Table 3. Effects of Schistosome Infection on Host Immune Response to HIV in the Genital Mucosa and Systemic Circulation.
| Study | Sample Size | Sex (% Female) | Age in Years (Weighted Mean) | Country | Species† | Immune Alterations in Schistosome Coinfected | Overall Effects of Schistosome on HIV Infection |
|---|---|---|---|---|---|---|---|
| Genital Mucosal Immune Effects | |||||||
| Kleppa 2014 [47]* | 44 | 100% F | 18 | South Africa | Sh | ↑ cervical HIV target cells & coreceptors (CD14+, CD4+CCR5+) | Genital mucosal immune alterations are potentially consistent with increased HIV susceptibility in women. |
| Yegorov 2019 [48]* | 36 | 100% F | 24.5 | Uganda | Sm |
↑ HIV viral entry into cervical CD4+
cells ↑ IFN-α after schistosome treatment |
|
| Dupnik 2019 [49] | 97 | 100% F | 28.9 | Tanzania | Sh, Sm | ↓ Anti-viral cytokine (IL-15) in Sh but not Sm | |
| Prodger 2015 [50]* | 34 | 0% F | 24.6 | Uganda | Sm | No differences in frequencies or activation of HIV target cells in foreskin | |
| Systemic Circulation Immune Effects | |||||||
| Kleppa 2014 [47]* | 44 | 100% F | 18 | South Africa | Sh | ↑ blood HIV target cells & coreceptors (CD14+, CD4+CCR5+) | Peripheral blood immune alterations are potentially consistent with increased HIV susceptibility in both men and women. |
| Yegorov 2019 [48]* | 36 | 100% F | 24.5 | Uganda | Sm | ↑ HIV viral entry into blood CD4+ cells | |
| Prodger 2015 [50]* | 34 | 0% F | 24.6 | Uganda | Sm | ↑ frequencies of Th1, Th17, and Th22 CD4+ T cell subsets in blood | |
| Secor 2003 [51] | 42 | 0% F | Age > 18 years | Kenya | Sm | ↑ density of CXCR4 on CD4+ T cells and CD14+ monocytes | |
| McElroy 2005 [52] | 35 | Not reported | 36.6 | Uganda | Sm |
↓ HIV Gag-specific CD8+
cytolytic T-cell responses ↑ Gag-specific IL-10-positive CD8+ T-cell responses |
|
| Erikstrup 2008 [53] | 378 | 80% F | 33 | Zim-babwe | Sh, Sm |
↑ IL-8 in Sm but not Sh ↓ TNF-α receptor and IL-8 after schistosome treatment |
|
| Obuku 2016 [54] | 50 | At least 28% F | 29 | Uganda | Sm |
↑ TNF-α after non-viral stimulation ↑ CD8+IFN-ɣ+ and CD4+IFN-ɣ+TNF-α+ T cells after Gag stimulation |
|
| Mouser 2019 [63] | N/A–in vitro study | N/A | N/A | N/A | Sm | ↓ trans-HIV infection after Sm antigen stimulation in dendritic cells that matured in Th2 conditions | |
| Animal Studies | |||||||
| Dzhivhuho 2018 [55] | Not reported | Mice, 100% F | N/A | N/A | Sm | ↓ IFN-ɣ and IL-2 in response to challenge with candidate HIV vaccines | Animal models support human studies, demonstrating potentially impaired immunity to HIV. |
| Actor 1993 [56] | Not reported | Mice, not reported | N/A | N/A | Sm |
↓ IFN-ɣ and IL-2 in response to challenge with vaccinia virus expressing gp160 ↓ CD8+ anti-viral cytotoxicity ↓ viral clearance |
|
| Marshall 2001 [57] | Not reported | Mice, 100% F | N/A | N/A | Sm | ↓ CD8+ anti-viral cytotoxicity related to a splenic immune cell population | |
| Actor 1994 [58] | Not reported | Mice, not reported | N/A | N/A | Sm | ↓ anti-viral cytotoxicity and vaccinia viral clearance began 6 weeks after Sm infection, associated with egg granuloma formation | |
| Lacroix 1998 [59] | Not reported | Mice, 100% F | N/A | N/A | Sm | ↑ IL-4 in mice with Sm-murine HIV coinfection | |
| Chenine 2005 [60] | 8 | Maca-ques, not reported | N/A | N/A | Sm |
↑ IL-4 and IL-10 in Sm ↑ sHIV viral loads in Sm |
|
| Ayash-Rashkovsky 2007 [61] | 15 | Maca-ques, not reported | N/A | N/A | Sm |
↓ CD4+CD29+
memory T cells in Sm ↑ IL-4 in Sm ↑ reactivation of previously undetectable sHIV in Sm |
|
| Buch 2001 [62] | 8 | Maca-ques, not reported | N/A | N/A | Sm | ↑ sHIV replication in tissue macrophages in Sm accom-panied by ↑ IL-4 and ↓ IFN-ɣ | |
* indicates study examined both genital mucosa and systemic circulation
†Sm = S. mansoni; Sh = S. haematobium; Sj = S. japonicum