Irradiation-attenuated sporozoites are still the most effective pre-erythrocytic malaria vaccine.However,limitation of purified sporozoites and difficulty in attenuation controlling of sporozoites hamper its use in practice.Understanding the mechanism of protective immunity induced by irradiation-attenuated sporozoites will be helpful for the design of the efficient pre-erythrocytic malaria vaccine.This is a review on research progress in the mechanism of protective immunity induced by irradiation-attenuated sporozoites and current status of pre-erythrocytic malaria vaccine development.

Objective To investigate the role of ribosomal protein S7(rpS7) in the defense of Anopheles dirus against infection. Methods rpS7 was amplified from Anopheles dirus hemocytes with degenerated primers designed according to the conservative region of S7, rpS7 was then cloned using T/A cloning kit and the inserted fragment was sequenced. The difference of the transcript abundance of rpS7 from Anopheles dirus hemocyte among non-blood-fed (N), normal-blood-fed (B) and Plasmodium yoelii infected groups (I) was also analyzed by RT-PCR and gel scanning system at d1, d2, d3, d4, d7 and d11 after blood feeding. Results There is no significant difference of rpS7 signal between the three groups. Conclusion Anopheles dirus S7 can be used as an internal control to study the role of Anopheles dirus related immune factors in Plasmodium infection.

Objective To prepare titanium dioxide (TiO2 ) nanoparticles with good near-infrared light and study the loading and release of doxorubicin. Methods The Sm doped TiO2 nanoparticles (Sm-TiO2 ) were synthesized using a modified solvothermal reaction and then observed with transmission electron microscope. The fluorescence spectrum, doxorubicin loading capacity and release profile were also determined. Results The obtained Sm-TiO2 nanoparticles with the length from 100-200 nm were fusiform and well dispersed. The emission wavelength was 640-670 nm. The drug loading capacity in water was 11. 5% . DOX in vitro was pH sensitive to release. Conclusion Sm-TiO2 nanoparticles have good near-infrared light, high drug loading capacity and controllable drug release are obtained and should be studied further more as a novel carrier.

Objective To study the change of intracellular free Ca2+ in the oocyst when it melanized and to find out the relationship between the melanized oocyst and its intracellular level of free Ca2+ in a Plasmodium-refractory strain of Anopheles dirus. Methods The distribution and experimental condition of the intracellular free Ca2+ in oocyst of Plasmodium yoelii was measured with Ca2+ sensitive dye Fluo-3/AM and Plutonic F-127 under confocal laser scanning microscope (CLSM) at different time. Results The best load condition was that the oocysts were incubated in 3 ?mol/ml Fluo-3/AM adding 1 ?l/ml 25% Pluronic F-127 for 60 min at 37 ℃ . Fluorescent imaging of oocysts was affected by an increase or decrease of the concentration of Fluo-3/Am and incubation time. The distribution of intracellular free Ca2+ was heterogeneous in the oocysts. The mean value of Ca2 + in the mature oocysts was (137.15 ?7.02) nmol/L(X?S) but was (18.44? 1.75) nmol/L in melanized oocysts with Ca2+ sedimentation in the wall of oocyst. Conclusion The results suggest that the level of the intracellular free Ca2+ in oocyst decreased and excreted during its melanization in a Plasmodium-reiractory anopheline mosquito species.

Objective　To explore the relationship between hemolymph phenol oxidase and the melanization of Plasmodium yoelii oocysts in Anopheles dirus. Methods　An Anopheles dirus-Plasmodium yoelii system was used Anopheles dirus were divided into 3 groups, that is, non-blood-fedding (N), normal-blood-fedding (B) and infected-blood-fedding (I). The activities of MPO and o-DPO in hemolymph from 3 groups were determined with native polyacrylamide gel electrophoresis (PAGE) and density scanning at 5, 7, 11 and 15 d after blood feeding. Results　Both MPO and o-DPO activity were significantly higher in group I than group N and B (P<0.05). But with the melanization of Plasmodium yoelii oocysts, both MPO and o-DPO activity in group I were decreased in comparison with group N, especially on the 15 th day after infected-blood feeding. MPO and o-DPO activity in group B were significantly stronger than those of group N. Conclusion　Blood feeding and infection of Plasmodium yoelii both can activate the cascade. The heamolymph phenol oxidase may play an important role in the melanization of Plasmodium yoelii oocysts in Anopheles dirus.

