectal route using A1(OH)3 as adjuvant.


RESULTS
Native LDH-C4, which elicited high antibody response after immunization with a primary (50 microgram) and three secondary doses (30 micrograms each) at an interval of 15 days each, did not reduce fertility significantly in mice. In contrast, study provides evidence that chemically modified LDH-C4 induces high infertility, since 85-100% of mice failed to conceive in two independent sets of experiments. Mice inoculated with modified LDH-C4 were associated with 2-3 fold anti-LDH-C4 antibody titre compared to antibody response elicited by native LDH-C4. Splenocytes from immunized non-pregnant mice were evaluated for polyclonal activation using Con A as mitogen. It was found that splenocytes primed with native LDH-C4 were significantly more stimulated than the non-immune control cultures. However cells primed with gossy-LDH-C4 were non-reactive to Con A and cells primed with glu-LDH-C4 were suppressed for ConA proliferation.


CONCLUSIONS
It is concluded that LDH-C4-gossypol adduct offers a potential application in the induction of infertility of homologous species in marked contrast to native LDH-C4. Application of A1(OH)3 as adjuvant in the induction of immune response through intra-rectal route has been suggested.
Gupta
G S
GS
Department of Biophysics, Panjab University, Chandigarh, India.
Syal
N
N
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000285:Administration, Rectal; D000536:Aluminum Hydroxide / Q000494:pharmacology; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology; D005260:Female; D005298:Fertility / Q000187:drug effects* / Q000276:immunology*; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains
D000276:Adjuvants, Immunologic; D007527:Isoenzymes; D003208:Concanavalin A; D000536:Aluminum Hydroxide; D007770:L-Lactate Dehydrogenase