Objective To observe the effect of blood feeding and plasmodium yoelii infection on the transcript abundance of ribosomal protein S7 from Anopheles dirus hemocyte Methods Anopheles dirus of 3～5 days old were divided into normal group (N), blood feeding group(B) and Plasmodium yoelii infection group(I) Hemocytes of 50 Anopheles dirus from each group were collected by centrifuge method on days 1, 2, 3, 4, 7 and 11 after blood feeding, respectively Then, all hemocyte samples were used for total RNA isolation and analyzed by RT PCR Finally, the same volume(10 ?l) of all the PCR products from each group was used for agarose gel electrophoresis and the data obtained were analyzed statistically Results There was no significant difference in ribosomal protein S7 signal between the three groups Conclusion Similar to Anopheles gambiae and human rpS7, Anopheles dirus rpS7 might be also used as an internal control for the studies of the role of Anopheles dirus related immune factors in attacking Plasmodium infection

Objective To construct cDNA library from adults of Anopheles dirus for cloning the immune genes or related genes for malaria parasites development. Methods The mRNA of adult Anopheles dirus was isolated. The library was constructed by using the Zap Express vector(Stratagene) and the quality was evaluated. Results The efficiency of the library was 2.1?10 6 pfu/ml with 98% clones positive. The average length of the insert fragment was over 1 kb. Conclusion cDNA library of adult Anopheles dirus with high efficiency can be constructed by using the Zap Express library construction Kit (Stratagene).

Objective To investigate the relationship between the immune defence reaction against Plasmodium infection and the prophenoloxidase (PPO) of the midgut by comparative analysis of the distributions and the changes of PPO in the midgut of Anopheles stephensi and Anopheles dirus before and after infection with Plasmodium yoelii . Methods Midguts were dissected out from both Anopheles stephensi and Anopheles dirus at 3, 5, 7, 11 and 15 d before and after infection with Plasmodium yoelii . Immunohistochemistry and Western blotting were performed respectively on the collected midguts using Manduca Sexta PPO IgG polyantibody. Results PPO in the midguts from both Anopheles stephensi and Anopheles dirus was mainly located in the circulation conduit of midgut before infection with Plasmodium yoelii , but aggregated and distributed at the interspace of midguts as pieced or/and stripped forms after infection. Furthermore, PPO in the midgut of Anopheles dirus was more concentrated than that of Anopheles stephensi . Western blotting revealed that the PPO band with about molecular weight of 67?10 3 was detected in the midguts of both Anopheles stephensi and Anopheles dirus before and after Plasmodium yoelii infection. There was significant difference before and after infection, and the PPO band was obviously enhanced after infection. PPO bands in the midgut of Anopheles dirus were more prominent than those of Anopheles stephensi . Conclusion PPO in the midgut of Anopheles mosquitoes may come from the hemolymph by the circulation conduit before Plasmodium yoelii infection. However, the different distributions and changes of PPO in the midguts resulted from the Anopheles mosquitoes infected with Plasmodia may be closely correlated with Plasmodia infection, which may be of important physiological significance and may be involved in the immune defensive reaction against Plasmodium .

Objective To investigate the expression patterns of serine proteases Adsp1 and Adsp3 in the main tissue of Anopheles dirus and the effects of blood feeding and Plasmodium infection on the transcript abundance of Adsp1 and Adsp3 from Anopheles dirus haemocytes. Methods Haemocytes were collected by centrifugation. The midguts and salivary glands were dissected from 50 adult female Anopheles dirus of 3-5 d old for the extraction of total RNA for amplification by RT PCR. Anopheles dirus of 3-5 d old were divided into normal group (N), blood feeding group (B), and Plasmodium yoelii infection group (I). Haemocytes of 50 adult female Anopheles dirus from each group after blood feeding were also collected, and the total RNA was isolated at 1, 2, 3, 4, 7, and 11 d, respectively. Then, the same volume (10 ?l) of total RNA was analyzed by semi quantitative RT PCR with Ads7 as the internal control. Agarose gel analysis was performed on PCR products from each group. Results Expression of both Adsp1 and Adsp3 mRNA was found in the haemocytes and salivary glands, but not in the midguts. Semi quantitative RT PCR indicated that transcript abundance of AdsP1 and AdsP3 from Anopheles dirus haemocytes was enhanced after blood feeding and Plasmodium yoelii infection, especially during melanotic encapsulation of Plasmodium yoelii . Conclusion AdsP1 and AdsP3 may be involved in the melanotic encapsulation response of Plasmodium yoelii by Anopheles dirus , and may be the prophenoloxidase activating enzyme of Anopheles dirus .

Objective To clone the partial cDNA sequence of prophenoloxidase (PPO) gene of Anopheles dirus . Methods Degenerative primers were designed according to the conserved sequence blocks within the prophenoloxidase of insects. RNA sequence of the larva of Anopheles dirus was amplified by RT PCR to get the prophenoloxidase cDNA which was then cloned into T vector and sequenced. The partial cDNA sequence of prophenoloxidase gene was analysed and compared with other prophenoloxidase gene of insects. Results The partial cDNA sequence of AdPPO4 was 597 bp, and its deduced amino acid sequence was 199aa. The cDNA sequence homology and amino acid sequence homology was 84% and 90%, respectively, as compared with the PPO4 gene of Anopheles gambiae . Conclusion The AdPPO4, with high sequence homology with the PPO4 gene of Anopheles gambiae , is successfully cloned from the larva of Anopheles dirus .